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iot.stackexchange.com

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2017-03-01T21:57:17.113

<p>No, you would not be able to reset a breaker. Their "smarts" are for monitoring the panels and breakers, not operating them.</p> <p>It would be a huge safety issue if homeowners could remotely reset breakers. Breakers pop for a reason - there's an unsafe condition nearby. But if you could reset the breaker from anywhere on the globe, you would have no idea if the problem's been fixed or not, and energizing the circuit could start a fire. Or consider that someone local may already be trying to fix the circuit that popped, and you remotely energized it while they're working on it. </p> <p>Breakers on transmission lines are different, because they're repaired and operated by trained engineers who follow strict safety protocols. But home and commercial equipment has to be as safe as possible by default.</p>

|smart-home|

Can I reset breakers from my computer with the Schneider Smart Panel?

1155

<p>I've been looking into <a href="http://www.schneider-electric.com/b2b/en/products/product-launch/smart-panels/overview.jsp" rel="noreferrer">Schneider smart panels</a> recently for home monitoring. From what I'm reading, it appears that they have the ability to monitor your home's electric usage on all the various circuits real time. They are connected by Ethernet (not wireless, unfortunately), so it appears that I will be able to see statistics from my home computer.</p> <p>One thing, however, remains unclear to me: Are you able to reset a circuit when it blows from your computer, or will I have to trek down to the utility room every time I accidentally plug two toasters into the same circuit?</p>

2017-03-03T17:06:44.980

<p>You can press the <a href="https://www.amazon.co.uk/gp/help/customer/display.html?nodeId=201602230" rel="nofollow noreferrer"><strong>microphone on/off button</strong></a> on the top of your device to disable the microphone before you go to sleep. Here's what it looks like for the Echo Dot:</p> <p><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/e/e1/Amazon_Echo_1_2017-02-23.jpg/180px-Amazon_Echo_1_2017-02-23.jpg?uselang=en-gb" alt="Amazon Echo Dot"> </p> <p>^{Source: <a href="https://commons.wikimedia.org/wiki/File:Amazon_Echo_1_2017-02-23.jpg?uselang=en-gb" rel="nofollow noreferrer">FASTILY</a> of Wikimedia Commons, CC-BY-SA 4.0}</p> <p>After pressing the microphone off button, your device will look more like this:</p> <p><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/4/4e/1024_amazon_Echo_Dot-2808.jpg/179px-1024_amazon_Echo_Dot-2808.jpg?uselang=en-gb" alt="Amazon Echo Dot (microphone disabled)"></p> <p>^{Source: <a href="https://commons.wikimedia.org/wiki/File:1024_amazon_Echo_Dot-2808.jpg?uselang=en-gb" rel="nofollow noreferrer">Hedwig Storch</a> of Wikimedia Commons, CC-BY-SA 4.0}</p> <p>Notice the illuminated microphone off button and the red ring. While the ring is red, your device will <strong>not</strong> be listening at all, until you press the microphone on/off button again. The Amazon Echo will look largely the same, except it's significantly taller. The icon on the microphone on/off button is the same as in the pictures above.</p> <p>Unfortunately, <a href="https://iot.stackexchange.com/questions/861/can-i-ask-alexa-to-turn-off-its-microphone/862#862">you can't turn off the Echo's microphone by voice</a>—the button must be <em>physically pressed</em>. Also, you can't turn the microphone back on by voice, because—well—the microphone is off, and can't listen to you, because you told it not to!</p>

|alexa|amazon-echo|

Keep Alexa from responding when I'm talking in my sleep

1164

<p>If I'm in a private meeting at my home, I don't really want Alexa piping up with her idle chatter if I or someone else accidentally says the wake word.</p> <p>Equally, if I'm talking in my sleep (which I do a lot of), I don't want to accidentally wake up Alexa and disrupt my sleep.</p> <p>Is there a way to silence the Amazon Echo temporarily so it doesn't respond to accidental wake ups when I want it to remain quiet?</p>

2017-03-04T13:59:59.843

<h2>As a consumer</h2> <p>Your options are often quite limited as a consumer, but you can minimise your risks in a few ways through carefully selecting the products you use and how you connect them.</p> <h3>Check what happens when your device loses Internet connectivity</h3> <p>Usually, you can just do a quick Google search to see what happens when a certain device disconnects from the Internet. Some devices will simply fail completely if their connection to a remote cloud server is lost, like the <a href="https://www.amazon.com/gp/help/customer/display.html?nodeId=201549640" rel="nofollow noreferrer">Amazon Echo</a>:</p> <blockquote> <p>Your Echo requires an active Wi-Fi connection to speak, process your commands, and stream media.</p> </blockquote> <p>Sometimes, there's a good reason (for example, the Echo has to stream commands to the cloud to process your instructions, as stated in '<a href="https://iot.stackexchange.com/questions/357/is-the-amazon-echo-always-listening-and-sending-data-to-the-cloud">Is the Amazon Echo &#39;always listening&#39; and sending data to the cloud?</a>'), but for others, it may just be an oversight or design flaw in your product.</p> <p>If you physically have the device, you could try unplugging your router to see what happens—this might not be a great test, because it's more likely a remote server will break but local connections will still work, but it's something to try.</p> <p>With enough time to <s>waste</s> <em>use productively to improve your setup</em>, you could potentially sniff packets from your devices, then apply a router-level block to certain domains—this way, you'd know what happened if <code>mydeviceserver.com</code> went down completely. Of course, this would take <strong>a long time</strong> so it might not be practical to test all of your devices in a large home with lots of 'smart' devices.</p> <h3>Use local connectivity</h3> <p>If you're just turning your lights on from your smart switch, you might not need to route all the traffic through the Internet, into a cloud server thousands of miles away, and back to your lightbulb—you might just be able to route the command through local devices instead. A lot of the time, these devices will use a protocol like ZigBee or Z-Wave, so you might need a hub to co-ordinate the traffic (see '<a href="https://iot.stackexchange.com/questions/958/why-do-i-need-hubs-for-some-devices-when-automating-my-home">Why do I need hubs for some devices when automating my home?</a>').</p> <h2>As a developer</h2> <p>For developers of IoT devices, careful design of a device can avoid problems like the recent S3 outage from affecting consumers. Of course, IoT designers <a href="http://www.theregister.co.uk/2017/03/02/chinese_iot_kit_backdoor_claims/" rel="nofollow noreferrer">aren't always known</a> for <em>careful</em> design, but if you're reading this, you're probably not in that group.</p> <h3>Design services to be redundant</h3> <p>For Amazon S3's recent outage in particular, there may not have been much you could do. There are some reports that <a href="https://aws.amazon.com/blogs/aws/new-cross-region-replication-for-amazon-s3/" rel="nofollow noreferrer">cross-region replication</a> could have potentially prevented services from going down, as explained in <a href="https://devops.stackexchange.com/questions/83/what-is-a-good-strategy-to-keep-my-site-online-when-s3-goes-offline">this question on DevOps Stack Exchange</a>, but it's <a href="https://www.reddit.com/r/aws/comments/5xat9a/s3_crossregion_replication_would_it_have_really/" rel="nofollow noreferrer">debated whether that's really true or just poor advice</a>. </p> <p>If feasible, having some sort of redundancy or backup would be ideal—although the costs are greater, the additional reliability is greatly needed—otherwise, people's lights stop responding, power switches refuse to work, etc.</p> <h3>Add better support for scenarios without Internet connections</h3> <p>I listed 'Use local connectivity' under the ways that a consumer could avoid this issue, <strong>but it's a losing battle</strong>. The devices often don't support connecting in any other way than through their approved web service, and manufacturers are reluctant to spend developer time on this. If the support was greater, there would be less reliance on cloud services, which benefits the manufacturer too, because they don't need to pay for so much server capacity.</p> <h2>With all these options, why were so many devices affected?</h2> <p><em>Because no-one wants to spend the time</em>—designing any sort of reliable system takes a lot of time and effort, and it's often far more complex than the comparable 'dumb' solution (e.g. simple electrical switches). </p> <p><a href="https://softwareengineering.stackexchange.com/questions/41050/why-isnt-software-as-reliable-as-a-car">Why isn't software as reliable as a car?</a> Because the software has so much more complexity, yet isn't tested nearly as rigorously as a car would be. The same issue seems to apply with IoT—controlling devices through a network is far more complex, so things can go wrong far more easily, as we've seen with the recent S3 incident.</p>

|smart-home|amazon-s3|

How can I avoid my IoT devices breaking when cloud services go down?

1168

<p>Recently, Amazon S3 <a href="http://www.theverge.com/2017/3/2/14792442/amazon-s3-outage-cause-typo-internet-server" rel="noreferrer">had an outage</a> which caused lots of web services to go down, including <a href="https://ifttt.com/" rel="noreferrer">IFTTT</a>, which is often used to link IoT devices together (e.g. connecting your Alexa to some Philips Hue bulbs).</p> <p><a href="https://twitter.com/nestsupport/status/836645719696027648" rel="noreferrer">Nest security cameras stopped working</a>, TP-Link smart switches refused to turn on, and someone <a href="https://twitter.com/callummr/status/836650454356480000" rel="noreferrer">wasn't able to change their mouse sensitivity because it syncs with the cloud</a> because of the outage, apparently.</p> <p>In a smart home with a few Philips Hue bulbs, an Amazon Echo and some smart switches, I'd like to try and avoid issues like that so my house doesn't 'go down' along with the cloud services.</p> <p><strong>How can I figure out if my devices rely on one single service and avoid it if possible?</strong></p>

2017-03-05T14:23:50.600

<blockquote> <p>...double the costs for a provider, making it technically infeasible.</p> </blockquote> <p>Doubling costs isn't really "technically infeasible", it justs make the situation more expensive. However, it's not really that bad.</p> <p>I work for a service that rents dedicated hardware at three different data centers from three different vendors, one in the west, one in the east, and one in the midwest. Our client application automatically, constantly, and seamlessly switches to whatever center responds quickest. (The server side doesn't even have to do "load balancing"; the client side does "load distribution" instead.) Since starting up years ago, there has never been a moment when at least 2 of the 3 centers wasn't responding.</p> <p>The costs to rent and operate those servers is minuscule. We could easily expand to more data centers using petty cash, but it's not necessary, because the three existing systems provide plenty of redundancy and plenty of throughput.</p> <p>Computers are cheap. Outages are expensive and get you bad press. Redundant servers is the cheapest solution.</p>

|cloud-computing|

How can IoT cloud services be made more reliable without excessive cost?

1173

<p>In <a href="https://iot.stackexchange.com/a/1169/12">one of my previous answers</a>, I mentioned that when designing a cloud service to connect to IoT devices, it would be best to make the servers redundant in some way so that if one data centre or server fails, the whole system still works.</p> <p><a href="https://iot.stackexchange.com/questions/1168/how-can-i-avoid-my-iot-devices-breaking-when-cloud-services-go-down#comment1995_1169">Sean Houlihane pointed out</a> that having true redundancy would probably double the costs for a provider, making it technically infeasible.</p> <p>So, I'm interested to know how a cloud service (perhaps like the service used for the Nest thermostat, which <a href="https://iot.stackexchange.com/q/1168/12">went down in the S3 outage</a>) could be made more reliable <strong>without</strong> duplicating every component, in a way that would be less disruptive to a company's business model.</p> <p>The sort of device I'm thinking of is something like a smart thermostat that needs to synchronise data from a phone app (outside the home's local network) to the thermostat itself, and stores the state in cloud storage like S3.</p> <p><strong>What can I do to ensure that the cloud servers have a <a href="https://en.wikipedia.org/wiki/High_availability" rel="nofollow noreferrer">high availability</a> without running two copies of every server in different locations?</strong></p>

2017-03-07T06:34:10.393

<p>There are many Android Modules based on LTE SOC like Qualcomm MSM8909 and Mediatek MT6735 MT6755 etc.</p> <p><a href="http://www.new-mobi.com/product/product.php?lang=en&amp;class1=44" rel="noreferrer">NewMobi</a> has a range of modules.</p>

|microcontrollers|mobile-data|

Why don't we have more 3G+ modem options available?

1181

<p>Spiritually similar to the question here <a href="https://iot.stackexchange.com/questions/943/embedded-modem-options">Embedded modem options</a></p> <p>Why is there such an enormous barrier to getting into something like a Snapdragon 410 with onboard LTE? After extensive research, LTE-equipped SoCs are everywhere, yet not available insofar as development kits, research material and so on. </p> <p>It's always "contact sales" or just a marketing brochure webpage along with literally 1 million phones that the SoC is tucked away in. If I actually want to do development with an LTE SoC (and I do) how do I even get started?</p> <p>I love my STM chips and the SIMCOMs are fun but it feels like diddling around in 2008 using that stuff.</p>

2017-03-07T17:24:50.840

<p>Sorry for the late reply. It turns out the problem was configuration related. I was using a 10k ohm resistor and I should have been using a 330 ohm one. The issue, in my opinion, stemmed from some decently confusing images in the Android Things "Getting Started" guide and the fact that the Raspberry Pi is more popular (so the instructions were geared toward that specific configuration).</p> <p>Thanks to everyone who replied. I figure this is at least useful in case someone who's super new to this (like me) makes the same mistake.</p>

|android-things|intel-edison|

Android Things: GPIO button/switch handler only responds once

1183

<p>I am working through the tutorial for the Android Things SDK and I have the following set up:</p> <p><a href="https://i.stack.imgur.com/tIUVI.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tIUVI.jpg" alt="pictures showing the Edison and its connections"></a></p> <p>I hooked up the hardware via the Android Things SDK and have a working handler for the button/switch working <strong>but</strong> it only works once. After that I need to restart the board to get the handler to fire again. </p> <p>I'm new to this stuff so not really sure how to diagnose it. The SDK isn't reporting any errors and restarting the android app will re-print out all the available GPIO and messages I have so I know the board is "frozen", but that input will not respond again until I restart the entire board.</p> <p>Any help or explanation appreciated.</p> <p><strong>Setup:</strong> Intel Edison. Red = power, black = ground. 10k resistor is connected to power (sorry for the photo).</p>

2017-03-07T18:54:08.183

<ol> <li><p>In addition to very nice discussion above, you can be own security expert starting with <strong>nmap</strong>, flagship tool from <a href="https://nmap.org" rel="nofollow noreferrer">Insecure.Org</a> so you can perform basic scan of target device(192.168.1.1) with simple command: </p> <p>[nmap -A -T4 192.168.1.1] </p> <p>More details, examples and hints how to scan yours network could be found on <a href="https://highon.coffee/blog/nmap-cheat-sheet/" rel="nofollow noreferrer">Nmap Cheat Sheet</a> pages.</p></li> <li><p>However, scan every single IoT device in yours network and recheck every device with suspicious port/ports opened. </p></li> </ol>

|smart-home|security|routers|

How do I protect my home from IoT devices being compromised and being used for DDoS attacks?

1184

<p>I am trying to understand the vulnerability of my home IoT devices. From what I understand, the big DDoS last year was caused by compromised IoT devices with generic or default usernames and passwords.</p> <p>All my IoT devices are behind my firewall (like my thermostats - Honeywell).</p> <p>They connect to the internet, but outgoing only. I have no port forwarding setup.</p> <p>If all my IoT devices are behind my router's firewall, and I do not have any port forwarding to those devices, where is the risk with having default usernames and passwords?</p>

2017-03-08T12:56:47.153

<p>I finally found <a href="https://sonyarouje.com/2016/03/15/mqtt-communication-with-arduino-using-esp8266-esp-01/" rel="nofollow noreferrer">a tutorial by Sony Arouje</a>. As it turns out I had to completely abandon manual sending of esp commands and had to use the library (WiFiEsp.h). Hint...It's better!</p> <p>Though initially it didn't work with my esp8266 because it had an older firmware and reported error "firmware not supported". I had to flash a newer Firmware (works with version 1.54 in my case). Anyone having problem flashing firmware may find some help referring this topic: <a href="https://iot.stackexchange.com/questions/1199/cant-flash-esp8266-latest-firmware-says-fast-flashing-error-and-invalid-hea">Can&#39;t Flash ESP8266 latest firmware, says &quot;Fast Flashing error&quot; and &quot;Invalid head of packet(&#39; &#39;)&quot;</a></p> <p>Also, I have saved a copy of all download tools and the tutorial page itself, so if in the future, the post is removed or if anyone doesn't finds the tools to flash. Get to me in comments or something (not posting here because I don't know if it's ok to post someone else's content)</p>

|mqtt|esp8266|

How to use MQTT on Arduino which uses serial com to send AT commands to ESP8266

1190

<p>I just started looking into MQTT protocol.</p> <p><strong>Situation</strong></p> <p>In my college project, currently, I use Arduino as main MCU and do every work in that and use Serial Comm. to send AT commands to esp8266 (for HTTP requests, to run scripts on server etc). I basically needed to push some data(from Arduino) on a webpage(hosted by a local server). I searched and found about <strong>MQTT</strong> protocol which enables to publish and subscribe data on clients(Exactly what I wanted). But most of the tutorials I am finding are either entirely on Arduino(with wifi shield) or entirely on esp8266. </p> <p>What I want to know is that is there a possible way to use MQTT as with my current configuration? That is, using Arduino to do all the work and by using its serial comm. Publishing data just by AT commands on MQTT. </p> <p>Additional Information about my project is mentioned here : <a href="https://iot.stackexchange.com/questions/1130/confused-about-which-technology-to-use-in-smart-home-system">Confused about which technology to use in Smart Home System</a></p>

2017-03-09T08:41:31.397

<p>The model that IoT Hub connected devices use is that they will never accept incoming connections. IoT Hub devices never act as a 'server', and this is a crucial part of the security model in Azure IoT. The definitive model on this is encapsulated in Clemens Vasters' <a href="https://blogs.msdn.microsoft.com/clemensv/2014/02/09/service-assisted-communication-for-connected-devices/" rel="noreferrer">'Service Assisted Communication'</a>.</p> <p>Therefore devices are always 'polling' an external service in order to send data or receive commands. The APIs make it look like data is being sent to a device, but it is always the device making the outgoing connection.</p> <p>IoT hub does this in two ways:</p> <ol> <li>By sending data to the device endpoint <code>/devices/{deviceId}/messages/devicebound</code>. This is an AMQP messaging endpoint, similar to a queue or topic subscription. The device, when reading commands, needs to acknowledged receipt if needed, which is part of the underlying AMQP protocol. This works the same with MQTT, and https is a valid fallback. The API wraps all of this up for you. There are additional concepts, such as 'direct methods' which are an API wrapper around essentially the same underlying message protocol</li> <li>By using the server-side device twin, which is a way to logically keep properties in sync between device and server. You set a property on the device twin, and when the device syncs up that property will be synced to the device. This is less message-based and built on top of the LWM2M device management protocol.</li> </ol> <p>A lot of the 'polling', connecting, sharing connections, receipts, etc should be taken care of as part of the AMQP (or MQTT) protocol, which in turn is wrapped up in the IoT Hub SDK. So the above is highly simplified, but to reiterate, IoT Hub cannot, and will not (ever) try and send data to a ip address/port on your device.</p>

|hardware|communication|aws-iot|microsoft-windows-iot|azure|

How does an Azure IoT Hub interact with Embedded/IoT devices?

1194

<p>I am working on the Azure IoT platform, and I understand how devices send data to the IoT hub (if I am not wrong, It is just web service call or something similar to that).</p> <p>But I wonder how the IoT hub sends Data/Command/Input to the devices, because we are not working on the IoT hub for Device communication (we don't have any requirement to push data to devices). <strong>Can the IoT hub directly interact with the devices?</strong> (Using the unique Id of device or using any unique identity like IP, Mac address, etc).</p> <p>Somewhere I've read that devices keep requesting to the IoT hub if IoT hub have any input for them, and the IoT hub then sends Data/Command/Input to devices in response. Is that true? If not, then please explain.</p>

2017-03-09T14:07:22.870

<p>_{N.B.: Including this answer here in hopes that it helps someone else.}</p> <h2>Yes, it's actually quite simple.</h2> <p>The issue is not so much with the operating system as it is that mydlink.com has not officially supported the Ubuntu operating system. Therefore, all that is necessary is to fake your user agent. There are several options on how to do this:</p> <h3>1. Directly from the Chrome console</h3> <p>Simply follow these steps:</p> <ul> <li>Press F12.</li> <li>Click on the Console Tab</li> <li>Click on the Hamburger Menu &gt; <code>More Tools</code> &gt; <code>Network Conditions</code></li> <li>Uncheck <code>Select Automatically</code></li> <li>Select <code>Chrome -- Windows</code> or <code>Chrome -- Mac</code></li> <li>Refresh the page.</li> </ul> <h3>2. Install an extension</h3> <p>There are several extensions available for Chrome that will do this for you. Some notable ones are <a href="https://chrome.google.com/webstore/detail/user-agent-switcher-for-c/djflhoibgkdhkhhcedjiklpkjnoahfmg" rel="noreferrer">User-Agent Switcher for Chrome</a>, <a href="https://chrome.google.com/webstore/detail/user-agent-switcher-for-g/ffhkkpnppgnfaobgihpdblnhmmbodake?hl=en" rel="noreferrer">User-Agent Switcher for Google Chrome</a>, and <a href="https://chrome.google.com/webstore/detail/user-agent-switcher/dbclpoekepcmadpkeaelmhiheolhjflj?hl=en" rel="noreferrer">User-Agent Switcher</a>.</p>

|digital-cameras|

Access D-link webcams on Ubuntu

1196

<p>I am the system administrator for some friends who have a couple of web-cams for professional surveillance at a small commercial plant. The cameras are D-Links from the DCS series.</p> <p>Currently, they are accessing them through the Mydlink portal. This works fine <em>(tm)</em> most of the time, unless you try to access them from a Ubuntu system. Then mydlink.com gives this error:</p> <blockquote> <h3>Unsupported Browser or Operating System Detected!</h3> <p>You are using an unsupported browser or operating system and therefore the mydlink web portal may not look, behave or function as intended.</p> </blockquote> <p>Looking at the list of available options, it appears that the only operating systems that are supported are Mac and Windows. Is there a way to access the cameras from Ubuntu short of setting up a custom web page with dynamic DDNS?</p>

2017-03-10T22:02:47.510

<p><a href="https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/overviews/understanding-custom-skills" rel="nofollow noreferrer">Custom skills</a> can capture text and send them to your Skill's API.</p> <p>If you're not completely familiar with how Alexa Skills work, here's a brief summary:</p> <ul> <li><p>First, you <a href="https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/registering-and-managing-alexa-skills-in-the-developer-portal" rel="nofollow noreferrer">register your Skill with Amazon</a>, providing an <a href="https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/defining-the-voice-interface#introduction" rel="nofollow noreferrer"><em>intent schema</em> and <em>sample utterances</em></a>. The intent schema defines which actions can be performed, and the <a href="https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/built-in-intent-ref/slot-type-reference" rel="nofollow noreferrer"><em>slots</em></a> for custom data to be sent to your API. The sample utterances provide examples of how a user can trigger each intent.</p></li> <li><p>When the user activates your Skill, Alexa will try to match what they said to one of your skill's sample utterances. If it <strong>does</strong> match, it will send an HTTPS request to your server to ask for a response.</p></li> <li><p>Your server provides a response (if all goes well) and then Alexa will give feedback to the user who triggered your skill.</p></li> </ul> <p>The <a href="https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/alexa-skills-kit-interaction-model-reference#literal-slot-type-reference" rel="nofollow noreferrer"><code>AMAZON.LITERAL</code> slot</a> allows you to accept virtually any input. Note that currently it is only supported in the English (US) region—English (UK) and German skills cannot use <code>AMAZON.LITERAL</code>.</p> <p>Your intent schema might look like this:</p> <pre class="lang-json prettyprint-override"><code>{ "intents": [ { "intent": "SaveTodo", "slots": [ { "name": "Todo", "type": "AMAZON.LITERAL" } ] } ] } </code></pre> <p>And your sample utterances might be like this:</p> <pre><code>SaveTodo remind me to {fetch the shopping|Todo} SaveTodo remind me to {write my English essay|Todo} SaveTodo remind me to {buy some dog food tomorrow|Todo} </code></pre> <p>When using <code>AMAZON.LITERAL</code>, you need to provide <em>lots</em> of sample utterances—at least one sample for each possible length of input, but ideally more. The Amazon documentation suggests that you should be aiming for hundreds of samples for slots where you could accept various types of inputs.</p> <p>It does seem a little tedious, but if you don't do this, it's unlikely that your skill will recognise text well. You could perhaps generate sample utterances from customer data (so long as personal information is removed beforehand!) so that the most common utterances are in your samples—I suspect Alexa will be slightly biased towards recognising utterances similar to the samples.</p> <p>Amazon <a href="https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/migrating-to-the-improved-built-in-and-custom-slot-types#literal" rel="nofollow noreferrer">discourage <code>AMAZON.LITERAL</code> slots though, and would prefer you to use custom slot types</a>, which require you to list the possible inputs. It's important to remember that:</p> <blockquote> <p>A custom slot type is not the equivalent of an enumeration. Values outside the list may still be returned if recognized by the spoken language understanding system. Although input to a custom slot type is weighted towards the values in the list, it is not constrained to just the items on the list. Your code still needs to include validation and error checking when using slot values.</p> </blockquote>

|alexa|

How does one capture the recognised text from Echo?

1198

<p>I know that some skills can capture spoken text, such as when adding to to-do lists and shopping lists, and third party skills can also do this, eg. <a href="https://smswithmolly.com/" rel="noreferrer">SMS with Molly</a>.</p> <p>So, how do they do this? Is there an API call that captures the recognized text and stores it somewhere?</p>

2017-03-11T09:01:57.617

<p><a href="https://i.stack.imgur.com/89mxh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/89mxh.png" alt="Configuration that worked for me"></a></p> <p>Okay found the solution.</p> <ol> <li>Firstly I think the detected info block tells the flash size. In Snap it could be seen as 8MBit.</li> <li>The 1.54 version of the firmware has two files, one for 8Mbit and the other for 32Mbit.</li> <li>I went for 8Mbit and checked both <code>SpiAutoSet</code> and <code>DoNotChgBin</code>, and volla. It was succesful this time.</li> <li>I set the baudrate to maximum (1500000) not sure though if it's necessary.</li> </ol> <p>PS: Please help improve the answer by mentioning any important information I need to mention in the answer or If anything is wrong.</p>

|esp8266|

Can't Flash ESP8266 latest firmware, says "Fast Flashing error" and "Invalid head of packet(' ')"

1199

<p>I can't figure out how to flash the firmware found on <a href="http://www.electrodragon.com/w/ESP8266_AT-Command_firmware" rel="noreferrer">http://www.electrodragon.com/w/ESP8266_AT-Command_firmware</a>. I am using <code>ESP8266 Download tool v3.4.4</code>. When I am adding a firmware in download path it goes on till a fixed percentage (77 or 99..mostly) and gives the error <code>Invalid head of packet, FAST FLASHING ERROR</code>. One more thing is that the tutorials I am using to do this have many download path entries filled in the download tool while mine are just blank. It says upload the combined file to <code>0x0000</code>. I tried uploading <code>V1.54...</code> file's content (both files) but still got the similar error.</p> <p><a href="https://i.stack.imgur.com/ZnTEH.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ZnTEH.png" alt="enter image description here"></a></p> <p>So anyone could just guide me through this as I am a complete newb into this. Please mention any other information needed in comments.</p> <p><strong>PS</strong></p> <ol> <li>I am pretty sure the power supply is adequate as I have been using esp8266 with the old firmware smoothly. I have also connected a 200uF capacitor b/w gnd and vcc(3.3v from FTDI).</li> <li>I have double checked the connections.(Yes, GPIO0 is grounded).</li> <li>I flashed an earlier version successfully <code>ai-thinker-v1.1.1.bin</code> but when I connected it to arduino IDE serial monitor it started giving unending gibberish text :P.</li> </ol>

2017-03-12T08:35:15.470

<p>Set your smartwatch alarm to snooze every 5 minutes.</p>

|smart-watches|

Which smartwatches have autorestart timers?

1203

<p>Please advise of</p> <ol> <li>any smartwatches that have <strong>timers</strong> that <strong>autorestart features</strong> namely where dismiss and reset are in one swipe and swipes are required</li> </ol> <p>or</p> <ol start="2"> <li>how certain smartwatch <strong>alarms</strong> can achieve such.</li> </ol> <p>Context:</p> <p>I had previously asked about <a href="https://softwarerecs.stackexchange.com/questions/30949/countdown-timer-or-pomodoro-for-android-that-is-automatically-restarted-but-asks/39551#39551">Pomodoro</a> or <a href="https://softwarerecs.stackexchange.com/questions/31167/hiit-timer-variant-for-android">HIIT</a> timer variants that have an autoreset feature unlike timer but still asked to be dismissed. Do Android smartwatches have something like what <a href="https://play.google.com/store/apps/details?id=com.kog.alarmclock&amp;hl=en" rel="nofollow noreferrer">I Can't Wake Up</a> has?</p> <p>Example:</p> <p>Let's say it is 11:59am. I want to be reminded of the time at 12:05pm and then be reminded every 5 minutes.</p> <p>Currently, I am using my phone.</p> <p>So either I set a timer for 5 minutes when it's 12pm or I set an alarm to ring at 12:05pm. If timer: I want an option to autorestart after dismiss (so far I haven't found any). If alarm: I want an option to snooze not so easily (with I Can't Wake Up, I can make it so that I have to slide up to snooze or slide down to dismiss).</p> <p>But it's a hassle to get my phone out every time wherein sometimes I have to first unlock the phone first snoozing the alarm (I Can't Wake Up has 'Quit Block', but I have yet to try this).</p> <p>I'm hoping some smartwatch has the ability to go off at 12:05pm or 5 minutes after I set the timer (which would be around 12pm) so that I just have to swipe my watch instead of taking out my phone.</p> <p>I haven't been able to find such features for any smartwatch, but I may be using wrong keywords.</p>

2017-03-12T10:06:32.267

<p>Starting from 1.5.1 the windows package support websocket, see changelog <a href="https://mosquitto.org/blog/" rel="nofollow noreferrer">https://mosquitto.org/blog/</a> You have just to edit mosquitto.conf file, specify to use the websocket protocol by adding "protocol websockets" (see definition around line 145) and eventually restart mosquitto if you run it as a service</p>

|mqtt|mosquitto|microsoft-windows|web-sockets|

How to enable WebSockets on Mosquitto running on Windows?

1205

<p>I have a Mosquitto broker up and running on my Windows machine. I don't remember if I installed it with Web Sockets support (Cause I didn't knew what that was, or if I needed it). But seeing now my requirement is to use JavaScript (Paho) to connect to MQTT, I want to know how to enable Web Socket support for my existing MQTT broker.</p> <p>I tried editing <code>mosquitto.conf</code> file by adding these lines to the file</p> <pre><code>listener 9001 protocol websockets </code></pre> <p>but doesn't seems to work. I am attaching an image that might provide a better picture:</p> <p><a href="https://i.stack.imgur.com/DEi1x.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DEi1x.png" alt="Windows Command Prompt Error Messages and mosquitto.conf"></a></p> <p>I am not very sure of commands either but they seem to work with default port 1883.</p> <p>So the question is: How do I make it work?</p>

2017-03-12T14:21:03.343

<p>Are you asking about the <em>protocol</em> or the <em>message format</em>? We often incorrectly use the term protocol when we mean the format of the data. I do this myself, often because the distinction isn't clear to everyone.</p> <p>Messaging protocols used in IoT tend to be fairly compact, at least more so than http and offer significant features that are important in messaging (sessions, flow control, reliability, etc). The message format is the of data in the message that get sent. I assume that this is what you are asking about.</p> <p>The most compact message format is a carefully considered hand-rolled binary format. It is frequently used when in low-bandwidth scenarios when you want to send a few bytes, and know exactly what those bytes look like. For larger messages the disadvantages are significant and, in general, should be avoided at all costs.</p> <p>I went through a detailed assessment on many different data serialisation options. I expected protobuf, messagepack to be fairly compact, which they were. However, my second problem was finding libraries that were maintained and available on a number of different platforms, including C on the device.</p> <p>The format that I settled on, surprisingly, was gzip compressed JSON. It is easy to implement and understand, runs everywhere, and, with the data that I was using, was about the same, or smaller, than other methods.</p> <p>Also beware that if you have a secure channel such as TLS, you're going to consume a chunk of data (>6KB) in TLS handshakes anyway.</p> <p>A few years ago, I expected a format like protocol buffers to dominate, but not much really happened. Probably because of the ease at which json can be written out and parsed (and compressed). I like the look of <a href="https://google.github.io/flatbuffers/" rel="noreferrer">Flatbuffers</a>, but the advantage is more on parsing speed than being compact.</p> <p>Since you are at the investigation stage, I suggest you write a bit of code on each, using data that is typical to you situation, and do some comparisons. Having hard data when you start helps confirm your choices.</p>

|communication|protocols|

What Messaging Type can be used for Cellular Network Oriented IoT Protocols?

1209

<p>This came to my attention recently when I found an amazing video on Youtube by:</p> <blockquote> <p><a href="https://www.youtube.com/watch?v=6DRFAOTGdjA&amp;list=PLlx98-upIVs9RBVFkUxeeL4JkSJl8Y_lt&amp;index=1" rel="noreferrer">Micheal E. Anderson: Comparing Messaging Techniques for the IoT, OpenIoTSummit, Linux Foundation</a>.</p> </blockquote> <p>The slides for his talk are Available <a href="http://events.linuxfoundation.org/sites/events/files/slides/IoT_Messaging_Anderson.pdf" rel="noreferrer">Here</a></p> <p>On Slide 26 and <em>41 minutes</em> of the video he is discussing about how (let me paraphrase):</p> <blockquote> <p>Cellular carriers prefer that their IoT consumers use <strong>HTML</strong>, <strong>XML</strong> or <strong>JSON</strong> type of messages since they consume more Data. More Data means they can charge the consumers more money for the service.</p> </blockquote> <p>I understand that a lot of proprietary protocols viz. <strong>SigFox</strong>, <strong>Wireless HART</strong> or <strong>Z Wave</strong> have lower data rates and sending <em>bulky</em> data over such carriers can be an expensive affair. </p> <h3>Question</h3> <ul> <li><p>Are there some other <em>light-weight</em> messaging formats that are being used for usage in Proprietary Protocols which makes them cost-efficient solutions for current and future IoT consumers? (Shot in a dark: some format called <em>lightweight XML or HTML or JSON</em> is lying somewhere?)</p></li> <li><p>Maybe something like <a href="http://cbor.io/" rel="noreferrer"><strong>CBOR</strong></a> is or maybe used ?</p></li> </ul>

2017-03-14T19:05:09.080

<p>I think you'll find a fairly high percentage of "#5, Other", because the list is missing one of the most common consumer IoT architectures: indirect communications via an in-home gateway. </p> <p>All the other methods you describe have drawbacks in the home: they're hard to configure, they're not secure, or they take a lot of expensive server resources. An in-home gateway avoids those problems for the individual devices, exposing only one device to the internet.</p> <p>The typical gateway serves several purposes. First, it's a protocol bridge. Wireless devices use all kinds of open and proprietary communications protocols, including Z-Wave, Zigbee, dedicated 900 MHz RF, dedicated 433 MHz RF, infrared light, Bluetooth, BLE, ANT+, Crestron, etc. These solve all kinds of niche problems, like per-device cost, battery life, self-configuring mesh networks, rapid response times, insecure communications, simple configurations using minimal storage, etc. This way most consumer IoT devices aren't using IP packets, but instead deliver their data inside much smaller frames in order to preserve battery life. The gateway will convert the proprietary protocol into something more transportable and interoperable with an IP based network.</p> <p>Also, the in-home gateway is a good place to store the rules of the system. If you're going to enable rules like "if you turn on the light at the top of the stairs, also turn on the entryway light, unless the kitchen light is on," you can place the rules in the light switches, a centralized web server, or the gateway. Putting the rules in each light switch makes for a brittle configuration that's hard to set up, change, or manage. Running the rules in a centralized server introduces latency because the message has to be translated to TCP, encrypted, sent across the internet, the action has to be received, decrypted, and translated back to Zigbee. The gateway enables the vendor to solve these problems by providing a single management point to back up and restore, and local processor to run the rules quickly.</p> <p>Security is a big issue: IoT devices need to be cheap, and cheap processors don't have big CPUs and storage for secure encryption functions. Not to mention the desire to avoid the massive expense of developing securely encrypted protocols. So they implement very weak (cheap) security in the consumer devices, or no security at all. They make up for this by only communicating within a very limited range - they only have to reach the in-home gateway. This way, the gateway handles the local unsecured communications, and only one device needs the processing power and storage needed to communicate to the cloud over TLS.</p> <p>Finally, the gateway can provide a convenient single point of human interface to the devices. Most gateways expose a web interface, allowing for GUI-based configuration. Imagine trying to Morse-code-configure a 12 character WiFi password into a device using only one button and one LED. Worse, imagine your company's phone support staff talking each customer through that process.</p> <p>Unfortunately, this still does not answer your question directly. But I expect the gateway architecture to be the most common way consumer-oriented devices connect to the internet.</p> <p>EDIT: In response to your comment about in-home gateways used for IoT devices, there are a few basic kinds: dedicated single purpose, dedicated multipurpose, and general purpose. In addition to the interfaces below, all of them have an Ethernet or WiFi interface to bridge messages to and from an IP network.</p> <p>A dedicated single purpose gateway speaks only to a particular manufacturer's devices. The simplest examples might be a USB dongle that receives data from a single device, like a Fitbit dongle. Other examples include the Philips Hue Bridge (which communicates only with Philips Hue light bulbs); the Liftmaster MyQ Gateway (which communicates only with Liftmaster, Chamberlain, or Craftsman garage door openers); or the Harmony Hub (which communicates with Logitech Harmony remotes and blinks IR to various home theater components.) </p> <p>An example of the dedicated multipurpose hub would be Samsung's SmartThings hub. SmartThings sells a wide variety of home automation devices, but they only speak the SmartThings protocol. The SmartThings hub can also communicate to many other device controllers via IP, and has native IFTTT integration.</p> <p>The general purpose gateways may have some proprietary components, but often support multiple interfaces and can serve as a primary smart home interface. Examples include the Wink Hub (which communicates to Zigbee, Z-Wave, Lutron, and Kidde RF devices); Vera Edge (which communicates to Z-Wave and Insteon devices, and extends to communicate to external devices). </p> <p>Finally there are also some very active open source efforts in the general purpose home automation domain, including Domoticz and OpenHAB. These are software programs that support communication to IoT devices through dedicated bridge devices (such as a Z-Wave USB dongle or a Zigbee radio), implement rules, and offer extensive integration capabilities such as IFTTT, MQTT, and others.</p>

|smart-home|security|networking|

How do consumer IoT devices typically enable Internet connection?

1222

<p>As far as I know there are 2 general methods for enabling remote (Internet, not LAN) access to IoT devices:</p> <ol> <li>Via a server that the device polls periodically (e.g. <a href="https://en.wikipedia.org/wiki/MQTT" rel="noreferrer">MQTT</a>)</li> <li>Direct remote access</li> </ol> <p>I'm assuming the second method is not straight forward as typically consumer devices are sitting behind a home router.</p> <p>My question is this: <strong>Roughly what percentage of currently sold IoT devices use which of the following methods to connect to them remotely</strong>:</p> <ol> <li>Via a <strong>server</strong> (device polls the server)</li> <li>Direct remote access that requires <strong>manually configuring a home router</strong> to enable port forwarding (or other way that exposes the device)</li> <li>Direct remote access where the <strong>device automatically configures the router via UPnP</strong> or other protocol</li> <li>Direct remote access using a device's <strong>static IPv6 address</strong> that does not require router setup</li> <li><strong>Other</strong> methods</li> </ol> <p>My question is related to consumer IoT devices, such as light bulbs, light switches, locks, thermometers, etc. from trusted manufacturers that are sold today and are installed in homes.</p> <p><strong>Update:</strong></p> <p>Found this <a href="https://iot.stackexchange.com/a/1118/1980">answer</a> by <a href="https://iot.stackexchange.com/users/12/aurora0001">@Aurora0001</a> to another answer on this site about <a href="https://en.wikipedia.org/wiki/Hole_punching_(networking)" rel="noreferrer">hole punching</a> to enable direct communication between 2 devices residing in different internal networks (e.g. behind a home router). This solution requires a server, but only for the initial handshake.</p> <p>I guess that would add another option...</p>

2017-03-17T16:26:12.297

<p>To answer your second question, yes, <a href="https://media.blackhat.com/us-13/US-13-Lee-Hacking-Surveilling-and-Deceiving-Victims-on-Smart-TV-Slides.pdf" rel="noreferrer">this attack was publicized in 2013 at Black Hat</a>. Two Korean researchers demonstrated an attack that was developed against Android. Attacking TVs was easier than phones, because they didn't have to worry about excessive battery draining giving away the existence of the bug.</p> <p>The link above is to the slide presentation. It has a lot of technical information about how to infect a target remotely, just like any other attack. Some of it might be useful in examining your TV.</p>

|smart-home|security|smart-tv|

Is my Samsung Smart TV vulnerable to the "weeping angel" attack?

1233

<p><a href="https://www.cnet.com/news/weeping-angel-hack-samsung-smart-tv-cia-wikileaks/" rel="nofollow noreferrer">On CNet</a>, there's a report about <a href="https://www.cnet.com/products/samsung-un75f8000/review/" rel="nofollow noreferrer">Samsung UNF 8000 smart TVs</a> being vulnerable to a hack developed by the CIA:</p> <blockquote> <p>In June 2014, the CIA and UK's MI5 held a joint workshop to improve the "Weeping Angel" hack, which appears to have specifically targeted Samsung's F8000 series TVs released in 2013.</p> <p>A "Fake-Off" mode was developed to trick users into thinking their TV was off (by turning off the screen and front LEDs), while still recording voice conversations. Based on what we know about the TV, the hack would have tapped into the microphone located in a TV's accompanying remote.</p> </blockquote> <p>I've read '<a href="https://iot.stackexchange.com/questions/90/can-i-monitor-my-network-for-rogue-iot-device-activity">Can I monitor my network for rogue IoT device activity?</a>' which gives some general ideas about how a network could be monitored, but I'm interested in <em>specific</em> ways that I could detect if my TV was infected and transmitting data to the cloud.</p> <p><strong>Is there any way that I could detect if my TV was recording and transmitting audio to a malicious party?</strong> </p> <p>I'm thinking about anyone who may have developed a similar attack, too, not just the CIA's specific exploit. A problem I can foresee with the general methods in the linked question is that it might be hard to differentiate between general network traffic and malicious traffic from my TV—is there any way I could tell between them easily?</p> <p>The TV is connected to a <a href="https://www.netgear.com/home/products/networking/wifi-routers/WNDR3400.aspx" rel="nofollow noreferrer">Netgear N600</a> router and I have no special monitoring equipment, but I'm happy to use Wireshark if necessary.</p>

2017-03-19T02:55:10.280

<p>I would look at some of Nordic SoC's solutions that have integrated protocols. Its a good way to have a chip that would allow you to test different scenarios, Nordic has SoC's with most of the common protocols (Bluetooth, WiFi, IEEE, ANT etc.) in one chipset. </p> <p>I would start with Bluetooth, its the simplest, most versatile IMHO solution. Though I am not sure about local-triangulation, seems like an overkill for your requirements, maybe look into Bluetooth beacons.</p>

|smart-home|wireless|

Which protocol should I use for automation devices in a home environment?

1242

<p>I have a project to automate things in a house. I am a developer but a beginner in electronics and IoT.</p> <p>What should I use to communicate wirelessly? Wi-Fi, Bluetooth... Where should I look?</p> <p>I need a <strong>cheap, low consumption</strong> and <strong>tiny</strong> solution, for example making extra wireless light interruptor, or, try to do things like local-triangularization with a integrated circuit armlet of my house-mates (there are no prisoners! The house is big and it is for having a "torch-mode"—the lights follow you, for energy savings)</p> <p>We also grow food (mushrooms), so optimization can be made on cultures in the future. I also want to open/close some doors.</p> <p>It must be modular so an API at the end can be cool.</p> <p>Is a Bluetooth-integrated circuit on IoT centralized by Raspberry Pi (server) and controllable by Wi-Fi (or directly through Bluetooth) a good thing to look at? What am I missing?</p>

2017-03-21T14:31:16.830

<p>Multicasting requires that all the devices you want to talk to are listening, so you have to start with a LoRaWAN class C stack, where devices are always listening. Using a "group address" is a trivial modification of the stack: you just have to add some code so that the device filter incoming frames that contains either its address, or the group address.</p> <p>What is complicated is making the communication secure as, if you use a group shared secret key, any device in that group that is compromised gives an attacker control of the whole group. Public key cryptography can be a solution but the math is quite intensive and takes a really long time to compute on a typical small embedded processor.</p>

|lora|

LoRaWAN Multicasting

1256

<p>Is there any real implementation of LoRaWAN multicasting? According to v1.0.2 LoRaWAN specification it is possible to send multicast frames but I have not found neither a node nor a network server for doing so. Nobody knows a way?</p>

2017-03-21T19:18:33.010

<p>The bulbs, in fact, do generate data. They report their state to central hubs or perhaps, faraway servers, and this data can be queried, or even acted on, like a bulb that autumatically turns off during the day.</p>

|smart-home|lighting|analytics|

Data generated from smart bulbs?

1257

<p>I'm trying to answer 2 questions mainly:</p> <ol> <li>What kinds of data are generated from 1 branch of IoT devices namely smart bulbs/smart lighting? </li> <li>How can we visualize the data generated by the same?</li> </ol> <p>I searched online specifically on the same but could not find a lot of useful information. If any of you could help answer this question with relevant resource URLs, it would greatly help me for a school presentation on the same. </p>

2017-03-21T23:17:34.440

<p>In-line dimmers have to be dimmers rather than switches because they have no neutral return at the switch. This makes any multi-way arrangement nigh impossible.</p> <p>The 'obvious' homebrew solution is a z-wave relay, and a unit to aggregate 'switch' requests into a control toggle. Probably requires an mcu or SBC to facilitate this, and this would extend to more than 2-way switching. Using a transmit only faceplace, Rx and Tx on your SBC, and Rx at some convenient point in the electrical circuit.</p> <p>Without the Z-wave requirement, you could pair a <a href="https://www.lightwaverf.com/product/400-dimmer-lw400/" rel="nofollow noreferrer">dimmer switch</a> with a <a href="https://www.lightwaverf.com/product/201-wire-free-switch-lw201/" rel="nofollow noreferrer">wire free control</a>. Wire free means there is no requirement to replicate the standard 4 wire, 2 way switch arrangement. All switches have an equal input on the lamp.</p>

|smart-home|hardware|zwave|ac-power|lighting|

Z-Wave switches with 2-way switched lights?

1262

<p>I'm looking for a set of Z-Wave (preferably Z-Wave Plus) components to use in order to merge two 2-way light switch circuits and allow control of both lights from all switch positions. I've looked at Fibaro FGD-212 modules but I don't think they'll meet my needs.</p> <p>I'll give as much detail below as I can about my current setup and what I've investigated.</p> <p>This is for UK home wiring, in case that matters.</p> <hr> <p>My lounge and stairs leading from it have one ceiling light each and both have two switches (making 4 distinct switches in total, no correlation in placement).</p> <p>I've also been investing (slowly) in Z-Wave equipment, and have started to design a replacement for the switches which would allow:</p> <ul> <li>Both the stairs switches to have 2 physical switches each, one controlling the upstairs hallway and another controlling the lounge</li> <li>One of the lounge switches to have 2 physical switches, with the controls the same as above</li> <li>The other lounge switch to have a single physical switch which only controls the lounge light (not a problem if they are all double, though)</li> </ul> <p>My initial hope was to use 3 * double switches and a single switch, wire them up and control it all with code, but that was before I learnt how 2-way circuits work.</p> <h2>Current setup</h2> <p>3-core (plus ground) 2-way light switch circuits for both the stairs/hallway and lounge:</p> <p><a href="https://i.stack.imgur.com/jHSJ6.png" rel="noreferrer"><img src="https://i.stack.imgur.com/jHSJ6.png" alt="current wiring diagram"></a></p> <h2>Explored approach</h2> <p>I stumbled upon <a href="http://www.vesternet.com/resources/application-notes/apnt-112" rel="noreferrer">a guide to using Fibaro Dimmer 2 modules to achieve this</a>, which would change the circuit to the following:</p> <p><a href="https://i.stack.imgur.com/pHVJL.png" rel="noreferrer"><img src="https://i.stack.imgur.com/pHVJL.png" alt="Circuit diagram with Fibaro Dimmer 2 modules"></a></p> <p>I can see how the wiring and module would work, but my issues with using the module are:</p> <ul> <li>The modules (<a href="http://manuals.fibaro.com/dimmer-2/" rel="noreferrer">FGD-212</a>) seem large to be wired behind the existing switch (20.3mm thick)</li> <li>They only use a single, standard light switch, so <strong>doesn't solve my initial problem</strong> as far as I can tell <ul> <li>Can't use z-wave switches on top of the hidden modules. I'd rather use smart switches rather than hidden modules (for indicator lights, multi-function buttons, etc)</li> </ul></li> <li>To use it with my CFL lights I'll need to buy another device with it, a Bypass 2 (FGB-002), which will increase the amount of stuff I have to fit behind my switch, or inside my light fixture.</li> <li>It only advertises to control dimmable lights, not switching <ul> <li>Their 'switch' equivalent modules are not capable of 2-way circuits</li> </ul></li> </ul> <p>I've considered changing the circuits so that only one of the switches in each physically control the light, but that isn't an option as I'd like to plan for a failure scenario which would leave one of the switches on each circuit useless.</p> <p>Is there a combination of z-wave switches which will enable 2-way switches? It must be a common problem.</p>

2017-03-22T14:26:47.870

<p>My experience is that <strong>it rarely matters</strong> — you can try to define precisely what is or isn't IoT, but you're probably wasting your time splitting hairs rather than solving problems.</p> <p>For a good overview of what different groups consider "IoT", you might want to read <em><a href="https://iot.stackexchange.com/questions/99/what-classifies-a-device-as-iot">What classifies a device as IoT?</a></em> — you quickly see that one question gives you at least ten different and conflicting views, and I'd suggest you ask yourself <em>"Why do I need to know if it's IoT anyway?"</em>.</p> <p>In direct response to your question, though, I think <em>most</em> authors would consider wearables part of the Internet of Things. <a href="http://www.mouser.co.uk/applications/article-iot-wearable-devices/" rel="nofollow noreferrer">Mouser Electronics</a> discuss this in an article on their website, which I found interesting:</p> <blockquote> <p>For example, the wearable devices’ question on many minds these days is “Are wearable devices going to just be peripherals for a smart phone, or is there a more important role for them as part of the Internet of Things?” If we are really moving toward a more pervasive deployment of intelligence into just about everything in our environment, shouldn’t this apply to wearable devices too?</p> <p>[...] The promise of the IoT is based on pervasive connectivity and when associated with large collections of connected devices, significant benefits can accrue. How can wearable devices benefit from this concept too? For example, could your wearable devices interact with the devices of others in a crowd? Would you want to know if someone sitting near you on the train had a high fever?</p> </blockquote> <p>The gist of their article is that the <em>interconnectivity</em> is the key part of whether they'll be part of the IoT—if your device doesn't allow you to aggregate, process and use data through a network, it's probably not an IoT device. For example, a <a href="https://en.wikipedia.org/wiki/Pedometer#/media/File:Omron_HJ112.jpg" rel="nofollow noreferrer">simple pedometer</a> is probably not IoT, but <a href="https://www.quora.com/Is-fitbit-an-IoT-device" rel="nofollow noreferrer">your Fitbit might be</a>!</p>

|definitions|wearables|

Are wearables considered IoT?

1274

<p>With the advent of several devices that are now considered wearables (fitbits, snapchat spectacles, apple watch, etc) are these devices considered IoT?</p> <p>Does it depend on the type of connectivity? For instance, the Apple Watch has WiFi and fitbits don't. Do they need to integrate with other services in order to be considered IoT? </p>

2017-03-25T16:37:43.887

<p>The LoRaWAN network seems to be more an enabling part than the main project aim. They're enabling various university groups (and others) with sensor deployment (and have the capability for city-wide coverage now, albeit at a fairly low bit rate).</p> <p>The back-end of the network is probably more interesting, with the ability to publish/subscribe data in real time. Some of the public data is presented here <a href="http://smartcambridge.org/" rel="nofollow noreferrer">http://smartcambridge.org/</a> (and you can see they're presenting this as a platform, rather than a transport layer).</p> <p>The project seems immediately to be mostly provided by the university (as a research vehicle), and used by the council to guide policy - but that doesn't rule out other applications. Since this is a fairly new innovation, access policies are probably a bit ad-hoc (although security and privacy shouldn't be new to the people involved).</p>

|lora|

Can I connect my devices to the Cambridge Intelligent City Platform?

1284

<p>According to <a href="http://www.cambridge-news.co.uk/news/cambridge-news/driverless-vehicles-travel-apps-cambridge-12774194" rel="noreferrer">Cambridge News</a>, a LoRaWAN network has recently been set up in Cambridge for the 'Intelligent City Plaform'—essentially, a smart city platform for IoT devices to sense and influence the environment:</p> <blockquote> <p>A new LoRa (low power long range) network has also been set up with the University to transfer data flowing from the sensors to the data hub, so that is can be analysed and visualised to plan smart solutions, including making transport systems more reliable and easier to use.</p> <p>The platform is among the first to collate data, which will allow citizens, third party developers and commercial partners to ‘test bed’ innovative applications including the new Cambridge mobile travel app, which will be available to download this summer.</p> </blockquote> <p>I found <a href="http://www.cambridgewireless.co.uk/iotboost/" rel="noreferrer">this page from IoTUK Boost</a> suggesting that the network is only open to people participating in the competition, but the article suggests that any developer might be able to connect.</p> <p><strong>Could a normal citizen connect to and use the smart city network, or is access restricted to those with prior permission?</strong></p>

2017-03-28T11:10:08.517

<p>I have managed to recompile the NodeMCU firmware with us timer enabled:</p> <ul> <li><p>Install docker build environment of Marcel Stör: <a href="https://hub.docker.com/r/marcelstoer/nodemcu-build/" rel="nofollow noreferrer">https://hub.docker.com/r/marcelstoer/nodemcu-build/</a></p></li> <li><p>change firmware files in your firmware directory (e.g. <code>./user/nodemcu-firmware</code>)</p> <ol> <li><p><code>./app/user/user_main.c</code> </p> <pre><code>void user_init(void) { </code></pre></li> </ol></li> </ul> <p>add right here the line: <code>system_timer_reinit();</code></p> <ol start="2"> <li><p><code>./sdk-overrides/osapi.h</code> add above the line <code>#include_next "osapi.h": #define USE_US_TIMER</code></p></li> <li><p><code>./app/modules/tmr.c</code> -> <code>static int tmr_start(lua_State* L){</code> change: <code>os_timer_arm</code> -> <code>os_timer_arm_us</code></p></li> <li><p><code>./app/modules/tmr.c</code> -> <code>static int tmr_interval(lua_State* L){</code> change: <code>os_timer_arm</code> -> <code>os_timer_arm_us</code></p></li> <li><p><code>./app/modules/tmr.c:</code> leave <code>os_timer_arm</code> in <code>int luaopen_tmr( lua_State *L ){</code>as is, otherwise you will get a watchdog reset upon start-up</p> <ul> <li>recompile firmware, and flash your ESP8266</li> </ul></li> </ol> <p>With CPU running at 160MHz, I have managed to sample ADC with 8.3kHz (timer delay of 125uS). If I go faster, the watchdog kicks in.</p> <p>Code:</p> <pre><code> local mytimer2 = tmr.create() local count = 0 local count2 = 0 local adc_read = adc.read mytimer2:register(125, 1, function (t2) count = count + 1; count2 = count2 + 1 local adc_v = adc_read(0) if (count2 == 500) then count2 = 0 end if count == 100000 then mytimer2:stop() print("Time at end: "..tmr.time()) print("Counter: "..count) end end) print("Time at start: "..tmr.time()) mytimer2:start() </code></pre> <p>Output:</p> <p>Time at start: 1</p> <p>Time at end: 13</p> <p>Counter: 100000</p> <p>100.000 reads in 12 sec.</p>

|esp8266|

Sub milisecond timer for ESP8266 in Lua

1289

<p>I'm trying to make a remotely controlled servo motor controller on ESP8266 which is controlled by a server. The problem I'm facing is how to make an asynchronous timer, like <code>tmr.alarm()</code>, but in microseconds. <code>tmr.delay()</code> doesn't work so well, because it stops everything else and is not so accurate. You can get this to work on Arduino, but how to implement this in Lua? </p>

2017-03-28T19:23:54.837

<p>I've not looked at the system in detail, but it looks like it really should have properly encrypted/authenticated transmission. This means that unless you can extract the app's private certificate, or otherwise man-in-the-middle the LAN traffic, you won't be able to just tap into the system as you propose. The first sign of this being done right would be observing the transmission as using <a href="https://en.wikipedia.org/wiki/Transport_Layer_Security" rel="nofollow noreferrer">TLS</a> (i.e HTTPS rather than HTTP).</p> <p>It may be that there is a key exchange happening when you first authenticate a phone onto the system, maybe you can legitimately use this process to acquire the right identification on your Pi.</p> <p>Does the system have any IFTTT integration? You still shouldn't be able to get direct access, but you can maybe send commands indirectly.</p>

|smart-home|communication|

Trying to switch my lights off in my smart home

1293

<p>My main objective is to make my arduino or create a app on android to control lights in the house.</p> <p>So my home has the Nexwell Tukan and I can control the lights and power outlets and more, it also has a LAN card with it so it can be controlled with a mobile phone or a PC, the app is called Nexovision. In that program you can control different things by adding them.</p> <p>So what I need to do is somehow get the packets that the software uses to turn on and off different things and make arduino/the android app send them.</p> <p>"l.soverom 1" is the name of my room in Nexwell, 6528 is when the lights are on and 0 is when they are off, my PC's IP is the one with 154 and the IoT's is 75.The first lines are the authentication probably, </p> <p>Here is the link to the <a href="https://drive.google.com/file/d/0B0-1_1Nl64MjRXk2MGMzNlIwdDA/view?usp=sharing" rel="nofollow noreferrer">WireShark .pcapng</a>.</p>

2017-03-30T14:42:32.703

<p>I couldn't find anyone to explicitly confirm it, but I think it's very likely. If you look carefully at the image they provide on <a href="https://store.smarter.am/products/fridgecam?variant=20094993093" rel="nofollow noreferrer">their website</a>:</p> <p><a href="https://cdn.shopify.com/s/files/1/0712/3461/products/Screen_Shot_2017-01-03_at_21.41.41_grande.png?v=1483743208" rel="nofollow noreferrer"><a href="https://i.stack.imgur.com/VSE8l.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VSE8l.png" height="400"></a></a></p> <p>You can see that the third menu item is <em>'Add expiry'</em>, which suggests that you have to manually do it. Also, note that almost none of the items in the image are in their original packages, and so they don't have their expiry dates written on them at all.</p> <hr> <p>As an aside, I suspect that detecting expiry dates would be a complicated job—far more difficult than just getting the user to do it. For a camera to be able to detect the expiry date:</p> <ol> <li>The item must be aligned the right way so the date is clearly visible</li> <li>The text must be large enough for the scanner to read, in an appropriate font</li> <li>The scanning software must be able to spot which bit <em>is</em> the expiry date on the package (you could perhaps just look for the first date you could see on the packaging, but many items have both <em>Best Before</em> and <em>Use By</em> dates, and might even have production dates on them. That's not even considering the different date formats that could be used!)</li> </ol> <p>As you can see, it's technically far easier to just have the user enter the date, and if they've already had to align the packaging the correct way, reading the date isn't much more effort.</p> <p>Maybe in future there will be a standard format to show the use by date... <a href="https://xkcd.com/927/" rel="nofollow noreferrer">But don't raise your hopes too much</a>!</p>

|smart-home|

Do I have to manually enter expiry dates with the Smarter FridgeCam?

1302

<p>I've been learning recently about the <a href="https://store.smarter.am/products/fridgecam" rel="noreferrer">Smarter FridgeCam</a>. According to their article, one of the features is:</p> <blockquote> <ul> <li>Expiry date notification: Automatic reminders sent to your phone on food expiration dates.</li> </ul> </blockquote> <p>One thing I have been unable to decipher, though. Do you have to manually punch in all those dates on your smartphone, or can you run the date by a scanner and have it automatically add an entry with that date and product?</p>

2017-04-03T10:36:03.070

<p>I'll be answering only this part, as I know of no 'out of the box' system for an unknown firwmare.</p> <blockquote> <p>maybe there are some best practices for implementing firmware upgrade over the air for embedded devices in secure and robust way?</p> </blockquote> <p>In term of practice, what I would do is as follow:</p> <p>1) Have a very minimal boot loader, something as dumb as possible only responsible to load the firmware with the following constraints:</p> <ul> <li>Ability to record last boot success/failure (to rollback to a working version in case of failure)</li> <li>Some kind of emergency process to accept a new firmware in case of catastrophic failure (optional, could be avoided if a "bricked" device is allowable)</li> </ul> <p>2) Set your storage to have two "boot banks" of reasonable size to handle future evolution and firmware growth.</p> <p>3) Checksum the firmware image after download to ensure it is correct before burning, checksum the bank of destination after burning to again ensure it won't fail booting for a missing bit somewhere.</p> <p>The overlooked point is usually the checksum of the downloaded image before and after burning, resulting in corrupted system written on the device. Using two banks and alternating usually ease the update process. </p>

|security|microcontrollers|over-the-air-updates|

Are there any ready cloud services or frameworks for firmware update over the air?

1313

<p>I have prototype of the resource constrained-device (8-bit MCU with no-OS firmware), interacting with a web server. I wonder are there any solutions, frameworks or cloud services for updating my device firmware from the web. From my research there is Microsoft IoT Hub, but I am afraid it does not suits for such resource-constrained devices. There is one more solution, I found - mbed Cloud portal, but I am not sure how it works. Can anyone help me via any advice, maybe there are some best practices for implementing firmware upgrade over the air for embedded devices in secure and robust way? </p>

2017-04-03T14:16:26.257

<p>In general: a fairly common denominator <strong>in large scale breaches</strong> is the fact that it are <strong>not the individual IoT devices</strong> (Teddy bears, toys, sensors and what more) that get hacked, but instead <strong>the central servers get compromised</strong>. </p> <p>Patches or security updates to the IoT device itself won't resolve that...</p> <p>Since the individual IoT devices have only limited compute capacity they uplink over the internet to large scale servers and datacenters operated by the manufacturer for their number crunching.<br> There data from your devices/toys gets sent, associated with your account and profile, and subsequently stored and processed. Often the algorithms processing your data improve when they get to work with more (aggregated) data and neither the stored original data nor such aggregated data will ever be deleted.</p> <p>Often access to that data proves to be secured insufficiently and when that security gets compromised it is not the data from a single device or user that gets leaked, but from many, if not all customers. </p> <p>That is the case as well in the article you linked to.</p> <p>After such large incidents and data breaches you, as an end-user, <em>might</em> get to see updates in the app/firmware/account homepage allowing you to opt-out of such data collection, but typically that comes with a (significant) reduction in functionality, if they device could actually still operate at all without such central data processing. </p>

|smart-home|security|

Keep my Teddy Bear from being hacked

1314

<p>I recently ran across an article on <a href="https://arstechnica.com/security/2017/02/creepy-iot-teddy-bear-leaks-2-million-parents-and-kids-voice-messages/" rel="noreferrer">arstechnica.com</a> which outlines a recently discovered hack for teddy bears. Apparently, <a href="http://spiraltoys.com/" rel="noreferrer">Spiral Toys</a>, the manufacturer of <a href="http://cloudpets.com/" rel="noreferrer">Cloud Pets Stuffed Animals</a>, implemented a security breach in their teddy bears which allowed for over 2 million voice recordings being leaked, as well as the e-mail addresses and passwords of over 800,000 accounts.</p> <p>Does anyone know anything more about this attack? Can these teddy bears be secured with a firmware update or something? How can a Cloud Pets Teddy Bear be kept from being hacked?</p>

2017-04-05T15:50:47.893

<p>On Android, a <strong>discovery devices</strong> functionality is implemented, maybe you can also implement it on your embedded device or at least find an API that provides it.</p> <blockquote> <p><strong>Discovering a device</strong></p> <p>Your application can discover USB devices by either using an intent filter to be notified when the user connects a device or by enumerating USB devices that are already connected. Using an intent filter is useful if you want to be able to have your application automatically detect a desired device. Enumerating connected USB devices is useful if you want to get a list of all connected devices or if your application did not filter for an intent.</p> </blockquote> <p>developer.androind.com <a href="https://developer.android.com/guide/topics/connectivity/usb/host.html" rel="nofollow noreferrer">source</a></p>

|hardware|system-architecture|usb|

How to check usb connectivity?

1320

<p>I want to check if UART usb is connected to PC or not from my embedded program. Is there any indication line I can get in usb to connect to interrupt pin to detect from.embedded setup? From PC side I can get indication of usb connected and disconnected. But I want to know from embedded hardware side.</p> <p>Details : Data will be sending continuously from embedded setup to PC through usb as soon as usb disconnected from PC I need to take some action in setup. For that I need to get indication of disconnect. It is time critical task so I can't add any heartbeat to keep both in sink. </p> <p>Is there any other line indication through usb?</p>

2017-04-05T19:08:46.357

<p>I faced <a href="https://www.linkedin.com/feed/update/urn:li:activity:6297381096170487808" rel="nofollow noreferrer">interesting discussion started by Theo Priestley</a> at LinkedIn about IoT and blockchain stating:</p> <blockquote> <p>IoT cannot</p> <p>-- authenticate millions/billions of service nodes (sensors, devices, etc.),</p> <p>-- secure data between sensors and the database,</p> <p>-- provide firmware &amp; operating system protection,</p> <p>-- manage IoT nodes without servers, nor</p> <p>-- manage provisioning of IoT services &amp; nodes.</p> <p>Having said this, blockchain can be adapted to IoT applications -- primarily in asset accounting, general ledger &amp; payments -- assuming IoT assets are allocated and in a static state.</p> </blockquote> <p>At least for me vision about a good match with these two in a sense of pure IoT technology conjuction was thrown to carbage after this read.</p> <p>Roger Attick (author of citation) is a source I appreciate about IoT and all new technologies.</p> <p>Reasoning is that the transaction rate possible by blockchain is so slow (original post by TP).</p>

|networking|blockchains|

Are there any applications where blockchain is used with IoT?

1322

<p>Since the emergence of these two Technologies, it can be a near future possibility that <a href="https://blockchain.info" rel="noreferrer"><strong>blockchain</strong></a> and other forms of <em>crypto-currency</em> will be used more frequently.</p> <p>According to <a href="http://www.cio.com/article/3027522/internet-of-things/beyond-bitcoin-can-the-blockchain-power-industrial-iot.html" rel="noreferrer">this article</a>:</p> <blockquote> <p>The decentralized, autonomous, and trustless capabilities of the blockchain make it an ideal component to become a foundational element of industrial IoT solutions. It is not a surprise that enterprise IoT technologies have quickly become one of the early adopters of blockchain technologies.</p> </blockquote> <p>Furthermore at the end of the Article, A company named <a href="https://filament.com" rel="noreferrer">Filament</a> is using BitCoin payment to enable sensors for particular applications in different geographical regions.</p> <p>Are there any open source applications available to peek into for <strong>BLOCKCHAIN+IoT</strong> currently?</p>

2017-04-10T09:33:57.120

<p>Google has <a href="https://blog.google/products/assistant/tomato-tomahto-google-home-now-supports-multiple-users/" rel="nofollow noreferrer">now announced</a> how to set up multiple accounts on the Google Home:</p> <ol> <li>Click the 'multi-user is available' card in the Google Home app</li> <li>A list of devices will pop up. Find the correct one, then click "Link your Account"</li> <li>A wizard will then guide you through the steps of adding a new user. To train the device to recognise your voice, you have to say "OK Google" and "Hey Google" twice, and from then on, your account is linked and your voice is recognised by the device.</li> </ol> <p>The voice recognition is apparently done locally on the device through a neural network, and I'm pretty surprised about how little training data the device needs to add a new user; the days of spending hours repeating sentences to train a speech-to-text program are gone!</p> <p>The function is apparently only available in the US at the minute—Google promise that it's coming to the UK soon enough, though.</p>

|google-home|voice-recognition|

How do I switch between users with my Google Home?

1334

<p>A new card in the Google Home app <a href="http://www.androidpolice.com/2017/04/10/google-home-app-says-multiple-users-now-supported/" rel="noreferrer">says that multiple users are now supported</a>:</p> <blockquote> <h2>Multiple users now supported</h2> <p>Now, you and others in your home can get a personalized experience from your Assistant on Google Home.</p> </blockquote> <p>How does my Google Home plan to tell between me and someone else using the device? Will I need to say who I am each time I use the device, or will it recognise my voice and switch automatically? </p> <p><a href="http://www.pocket-lint.com/news/140454-google-home-may-add-multiple-user-support-and-voice-recognition" rel="noreferrer">This article</a> subtly hints at the Google Home getting the voice recognition feature, but I couldn't find any authoritative sources confirming it.</p> <p>Is there any information to confirm how the multi-user feature will work yet?</p>

2017-04-10T14:57:33.483

<h2>DDoS vs. "PDoS"</h2> <p><strong>1. DDoS (for reference)</strong></p> <p>A conventional distributed denial of service attack (DDos) is a class of denial of service (DoS) attacks in which a <a href="https://en.wikipedia.org/wiki/Overlay_network" rel="noreferrer">distributed system</a> (botnet) consisting of nodes controlled via some application (<a href="https://security.radware.com/ddos-threats-attacks/threat-advisories-attack-reports/mirai-botnet/" rel="noreferrer">Mirai</a>, <a href="http://krebsonsecurity.com/2015/01/lizard-stresser-runs-on-hacked-home-routers/" rel="noreferrer">LizardStresser</a>, <a href="https://krebsonsecurity.com/2016/09/krebsonsecurity-hit-with-record-ddos/#more-36426" rel="noreferrer">gafgyt</a>, etc.) is used to consume the resources of the target system or systems to the point of exhaustion. <a href="https://security.stackexchange.com/questions/22809/what-is-a-dos-attack-and-how-does-it-differ-from-a-ddos-attack">A good explanation of this is given on security.SE</a>.</p> <p>An explanation of how Mirai-controlled botnets accomplish denial of service can be found in an <a href="https://www.incapsula.com/blog/malware-analysis-mirai-ddos-botnet.html" rel="noreferrer">analysis by Incapsula</a>:</p> <blockquote> <p>Like most malware in this category, Mirai is built for two core purposes:</p> <ul> <li>Locate and compromise IoT devices to further grow the botnet.</li> <li>Launch DDoS attacks based on instructions received from a remote C&amp;C.</li> </ul> <p>To fulfill its recruitment function, Mirai performs wide-ranging scans of IP addresses. The purpose of these scans is to locate under-secured IoT devices that could be remotely accessed via easily guessable login credentials—usually factory default usernames and passwords (e.g., admin/admin).</p> <p>Mirai uses a brute force technique for guessing passwords a.k.a. dictionary attacks...</p> <p>Mirai’s attack function enables it to launch HTTP floods and various network (OSI layer 3-4) DDoS attacks. When attacking HTTP floods, Mirai bots hide behind the following default user-agents...</p> <p>For network layer assaults, Mirai is capable of launching GRE IP and GRE ETH floods, as well as SYN and ACK floods, STOMP (Simple Text Oriented Message Protocol) floods, DNS floods and UDP flood attacks.</p> </blockquote> <p>These types of botnets accomplish resource exhaustion resulting in denial of service by using controlled devices to generate such large volumes of network traffic directed towards the target system that the resources provided by that system become inaccessible for the duration of the attack. Once the attack ceases, the target system no longer has its resources consumed to the point of exhaustion and can again respond to legitimate incoming client requests.</p> <p><strong>2. &quot;PDoS&quot;</strong></p> <p>The BrickerBot campaign is fundamentally different: instead of integrating embedded systems into a botnet which is then used to orchestrate large-scale attacks on servers, the embedded systems themselves are the target.</p> <p>From Radware's post on BrickerBot <a href="https://security.radware.com/ddos-threats-attacks/brickerbot-pdos-permanent-denial-of-service/" rel="noreferrer">“BrickerBot” Results In Permanent Denial-of-Service</a>:</p> <blockquote> <p>Imagine a fast moving bot attack designed to render the victim’s hardware from functioning. Called Permanent Denial-of-Service (PDoS), this form of cyber-attack is becoming increasingly popular in 2017 as more incidents involving this hardware-damaging assault occur.</p> <p>Also known loosely as “phlashing” in some circles, PDoS is an attack that damages a system so badly that it requires replacement or reinstallation of hardware. By exploiting security flaws or misconfigurations, PDoS can destroy the firmware and/or basic functions of system. It is a contrast to its well-known cousin, the DDoS attack, which overloads systems with requests meant to saturate resources through unintended usage.</p> </blockquote> <p>The embedded systems targeted for permanent incapacitation do not have some application downloaded onto them for purposes of remote control and are never part of a botnet (emphasis mine):</p> <blockquote> <p><strong>Compromising a Device</strong></p> <p><strong>The Bricker Bot PDoS attack used Telnet brute force - the same exploit vector used by Mirai - to breach a victim’s devices. Bricker does not try to download a binary</strong>, so Radware does not have a complete list of credentials that were used for the brute force attempt, but were able to record that the first attempted username/password pair was consistently 'root'/'vizxv.’</p> <p><strong>Corrupting a Device</strong></p> <p>Upon successful access to the device, the PDoS bot performed a series of Linux commands that would ultimately lead to corrupted storage, followed by commands to disrupt Internet connectivity, device performance, and the wiping of all files on the device.</p> </blockquote> <p>A third difference is that this campaign involves a small number of attacker-controlled devices, instead of many thousands or millions:</p> <blockquote> <p>Over a four-day period, Radware’s honeypot recorded 1,895 PDoS attempts performed from several locations around the world.</p> <p>The PDoS attempts originated from a limited number of IP addresses spread around the world. All devices are exposing port 22 (SSH) and running an older version of the Dropbear SSH server. Most of the devices were identified by Shodan as Ubiquiti network devices; among them are Access Points and Bridges with beam directivity.</p> </blockquote> <h2>Summary</h2> <p>Given the number of ways that the BrickerBot &quot;PDoS&quot; campaign fundamentally differs from conventional &quot;DDoS&quot; campaigns like Mirai, using similar-sounding terminology is likely to result in confusion.</p> <ul> <li>DDoS attacks are typically conducted by a botmaster with control over a distributed network of devices in order to prevent clients from accessing server resources for the duration of the attack, whereas &quot;BrickerBot&quot; is a campaign to &quot;brick&quot; embedded systems</li> <li>Botnet clients are controlled via an application installed on the client by the attacker. In the BrickerBot campaign, commands are remotely executed via telnet without the use of a controlling application (e.g. malware)</li> <li>DDoS attacks employ a large number (thousands, millions) of controlled devices, whereas the BrickerBot campaign uses a comparatively small number of systems to orchestrate so-called &quot;PDoS&quot; attacks</li> <li>the BrickerBot campaign targets embedded systems for incapacitation, whereas Mirai and the like target embedded systems in order to integrate them into a botnet</li> </ul>

|security|mirai|

What is the difference between a DDoS attack and a PDoS attack?

1338

<p>I've read a certain amount about the <a href="https://iot.stackexchange.com/questions/tagged/mirai">Mirai</a> worm, a virus that attacks Internet of Things devices using default usernames and passwords and essentially is wired to produce a Distributed Denial of Service (DDoS).</p> <p>However, I've recently read about another worm, <a href="https://techxplore.com/news/2017-04-honeypot-reveals-brickerbot-internet-device.html" rel="noreferrer">BrickerBot</a>, also a virus attack on Internet of Things devices. According to <a href="https://thenextweb.com/insider/2017/04/10/iot-devices-are-intentionally-getting-bricked-by-malware-and-maybe-thats-okay/" rel="noreferrer">this article on thenextweb.com</a> results in a Permanent Denial of Service (PDoS).</p> <p>What is the difference between these two attacks as relates to the denial of service? Otherwise stated, what is the difference between DDoS and PDoS as relates to these IoT attacks?</p>

2017-04-10T14:59:01.803

<p>Assuming you need to handle firmware updates (otherwise, you're insecure by default) then you will also need to sign the updates (and manage updates in a secure way). Otherwise, an attacker can simply present your device with a compromised update package. Clearly, if you do this, you make it impossible for the user to apply firmware updates in the same way, but you don't necessarily need to lock them out entirely (since they have physical access).</p> <p>In addition, you'll need to provide a secure way of provisioning each device with a unique ssh key visible to the end user (but they could be contained on the device if you're accepting physical access means ownership).</p>

|security|linux|authentication|

How to secure root on IoT device while remaining open to tinkerers

1339

<p>I'm currently spitballing ideas for an Internet of Things device. It will be running Linux on a widely available development board, I'm not too concerned about physical security or the end user doing something bad to it however I'd like to secure it from botnets such as the mirai botnet.</p> <p>For things such as the root user account, how should I secure it: should I use key based authentication or just a regular password? I want to be able to give end users access to the root user account upon request or provide it out of the box. </p> <p>I don't want to have any extra user accounts or store any authentication details on my servers in case of a breach.</p>

2017-04-10T22:54:47.857

<p>If, on the other hand, we look the <a href="https://support.smartthings.com/hc/en-us/article_attachments/115004583883/arlo_pro_user_manual_en.pdf" rel="nofollow noreferrer">user guide</a>, we will see that WiFi is providing a 100% cordless connection from the camera to the base station and Ethernet is the way for connecting the whole system to the Internet.</p> <p>The thought of connecting WiFi for Internet is not correct according to that document. Also connecting wire to Ethernet in previous step does not mean that local home WiFi would be involved to pairing process in any way. These are separate steps for separate functions and always base station and cameras share a WiFi that belongs to them only and is created by base station, not your local WiFi station.</p> <p>Answer to the question: cameras connect to base station directly via WiFi.</p>

|security|networking|digital-cameras|surveillance-cameras|

Does Arlo Pro communicate via WiFi?

1348

<p>I just setup an Arlo Pro security camera (made by Netgear) and found it interesting that the system didn't explicitly have me configure a WiFi connection. The setup process consists of hard-wiring the base receiver to my network, then simultaneously pressing sync buttons on both the base receiver and camera.</p> <p>So, do Arlo Pro cameras connect via WiFi or some other form of wireless to connect to its base receiver?</p>

2017-04-11T16:54:53.693

<p>This ended up working for me:</p> <ul> <li>Create a new mode in Arlo app. Have it do any recording or notifications</li> <li>Connect Arlo to SmartThings (using Arlo Connect SmartApp)</li> <li>Add each Arlo device as needed</li> <li>Select each newly added Arlo device and set it to Inactive (click the green camera icon from status screen of Thing)</li> <li>As needed, update Smart Home Monitor routines (ie Good Morning!, Good Night!, Goodbye!, and I'm Back!) to turn off/on the cameras as switches</li> </ul> <p>By turning off/on the camera as a switch in SmartThings, it is essentially the same as turning off/on the <strong>Camera</strong> switch when configuring camera settings through the Arlo app.</p> <p>Configuring SmartThings/Arlo Camera Status (only needs to be done in SmartThings) <a href="https://i.stack.imgur.com/VLLfbm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VLLfbm.png" alt="SmartThings Camera Status"></a><a href="https://i.stack.imgur.com/EgP3Um.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EgP3Um.png" alt="Arlo camera configuration"></a></p> <p>Configuring automation routines. Activating in SmartThings, tasks are handled in Arlo mode: <a href="https://i.stack.imgur.com/vLd7zm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vLd7zm.png" alt="Setting the Smart Home Monitor routine in SmartThings"></a><a href="https://i.stack.imgur.com/xEyWqm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xEyWqm.png" alt="Setting the Arlo mode to SmartThings for recording"></a></p>

|security|samsung-smartthings|digital-cameras|mobile-applications|

Set Arlo Mode with SmartThings

1362

<p>If it's possible, how can I set the "Mode" for an Arlo device using a SmartThings Routine? Ideally, I would simply set the camera modes when SmartThings goes into various security modes.</p> <p>I've found that I don't really like the Arlo security modes and have created my own notification/recording modes and set them to a schedule in the Arlo app. But I'd prefer it to be triggered by our family's presence like with SmartThings.</p> <p>Looking into SmartThings Routines, it appears that I can "turn on" the camera in a routine, but I'm not quite sure what that means. There doesn't appear to be an option to record video through SmartThings except when viewing the device.</p> <p><strong>Update</strong>:</p> <p><a href="https://community.smartthings.com/t/question-about-new-arlo-integration/56048/14" rel="noreferrer">This SmartThings post</a> helped quite a bit in how to integrate Arlo into routines. hirsti's Step by Step instructions help the most (it didn't seem to have an anchor...)</p> <p>See my answer below for steps</p>

2017-04-12T16:49:00.067

<p>Bluetooth (and pretty much every other transmission protocol in contrast to sensors like radar) are based on digital protocols. This means that the signals are both binary, and protected by error detection/correction codes.</p> <p>So long as the signal is strong enough that there are only a few errors in any one packet, the resulting sensor reading which is sent will not change. Specifically in the case of BLE, there is no error correction overhead in the packets, just a CRC. Any received packet which is errored will not be acknowledged. This causes the packet to be re-sent (so increasing latency as a trade-off for improved typical throughput). (from <a href="http://ecee.colorado.edu/~liue/teaching/comm_standards/2015S_Bluetooth_Low_Energy/index.htm" rel="nofollow noreferrer">here</a>, as per @Aurora0001)</p> <p>More power can sometimes cause problems, where you have lots of sensors sharing the same band.</p>

|sensors|bluetooth-low-energy|beacons|data-transfer|

How does transmit power influence the accuracy of beacon sensor readings?

1367

<p>I have some Bluvision Beeks beacons equipped with temperature sensors. I can adjust their transmit powers. I am wondering if setting a higher transmit power for a particular beacon will result in a better sensor reading than if the beacon were set to a lower transmit power in general. Or is higher transmit power only provided in order to achieve a longer range?</p>

2017-04-14T15:14:00.093

<p>You might want to look at the concept of <a href="http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-dead-letter-queues.html" rel="noreferrer">dead-letter queues of AWS SQS</a>. From the AWS docs:</p> <blockquote> <p>A dead letter queue is a queue that other (source) queues can target for messages that can't be processed (consumed) successfully. You can set aside and isolate these messages in the dead letter queue to determine why their processing did not succeed.</p> </blockquote> <p>So, if you point the main subscriber to listen from the normal queue and the secondary subscriber to listen from the dead-letter queue, the failover problem should be solved.</p> <p>Also, with this, 1, 2 and 3 of your problems are taken care of. The main and secondary subscribers don't need to talk to each other in this case.</p> <p>Also, building upon Tensibai's answer, make sure your subscriber code is written so as to receive one message at a time <strong>if multiple subscribers are listening to the same queue</strong> due to the <code>visibility timeout</code></p> <hr> <p>Downside would be that it would introduce a delay in processing, messages enter the dead letter queue only after a while.</p> <p>So, in case you wouldn't want that, then you can go ahead with Tensibai's answer. And if you can tolerate that, instead of having an extra Dynamo table for status checks, then you can use this.</p>

|mqtt|aws-iot|aws|

How can I set up main and failover MQTT subscribers for a job queue with AWS IoT?

1371

<p>I have an system where a client (let's call it ClientA) can publish requests to a particular MQTT topic. The broker, in case it matters, is Amazon Web Services. Then I have another client (let's call it MainSubscriber) which is always subscribed to the same topic so that it can pick up requests from ClientA and do some work that, in the end, turns into a database operation. The database, in case it matters, is DynamoDB.</p> <p>Since the MainSubscriber may not be always accessible/online, there is a desire to have a failover subscriber to be the failover backup of the main subscriber. The idea is that if the main subscriber does not handle the request in a timely manner, then the failover subscriber would kick in and do the equivalent work/database operation. <strong>The challenge is that the "work" and the resulting "database operation" must not be duplicated by both main and failover subscribers.</strong></p> <p>Here's a logical system architecture drawing for this system.</p> <pre><code> -----&gt; MainSubscriber ---- / \ ClientA --&gt; Broker ---&gt; Database \ / ---&gt; FailoverSubscriber -- </code></pre> <p>Clearly, there are some challenges with such a system:</p> <ol> <li>How does the main subscriber indicate to the failover subscriber that it is working on the request?</li> <li>How does the failover subscriber detect that the main subscriber has not picked up the request and needs to start working on it?</li> <li>How does the failover subscriber then hold off the main subscriber in case it all of a sudden comes back online and picks up the request?</li> <li>How to deal with synchronicity issues between main and failover subscribers?</li> </ol> <p>I would rather not have to reinvent the wheel if an existing solution already exists for such a scheme. So, my first question is whether there is something out there already?</p> <p>If not, then I was thinking of using DynamoDB with Strongly Consistent reads to act as the mediator between the Main and Failover subscriber. So, my second question is whether there any well established schemes for doing this?</p>

2017-04-19T19:42:10.710

<p>I've found another way quite expensive yet working with external processes such as PHP's <code>system</code> : <strong>screen</strong></p> <p>First, install it :</p> <pre class="lang-bash prettyprint-override"><code>sudo apt-get install screen </code></pre> <p>Then call your function</p> <pre class="lang-bash prettyprint-override"><code>screen -dm -S taskid bash -c 'sleep 20 &amp;&amp; command' -dm : detach process -S : identify screen by name </code></pre> <p>To list your tasks</p> <pre class="lang-bash prettyprint-override"><code>ls /var/run/screen/S-www-data (or S-anotheruser, warning it is user bound, or sudo it) </code></pre> <p>To kill it</p> <pre class="lang-bash prettyprint-override"><code>screen -S taskid -X kill -S : identify screen by name -X : access the screen and perform this command </code></pre>

|smart-home|domoticz|

Reliable timers for always on/timed/off lamps

1386

<p>I have a ZWave light bulb and a ZWave 4-button wall switch, both connected to Domoticz installed on a Raspberry Pi.</p> <p>I'd like the following scenarios :</p> <ul> <li>Button 1 : lamp on for 30 minutes</li> <li>Button 2 : lamp off</li> <li>Button 3 : lamp always on</li> <li>Button 4 : summon Cthulhu</li> </ul> <p>Each buttons overrides the previous action (Button 3 -&gt; Button 1 = on for 30 minutes)</p> <p>Wiring and programming the buttons is easy, but now, how about the timer ? I'd like to avoid creating a homemade service because I'm afraid of messing with <code>init.d</code>.</p> <p>I have 3 possibilities :</p> <hr/> <h2>Domoticz dummy switch</h2> <p>Domoticz allows to create a dummy switch which can change states after some time given in an interface :</p> <p><a href="https://i.stack.imgur.com/tj0dA.png" rel="noreferrer"><img src="https://i.stack.imgur.com/tj0dA.png" alt="domoticz dummy switch" /></a></p> <p><strong>Pros</strong></p> <ul> <li>off-the-shelf timer!</li> <li>I can interact quite quickly between my wall switch and the lamp</li> </ul> <p><strong>Cons</strong></p> <ul> <li>although Domoticz handles MQTT, there will be a lot of LUA script and &quot;blocky&quot; to interconnect devices</li> <li>time might not be easily configurable...</li> </ul> <hr/> <h2><code>at</code> and <code>atq</code></h2> <p><a href="http://www.computerhope.com/unix/uat.htm" rel="noreferrer"><code>at</code></a> is a linux command to plan an action in time, as simple as</p> <pre><code>at [when] &lt; [what] </code></pre> <p><strong>Pros</strong></p> <ul> <li>multi-timer service</li> <li>easy to use and call</li> </ul> <p><strong>Cons</strong></p> <ul> <li>at only gives an unique ID, unless parsing the planned command I can't give a name to the job (unless with a magic linux command...)</li> <li>therefore I need to code/implement a job matcher using a database</li> </ul> <hr/> <h2>Crontab</h2> <p>Crontab is a linux service to plan repetitive tasks. In my case it will be a simple</p> <pre><code># check every minute * * * * * /path/checktimer.sh </code></pre> <p><strong>Pros</strong></p> <ul> <li>Reliable time trigger</li> </ul> <p><strong>Cons</strong></p> <ul> <li>Cannot manage seconds...</li> <li>Still forced to maintain somewhere a job matcher</li> </ul> <hr/> <p>To my question :</p> <ul> <li><strong>Did you have to manage timers like this kind?</strong></li> <li>Did I miss other more reliable/configurable solutions?</li> <li>Do you have a preference with on the solutions above?</li> </ul>

2017-04-23T13:36:34.087

<p><em>Disclaimer: some of the content is conjecture</em> </p> <p>A summary of the experiment is described in the introduction (page 2). The claim is in bold:</p> <blockquote> <p>Our initial discovery was that <strong>the Atmel stack has a major bug in its proximity test, which enables any standard ZigBee transmitter (which can be bought for a few dollars in the form of an tiny evaluation board) to initiate a factory reset procedure which will dissociate lamps from their current controllers, up to a range of 400 meters. Once this is achieved, the transmitter can issue additional instructions which will take full control of all those lamps</strong>. We demonstrated this with a real war-driving experiment in which we drove around our university campus and took full control of all the Hue smart lamps installed in buildings along the car’s path. Due to the small size, low weight, and minimal power consumption of the required equipment, and the fact that the attack can be automated, we managed to tie a fully autonomous attack kit below a standard drone, and performed war-flying in which we flew hundreds of meters away from office buildings, forcing all the Hue lamps installed in them to disconnect from their current controllers and to blink SOS in morse code.</p> </blockquote> <p>The researchers provide empirical evidence of this in their demonstration that a signal can be sent from a transmitter to a vulnerable device from a distance of up to 400 meters away. The researchers sent signals from transmitters 50, 150, and 350 meters away in their wardriving and warflying tests.(See sections 8.1.1 "Wardriving" and 8.1.2 "Warflying"). The maximum theoretical effective range of 400 meters is derived from the outdoor Zigbee wireless range: </p> <blockquote> <p>Our novel takeover attack uses a bug in Atmel’s implementationof the ZLL Touchlink protocol state machine (used in Philips Hue lamps) to take over lamps from large distances (<strong>up to ZigBee wireless range that can be as far as 70 meters indoors or 400 meters outdoors [14]</strong>), using only standard Philips Hue lamps. </p> </blockquote> <p>This is quite different from the rather more sensational claim that it is theoretically feasible to seize control of all such Philips lamps by infecting an exploitable lamp with a program that self-propagates directly from lamp to lamp via Zigbee (the claim is in bold):</p> <blockquote> <p>Our new attack differs from previous attacks on IoT systems in several crucial ways. First of all, previous attacks used TCP/IP packets to scan the internet for vulnerable IoT devices and to force them to participate in internet-based activities such as a massive DDOS attack. Since internet communication is heavily monitored and can be protected by a large variety of security tools, such attacks can be discovered and stopped at an early stage, at least in principle. Our attack does not use any internet communication at all, and the infections jump directly from lamp to lamp using only unmonitored and unprotected ZigBee communication. Consequently, it will be very difficult to detect that an attack is taking place and to locate its source after the whole lighting system is disabled. </p> <p>Another major difference is that our attack spreads via physical proximity alone, disregarding the established networking structures of lamps and controllers. As a result, such an attack cannot be stopped by isolating various subnetworks from each other, as system administrators often do when they are under attack. In this sense the attack is similar to air-borne biological infections such as influenza, which spread almost exclusively via physical proximity. </p> <p>Finally, previously reported attacks are carried out via linear scans and infections which are all carried out in a star-shaped structure with a centrally located attacker, whereas <strong>our chain reaction attack spreads much faster by making each infected lamp the new source of infection for all its adjacent lamps; the attacker only has to initiate the infecting with a single bad lamp, and can then retire and watch the whole city going dark automatically.</strong></p> </blockquote> <p>The researchers support this claim using a mathematical model in which the effective range of the lamps is assumed to be 50 meters:</p> <blockquote> <p>Consider a city whose area is A, and assume that its shape is roughly circular (i.e., it is flat, convex, not too elongated, and without holes). We place N smart lamps at random locations within the city, and define an infection graph by connecting any two lamps whose distance is smaller than D by an edge. The connected components in this graph define the possible infection patterns which can be started by plugging in a single infected light. For a small N all the components are likely to consist of just a few vertices, but as N increases, the graph goes through a sudden phase change in which a single giant connected component (that contains most of the vertices) is created. This is the critical mass at which the infection is likely to spread everywhere in the city instead of remaining isolated in a small neighborhood.</p> <p>The mathematical field dealing with such problems is called Percolation Theory, and the critical N is called the Percolation Threshold. A good survey of many variants of this problem can be found in [15], and the particular version we are interested in appears in the section on thresholds for 2D continuum models, which deals with long range connectivity via overlapping two dimensional disks of radius R, as described in Fig 1. Since two points are within a distance D from each other if and only if the two disks of radius R = D/2 around them intersect, we can directly use that model to find the critical mass in our model: It is the value N for which the total area of all the randomly placed disks (i.e., πR2N) is about 1.128 times larger than the total area A of the city. In other words, N = 1.128A/π(D/2)2.</p> <p>To get a feeling for how large this N can be, consider a typical city like Paris, which is fairly flat, circular in shape, and with few skyscrapers that can block the available lines of sight. Its total area is about 105 square kilometers [16]. According to the official ZigBee Light Link website [14],the range of ZigBee communication is between 70 meters indoors and 400 meters outdoors¹. There is probably no single number that works in all situations, but to estimate N it is reasonable to assume that one lamp can infect other lamps if they are within a distance of D = 100 meters, and thus the disks we draw around each lamp has a radius of R = 50 meters. By plugging in these values into the formula, we get that the critical mass of installed lamps in the whole city of Paris is only about N = 15, 000. Since the Philips Hue smart lamps are very popular in Europe and especially in affluent areas such as Paris, there is a very good chance that this threshold had in fact been exceeded, and thus the city is already vulnerable to massive infections via the ZigBee chain reaction described in this paper.</p> <ol> <li>The Philips engineers we talk with stated that in a dense urban environment, the effective range can be less than 30 meters</li> </ol> </blockquote> <h2>Argument</h2> <p>The researchers claim that the exploit vector and propagation technique employed in their experiment makes it possible to infect all vulnerable devices in an urban environment can be framed as an argument, which goes something like this:</p> <ol> <li><blockquote> <p>the Atmel stack has a major bug in its proximity test, which enables any standard ZigBee transmitter (which can be bought for a few dollars in the form of an tiny evaluation board) to initiate a factory reset procedure which will dissociate lamps from their current controllers, up to a range of 400 meters. Once this is achieved, the transmitter can issue additional instructions which will take full control of all those lamps.</p> </blockquote> <p>and</p> <blockquote> <p>Our novel takeover attack uses a bug in Atmel’s implementationof the ZLL Touchlink protocol state machine (used in Philips Hue lamps) to take over lamps from large distances (up to ZigBee wireless range that can be as far as 70 meters indoors or 400 meters outdoors [14]), using only standard Philips Hue lamps.</p> </blockquote> <p><strong>Premise 1:</strong> Philips Hue lamps have a vulnerability that allows them to be exploited over ZigBee.</p></li> <li><blockquote> <p>Our attack does not use any internet communication at all, and the infections jump directly from lamp to lamp using only unmonitored and unprotected ZigBee communication.</p> </blockquote> <p>and </p> <blockquote> <p>According to the official ZigBee Light Link website [14], the range of ZigBee communication is between 70 meters indoors and 400 meters outdoors¹</p> </blockquote> <p>and</p> <blockquote> <p>There is probably no single number that works in all situations, but to estimate N it is reasonable to assume that one lamp can infect other lamps if they are within a distance of D = 100 meters, and thus the disks we draw around each lamp has a radius of R = 50 meters.</p> </blockquote> <p><strong>Premise 2:</strong> In an urban environment, Philips Hue lamps have an effective range of 50 meters on average.</p></li> <li><blockquote> <p>Consider a city whose area is A, and assume that its shape is roughly circular (i.e., it is flat, convex, not too elongated, and without holes). We place N smart lamps at random locations within the city, and define an infection graph by connecting any two lamps whose distance is smaller than D by an edge. The connected components in this graph define the possible infection patterns which can be started by plugging in a single infected light. For a small N all the components are likely to consist of just a few vertices, but as N increases, the graph goes through a sudden phase change in which a single giant connected component (that contains most of the vertices) is created. This is the critical mass at which the infection is likely to spread everywhere in the city instead of remaining isolated in a small neighborhood.</p> </blockquote> <p>and </p> <blockquote> <p>the critical N is called the Percolation Threshold</p> </blockquote> <p>and</p> <blockquote> <p>Since two points are within a distance D from each other if and only if the two disks of radius R = D/2 around them intersect, we can directly use that model to find the critical mass in our model: It is the value N for which the total area of all the randomly placed disks (i.e., πR2N) is about 1.128 times larger than the total area A of the city. In other words, N = 1.128A/π(D/2)2.</p> <p>To get a feeling for how large this N can be, consider a typical city like Paris, which is fairly flat, circular in shape, and with few skyscrapers that can block the available lines of sight. Its total area is about 105 square kilometers [16].</p> </blockquote> <p>and</p> <blockquote> <p>to estimate N it is reasonable to assume that one lamp can infect other lamps if they are within a distance of D = 100 meters, and thus the disks we draw around each lamp has a radius of R = 50 meters. (Premise 2)</p> </blockquote> <p><strong>Premise 3:</strong> </p> <blockquote> <p>By plugging in these values into the formula, we get that the critical mass of installed lamps in the whole city of Paris is only about N = 15, 000.</p> </blockquote></li> <li><blockquote> <p>the Philips Hue smart lamps are very popular in Europe and especially in affluent areas such as Paris</p> </blockquote> <p><strong>Premise 4:</strong> Popularity of the Philips Hue lamp is indicative of its prevalence in Paris</p></li> </ol> <p><strong>Conclusion:</strong> </p> <blockquote> <p>there is a very good chance that this threshold had in fact been exceeded, and thus the city is already vulnerable to massive infections via the ZigBee chain reaction described in this paper</p> </blockquote> <h2>Analysis (with conjecture)</h2> <p>This is a weak argument, since only premise 1 is supported by empirical evidence from reproducible experiments.</p> <p><strong>Challenges to the arguments</strong></p> <p>While it has been demonstrated in the experiment that a vulnerability in the lamps can be exploited over ZigBee at distances of 50, 150 and 300 meters, and the program that exploited the vulnerability successfully propagated itself over ZigBee to the other lamps within range, it was never demonstrated that this propagation would take place outside of the controlled environment in the experiment <em>on the scale claimed by the researchers</em> (that is, city-wide propagation). </p> <p>In the mathematical model based on percolation theory used by the researcher to model a "typical" urban environment, the average effective range between lamps was given to be 50 meters. Use of this value as the average effective range can be easily challenged by information readily provided by the manufacturer.</p> <p>The model also relies on a random distribution of lamps throughout the city, but this seems unlikely, since consumers of this product typically have a higher disposable income, and this type of consumer is probably not randomly distributed throughout the city of Paris, the city used for the model.</p> <p>Here is their characterization of a typical city:</p> <blockquote> <p>To get a feeling for how large this N can be, consider a typical city like Paris, which is fairly flat, circular in shape, and with few skyscrapers that can block the available lines of sight. Its total area is about 105 square kilometers [16].</p> </blockquote> <p>The choice of using Paris as model for what it means to be a typical can be challenged easily as well. I'm no expert, but a city with few skyscrapers does not seem to be typical.</p> <p>The problems with the claim are more easily recognized when the claim is examined in terms of conditions required for city-wide propagation of a program that infects Philips Hue lamps over ZigBee.</p> <p>Given that</p> <ol> <li>the city is approximately round AND</li> <li>the city city is flat AND</li> <li>the city has few skyscrapers AND</li> <li>the distribution of Philips Hue lamps across the city is random</li> </ol> <p>then the distribution of lamps can be modeled using percolation theory, and if, in addition to this,</p> <ol start="5"> <li>there are enough Philips Hue lamps in the city to reach the percolation threshold AND</li> <li>the average effective range of the lamps in this environment is 50 meters </li> </ol> <p>then, according to the model, <del>everyone will die</del> </p> <blockquote> <p>our chain reaction attack spreads much faster by making each infected lamp the new source of infection for all its adjacent lamps; the attacker only has to initiate the infecting with a single bad lamp, and can then retire and watch the whole city going dark automatically.</p> </blockquote> <p>and </p> <blockquote> <p>the city is already vulnerable to massive infections via the ZigBee chain reaction described in this paper</p> </blockquote> <p>Unless these conditions are fulfilled, the model does not work. This is probably part of the reason why Paris was chosen as an exemplar for this paper, even though the research was conducted on the campus of Dalhousie University, Halifax, Canada.</p> <h2>To answer the question directly</h2> <blockquote> <p>Is a 'chain reaction' of ZigBee bulbs being hacked feasible?</p> </blockquote> <p>In an ideal setting, namely a hypothetical city that conforms to the favorable parameters in the model, a city-wide "chain-reaction" is feasible <em>according to percolation theory</em>.</p> <p>The researchers demonstrated that their program automatically self-propagates over ZigBee and infects vulnerable lamps within the range of any one of the previously infected lamps. Everything beyond that is hypothetical.</p> <p>When the researchers say that this would enable them to "watch the whole city going dark automatically", this would only be the case if the above conditions were met <em>plus</em> the majority the lights in the city were Philips Hue lamps, which seems to be...unrealistic. </p>

|security|philips-hue|

Is a 'chain reaction' of ZigBee bulbs being hacked feasible?

1394

<p>I recently saw <a href="https://www.youtube.com/watch?v=Ed1OjAuRARU" rel="noreferrer">this video</a>, in which some students attached an 'attack kit' to a drone and flew it near office blocks. </p> <p>According to <a href="http://iotworm.eyalro.net/iotworm.pdf" rel="noreferrer">their paper</a>:</p> <blockquote> <p>We managed to tie a fully autonomous attack kit below a standard drone, and performed war-flying in which we flew hundreds of meters away from office buildings, forcing all the Hue lamps installed in them to disconnect from their current controllers and to blink SOS in morse code</p> </blockquote> <p>They then go on to say:</p> <blockquote> <p>We use results from percolation theory to estimate the critical mass of installed devices for a typical city such as Paris whose area is about 105 square kilometers: The chain reaction will fizzle if there are fewer than about 15,000 randomly located smart lamps in the whole city, but will spread everywhere when the number exceeds this critical mass (which had almost certainly been surpassed already)</p> </blockquote> <p>Although it's an interesting thought, I'm not sure whether this is really likely. They say that a reasonable range for the bulbs is 100 m, but later note <em>"The Philips engineers we talk with stated that in a dense urban environment, the effective range can be less than 30 meters"</em>. I reran their formula with <a href="http://www.wolframalpha.com/input/?i=%3D+(1.128(105,000,000))%2F(%CF%80(30%2F2)%5E2)" rel="noreferrer">that figure</a> and came out with needing about 168,000 bulbs.</p> <p>On the other hand, if we go with the 'optimistic' estimate of 400 m, the formula predicts that you'd need <a href="http://www.wolframalpha.com/input/?i=%3D+(1.128(105,000,000))%2F(%CF%80(400%2F2)%5E2)" rel="noreferrer">less than 1000 bulbs</a>!</p> <p>Obviously, the 400 m estimate is <em>very</em> optimistic, so I'm not inclined to trust it much, especially considering all the radio interference that's likely to be around in an urban environment. <a href="http://www2.meethue.com/en-us/support/faq-categories/product/hue-bridge/" rel="noreferrer">Philips</a> only promise 'up to 30 m' range, so 400 m seems incredibly optimistic.</p> <p><strong>Is the 'chain reaction' idea unrealistic/slightly exaggerated?</strong> It seems to me to just be an attention-grabbing headline, if my calculations are correct. Is there any evidence to show that the range of the bulbs is nearer 100 m, and hence the chain reaction idea is possible?</p>

2017-04-25T12:45:03.510

<p>The SX127x family of chips from Semtech are modems supporting both LoRa and (G)FSK modulations (including ultra-narrow band FSK). Coupled with a microcontroller implementing the relevant stack(s), they are already used for with following IoT network protocols: <strong>LoRaWAN</strong>, <strong>Sigfox</strong>, <strong>Wireless M-Bus</strong>, <strong>DASH7</strong> and <strong>Symphony Link</strong>. They could probably also be used with EnOcean, Zigbee sub-gigahertz and Z-Wave but I know no examples of that, and some of those are very closed ecosystems.</p> <p>LoRaWAN stacks are available publicly, license-free. The availability of other stacks is variable, and you will have to do the co-integration of several stacks yourself. If you only need to support one stack at a time, and just want the ability to switch networks by re-flashing your micro, then the problem is simpler. With a modem from TI or SiLabs you can support most of the FSK-based protocols. With a circuit from Semtech you gain additional support for the few LoRa-based protocols.</p> <p>To future-proof a LPWAN product, some modules are already available with a dual LoRaWAN/Sigfox stack: <a href="http://www.nemeus.fr/en/nemeus-mm002-2/" rel="noreferrer">http://www.nemeus.fr/en/nemeus-mm002-2/</a> You cannot connect a module that is not qualified by Sigfox to the Sigfox network, so using this kind of module can save a lot of time and hassle.</p> <p>If a module is too big, there is a SIP combining a SX1276 and a microcontroller: <a href="http://www.acsip.com.tw/index.php?action=products-detail&amp;fid1=19&amp;fid2=&amp;fid3=&amp;id=79" rel="noreferrer">http://www.acsip.com.tw/index.php?action=products-detail&amp;fid1=19&amp;fid2=&amp;fid3=&amp;id=79</a> but in that case you will have to provide the stack yourself.</p> <p>There are no single chip available right now that combine a microcontroller, a LoRa/FSK modem and a ROMed stack like you can find for Bluetooth. Given the minimum size requirement for an acceptable 868 MHz antenna (> 10 cm²), gaining a few square millimeter of chip area by doing a RF SoC is probably not worth it.</p>

|lorawan|sigfox|

Are there any all-in-one chipsets that support LoRaWAN and Sigfox?

1402

<p>Connectivity technologies are diverging in the last times to adapt to the continuous demands. In the lack of any GSM standard there are several communication technologies. I'm interested to know if there exist chipsets with support for several technologies. I'm trying to avoid the beta-vhs problem, so I'm looking if there are any chipsets that support multiple protocols; Does someone know of any?</p>

2017-04-26T13:59:17.573

<p>A module is a physical unit, which satisfies some function (e.g. a WiFi module), and is normally made of smaller parts. These parts have been incorporated into one monolithic item. A chipset is a collection of individual elements which have been integrated to provide a function (for example, allowing the exchange of information between a processor, peripherals and memory).</p>

|definitions|

What is the difference between a module and a chipset?

1412

<p>From <a href="https://iot.stackexchange.com/questions/1402/are-there-any-all-in-one-chipsets-that-support-lorawan-and-sigfox">this question comments</a> I found out there is some drastical difference if we speak about a chipset or a module.</p> <p>I could not find a definition, that clearly would distinguish these terms to me, as my English skills nor wikipedia search did not give enough information.</p> <p>So, how would you explain these two that the difference comes clear?</p>

2017-04-28T12:17:45.903

<blockquote> <p>I was wondering whether there are any existing protocols that are geared towards send and receiving commands and configuring remote devices?</p> </blockquote> <p>Yes, there is a better protocol for device management in IoT. It is <a href="https://www.avsystem.com/blog/lightweight-m2m-lwm2m-overview/" rel="nofollow noreferrer">LwM2M</a> - It is much more efficient than MQTT and above COAP, MQTT and HTTP.</p> <p>LwM2M comes with a well-defined data and device management model, offering a variety of ready-to-use standard objects (IPSO Smart Objects), connectivity monitoring, remote device actions and structured FOTA and SOTA updates, whereas in MQTT these features are entirely vendor and platform-specific. What follows is that with MQTT, firmware updates or any other management features must be created from scratch. Contrastingly, LwM2M offers firmware upgrades as one of its basic functionalities, so there is no need to invent any new building blocks for communication.</p> <p>Here you have comparison <a href="https://www.avsystem.com/crashcourse/lwm2m/" rel="nofollow noreferrer">MQTT vs LwM2M</a> and whole crash course.</p>

|networking|mqtt|protocols|

Protocol for configuring IoT device settings

1419

<p>MQTT is widely used in IoT when it comes to exchanging application data between the end device and the host service. The publish-subscribe model makes it easy to use: no handshaking, negotiating etc (at least above the MQTT protocol layer). It's primarily geared towards data-producers being able to distribute their data easily to consumers.</p> <p>However, when it comes to a central server wanting to configure settings on an end device, I'm not sure that the model is very suitable. The server will want to send a command to the device and wait for a response back (e.g. read a specific setting, wait for response), which doesn't really suit MQTT's publish-subscribe model.</p> <p>I was wondering whether there are any existing protocols that are geared towards send and receiving commands and configuring remote devices?</p>

2017-04-30T20:36:26.087

<p>The difference between developing an application with a Pi can be very different or somewhat similar to developing an application with a microcontroller due to hardware differences as well as software development toolchain differences.</p> <p>There are a wide range of microcontrollers available that are anywhere from 8 bit to 64 bit processors and having anywhere from a few K of RAM to a few gigabytes of RAM. More capable microcontrollers provide a more Pi like experience. Less capable microcontrollers do not.</p> <p>And even with the Pi there are large differences between developing for the Windows 10 IoT operating system versus developing for Raspian, Mate, or other Linux based OS. Windows 10 IoT requires a development PC using a Visual Studio toolchain with remote debugger targeting the Universal Windows Program (UWP) environment. Development for Raspian or Mate can actually be done on a Pi with the tools available on the Pi.</p> <p>The <a href="https://en.wikipedia.org/wiki/Constrained_Application_Protocol" rel="nofollow noreferrer">Constrained Application Protocol</a> is used for small, constrained devices being used with the Internet of Things environment. To get an idea of the variety of microcontroller hardware and software, this page on the <a href="http://coap.technology/impls.html" rel="nofollow noreferrer">CoAP protocol implementation</a> provides an idea of the environment it is targeting. It mentions the <a href="http://www.contiki-os.org/" rel="nofollow noreferrer">Contiki operating system</a> which I have vaguely heard of along with better known OSs such as iOS, OSX, and Android. Programming languages mentioned are Java, JavaScript, C, C#, Ruby, Go, Erlang, Rust, and Python.</p> <p>The tool chain used for development with microcontroller varies depending on the manufacturer as well as what kinds of resources are available from development communities and open source initiatives. In some cases you get a cross assembler, in other cases you get a C cross compiler, and in other cases you get a nice tool chain with all the bells and whistles and emulators and such similar to the Visual Studio toolchain for Windows 10 IoT.</p> <p>The actual development environment for a microcontroller may involve using an <a href="https://en.wikipedia.org/wiki/EEPROM" rel="nofollow noreferrer">EEPROM</a> programmer and the software tools to create a new image and push it to the device or the device may have the necessary connectivity to allow a new image to be downloaded over a serial connection or over a network connection.</p> <p>My impression is that most microcontrollers have a C cross compiler though the compiler may only support older standards such as K&amp;R or maybe C98. C cross compilers often have non-standard keywords for microprocessor specific features for example the <code>far</code> and <code>near</code> keywords for pointers with the old 8080 and 8086 processors with their segmented memory.</p> <p>There are also specialty languages that target microcontrollers such as <a href="https://en.wikipedia.org/wiki/Forth_(programming_language)" rel="nofollow noreferrer">FORTH programming language</a>. These languages often have a run time design that targets the bare metal so that there is no operating system other than the language run time.</p> <p>Operating system may range from practically non-existent to a bare bones Linux to a specialty OS such as <a href="http://www.freertos.org/" rel="nofollow noreferrer">freeRTOS</a> or Windows Embedded or a full blown Linux or Microsoft Windows. See this <a href="https://sourceforge.net/projects/minibian/" rel="nofollow noreferrer">SourceForge project MINIBIAN for Raspberry Pi</a>. See as well this eBook, <a href="http://www.e-booksdirectory.com/details.php?ebook=8055" rel="nofollow noreferrer">Baking Pi: Operating Systems Development</a> which describes the development of a rudimentary OS for Raspberry Pi in assembler.</p> <p>This article from Visual Studio Magazine, <a href="https://visualstudiomagazine.com/articles/2017/08/01/internet-of-things.aspx" rel="nofollow noreferrer">Programming the Internet of Things with Visual Studio</a>, provides an overview of the many different devices available followed by an overview of using the Visual Studio IDE for development for Linux as well as Windows.</p> <blockquote> <p>There's a huge and growing universe of off-the-shelf, programmable, networkable microcontroller devices available now. At a very low level you have a variety of simple 16- and 32-bit devices from a variety of traditional chip makers like Texas Instruments. (I played a bit with the SensorTag development kit and it's a lot of fun, making me think the Watch DevPack might be a great learning toolset, too.)</p> <p>Some better-known microcontroller devices include Arduino, BeagleBoard and Raspberry Pi. These environments all have extensive community support and are ready to plug in to a huge number of ready-made external sensors, motors, servos and whatever else you might imagine. Adafruit, the electronics learning superstore founded by Limor "Ladyada" Fried, provides all sorts of peripherals for these boards, along with its own line of lightweight Feather development boards.</p> </blockquote> <p>...</p> <blockquote> <p>The most interesting universe of devices for developers familiar with the Microsoft .NET Framework and Visual Studio may be Windows 10 IoT Core-compatible environments. These are x86 and ARM-powered devices that support Universal Windows Platform (UWP) apps written in a variety of languages including C#, Visual Basic, Python and Node.js/JavaScript. Windows 10 IoT core supports devices including Raspberry Pi, Arrow DragonBoard 410C, Intel Joule and Compute Stick and MinnowBoard. There are also interesting product platforms, such as the Askey TurboMate E1 wearable.</p> </blockquote> <p><strong>A Specific Example of a Microcontroller application</strong></p> <p>This is an image of a microcontroller board from an automated coffee maker. This appears to be a standard component for automated coffee makers manufactured in China. The web site for the manufacturer is printed on the PCB.</p> <p>The image is composed of two views. The view on the left is the back of the board containing the microcontroller and supporting circuitry. The view on the right is the front of the board with the LCD screen and a set of buttons which are used to set the current time and to perform actions such as programming a start time, etc.</p> <p>The view on the right fits into a carrier which then fits into an opening in the front of the coffee maker. The switches on the lower PCB are actuated with rocker arm switches. The LCD, which seems to be special purpose, is used to display the current time and status as well as to display the user interface when changing the settings of the coffee maker. The red LED is used to indicate when the coffee maker is actually making coffee and to indicate when done by turning the illumination back off.</p> <p><a href="https://i.stack.imgur.com/MOTgi.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/MOTgi.jpg" alt="enter image description here"></a></p> <p>The microcontroller is an <a href="http://www.alldatasheet.net/datasheet-pdf/pdf/118231/EMC/EM78P447NAM.html" rel="nofollow noreferrer">ELAN Microelectronics Corp EM78P447NAM (datasheet)</a> which is an 8 bit microcontroller. Some of the basic stats show what a small and minimal device this is however it works nicely for its intended purpose. The intent is to develop software which is then downloaded into the write once ROM as a part of manufacturing.</p> <blockquote> <p>• Low power consumption:</p> <pre><code>* Less then 2.2 mA at 5V/4MHz * Typically 35 µA, at 3V/32KHz * Typically 2 µA, during sleep mode </code></pre> <p>• 4K × 13 bits on chip ROM</p> <p>• Three protection bits to prevent intrusion of OTP memory codes</p> <p>• One configuration register to accommodate user’s requirements</p> <p>• 148× 8 bits on chip registers(SRAM, general purpose register)</p> </blockquote>

|microcontrollers|raspberry-pi|

Is there a big jump between prototyping on a Pi, and using a microcontroller?

1425

<p>This <a href="https://iot.stackexchange.com/questions/1422/power-reduction-for-raspberry-pi-gps-gsm-tracker">question</a> asks, amongst other things, if there is a big learning curve between using Python on a Raspberry Pi to prototype an endpoint, and using a microcontroller.</p> <p>Clearly there is a big improvement in power consumption (at the cost of reduced processor throughput) so there are good reasons to take the MCU approach for a product which needs to be battery powered.</p> <p>One of the potential reasons to stick with a single-board computer which runs Linux is that there is no new software to learn (above python or similar) assuming the application can be written in a high level language (where there should be plenty of standard libraries).</p> <p>On an embedded development platform, the likely choices are C++ (mbed or arduino), or micropython. My impression is that these are not significantly different or more complex than writing code to run under Linux - although the platforms do have individual advantages. Have I missed anything which is relevant to a software developer?</p> <p>Specifically, I'm asking about IoT endpoints - so it's not essential to have the full resources of a Linux system for the applications I'm interested in here. It's also worth emphasising that power and latency considerations make the mcu implementation a hard requirement in this type of application.</p>

2017-05-03T15:38:30.177

<p>From <a href="http://rads.stackoverflow.com/amzn/click/B0186JAEWK" rel="nofollow noreferrer">Amazon publish</a>:</p> <blockquote> <p>"Submit two photos for a second opinion on which outfit looks best on you based on fit, color, styling, and current trends. Over time, these decisions get smarter through your feedback and input from our team of experienced fashion specialists."</p> </blockquote> <p>So, they want to give their two best choices and from them machine will guess with wisdom the best.</p> <p>This gives some hint what the machine should identify and learn to gain the wisdom:</p> <ol> <li><p>First of all identify which clothes in different pictures are same in real life. Helps to compare to other similar decisions.</p></li> <li><p>Identifying people characteristics to be combined to different type of clothing. Different clothes fit to different kind of people.</p></li> <li><p>Much own opinions of people collected from statistics of selling or the experts, maybe growling through fashion pages.</p></li> <li><p>What kind of clothes belong mostly to your own top 2.</p></li> <li><p>If there is some theory to be found what 'to fit' means to you and others.</p></li> <li>Etc</li> </ol> <p><strong>edit:</strong></p> <p><a href="http://www.pocket-lint.com/news/140903-what-is-amazon-echo-look-and-how-does-it-work" rel="nofollow noreferrer">Pocket-lint opens the backgrounds</a> and says the feature is originally a premium feature of Amazon's shopping app. I got an impression on the article that the analysis is maybe not quite instant and thus the wisdom behind maybe is only brute human source. Who knows.</p>

|alexa|machine-learning|amazon-echo-look|

How does the Amazon Echo Look determine your 'style rating'?

1435

<p>Amazon's recently released its new <a href="https://rads.stackoverflow.com/amzn/click/com/B0186JAEWK" rel="noreferrer" rel="nofollow noreferrer">Echo Look</a> device, which is a modified Amazon Echo device with a camera added. One of the new features is a <a href="https://images-na.ssl-images-amazon.com/images/I/61r7mS-c9kL._SY500_.jpg" rel="noreferrer">'style check'</a>. From <a href="https://techcrunch.com/2017/04/26/amazons-new-echo-look-has-a-built-in-camera-for-style-selfies/" rel="noreferrer">TechCrunch</a>:</p> <blockquote> <p>The device also works with the company’s Style Check, a feature of the Echo Look app, which uses machine learning to compare different outfit choices, awarding them an overall style rating.</p> <p>The app uses a combination of machine learning and advice from experts in the style space. Letting AI pick out your clothing in the morning should be a pretty interesting experiment.</p> </blockquote> <p>I'm interested in how, exactly, the <em>'machine learning'</em> determines which clothes are more or less stylish. I would imagine that style is a very subjective measure which is difficult to capture with a computer, but I'm not particularly familiar with developments with regards to using computer vision for fashion.</p> <p>I'm not holding my hopes too high that Amazon would disclose how their algorithms work, but are there any similar approaches with regard to computer vision and style? Is there any information about how Amazon might have implemented this, or already-known methods?</p>

2017-05-08T18:29:23.540

<p>There is a big difference between current best practice, what is practical to implement at a sensible cost today, and the products designed in the past few years.</p> <p>Not too long ago, we saw bluetooth locks appear, kickstarter style, as much as a proof of concept as anything else. As I remember, none were anything other than trivially insecure - but they were useful to explore the possibilities. As always, it will take a couple of product iterations to close out the less obvious holes.</p> <p>The realities of a standardised platform are not quite here. As a <a href="https://iot.stackexchange.com/questions/1313">recent question identified</a>, a good, standardised, secure firmware-over-the-air platform is yet to emerge. The MCU devices in production do support this now (banked flash, etc). There are several possibilities, but may developers would need to start some research before implementing something today.</p> <p>On cryptography, the larger endpoint devices are capable today (phone CPUs with signed bootloaders and strong isolation between secure code and applications are not new), but there is less choice at the low end.</p> <p>As the article identifies, there is no big step change coming. It will take a while for all of today's best practices to become ubiquitous. </p> <p>Pervasive connectivity is not here yet either - Cambridge only just rolled out a development LoRa network (for researchers). Suitable technology exists, but it's not as available as (for example) assuming nearly every home has better than 200kbps broadband upload capability (contrast now to 5 or 10 years ago).</p>

|definitions|

Is TechCrunch's definition of "IoT 2.0" significantly different to current best practices?

1441

<p>TechCrunch recently <a href="http://www.techradar.com/news/a-closer-look-at-the-internet-of-things-20-and-why-its-inevitable" rel="noreferrer">ran an article</a> on the "Internet of Things 2.0", and seem to say that it will be a major architectural change from what currently goes on.</p> <p>Some examples of what they consider "IoT 2.0":</p> <ul> <li><p>“Most IoT devices will require a non-interactive method to login, so the use of cryptographic materials such as certificates and private keys becomes ever more necessary,”</p></li> <li><p>"One of the key characteristics of the IoT 2.0 will be common standards. The IoT umbrella is vast, and the many industries it covers – from factories and automotive through to building automation and networking – each have their own protocols, interfaces and hardware."</p></li> </ul> <p>They also say:</p> <blockquote> <p>It might be five years distant, but IoT 2.0 is on its way, with device miniaturisation, better power efficiency and connectivity, more sophisticated system architectures, and new machine learning algorithms all in the pipeline. Says Tcherevik: “IoT 2.0 is all but inevitable.”</p> </blockquote> <p>However, some of the points made there <a href="https://iot.stackexchange.com/a/151/12">already seem to be considered good practice</a>, so it seem to me that their idea of an "IoT 2.0" is mostly just confusing and not very valuable.</p> <p><strong>Is there anything I'm missing, or does the article just bundle together current best practices and call it "IoT 2.0"?</strong> </p> <hr> <p>^{Obviously, it's difficult to speculate on what the future actually will hold, so I don't expect to discuss what <em>could</em> happen, rather: aren't most of the things mentioned already possible, just not adopted for cost-saving/complexity reasons?}</p>

2017-05-10T12:57:00.240

<p>How far away from your base computer do the terminals need to be? Does it need to be a relatively real-time system or can the check-ins be cached for a few seconds? </p> <p>If you could get away with the range of wifi, and the potential latency of an mqtt message (a good protocol if you need <a href="https://learn.adafruit.com/mqtt-adafruit-io-and-you/qos-and-wills" rel="noreferrer">QOS</a>) I think an esp8266 microcontroller with one of the <a href="https://www.aliexpress.com/item/PN532-NFC-RFID-Module-V3-Kits-Reader-Writer/32314149950.html" rel="noreferrer">these</a> RFID readers would be a nearly ideal setup. </p> <p>(I personally have a couple of <a href="https://www.aliexpress.com/store/product/D1-mini-Mini-NodeMcu-4M-bytes-Lua-WIFI-Internet-of-Things-development-board-based-ESP8266/1331105_32529101036.html" rel="noreferrer">wemos D1 mini's</a> *note this is not the cheapest they can be found, but I try not to promote knock off's)</p> <p>I've primarily used the <a href="https://nodemcu.readthedocs.io/en/master/" rel="noreferrer">NodeMCU</a> firmware, but there's no baked in library for pn532 RFID chips, so you'd have to read/write i2c/spi registers manually. Adafruit has <a href="https://github.com/adafruit/Adafruit-PN532" rel="noreferrer">a library</a> for the Arduino IDE, but it only works with i2c (seems under-tested / under-developed for the esp8266)</p> <p>One of the benefits of a setup like this is that you could quite easily make these battery powered with a usb battery bank (watch out because some turn off if they don't sense enough current draw).</p> <p>If I were to build these with parts from aliexpress (super cheap) this would be my shopping list:</p> <ul> <li><a href="https://www.aliexpress.com/item/1-PCS-100x60x25mm-Black-DIY-Enclosure-Instrument-Case-Plastic-Electronic-Project-Box-Electrical-Supplies/32791612746.html" rel="noreferrer">project box</a>: ~$1-$2</li> <li><a href="https://www.aliexpress.com/store/product/D1-mini-Mini-NodeMcu-4M-bytes-Lua-WIFI-Internet-of-Things-development-board-based-ESP8266/1331105_32529101036.html" rel="noreferrer">esp8266 module</a>: ~$4</li> <li><a href="https://www.aliexpress.com/item/PN532-NFC-RFID-Module-V3-Kits-Reader-Writer/32314149950.html" rel="noreferrer">pn532 RFID module</a>: ~$5</li> <li><a href="https://www.aliexpress.com/item/MaGeek-Atom1-3200mAh-Lipstick-Sized-Portable-Charger-External-Battery-with-UniCharge-Technology-PB101-1S1-Sliver/32383486216.html" rel="noreferrer">battery bank</a>: ~$11</li> <li>misc (hot glue, solder, blood, sweat, tears): ~$5 </li> <li>total: &lt;$30 per terminal (very rough estimate)</li> </ul> <p>Then for deployment, you'd need some sort of decent wifi access point that can handle a bunch of lightweight connections (some have a cap on # of connections) and probably a laptop running the mqtt host and your web app server.</p>

|nfc|rfid|

Should I use NFC, RFID or something else?

1448

<p>I'm a web developer - so IoT is not my speciality at all - and I've been asked to find the cheapest and most efficient way (in this order of priority) to build a gizmo for a sport event (can't be more specific). This is how it should work : </p> <ol> <li>A Competitor wear a wristband carrying his unique ID.</li> <li>At one place there is a terminal which will scan the wristband once in contact, so organizers will know at what time the competitor arrived to this terminal via a web app.</li> <li>The Competitor must stay 3secs at the terminal and can't just extend arms forward, they must be at the terminal.</li> <li>The Competitor is acknowledged that his wristband has been successfully scanned and can now move to the next terminal. And so on</li> </ol> <p>So my question is, what should I use for the wristband and the terminal knowing that the bracelets are throwaways ?</p> <p>EDIT - More details :</p> <ul> <li>Competitors can't have their phone nor any device with them during the event.</li> <li>There will be between 40 and 50 terminals max</li> <li>I've been asked for the cheapest solution but I don't have a min/max cost and I'm not limited by dev time (must be reasonable though) </li> </ul>

2017-05-10T14:13:00.953

<p>For android the app, at least mine from June 26, 2017, does not have the option to enable Drop In for specific contacts. However I installed version 2.1.22 of the <strong>iOS</strong> version, which has that option. Probably later versions will also work. So now I can use Drop In to reach another specific device in my household.</p>

|alexa|amazon-echo|

How do I enable drop-in calling on Alexa?

1449

<p>I've configured my Echo and the associated Alexa app for calling and can call registered users. However, though I've read about the drop-in calling feature, I don't see any way to enable it. How do I enable and use drop-in?</p>

2017-05-16T06:23:25.667

<p>This question has been answered, but perhaps this will be valuable for others.</p> <p>You can wire an ESP32-based board or module to your Arduino, and use <a href="https://vcon.io" rel="nofollow noreferrer">https://vcon.io</a> for a remote OTA. vcon firmware can act as an AVR (and not just AVR) programmer, and reflash your Arduino remotely.</p> <p>Also, as a side-effect, you'll get remote control capability for your Arduino. <a href="https://dash.vcon.io" rel="nofollow noreferrer">https://dash.vcon.io</a> cloud service gives you device dashboard and an API for remote control and OTA.</p> <p>Disclaimer: I do represent <a href="https://vcon.io" rel="nofollow noreferrer">https://vcon.io</a> product.</p>

|over-the-air-updates|arduino|

Remote Firmware Update Arduino Nano

1475

<p>I am working on <strong>Arduino Nano</strong> <em>(32Kb flash memory of which 2Kb used by boot loader, 2Kb SRAM, 1Kb EEPROM)</em>. </p> <p>The micro-controller takes input from an electrical device via <strong>RS485</strong> module and posts the data read to a remote server using <strong>GPRS A6</strong> module. The product is supposed to interact with the remote server, posting data at intervals.</p> <p>I have completed the integration part and the device works fine, collecting data and posting on the server (appx 10-15 Km away). <strong>The only challenge I am facing is</strong> that if there are 100 such devices and I need to update the firmware, using the remote server (or any other suitable mechanism), how should I proceed with it.</p> <p>I have been through many posts that suggest using another Arduino as ISP, this could be my last approach (as it would increase the final cost of product). </p> <p>Over the air firmware update is still unclear as on Stack Exchange community for low-end micro-controllers. Any discussion can be a great help for many.</p>

2017-05-16T12:32:35.133

<blockquote> <p>By continuously I mean that streams like video are continuous</p> </blockquote> <p>If you are considering continuous video streaming from Pi then LIVE555 Streaming Media is a may serve your purpose. <a href="http://www.live555.com/" rel="nofollow noreferrer">Live555</a> will provide following:</p> <ul> <li>Source distribution for standards based RTP/RTCP/RTSP/SIP multimedia streaming</li> <li>Suitable for embedded and/or low-cost streaming application</li> </ul>

|communication|raspberry-pi|data-transfer|

Raspberry Pi to send sensor's data to server continuously and receive commands from server

1479

<p>I would like to design a system using Raspberry Pi that sends the sensor's data to server continuously and receive commands from server.</p> <p>Will MQTT suit my needs ? </p> <p>Is there any way to do so if I use Java on my Pi?</p> <p><strong>Edit</strong></p> <p>By continuously I mean that streams like video are continuous and other text based data is sent twice every minute.</p> <p>The sensors are:</p> <p>Humidity sensor - <a href="http://www.amazon.in/DHT11-Temperature-Humidity-Sensor-Module/dp/B01HI9G9ZU?tag=googinhydr18418-21&amp;tag=googinkenshoo-21&amp;ascsubtag=710c9d6b-87d0-41e2-b3e0-06a1045769f3" rel="noreferrer">http://www.amazon.in/DHT11-Temperature-Humidity-Sensor-Module/dp/B01HI9G9ZU?tag=googinhydr18418-21&amp;tag=googinkenshoo-21&amp;ascsubtag=710c9d6b-87d0-41e2-b3e0-06a1045769f3</a></p> <p>A 5MP camera (Webcam connected to USB of the Pi.)</p> <p>LDR(Light and Dark) - Sensor</p> <p>The server is based on a cloud hosting location.</p>

2017-05-16T14:20:47.207

<p>Okay. Given the comments so far, here's how I'd approach it:</p> <ol> <li>Set up DDNS through any competent provider.</li> <li>Set up OpenVPN on your PI, and route UDP port 1194 (or whatever port you set it up on) from the router to the PI. All external connections to your PI will have to have a properly configured OpenVPN client (you could even use a phone!)</li> <li>As a secondary measure, secure inbound access on the PI using IPTables. It's a pain in the butt to do by hand, so install Webmin (Debian) to configure it. From here, do a Google search on ways to harden your IPTables configuration against DDOS.</li> </ol> <p>You might prefer some other VPN, but I've used OpenVPN for about 10 years now for its incredible flexibility.</p>

|security|networking|raspberry-pi|

How to protect Raspberry Pi from attack in an IoT setup connected through a Broadband network?

1482

<p><strong>The Setup:</strong></p> <p>I have a Raspberry Pi as the master node which is connected to the internet through a broadband connection, the raspberry pi connects several sensors and other microcontrollers. The Pi is continuously connected to a server at a Cloud Hosting Provider.</p> <p><strong>The Questions are:</strong></p> <ul> <li>How do I stop unauthorized users from accessing my raspberry Pi?</li> <li>How do I prevent a DDoS attack on the Pi?</li> <li>How and should I go about using DDNS (Dynamic DNS) for accessing my Pi?</li> </ul>

2017-05-18T08:34:14.997

<p>They're comparable in that both allow you to have full-duplex communication such that the server can immediately pass data to the client, without the client polling for it (as might be with HTTP). </p> <p>However, Websockets is designed for a simple point-to-point connection between a client and a server. MQTT layers extra abstractions on top of basic message sending, so that multiple interested parties can subscribe to messages that may interest them. Messages can therefore be routed by 'message topic' so that many clients can share a notional queue, where a server can choose to hear all messages from all clients, but may also filter by topic. </p> <p>MQTT has a variety of other useful features, e.g. retained messages, such that subscribers immediately receive the message, and the LWT (Last Will and Testament) which is a message that can be sent automatically if the client abnormally disconnects. In summary, MQTT is 'higher up the stack' offering features and abstractions that a simple Websocket does not.</p>

|communication|monitoring|mqtt|

What is the difference between MQTT and Web Sockets, and when should I use them?

1492

<p>What are the major differences between MQTT and Web Sockets?</p> <p>When using IoT for home automation - control and monitoring access over different devices, which one of them should be used when Rest API based and browser based accessibility is required.</p> <p>I am using Java (Pi4J Library) on a Raspberry Pi 2 B+.</p> <p>I have a setup of several sensors like light and dark, humidity, PID etc.</p> <p>I also have a cloud server where I can send the data if required.</p>

2017-05-18T17:28:51.923

<p>The given settings in <code>/etc/config/network</code> are correct. However, to apply the settings, it isn't sufficient to restart the network via <code>/etc/init.d/network restart</code> but also applying the DNS servers via <code>/etc/init.d/dnsmasq restart</code> which had not been done. After that, the Onion Omega2 is able to connect to the internet via its ethernet connection.</p>

|networking|ethernet|ip-address|onion-omega2|

Connect Onion Omega2 to static ethernet

1494

<p>I can't get my <a href="https://onion.io/store/omega2/" rel="nofollow noreferrer">Onion Omega2</a> to connect to my ethernet via a static IP address and two DNS addresses. To connect my PC, I have to set the following:<br> IP address: <code>82.149.xxx.xxx</code><br> subnet mask: <code>255.255.255.0</code><br> gateway: <code>82.149.xxx.xxx</code><br> DNS server: <code>212.xxx.xxx.xxx</code>, <code>83.xxx.xxx.xxx</code> </p> <p>Which settings have to be made in <code>/etc/config/network</code> and possibly elsewhere?</p> <p>I tried the following without success:</p> <pre><code>config interface 'wan' option proto 'static' option ifname 'eth0' option ipaddr '82.149.xxx.xxx' option netmask '255.255.255.0' option gateway '82.149.xxx.xxx' list dns '83.xxx.xxx.xxx' list dns '212.xxx.xxx.xxx' </code></pre>

2017-05-25T17:29:36.290

<p>The times when it makes sense to roll-your-own are quite limited. When it comes to device constraints, its important to look at the whole system performance. For sure, the state of the art does move on but the goal should be optimising endpoint energy performance rather than working out how to cope with a device that hasn't got a good entropy source, or enough memory to support a suitable standard.</p> <p>These are the scenarios where it <em>does</em> make some sense.</p> <ol> <li><p>Roll your own to learn. Particularly if you're interested in prototyping and making relative comparisons. Once you've learnt, pick the best standard guided by your research.</p></li> <li><p>Improve on the current state-of-the-art. More secure, and more efficient sounds like a win. Might even make you rich.</p></li> <li><p>Roll your own to cope with an environmental constraint (not product choice) which no existing protocol accommodates - but this is likely to be more at the physical/transfer layer. For example, a highly error prone channel or a demand for high resilience to blocking. Even then, the elements you need probably already exist, and just need to be assembled.</p></li> </ol> <p>If it's a product design, you're unlikely to differentiate by saving $0.5 in hardware. You have either a good value-add for your customer, or an insecure product that no one wants even if it sounds cool.</p>

|security|communication|protocols|

Is it ever a good idea to 'roll your own' protocol for IoT device communication?

1517

<p>I've heard many people mention that their embedded IoT devices aren't powerful enough to process known protocols, like <a href="https://en.wikipedia.org/wiki/HTTPS" rel="noreferrer">HTTPS</a> or even <a href="https://en.wikipedia.org/wiki/Transport_Layer_Security" rel="noreferrer">TLS</a> security for sockets.</p> <p>Instead, they turn to creating their own protocol to produce a custom communication system that suits their particular use case, although, typically, little time is actually spent developing the protocol, because it's not a particularly important factor. Usually, these <em>homebrew</em> protocols include authentication, security, encryption, etc.</p> <p><a href="https://cardinalpeak.com/blog/using-udp-in-internet-of-things-devices/" rel="noreferrer">This article</a> suggests some of the many pitfalls which would seem to be waiting for anyone who did go down the route of writing their own protocol, and it's well known that you shouldn't try to <a href="https://crypto.stackexchange.com/questions/43272/why-is-writing-your-own-encryption-discouraged">write your own encryption</a>. </p> <p><strong>Are there ever any cases where you would have to write your own protocol, rather than using an existing, tested protocol? How can you tell if rolling your own is a reasonable idea, rather than a big security risk?</strong></p>

2017-05-26T12:01:13.597

<p>Significantly, it looks like you don't need to use the LightwaveRF hub, both the Echo and Google Home descriptions avoid mentioning the hub (which is needed if you want to use IFTTT directly for example)</p>

|smart-home|lightwave-rf|

What is the nature of the partnership between LightwaveRF and Google Home / Amazon Echo?

1521

<p>I read an article recently from <a href="https://www.ft.com/content/e77d1710-3bef-11e7-ac89-b01cc67cfeec" rel="nofollow noreferrer">ft.com</a> (dated May 21, 2017) which details the progress of the IoT company <a href="https://www.lightwaverf.com/solution/smart-home/" rel="nofollow noreferrer">LightwaveRF</a>. One thing I found very interesting in the article, and that is that they claim that:</p> <blockquote> <p>Last week, LightwaveRF’s shares rose 40 per cent when it announced a partnership with Google Home and Google Assistant. It signed a similar tie-up with Amazon’s Alexa in November. Already 5,000 or so of LightwaveRF’s customers are Alexa groupies.</p> </blockquote> <p>What is the nature of these partnerships? Should we expect LightwaveRF thermostats to start looking more like Nest Thermostats, etc., or are they simply trying to make compatibility between Amazon Echos and Google Homes etc. with their devices smoother?</p>

2017-05-26T12:16:56.980

<p>A lot of ISP providers do not allow residential customers to use port 80 or 8080. Try using a different port number with Motion, and also check with your ISP to see which ports are allowed. You also need to activate port forwarding on the Netgear router, so traffic is routed to the Raspberry Pi</p>

|networking|raspberry-pi|remote-access|

How to access camera feed of Raspberry Pi out of a local broadband network?

1523

<p><strong>BACKGROUND</strong></p> <p>The current setup I have for the Raspberry Pi is:</p> <pre><code>USB Webcam -&gt; Raspberry Pi -&gt; Netgear Router -&gt; Local ISP -&gt; Internet </code></pre> <p>My ISP gives me a captive portal through which I can login to access the internet and my public IP address is shown something like 203.xxx.xx.xx, when I try to access this IP from the browser, I am taken to the ISP's Captive Portal Page and not allowed to access anything further.</p> <p>There are many other people connected to the same ISP and they are given the same IP too (obviously).</p> <p>The ISP is not ready to allot a dedicated IP or open up any ports for me so that I can configure my Netgear router to forward ports etc.</p> <p><strong>Question</strong></p> <p>I have installed motion on my Pi and I can access it via 192.168.1.3:8080 via my local lan i.e inside my Netgear Router Network. How can I access from outside my Network i.e from a remote location like my office.</p> <p>I would not like to use third party software like teamviewer to relay my whole Pi system over the internet.</p> <p>Is there any way I can upload the stream to a cloud server efficiently and then access it?</p>

2017-05-27T12:01:23.037

<p>^{I'm including the answer with a link to the official article, since I had a hard time finding it. Hopefully, it will help someone.}</p> <h3>The status has indeed changed.</h3> <p>Belkin published <a href="http://www.belkin.com/us/pressreleases/8804624237628/" rel="nofollow noreferrer">this article</a> on May 25 in which they explain that integration to Apple HomeKit is indeed in the foreseeable future: Fall 2017 is supposed to see the introduction of the Wemo Bridge, which Bridges between your Wemo switches and your Apple HomeKit. Here's a quote from the article referenced:</p> <blockquote> <p>Continuing to expand its award-winning Internet of Things ecosystem, Wemo®, the smart home brand from Belkin International, today announced it plans to enable Apple® HomeKit™ compatibility to more than two million Wemo solutions on the market. With the HomeKit enabled Wemo Bridge, Wemo users will be able to ask Siri® on their iPhone, iPad or Apple Watch - “Siri, turn on Wemo” or “Siri, dim the living room lights,” or use the Apple Home app on any of these devices. Users will also be able to include Wemo products into scenes and rooms to work with more than one hundred other HomeKit compatible products and access them while on the go.</p> </blockquote> <p>So the answer is, <strong>yes, you should be able to link your Wemo Switches and Apple HomeKit soon.</strong></p> <hr /> <h2>Edit:</h2> <p>And... <a href="http://www.belkin.com/us/p/P-F7C074/" rel="nofollow noreferrer">it's live!</a></p>

|wemo|apple-homekit|

Do Belkin Wemo switches integrate with Apple HomeKit?

1526

<p>In March of 2016, <a href="http://www.belkin.com/us/support-article?articleNum=187953" rel="noreferrer">Belkin announced</a> that they would not be supporting Apple HomeKit any time in the near future. This meant that integration was basically impossible across Apple devices. </p> <p>However, that article was over a year ago now. Has the status changed at all? Is Belkin planning on integrating HomeKit any time soon?</p>

2017-05-28T16:03:19.533

<p>At least Cytron has a model, that says (embhasis my own):</p> <blockquote> <ul> <li><p>Direct access to any MCU through Serial UART operation and integrated with low current warning.</p> </li> <li><p>Able to retrieve fingerprint <strong>raw data</strong> and fingerprint identity files.</p> </li> </ul> </blockquote> <p><a href="https://www.cytron.com.my/p-sn-fpr-uart" rel="noreferrer">https://www.cytron.com.my/p-sn-fpr-uart</a></p> <p>It is little bit expensive, but you are supposed to find a cheaper too because there exists so many general purpose fingerprint sdks in Github and they won't be made for one manufacturer only.</p> <p>Write to Google Search: <em>github fingerprint detection</em> for sdks.</p>

|biometrics|

Is there a biometrics fingerprint scanner that directly sends raw biometrics data?

1535

<p>I have this payroll project where my client wants to use biometrics to easily keep track the time attendances of his 400 employees. However, the problem is his company has a high employee turnover rate. It implies that the biometrics fingerprint scanner which usually has only a limited number of available fingerprint templates from 1000 to 2000, the biometrics may eventually run out of memory. </p> <p>The better solution I can think of is to use the payroll system directly as the data store for the biometrics fingerprint scanner. However, I can't seem to find any biometrics fingerprint scanner that allows to send raw biometrics data to the computer for storage. </p> <p>Is there a biometrics scanner available in the market where it offers an SDK which allows developers to interface the scanner directly to the software so that it can be used as a large data store?</p>

2017-05-30T13:00:12.917

<p>The solution you posted should work fine, but if not, there's also a workaround posted on <a href="http://lovemyecho.com/2017/02/14/another-alexa-intercom-life-hack-send-messages-alexa-devices/" rel="nofollow noreferrer">lovemyecho.com</a> that would allow you to use your Amazon Echo as a 1-way intercom, though it doesn't use the calling system.</p> <p>Basically, you have to follow <strong>these three steps:</strong></p> <h3>1. Record a custom mp3 file</h3> <p>Basically just record an mp3 of whatever you want to communicate to the people in the other room, ie: &quot;Lunchtime!&quot; or whatever.</p> <h3>2. Upload the mp3 file to Amazon Music</h3> <p>Upload the file in a &quot;Messages Playlist&quot;, being sure to use good names: they suggest something like <code>MSG_something</code> or something along those lines.</p> <h3>3. Send the message to an Echo / Dot</h3> <p>Go to the Alexa app and choose the message you want to send from the &quot;Music / Books&quot; area. Having used the <code>MSG_something</code> file names and having the files in the playlist should make them easier to find.</p> <hr /> <p>Obviously, if you want 2-way communication, this would clearly be impracticable, but the advantage of this system is that if there is a message that you frequently want to send, it doesn't require the person on the other end to &quot;pick up the line.&quot;</p>

|smart-home|alexa|

Can I call other Echo devices in my house?

1558

<p>Recently, Amazon introduced <a href="https://techcrunch.com/2017/05/09/amazon-enables-free-calls-and-messages-on-all-echo-devices-with-alexa-calling/" rel="noreferrer">calling</a> between devices with Alexa Calling. With this, you can ask Alexa to call other people who have Echo devices (and have enabled the feature).</p> <p><strong>Is it possible to tell Alexa to call yourself, so that you could use it as an intercom in the house if both devices are linked to the same account?</strong></p> <p>Clearly, calling a device on a different account should work, but I couldn't find any authoritative reference confirming that calling between devices on the same account works.</p>

2017-05-30T21:38:31.120

<p>This belongs more on the SQA SE, but here there is better context. Usually you would want three levels of testing</p> <ul> <li><p>Unit tests, in your case this can be testing the generated code even without an OS. You can achieve it by mocking whatever is missing.</p></li> <li><p>Integration tests, mocking everything will check the generated code but will tell you nothing about how it behaves in a real system using a real OS. Starting from small things like "will the code compile" to more subtle things like sending the correct parameters to external functions, or taking into considerations timing. Integration tests might need to run on the real system and hardware, but will not need external dependencies like a network or servers.</p></li> <li><p>End to end or system tests, finally you will really want to see that everything works together using real system and environment. in E2E tests you will find things that are hard to simulate, for example extreme timing conditions, malformed or lost messages, or different input formats.</p></li> </ul>

|protocols|testing|

Testing a telemetry and telecommand interface

1563

<p>I am currently writing a generic telecommand and telemetry library which I plan to use on Zephyr RTOS.</p> <p>Given an input CSV file, it generates some C++ code which can then easily be integrated in the rest of the project. Specifically, it generates a telecommand function and a telemetry function per defined subsystem. Each subsystem has a set of valid TM and TC data points, but those are known only at generation time.</p> <p>How should I go about testing that the library can work? I am thinking about defining stub functions which could check that the correct telemetry is read and the correct telecommand is acted upon.</p> <p><strong>Are stub methods the usual testing methodology for embedded/IoT device testing? If not, what is the more common practice?</strong> </p>

2017-05-31T14:49:49.643

<h2>What are the steps to the privacy leak described?</h2> <p>Basically there are three parts in getting the information described in the paper.</p> <ol> <li>An interested party recording the outgoing traffic (2)</li> <li>Said party being able to split the traffic streams (4.1)</li> <li>Analyzing the different traffic streams <ul> <li>Identifying device (type) (4.2)</li> <li>Analyzing device pattern (5)</li> </ul></li> </ol> <p><strong>Recording the outgoing traffic</strong></p> <p>While the attacker is simply assumed in the paper as prerequisite this is already quite the hurdle.</p> <blockquote> <p>Specifically, an adversary in this model can observe and record all wide-area network traffic, including traffic to and from home gateway routers.</p> </blockquote> <p>That's not a lot of potential attackers. Basically, that's the ISP you use to connect to the Internet, the WAN carriers and interested intelligence agencies. Thankfully the one with the easiest access, your ISP, is likely not interested since it doesn't really help their business model. On the other hand, the ISPs are the ones courts can compel to record and provide these information.</p> <blockquote> <p>We assume that ISPs are typically uninterested in performing targeted active attacks on individual users.</p> </blockquote> <p>Whilst not being interested in these attacks, they might very well be forced to provide the information. Of course, that depends on the laws of the country they operate in.</p> <p>Assuming you haven't gotten a court to compel your ISP or attracted the attention of an intelligence agency with the necessary capabilities to record the traffic the likeliest attacker that can use the further steps would be a compromised home router.</p> <p><strong>Splitting traffic streams</strong></p> <p>The split into traffic streams is assumed to be performed by grouping them by the external communication partner, e.g. the services the IoT devices communicate with. The aforementioned attacker obviously has the target IP, after all the information is needed to get the information where they belong.</p> <p>A good possibility that <a href="https://iot.stackexchange.com/a/1569/78">Mawg describes in his answer is the use of a VPN service provider.</a> With the use of a VPN the ISP or otherwise capable attacker cannot deduce the actual target of the communication since every communication is addressed at the VPN service provider. However, that enables another party to be the attacker of this model—the VPN service provider.</p> <p>By using a VPN router you essentially enable another party to be this attacker. The advantage of the <a href="https://en.wikipedia.org/wiki/Tor_(anonymity_network)" rel="nofollow noreferrer">TOR network</a> as mentioned in <a href="https://iot.stackexchange.com/a/1567/78">Sylvain's answer</a> is the obfuscation of streams while simultaneously not enabling another player to the proverbial man-in-the-middle. If you're using TOR you'll need either really bad luck in TOR nodes or really really interested parties to enable the attacker to identify the streams. </p> <p>This <a href="https://en.wikipedia.org/wiki/Tor_(anonymity_network)#Autonomous_system_.28AS.29_eavesdropping" rel="nofollow noreferrer">Wiki article subsection</a> describes the theoretical possibilities to still identify source and target of TOR communications. Although, these methods require serious resources and access to the basic Internet structure, which again brings us back to the same group of potential attackers than mentioned before. However, they would need <em>even more motivation</em> to invest the effort to track that traffic.</p> <p>If you VPN with either solution over jurisdictions (continents or at least countries, not counties or the like) you are likely safe from court proceedings.</p> <p><em>Summary:</em> </p> <ul> <li>When using a dedicated VPN provider you have to weigh the trustworthiness of said provider versus your own ISP. This just moves the ability of attack to another party.</li> <li>When using TOR consider how it works and who owns (and pays for) the exit nodes</li> <li>Either solution adds significant hurdles in splitting the traffic stream.</li> <li>Either solution will likely make court proceedings to get the data useless when spanning several jurisdictions. ¹</li> </ul> <p><strong>Analyzing the different traffic streams</strong></p> <p>This is actually trivial for anyone who has jumped the first two hurdles. Unless you have a home-made solution the traffic patterns of any IoT device can be easily recorded and afterwards recognized when the data set is sufficient.</p> <p>However, as <a href="https://iot.stackexchange.com/a/1568/78">Sean describes in his answer</a> you can still muddy the waters. If you device sends additional spoofing data or bulk transmits data that does not have to be real-time the pattern analysis gets really complicated.</p> <hr> <p>_{1 not a lawyer}</p>

|privacy|https|tls|

How can I prevent my device leaking sensitive data through traffic fingerprinting?

1566

<p>According to the recent paper <a href="https://arxiv.org/pdf/1705.06805.pdf" rel="nofollow noreferrer"><em>A Smart Home is No Castle: Privacy Vulnerabilities of Encrypted IoT Traffic</em></a>, many smart home devices can be 'fingerprinted' by their connection patterns. Since most devices connect to a small set of URLs when they're invoked, it's possible for an attacker (or an unfriendly ISP) to determine when you use each device.</p> <p>For example, they tracked the traffic going to the Alexa servers from a home router (the URLs they used are in Figure 1 in the paper):</p> <p><a href="https://arxiv.org/pdf/1705.06805.pdf" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1cOAz.png" alt="Alexa Traffic Pattern"></a></p> <p>They also show that a similar principle can be used to determine when a sleep monitor is used (and hence when you wake up/go to sleep), or when a smart switch is toggled.</p> <p>Clearly, it's disturbing that you can get so much information from a device, despite it being encrypted. It seems harder to get much information from computer traffic, because the servers accessed are much more diverse, but for an IoT device that only 'calls home' to a specific server, it appears easy to track which device was used, and when. </p> <p>Since <a href="https://en.wikipedia.org/wiki/Telecommunications_data_retention" rel="nofollow noreferrer">many countries</a> store metadata such as this, it's feasible that they would be able to use this method themselves to determine your activity, and the same amount of data would be leaked to any network-level attacker.</p> <p><strong>Are there any ways to prevent traffic from being fingerprinted in this way, or at least to reduce the amount of sensitive data that can be extracted?</strong></p>

2017-06-01T12:13:15.490

<p>As far as I can tell, there's no IoT-related 'smartness' despite the name. As mico points out, the lights work by producing frequencies of light that humans can see, but that will not affect the turtle breeding cycle.</p> <p>On their website, they promote the energy saving benefits, but don't mention any networking features, as you'd expect from a 'smart bulb' like the Philips Hue, for example.</p> <p>Note that they also say:</p> <blockquote> <p>ILLUMINATE INTELLIGENTLY</p> <p>Reduce your energy consumption, maintenance and servicing costs. </p> </blockquote> <p>That seems like a clear signal to me that their definition of "intelligence" is that it uses less energy, and requires less maintenance.</p> <p>So, <strong>no</strong>, the bulbs aren't IoT connected, as far as I can see; the "smart" description is just part of the branding/sales pitch.</p>

|lighting|

Are the Smart Lights saving turtles actually Smart?

1571

<p>My curiosity was recently piqued by <a href="http://iotpodcast.com/2017/05/episode-113-google-home-gets-way-better/" rel="noreferrer">IOTpodcast.com</a>. They mention in the description of the podcast that one of the things to discuss is how smart lighting is saving sea turtles. I then found <a href="http://smartledconcepts.com/smart-led-eco-friendly-lighting-keeps-business-booming-during-sea-turtle-nesting-season/" rel="noreferrer">this article</a> from smartledconcepts.com which states that the lights are tuned to specific frequencies to encourage the sea turtles to go in the right direction. I also found an article <a href="https://blogs.scientificamerican.com/extinction-countdown/oil-spill-fines-pay-for-turtle-saving-led-lights/" rel="noreferrer">here on scientificamerica.com</a> which gives a detailed scientific explanation for how the specific wavelengths direct the turtles.</p> <p>However, I'm more interested in the "Smart" part. <strong>Are these lights actually "Smart" in that they turn on and off at times sea turtles are likely to need them on or off, or in their connections one to another, or are they just called "Smart" because they were made by the SmartLED company?</strong></p>

2017-06-02T08:07:07.173

<p>It is important to identify whether the problem is :</p> <ul> <li>Devices or network deployment </li> <li>Devices or network configuration. </li> <li>Devices Hardware (or firmware versions)</li> <li>Environment</li> <li>Security configuration</li> </ul> <p>The paths to take here are too diverse so you need to narrow down the cases. Sometimes a photo helps to spot the possible deployment issues.</p> <p>Here are some ideas:</p> <ol> <li>A nearby lift can reduce the signal due to the amount of <strong>metal</strong> in it </li> <li>Also consider the <strong>water</strong> as strong signal attenuation, this includes humans, to if that is a crowded area it is better to have the antennas above 2m.</li> <li>I have seen communication problems and it was due to the wiring was badly bended in a sharp 90 degree angle, this damaged the internal filaments.</li> <li>Another case I saw is that <strong>too many Zigbee gateways</strong> (Access Point) can produce conflict since the clients may roam from one to another, this depends on the local distribution of the gateways and the signal strength. If the clients are statically located I would assign them fixed gateways</li> <li>The proportion between the amount of clients and the amount of Gateways has to me calculated and check.</li> <li>Don't forget to check also the configuration, maybe there is a <strong>bottle neck</strong>, this is, many clients use the same subnet, so all the packages are forwarded to a single switch/router. In that case splitting the clients in <strong>groups or subnets</strong> and diverging the traffic can be a possible solution.</li> <li>Are all the client devices and gateways running the same <strong>firmware</strong> (SW) versions? Are all up-to-date</li> <li>Is there any difference in the <strong>security configuration</strong>? The encryption and VPN usually slow down the traffic if we compare them with non-protected networks.</li> <li>I almost forgot to say that the <strong>logs from the clients or the Gateway</strong> will provide you relevant information about the communication. If all the net goes off abruptly and remains in that state for days, I will go for the gateway logs an see if the is some indications that the communication is lost.</li> <li>Check for duplicated IP address, the behavior you describe can also be due to 2 devices with the same IP and when one of them is on the net, the other is not communicating at all. Check the routers IPs in this case.</li> <li>Once I experienced communication lost in a customer and it turned out that the <strong>security</strong> of the net did not allow clients to reconnect more than 3 times in a row, then the router would ban my client for hours. All this was security configuration in the router/gateway.</li> </ol> <p>But of course for all this we need more information about the deployment and the configuration</p>

|zigbee|routers|rfid|

Zigbee network intermittent issues

1575

<p>My Zigbee network connection seems to be intermittent. Suddenly all routers will lose connection, for example unable to ping any of the routers. After awhile (e.g overnight or a period of a few days) the network will be up again.</p> <p>Set up: </p> <ul> <li>1x coordinator</li> <li>21x routers</li> <li>42x end devices(in use)</li> </ul> <p>Currently using channel 25.</p> <p>I want to find out if mounting the Zigbee router on metal partitions(wall) will cause problems for the network. The part of the network that is in another building with no metal partitions seems to be more stable. Or are there any other factors that will cause the network to be unstable?</p>

2017-06-02T22:51:04.937

<p>It is said already in other answers that you should use MQTT in your case.</p> <p><strong>But why?</strong></p> <p>MQTT is The Protocol if your things are behind a firewall in a private network [1]. All tricks are an outbound rule for port 1833 or with some configuration maybe not even that [2].</p> <p><strong>How will the things change after taking MQTT and not http?</strong></p> <p>You will need one block more to your combo of</p> <blockquote> <p>Turn On Light (from internet) --&gt; Digital Ocean Server--&gt; My Home Router --&gt; Raspberry Pi</p> </blockquote> <p>Your flow would be:</p> <blockquote> <ol> <li>Subscribe for Lights on event on Raspberry Pi (message between Broker and RP)</li> </ol> <p>..later night:</p> <ol start="2"> <li>Publish Lights on event on Server (message goes Server -&gt; Broker -&gt; RP)</li> </ol> </blockquote> <p><strong>What is Broker?</strong></p> <p>Message Broker is a service, that can run in the Digital Ocean and it takes in Publish andSubscription requests. [3]</p> <p>One such Broker is called Mosquitto and it is open source and easy to install. You install the service and run it. No coding involved, maybe little config. [4]</p> <p><strong>Publish and subscribe?</strong></p> <p>If you are familiar with php, you may use it also with Mosquitto [5]. Sample code at least looks straight forward, link contains more examples:</p> <pre class="lang-php prettyprint-override"><code>&lt;?php $c = new Mosquitto\Client; $c-&gt;onConnect(function() use ($c) { $c-&gt;publish('mgdm/test', 'Hello', 2); }); $c-&gt;connect('test.mosquitto.org'); for ($i = 0; $i &lt; 100; $i++) { // Loop around to permit the library to do its work $c-&gt;loop(1); } echo &quot;Finished\n&quot;; </code></pre> <p><strong>Sources:</strong></p> <p>[1] <a href="https://mongoose-os.com/blog/why-mqtt-is-getting-so-popular-in-iot/" rel="noreferrer">https://mongoose-os.com/blog/why-mqtt-is-getting-so-popular-in-iot/</a></p> <p>[2] <a href="https://stackoverflow.com/questions/32174272/how-mqtt-works-behind-the-firewall">https://stackoverflow.com/questions/32174272/how-mqtt-works-behind-the-firewall</a></p> <p>[3] <a href="http://www.hivemq.com/blog/mqtt-essentials-part2-publish-subscribe" rel="noreferrer">http://www.hivemq.com/blog/mqtt-essentials-part2-publish-subscribe</a></p> <p>[4] <a href="https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-the-mosquitto-mqtt-messaging-broker-on-ubuntu-16-04" rel="noreferrer">https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-the-mosquitto-mqtt-messaging-broker-on-ubuntu-16-04</a></p> <p>[5] <a href="https://github.com/mgdm/Mosquitto-PHP" rel="noreferrer">https://github.com/mgdm/Mosquitto-PHP</a></p>

|smart-home|networking|raspberry-pi|

Communication Between Server and Raspberry Pi

1578

<p>I am working on my home automation project. I have a server on digital ocean. I want to put my php code on that server and that server will connect to my Raspberry Pi. How can I pass messages between my server and Raspberry Pi. I want to control my website over internet.</p> <p>Turn On Light (from internet) --> Digital Ocean Server--> My Home Router --> Raspberry Pi</p> <p>And vice versa. So the reason I am writing this question is How to connect these things? Each time server receives message it has to pass message to Raspberry Pi (push) or Raspberry Pi has to check whether there is any message for me or not (poll). But how to do this? How to pass messages between intranet and internet.</p> <p><br>UPDATE:I have found some stuff. Can anyone tell me whether it is useful or not. Because I am new to this. <br><a href="https://nodejs.org/api/http.html#http_http" rel="noreferrer">https://nodejs.org/api/http.html#http_http</a><br> <a href="http://aiohttp.readthedocs.io/en/stable/client.html" rel="noreferrer">http://aiohttp.readthedocs.io/en/stable/client.html</a> </p>

2017-06-06T10:58:08.563

<p>There are a lot of devices out there that allow you to control digital I/O over a network. The difference between this and relay control is very little as you can very easily add a <a href="http://rads.stackoverflow.com/amzn/click/6374820011" rel="noreferrer">Solid State Relay</a> to a digital output.</p> <p>Products in this space can vary from <a href="https://www.sainsmart.com/sainsmart-rj45-tcp-ip-remote-controller-board-with-8-channels-relay-integrated.html" rel="noreferrer">hobbyist</a> to <a href="http://rads.stackoverflow.com/amzn/click/B00YCL7VCS" rel="noreferrer">home</a> to <a href="http://www.controlbyweb.com/" rel="noreferrer">industrial</a>.</p> <p>When selecting, there are some other things you should consider when using these in a business environment.</p> <ul> <li>Does the item integrate well into my company's network (is it just static IP, does it do DHCP, DNS, etc.). Will your IT department allow it on their network.</li> <li>How remotely do you need to access it (just within the LAN or WAN or internet).</li> <li>Are there any safety concerns regarding the remote activation? Turning on a 5V LED is a lot lower concern than turning on an 110V AC light. What if someone was servicing it and it was turned on remotely?</li> </ul>

|hardware|industry-4.0|

Looking for a relay that can be controlled from .net web application (via TCP/IP)

1589

<p>As part of one new requirement for web application I am maintaining, we need to send a signal to a device in a factory when certain conditions are met in the application.</p> <p>Sending a signal is simply short-circuiting 2 wires (physical push button). The controlled device is not anywhere near the web server that is hosting application, but it is on the same network. S the idea is to buy boards that already have hardware relays and can accept activation commands via TCP/IP. The ability to secure a board with password protection is a plus but not a must.</p> <p>As one of goals is to have as much standard interfaces as possible. We would like to avoid making our own Arduino- or Raspberry- based boards. I am asking if there are some known and simple industry-grade relays/switches with a TCP/IP interface?</p> <p>Is there a name for such device? </p> <p>I tried to search for it and closest I found is this <a href="http://www.ebay.com/itm/LAN-Ethernet-2-way-Relay-Board-Delay-Switch-TCP-UDP-Controller-Module-WEB-server-/272469922686?_trksid=p2385738.m2548.l4275" rel="nofollow noreferrer">Chinese board that allows steering 2 relays through TCP/IP</a>.</p> <p>This seems like a long shot to ask here but I am hoping someone worked with similar devices and it would be great if I can get a name of a reputable company that produces such devices.</p>

2017-06-06T15:35:48.777

<p>Try this web server for IoT and realtime GPS tracking, <a href="https://iot.electronixforu.com" rel="nofollow noreferrer">https://iot.electronixforu.com</a> It supports Passthrough mode of ESP8266, it means you can send data as fast as you can (normally 1 second interval), details are available at <a href="https://electronixforu.com/iot.html" rel="nofollow noreferrer">https://electronixforu.com/iot.html</a></p>

|smart-home|networking|esp8266|streaming|

How to write/post files to website server through ESP 8266

1590

<p>I want to know if there is a way to send files to a website with sm ESP 8266 or any other IoT device. I intend that the IoT device will be the client. A PHP or scripting file on the website will act as the server. It will look like the IoT device is uploading the files to the website.</p>

2017-06-06T18:12:30.747

<p>Perhaps the software featureset has changed but I've found that the following works. This is from my DIY code for nodemcu/D1 mini ESP8266 module using esp8266 webserver listening for local UDP broadcasts. I noticed in the Alexa calls to /upnp.control/basicevent1 that the requests were changing subtly. It all boils down to the same event, but the xml of the request has either <code>&lt;SetBinaryState&gt; or &lt;GetBinaryState&gt;</code></p> <p>So long as you're holding state in your sketch, something like this will work...</p> <pre><code> void Switch::handleUpnpControl(){ Serial.println("########## Responding to /upnp/control/basicevent1 ... ##########"); String request = server-&gt;arg(0); Serial.print("request:"); Serial.println(request); if (request.indexOf("&lt;u:SetBinaryState") &gt; 0) { Serial.print("Got setState update..."); if(request.indexOf("&lt;BinaryState&gt;1&lt;/BinaryState&gt;") &gt; 0) { Serial.println("Got Turn on request"); state = 1; onCallback(); } if(request.indexOf("&lt;BinaryState&gt;0&lt;/BinaryState&gt;") &gt; 0) { Serial.println("Got Turn off request"); state = 0; offCallback(); } server-&gt;send(200, "text/plain", ""); } if (request.indexOf("&lt;u:GetBinaryState") &gt; 0) { Serial.println("Got inquiry for current state:"); String statusResponse = "&lt;s:Envelope xmlns:s=\"http://schemas.xmlsoap.org/soap/envelope/\" s:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\"&gt;" "&lt;s:Body&gt;" "&lt;u:GetBinaryStateResponse xmlns:u=\"urn:Belkin:service:basicevent:1\"&gt;" "&lt;BinaryState&gt;" + String(state) + "&lt;/BinaryState&gt;" "&lt;/u:GetBinaryStateResponse&gt;" "&lt;/s:Body&gt;" "&lt;/s:Envelope&gt;\r\n" "\r\n"; Serial.print("Sending status response: "); Serial.println(statusResponse); server-&gt;send(200, "text/plain", statusResponse); } } </code></pre>

|alexa|esp8266|wemo|

Getting status from WeMo device using Alexa

1595

<p>I am using an ESP8266 to emulate a WeMo device with wemos and fauxmoESP arduino code found on the internet. Now that I understand the basic interaction of on and off commands, I'd like to add a status response for the state of some pins on the device. It appears that "turn on" and "turn off" are basic Alexa skills and those work. But there is no "status" or "state" verbal command.</p> <p>I've found places in the code that handle the <code>eventservice</code> XML for example:<code>&lt;binarystate&gt;1&lt;/binarystate&gt;</code> to turn it on, but I cannot find any documentation on getting status or <code>&lt;getdevicestate&gt;</code>. Example of use: If I can't see a light on somewhere, I'd like to query the device to see if it is on or off.</p> <p>Since the device emulates a belkin on/off switch, the setup.xml packet only has:</p> <pre class="lang-xml prettyprint-override"><code>&lt;service&gt; &lt;serviceType&gt;urn:Belkin:service:basicevent:1&lt;/serviceType&gt; &lt;serviceId&gt;urn:Belkin:serviceId:basicevent1&lt;/serviceId&gt; &lt;controlURL&gt;/upnp/control/basicevent1&lt;/controlURL&gt; &lt;eventSubURL&gt;/upnp/event/basicevent1&lt;/eventSubURL&gt; &lt;SCPDURL&gt;/eventservice.xml&lt;/SCPDURL&gt; &lt;/service&gt; </code></pre> <p>and the basic event is not enough to get status or further capability.</p> <p>This is all done without writing an AWS skill and is handled with direct dialog on the local LAN between the ESP8266 webserver and fauxmoESP to and from the Echo Dot. I can see the packets by sniffing the LAN (wireless)and believe it would be straightforward to add more capabilities if I could find the documentation on the control messaging XML packets.</p> <p>Where can I find these control XML dialog templates and hopefully examples of how to use them? I am getting the sense that this can only be accomplished by using an AWS skill but it seems so unnecessary. Can someone give me some guidance here?</p> <p>Also, what is the utterance for Alexa to check status of a device? It could be that there is no built in utterance for this and I will need to write an AWS skill (which I don't want to do if possible.)</p>

2017-06-07T13:45:26.017

<blockquote> <p>if the MQTT IoT devices are completely different from other types like HTTP in features, or is the difference only about communication protocols?</p> </blockquote> <p>The difference is at the protocol level. Same device may run MQTT as well as HTTP if required. But, device maker will choose a protocol based on the problem statement.</p> <blockquote> <p>Can a device that marked with "MQTT" be swapped to "HTTP" or vice versa?</p> </blockquote> <p>Yes, you can make your own device based on RPi board with a temperature and a humidity sensor attached. And you can choose to report the sensor data over MQTT/HTTP as required.</p> <blockquote> <p>Eclipse Hono</p> </blockquote> <p>Hono's goal is to enable connection to a large numbers of IoT devices to a back end and enable business application's interaction with devices in an uniform way regardless of the device communication protocol. The Hono adapters help to achieve this. The Hono server interacts with the MQTT/HTTP enabled devices via the respective adapter, that way any type of device can be deployed on the filed. The application interacts with the Hono Server using AMQP.</p> <p>Now to put this in perspective, lets say you are writing an application that sits in the control room of a nuclear power plant showing data from all sensors in a single dash board. The power plat may be sourcing sensors from different vendors. Some sensors may be built to use MQTT whereas others may be built to use HTTP. If your application had to implement adapters for all, that would be tedious. Hono is offering to do that. Your application can be simpler and interacts with Hono server. The sensors on field may go bad and eventually a sensor-A (using MQTT) from vendor-A may be replaced by a sensor-B (using HTTP) from vendor-B. As hono is providing both adapters switching the sensors is trivial as your application is least impacted and still gets the data the same way as usual.</p>

|protocols|system-architecture|

What are the differences between MQTT, HTTP, CoAP devices (besides communication protocol)?

1598

<p>I am new to IoT platform and after days of reading I am still confused about different types of IoT devices. Currently, I have read about smart devices that connect to the cloud through different ways like MQTT, HTTP, LWM2M, and maybe more. Are the IoT devices are really fragmented (like MQTT devices, HTTP devices) or I just misunderstood about that. If they are divided then what are the characteristics of each type (like smarter, faster compared to other types) ?</p> <p>To be more specific I am doing a study on the Eclipse IoT projects, especially Eclipse Hono. Hono provides different protocol adapters like MQTT and REST, and each of them are meant to connect to a type of device as they've shown in the first drawing in this link <a href="https://www.eclipse.org/hono/architecture/component-view/Component-View/" rel="nofollow noreferrer">Hono</a>. My question is if the MQTT IoT devices are completely different from other types like HTTP in features, or is the difference only about communication protocols? Can a device that marked with "MQTT" be swapped to "HTTP" or vice versa? </p> <p>It would be great if you could give me some examples of the devices which are categorized as MQTT, HTTP, or LWM2M, so I can visualize more easily.</p>

2017-06-11T11:46:19.750

<p>It's easy to build your own platform to stream video/security camera for less that $50. You can use any Pi, buy one used for cheap or a Pi Zero W (it has wireless) for less than $10.</p> <p>Here are a few examples of how this can be achieved using both Raspbian and Windows IoT Core. You can use the Raspberry Pi Camera Module or a Webcam.</p> <p><a href="https://www.hackster.io/dataplicity/stream-live-videos-on-the-internet-98bc61" rel="nofollow noreferrer">Raspbian - Streaming to the public internet</a></p> <p><a href="https://www.hackster.io/sascha/browser-webcam-live-stream-with-windows-iot-core-raspberry-3-1dc38b" rel="nofollow noreferrer">Windows IoT Core - Streaming on your local network</a></p>

|smart-home|raspberry-pi|data-transfer|

Cheap video streaming platform using Raspberry Pi

1610

<p>I have a questions as stated in title - I hope it will not be "primarily opinion based" since I wanted to ask you if what I have in mind is even doable.</p> <p>I want to create network of couple cameras that could stream from given location to local server.</p> <p>Few requirements for my project:</p> <ul> <li><p>attaching another camera to network should be easy (REST API?)</p></li> <li><p>cheap &amp; relatively good quality, around 720p (Microcontroler like Arduino, Raspberry PI, surveilance cam?)</p></li> <li>should have one main router (Raspberry Pi?) that would stream the data to other devices</li> </ul> <p>In the internet I saw simple examples where 1 cam = 1 Raspberry Pi but I don't know if it isn't overkill since that setup costs around 50 euro and you get OS for one job</p>

2017-06-11T12:08:04.393

<p>The support is generally pretty good for locations outside of the UK, US and Germany (although it's not officially supported yet).</p> <p><a href="https://iot.stackexchange.com/a/204/12">Coomie's experience of using the device in Australia</a> is useful to read—here's a brief summary:</p> <blockquote> <p><strong>What does work?</strong></p> <p><strong>Core</strong> - Amazon itself works as long as it has power and internet.</p> <p><strong>Smart home</strong> - All the smart home devices that would otherwise work in your country work.</p> <p><strong>Time zones</strong> - You can set your timezone to anywhere in the world.</p> <p><strong>Music</strong> - It can play music if you would otherwise be able to play it, e.g. Amazon Play, Pandora &amp; Spotify all work for me.</p> <p><strong>Weather</strong> - It can get weather for most cities in the world, but you must ask about your city. e.g. "<em>Alexa, what is the weather in Cairo, Egypt?</em>"</p> <p><strong>More Skills</strong> - All the skills that don't require your location have worked for me.</p> </blockquote> <p>However, I've heard that there are workarounds to set your location, despite it not being officially supported. It's a bit involved, but <a href="https://beebom.com/how-to-set-up-and-use-amazon-echo-outside-us/" rel="noreferrer">Beebom</a> outline the steps to set a custom location through the Alexa website (<a href="http://alexa.amazon.com/" rel="noreferrer">alexa.amazon.com</a>). You need to edit the device location, then:</p> <blockquote> <ul> <li><p>Start typing any US based address here, we used “2201 Westlake Avenue, Suite 200, Seattle, WA 98121”, and then click on “Save”. In the Developer Tools, you will see a couple of entries, select the one on the bottom. Right click on it, and select “Copy as curl“.</p></li> <li><p>First off, paste the copied curl command into an editor such as Sublime Text, or Notepad++. [...] Change the "timeZoneId" to whatever time zone you are in. For us, it was “Asia/Kolkata”.</p></li> <li><p>Once that is done, change the following fields to reflect your local values: city (“Delhi”, in our example) countryCode (“IN”, in our example) county (null for us, if you have a county, you can put that value here.) district (null, for us) houseNumber (null, for us)</p></li> <li><p>Now, send the curl command.</p></li> </ul> </blockquote> <p>You can find the curl documentation <a href="https://curl.haxx.se/" rel="noreferrer">on their website</a>, although it's helpful to be comfortable with the command line if you want to do that.</p> <p>You <em>can</em> just set a location in your device's region, though, if you don't want to go through all of this—location-based services <strong>will</strong> be wrong, but if you don't mind, it's far easier than sending API requests.</p> <hr> <p>In summary:</p> <ul> <li>all the core functionality works fine, even outside the UK.</li> <li>you can manually set your location using the API (but that might break some skills that are expecting a UK-based location—I haven't tested, but I bet TuneIn would break with a non-UK location).</li> </ul> <p>You might want to test Alexa through a different device before buying an Echo to test for yourself. You could try using <a href="https://echosim.io/welcome?next=%2F" rel="noreferrer">this Echo simulator</a> after setting up an account with Amazon and following the steps above. It should behave near identically to a real Echo, so you'll get a feel for what works and what doesn't.</p>

|amazon-echo|

Does Amazon Echo work in countries where Amazon is yet to launch Echo officially?

1611

<p>I am considering to get an Echo Dot in UK but will use in it a country where Amazon is yet to launch officially. Will Echo even work? If anyone from community has tried something similar can you please list what features on Echo are limited in countries outside the supported list?</p> <p>I intend to use Echo for following thing to begin with:</p> <ul> <li>Controlling smart home devices, lights, plugs</li> <li>Creating to do lists</li> <li>Use tune in</li> <li>Setting alarms</li> <li>Checking some facts quickly </li> </ul>

2017-06-13T08:29:20.530

<p>I posted this same question to the Microsoft forums and got a reply from IoTGirl saying that WiFi Direct is an option: <a href="https://social.msdn.microsoft.com/Forums/en-US/fc77339d-25fc-40e2-bf59-31e51361f893/windows-iot-core-wifi-mesh?forum=WindowsIoT" rel="nofollow noreferrer">Windows IoT Core WiFi Mesh</a> </p> <p>I need to confirm whether the RPi3B supports WiFi Direct and then also find out if it supports many-to-many via WiFi Direct. (if anyone has any experience on this, feedback would be much appreciated) </p> <p>Hope this keeps this conversation going or at least helps someone else.</p>

|mesh-networks|arduino|microsoft-windows-iot|

WiFi Mesh on Windows IoT core

1626

<p>I have a project where I need to create a Wi-Fi mesh network of nodes sharing a distributed mesh database that requires relatively quick search access on each node. I was initially thinking of running this using nodes consisting of ESP8266's (<a href="https://github.com/Coopdis/easyMesh" rel="nofollow noreferrer">https://github.com/Coopdis/easyMesh</a>) each containing an SD card (to store the database), but I'm concerned that most of the Arduino type code I've seen mostly runs in memory. Does this mean I have to load the "database" (In reality probably just a list with 2 or three fields for each record) into memory? I don't want to loop through the list to find the record I'm looking for as I think this will not be efficient. I was hoping to implement some kind of binary search algorithm. Note that entries in this database could go to about 40 000+ entries.</p> <p>My fallback option is to run Windows IoT Core on a Raspberry Pi where I can use C# and possibly even a real database. My issue with this solution is that I have not been able to find an example of running a mesh network using Windows IoT Core.</p> <p>Any thoughts or assistance would be much appreciated.</p>

2017-06-14T06:25:23.717

<p>RFID card does not emit any electromagnetic signals when it is not close to a reader, it is designed to be passive. It is activated when brought in proximity to the reader. So RFID card cannot really damage your phone while it is in back case of you phone.</p>

|rfid|

Is it safe to have a RFID card in the back of a Cellphone case

1631

<p>I hope this is the right Stack Exchange to ask this, but since RFID Cards are becoming more common and with new Microcontrollers a lot of home-built Internet of things devices can be RFID i figured here seemed right, if not i am truly sorry and will find somewhere else to ask.</p> <p>I am wondering if it is safe to keep a RFID card in the back of a cellphone case (pressed right against the phones back) and to keep it in the case while using both the phone and the card.</p> <p>Basically i keep my IPhone 6S in a drop-case and want to put my doors RFID proximity card in the back of the case so i don't have to carry an additional card when my phone is typically in my hand.</p> <p>But i don't want to waste the money on the RFID card replacement, and more impotently i don't want to damage the 600+ IPhone.</p> <p>Any help would be appreciated, little tid-bits i found around seems to indicate it would be okay, but i haven't found anything definitive.</p> <p>Thanks in advance, Lin.</p>

2017-06-14T09:52:43.670

<p>The message above decoded:</p> <pre><code>MQIsdp{03}{02}{00}{14}{00}{11}evolan_12345678900!{00}{06}evolanHello eevoLAN!à{00} </code></pre> <p>It is mixed Ascii/Hex (topic, clientID and payload are plain ascii, special chars are {hex}. </p> <p>It turns out, that this packet always contains the connect / disconnect option (refer to this table <a href="http://docs.solace.com/MQTT-311-Prtl-Conformance-Spec/MQTT%20Control%20Packet%20format.htm#_Table_2.1_-" rel="noreferrer">http://docs.solace.com/MQTT-311-Prtl-Conformance-Spec/MQTT%20Control%20Packet%20format.htm#_Table_2.1_-</a>)</p> <p>So I rewrote my method for publishing and split it into separate Connect/Disconnect and Publish methods. (The examples for Paho embedded are very bad documented, so I didn't know that I have always sent a connect/disconnect request within my published message)..</p> <p>Programming details:</p> <p><strong>Connect method</strong></p> <pre><code>MQTTPacket_connectData data = MQTTPacket_connectData_initializer; char m_buf[200]; uint32_t m_len = sizeof(m_buf); data.clientID.cstring = "&lt;your client id string&gt;"; data.keepAliveInterval = 20; data.cleansession = 1; data.MQTTVersion = 4; uint32_t len = MQTTSerialize_connect(m_buf, m_len, &amp;data); your_ethernet_driver_send_method(m_buf, len); </code></pre> <p><strong>Send method</strong></p> <pre><code>char m_buf[200]; uint32_t m_len = sizeof(m_buf); MQTTString topicString = MQTTString_initializer; uint32_t payloadlen = strlen(m_payload); topicString.cstring = m_topic; uint32_t len = 0; len += MQTTSerialize_publish(m_buf + len, m_len - len, 0, 0, 0, 0, topicString, m_payload, payloadlen); your_ethernet_driver_send_method(m_buf, len); </code></pre> <p><strong>This works now, I can confirm getting packets on mqtt-spy!</strong></p> <p><strong>So, unfortunately I couldn't find a tool for validating my packet, but what I did is outputting it to a text editor and highlight the special chars as hex values. Then I compared the header bytes to the definition posted above.</strong></p>

|mqtt|paho|

MQTT packet validity check

1634

<p>Is there any tool to check my generated packets for being a valid MQTT (3.1.1) packet? Background: I'm using Paho embedded (MQTTPacket) on my microcontroller to generate packets to be send over my ethernet driver. But something seems to be wrong with my packets as they aren't displayed in mqtt-spy. </p> <p>i.e. this packet:</p> <pre><code>0x10 0x1D 0x04 0x00 0x4D 0x51 0x54 0x54 0x04 0x02 0x00 0x14 0x00 0x11 0x65 0x76 0x6F 0x6C 0x61 0x6E 0x5F 0x31 0x32 0x33 0x34 0x35 0x36 0x37 0x38 0x39 0x30 0x30 0x15 0x00 0x06 0x65 0x76 0x6F 0x6C 0x61 0x6E 0x48 0x65 0x6C 0x6C 0x6F 0x20 0x65 0x65 0x76 0x6F 0x4C 0x41 0x4E 0x21 0xE0 0x00 0x29 0x90 0x20 </code></pre> <p>is it valid? </p>

2017-06-15T08:42:56.440

<p>This mostly depends on how much resources your embedded device has.</p> <p>For example, on ESP8266 devices your options are limited to your own application and C (possibly Lua) programming. There are no resources to run anything else.</p> <p>On a devices like Onion Omega2 with 32Mb flash and 128Mb RAM you can install LuCi (thx!) from OpenWRT, and add more pages using a scripting language like Lua or Python.</p> <p>Finally on a larger devices like Raspberry PI Zero with 512+Mb RAM and multi-gigabyte storage you can use something like Webmin.</p>

|networking|software|

Web admin panel for embedded Linux IoT devices

1647

<p>Devices like routers always have a web-based administrative interface that allows you to configure many aspects of the device from a web browser. Obviously, this is essentially a web server running on the embedded devices, where requests to the web site carry out different tasks. </p> <p>I was wondering whether there was a free (both for personal and commercial use) web admin interface that can be installed on embedded devices and allows pages to be added/customised.</p>

2017-06-18T00:05:59.250

<p>I had the same requirement as you, so I have modified mosquitto v1.5.3 source code, and added a custom <code>log_type</code> in <code>mosquitto.conf</code>:</p> <pre><code>log_type ping </code></pre> <p><a href="https://github.com/yurenchen000/mosquitto/commit/61ce98cdcb0297f38c52a47c1d9c6247f713dd37" rel="nofollow noreferrer">Source on Git Hub</a>.</p>

|mosquitto|

Mosquitto debug level log - How to keep all entries but PINGREQ/PINGRESP

1671

<p>I discussed <a href="https://iot.stackexchange.com/questions/1641/prevent-ping-logging-in-mosquitto-server">here</a> how to avoid ping messages in logs. By changing <code>log_type</code>(s) in <code>mosquitto.conf</code> I found that pings are reported under <code>DEBUG LEVEL</code>. I would comment this log type in the conf to avoid pings in log, but sadly <code>PUBLISH</code> entries are under the same log level and they are all relevant for me. So, I wonder if it is there any way to avoid exclusively pings from being logged.</p> <p>Here is my <code>mosquitto.conf</code>:</p> <pre><code># Place your local configuration in /etc/mosquitto/conf.d/ # # A full description of the configuration file is at # /usr/share/doc/mosquitto/examples/mosquitto.conf.example pid_file /var/run/mosquitto.pid #persistence false persistence true persistence_location /var/lib/mosquitto/ #log_dest file /var/log/mosquitto/mosquitto.log log_dest syslog log_type error log_type warning log_type notice log_type information log_type debug log_type subscribe log_type unsubscribe log_type websockets #log_type all connection_messages true log_timestamp true include_dir /etc/mosquitto/conf.d </code></pre>

2017-06-20T02:40:44.997

<p>Your thing probably doesn't have a unique IP address in this context, unless it uses IPv6. It will have an address in a private space, such as 10.0.0.0 – 10.255.255.255 or 192.168.0.0 – 192.168.255.255, this will be behind a NAT gateway (which has the ISP assigned public address).</p> <p>Your thing can <em>probably</em> initiate outbound connections to a server (which can include a 2-way communication), but ultimately, your thing needs to 'phone home' in order for your server to communicate with it. Your thing's IP address shouldn't need to be something you care about, unless one thing needs to talk directly to another. If you need it's IP address, your target's router will need to port forward for you.</p>

|networking|ip-address|

How to find remote thing's IP address?

1687

<p>I have a physically remote thing. It's on someone else's network so I can't get a static IP address for it. What is the best way to track its IP address?</p> <p>I can imagine just publishing a "heartbeat" that includes the IP address to some service that will store it for me. If there is some sort of software problem on my thing's end, I could potentially lose it forever in this setup.</p> <p>Is there a more robust way to keep track of the thing's IP address?</p>

2017-06-22T16:33:31.737

<blockquote> <p>I'd like to know what are some specific actual real world use cases</p> </blockquote> <p>Visit <a href="https://medium.com/@cstoecker/implementing-first-industry-4-0-use-cases-with-iota-dag-tangle-machine-tagging-for-digital-twins-baf1943c499d" rel="nofollow noreferrer">"Implementing first Industry 4.0 Use Cases with IOTA DAG Tangle — Machine Tagging for Digital Twins"</a> to read about an actual use case by <a href="https://www.innogy.com/" rel="nofollow noreferrer">Innogy SE</a> (energy company based in Germany, a subsidiary of the German energy company RWE).</p> <p>To quote briefly from the article:</p> <blockquote> <p>In this blogpost my preferred industry 4.0 use case will be described as a first example where the IOTA protocol can be applied in practice today: IOTA for tagging of physical machines in a digital twin architecture (proof-of-concept). This use case combines some very important decentral technologies such as IPFS, IPLD and BigchainDB for file storage and database layer with the DAG (directed acyclic graph) tangle as well.</p> </blockquote> <p>[...]</p> <blockquote> <p>A practicable first application of a digital twin with IOTA is CarPass for vehicles telematics data. The CarPass solution securely captures telematics data (e.g. mileage, trips, environmental, maintenance data) and stores them immutable in the digital twin for private passenger, fleet or commercial vehicles.</p> </blockquote>

|cryptography|iota|

How is the IOTA cryptocurrency network useful for devices in the IoT?

1693

<p>I found out about IOTA, which is apparently a big solution for IoT <a href="https://iota.org" rel="noreferrer">https://iota.org</a></p> <p>But the info about feels a bit abstract to me. I'd like to know what are some specific actual real world use cases of how it can be useful?</p>

2017-06-27T14:47:58.173

<p>From this [1] article from 2015 it tells:</p> <blockquote> <p>To use multiple accounts with Echo, you’ll need to set up an Amazon Households account, which allows two adults in the same house to share Prime benefits, and allows parents to share content with up to four children. Amazon says it’s not supporting children’s accounts on Echo at the moment, however.</p> <p>As ZDNet notes, families can now say “Alexa, switch accounts” to cycle between the two adult account holders.</p> </blockquote> <p>If situation does not have changed, children are blocked by restrictions.</p> <p>[1] <a href="http://www.techhive.com/article/2977784/connected-home/new-update-makes-amazon-echo-more-family-friendly.html" rel="nofollow noreferrer">http://www.techhive.com/article/2977784/connected-home/new-update-makes-amazon-echo-more-family-friendly.html</a></p>

|alexa|amazon-echo|

A practical guide to Amazon Echo, families with children?

1717

<p>I have an Amazon account, as does my wife. We share Amazon Prime through household setup, and have added our daughter to our kids list. We purchased an Echo Dot for our daughter, and are likely going to get a few more for around the house.</p> <p>The confusion lies in how to set this up for <strong>her</strong>. She can't have an Amazon account apparently, so not sure how to even setup the new intercom features, etc. The only way I've seen so far is I have to set it up under my name.</p> <p>I'd like for her to be able to have her own reminders, calendar, features, etc. </p> <p>Can someone please outline a practical way to set this up? I'd rather not sign into my Amazon account and be blasted with advertisements for all the new Pop songs or things to buy, based on her usage of the echo. </p> <p><strong>Update</strong> In comments:</p> <blockquote> <p>It would help for non-experts if you're specific about what prevents user specific accounts, or prevents you setting up a sockpuppet account</p> </blockquote> <p>On the apparent issues, or what I ran into was when setting up the echo for the first time, it would not allow me to select my child's account in the list, only mine or my wife's. Sockpuppet? As in a fake account? Was hoping to avoid that route :)</p>

2017-06-27T23:13:04.407

<p>Apple is keeping the technology it uses for AirPods under wraps, hence my answer is best attempt based on the information in public domain.</p> <blockquote> <p>Do both Airpods use Bluetooth technology?</p> </blockquote> <p>Yes, because</p> <ul> <li>Power efficiency that Airpods come with can be achieved via Bluetooth.</li> <li>Airpods are inter-operable with Android and Windows, this proves Apple has used standards compliant Bluetooth.</li> </ul> <blockquote> <p>Do both Airpods connect to the phone? Or does one Airpod connect to the phone and the other Airpod?</p> </blockquote> <p>I think Apple has implemented its own patent <a href="https://www.google.com/patents/US8768252" rel="noreferrer">US8768252: Un-tethered wireless audio system</a> for the Airpods. What they may have got in place is a <a href="https://en.wikipedia.org/wiki/Scatternet" rel="noreferrer">Bluetooth Scatternet</a> with one <a href="https://en.wikipedia.org/wiki/Piconet" rel="noreferrer">piconet</a> having phone and one of the pods, and the other piconet has both the airpods.</p> <p>The complete theory of operation is described in the patent. The key concept is captured in the following diagram from the patent. <a href="https://i.stack.imgur.com/XcAph.png" rel="noreferrer"><img src="https://i.stack.imgur.com/XcAph.png" alt="Airpod piconets"></a></p> <p>So it seems effectively one of the airpods is actively connected to the phone and the other is in promiscuous mode.</p>

|hardware|bluetooth|bluetooth-low-energy|

How do the AirPods communicate with the phone?

1719

<p>By reading the <a href="https://www.ifixit.com/Teardown/AirPods+Teardown/75578" rel="nofollow noreferrer">iFixit Teardown</a>, one can realize that the AirPods use the W1 chip for wireless communications. Since both Airpods are wireless, there are questions still unanswered.</p> <p>Do both Airpods connect to the phone? Or does one Airpod connect to the phone and the other Airpod? Do both Airpods use Bluetooth technology? </p> <p>From the iOS/Android perspective, is it possible to connect to multiple Bluetooth devices simultaneously?</p> <p>Here is a small prompt from the <a href="https://www.ifixit.com/Teardown/AirPods+Teardown/75578" rel="nofollow noreferrer">IFixit Teardown</a> that lists the components inside the Airpods:</p> <ul> <li>Apple 343500130 is suspected to be the <a href="https://www.theverge.com/2016/9/7/12829190/apple-w1-chip-iphone-7-wireless-headphones" rel="nofollow noreferrer">W1</a> wireless communication chip (red)</li> <li>Cypress <a href="http://www.cypress.com/documentation/datasheets/psoc-4-psoc-4100s-family-datasheet-programmable-system-chip-psoc" rel="nofollow noreferrer">CY8C4146FN</a> programmable system on a chip (orange)</li> <li>Maxim <a href="http://www.mouser.com/ProductDetail/Maxim-Integrated/MAX98730EWJ+T/?qs=AAveGqk956GR2qzDJXyWOg%3D%3D" rel="nofollow noreferrer">98730EWJ</a> low power stereo audio codec (yellow)</li> <li><p>Texas Instruments TPS743 (green)</p> <p><a href="https://i.stack.imgur.com/PRfR5.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PRfR5.jpg" alt=" Airpod&#39;s inside front-side"></a></p></li> </ul>

2017-06-28T18:49:05.157

<p>You probably need a relay rather than a 'smart light switch'. This is because the light switches frequently rely on leakage through the lamp to power the electronics in the switch. With a fan motor, this might not work as intended. You would also risk some damage in using a dimmer to control the motor.</p> <p>The key difference with a smart relay is that the switching element takes feed and return power directly, providing independent terminals for the load. They can use either mechanical relay or electronic ones - just make sure it is suitably rated for an inductive load.</p> <p>As an example, <a href="https://www.lightwaverf.com/product-manuals/" rel="nofollow noreferrer">LW821</a>. You would typically wire this in the ceiling void, and then have the challenge of how to manage the switch - so you might replace the switch with a LW-RF transmitter (confusingly described as a wire free switch) - rather than trying to come up with a 3-way control.</p> <p>You will not be able to mount the relay at the switch location because there is no 'common return/neutral' in a normal switch location. Effectively, you need to install a switched spur (and this most likely means some places require an electrician to certify the work).</p>

|smart-home|alexa|apple-homekit|

Ceiling fans - Can I use a smart switch to control a dumb fan?

1724

<p>There are a handful of "smart ceiling fans" available that are really expensive (up to $500). </p> <p>Is there an easy way to just add a smart wall switch with a cheap dumb ceiling fan to get the same result? The fans in question are hardwired, not using any plug.</p> <p>Some details:</p> <ul> <li>Amazon Alexa switch or HomeKit switch, either would be fine</li> <li><em>Would not need</em> to control a fan light, only the fan itself</li> <li><em>Would need</em> to also control fan speed. Maybe one switch to turn the fan on and off, and a dimmer switch to control the fan speed? </li> </ul>

2017-06-29T18:54:49.727

<p>Currently, there is no support for NFC on the Google Home. I couldn't find an authoritative source to say that there <strong>isn't</strong> support, but there are no known features as of writing that use NFC capabilities. I'm also not aware of any plans in the near future to use the chip.</p> <p>Note that the chip is used by several other devices (most notably the <a href="https://www.nfcworld.com/2013/11/25/327049/xbox-one-ships-nfc-chip/" rel="nofollow noreferrer">Xbox One</a>) which do not actually use the NFC capability of the chip at all. And, as noted by IFixIt, the Google Home is internally very similar to the <a href="https://www.ifixit.com/Teardown/Chromecast+2015+Teardown/50189#s108831" rel="nofollow noreferrer">Chromecast</a>, which also has a NFC-enabled chip without actually using it:</p> <blockquote> <p>Marvell Avastar <a href="http://www.marvell.com/wireless/assets/Marvell_Avastar_88W8897_SoC-003_PB.pdf" rel="nofollow noreferrer">88W8887</a> VHT WLAN, Bluetooth, NFC and FM Receiver</p> </blockquote> <p>I would conjecture that the chip is simply the best option that is mass produced for Google's device, and the fact that NFC is supported was not a factor in their chip choice.</p> <p>Similarly, the Google Home <a href="https://www.reddit.com/r/googlehome/comments/5aydj0/google_home_and_bluetooth_connectivity/" rel="nofollow noreferrer">has full Bluetooth support, but didn't use it</a>... <a href="https://9to5google.com/2017/06/29/google-home-blutooth-streaming-rollout/" rel="nofollow noreferrer">until very recently</a>. It's a sign that they probably <em>could</em> support NFC in future, but a suitable use case would need to be devised. However, there are no known plans right now.</p>

|google-home|google-assistant|nfc|

Does Google Home support any NFC use cases?

1731

<p>The <a href="https://www.ifixit.com/Teardown/Google+Home+Teardown/72684" rel="nofollow noreferrer">IFIXIT Google Home tear-down</a> reveals the <a href="http://www.marvell.com/wireless/assets/Marvell_Avastar_88W8897_SoC-003_PB.pdf" rel="nofollow noreferrer">Marvell Avastar 88W8897</a> WLAN/BT/NFC SoC.</p> <ul> <li>Are there any known NFC use cases that the Google Home supports? </li> <li>Any announcements from Google if the device will enable a NFC related feature by the way of future software updates?</li> </ul>

2017-07-02T13:23:38.397

<p>At the moment, it is impossible to set a schedule for Alexa's volume, according to <a href="https://www.reddit.com/r/amazonecho/comments/4maoft/any_idea_how_to_automatically_reduce_the_volume/" rel="nofollow noreferrer">this reddit thread</a>. Instead, you must manually tell Alexa to <em>"set volume to 0"</em> at night, then <em>set volume to [your preferred value]"</em> in the morning.</p> <p>I believe you can set the alarm/notification volume separately to the master volume in the app (certainly <a href="http://www.echotalk.org/index.php?topic=1248.0" rel="nofollow noreferrer">as of December 2016</a>), but I'm unaware of a setting to change music volume separately to voice volume for Alexa's replies.</p> <p>As always, it may be worth <a href="https://www.amazon.co.uk/gp/help/customer/display.html?nodeId=201601960" rel="nofollow noreferrer">sending feedback</a> requesting this feature if there isn't a solution available; Amazon's team does seem to listen to and prioritise requested features.</p>

|alexa|amazon-echo|smart-assistants|

Can Alexa be trained to use preferred volume levels?

1750

<p>Is there a way to train Alexa to use preferred volume levels, such that Alexa</p> <ul> <li>plays music at volume X</li> <li>replies at volume Y</li> <li>sets volume to 0 every night at 9 PM, and back to last set volume at 6 AM</li> </ul>

2017-07-03T16:06:13.640

<p>The default operation of the camera(s) <a href="https://www.google.com/url?sa=t&amp;rct=j&amp;q=&amp;esrc=s&amp;source=web&amp;cd=1&amp;cad=rja&amp;uact=8&amp;ved=0ahUKEwjEz9-Wn-7UAhUg0IMKHT6KDRsQFggmMAA&amp;url=http%3A%2F%2Fwww.pcworld.com%2Farticle%2F3134039%2Fhacking%2Fchinese-firm-admits-its-hacked-products-were-behind-fridays-massive-ddos-attack.html" rel="nofollow noreferrer">may not be secure</a>. If security features are enabled, it will likely include authorization and encryption to get at the video feed.</p> <p>However, your are best assuming that even with security features enabled - your cameras are not secure. There are back doors baked into these products on many levels before the device is ever assembled. This is widely reported already.</p> <p>If you want to keep something secret, do not record or transmit it.</p>

|home-security|surveillance-cameras|nest-cam|

What kind of network security is employed in live streaming surveillance cameras?

1752

<p>Surveillance camera, such as the Nest Cam, provide live stream of feed. Now given such a device which is always connected and streaming what kind of network security model do such products employ?</p> <p>I assume such products cannot afford to let the stream be eves-dropped or tampered.</p>

2017-07-06T09:57:45.240

<p>In the code it could look like this if you're using node.js </p> <pre><code>const LaunchRequestHandler = { canHandle(handlerInput) { return handlerInput.requestEnvelope.request.type === 'LaunchRequest'; }, handle(handlerInput) { var reprompt = ''; const speakOutput = 'Protokollaufnahme gestartet.'; return handlerInput.responseBuilder .speak(speakOutput) .reprompt(reprompt) .withSimpleCard('Protokollaufnahme', speakOutput) .withShouldEndSession(false) .getResponse(); }, }; </code></pre> <p>The card is initialized in the response like this: </p> <pre><code>.withSimpleCard('title', 'content') </code></pre> <p>With this it is automatically added to the json output</p>

|alexa|amazon-echo|

How to create a home card in Alexa

1766

<p>I'm trying to develop my first skill and I do not find proper information on how to create a home card </p> <p><a href="https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/providing-home-cards-for-the-amazon-alexa-app#creating-a-basic-home-card-to-display-text" rel="noreferrer">https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/providing-home-cards-for-the-amazon-alexa-app#creating-a-basic-home-card-to-display-text</a></p> <p>says I had to add it to the JSON response, I do not understand where exactly the JSON response is?</p> <p>Any help is much appreciated.</p>

2017-07-06T12:55:59.843

<p>There are several ways that you can create a modified distro, and the best approach will depend on your environment and how you anticipate that evolving over time.</p> <ul> <li><p><strong>Yocto</strong> is good if you need to apply some patches and build your own custom kernel/distribution. It seems like you are not working at this level.</p></li> <li><p><strong>Package Managers</strong> would be good if you want to be able to pull in your application to existing systems</p></li> <li><p><strong>On Device Scripts</strong> is effectively the same effect as a package manager will provide, just not as clean.</p></li> <li><p><strong>Configure and Clone</strong> Set-up a single SBC, un-mount the root partition and re-package it to copy onto all targets. This is (crudely) how people often make ROMs for phones and the like. You need to remember to reset any files which control the startup scripts.</p></li> <li><p><strong>Unpack and modify</strong> You might chose to download an existing distro, modify it using scripts, and package. This could be good if you plan to support updates to the underlying distro with minimal work.</p></li> </ul> <p>In your case, it sounds like you probably want to take one board, perform the customisation, shut-down, and clone the uSD card as many times as necessary. If you have per-device customisation, maybe a 'run-once' script can handle the uniquification by an interaction with a server.</p> <p>Deciding which of these is best will depend on your production scale and how long you plan on doing this work. Does it need to scale to next year's distro, new hardware, new platforms? Will the payloads need to auto-update, and how will you cope with keeping the base OS patched?</p> <p>As an example of how a custom image can be built, you could look at this Raspian image generator: <a href="https://github.com/davidferguson/pibakery" rel="nofollow noreferrer">PiBakery</a> or any others that google will offer.</p>

|linux|software|

Which tools/frameworks do you use to configure an array of SBCs

1768

<p><strong>Use case:</strong></p> <ol> <li><p>I have a lot of <a href="http://www.compulab.co.il/utilite-computer/web/utilite2-overview" rel="nofollow noreferrer">Utilite2</a> single board computers to configure</p></li> <li><p>On each device I installed Linaro (Ubuntu-based), booted from MicroSD card. Linaro is recommended OS for Utilite2</p></li> <li><p>On each device I have to do a lot of manual steps (all of them from command line):</p> <ul> <li>Change default passwords</li> <li>Change hostname</li> <li>Edit resolv.conf file</li> <li>Install some required packages</li> <li>Set the specific timezone</li> <li>Download few bigger files from the Internet (wget)</li> <li>Edit PATH variable</li> <li>Configure static IP address</li> </ul></li> </ol> <p>I would like to automate whole manual work described in point no. 3. I can write a bash script which will do it for me, but I would like to ask you: is there any better way than scripting it?</p> <p>When you work with web-apps on server side, you probably use tools like <a href="https://www.chef.io/" rel="nofollow noreferrer">Chef</a> or CloudFormation templates, to setup servers and clusters. You don't configure each server manually. This approach has another big advantage - you can keep your configuration as code and reuse it for each server. I need to understand how to do this for physical hardware.</p> <p>When it comes to IoT, most resources and presentations which I found focus on the big picture. They show how devices "talk" to each other and how system's architecture looks like. But we can not forget that before each device is in the system, it needs to be configured somehow.</p> <p>From my point of view (beginner in IoT) there are following options to achieve this:</p> <ul> <li>Configure each device manually - this solution is not efficient one, so to speak...</li> <li>Run parametrized setup script on each device - scripts written in bash or python </li> <li>Create pre-configured OS image or distro - @sob in his answer mentioned Yocto, so thanks for that - I didn't know it.</li> <li>Create a package with configuration and install it on each device - <a href="http://www.yadt-project.org/" rel="nofollow noreferrer">Yadt</a> works like that</li> <li>Use some kind of tools like Chef, but IoT-specific - I don't know any of them and I'm wondering if you know any.</li> </ul>

2017-07-08T19:53:25.307

<p><strong>Stage 1:</strong></p> <p>PC side peripherals, specially input devices like mouse, scanner, keyboard are equivalents to sensors. Relevant is the correct pins, correct protocols and signal forms etc.</p> <p><strong>Stage 2:</strong></p> <p>Bus between internal parts of PC and between processor and outer devices equals data acquisition and networking.</p> <p><strong>Stage 3:</strong></p> <p>Edge processing is equal to sound card or video processor on screen. Same kind of externalization of tasks from the main CPU.</p> <p><strong>Stage 4:</strong></p> <p>CPU is the cloud of computer.</p>

|hardware|system-architecture|software|

Drawing parallels between building an IoT system and building a PC?

1775

<p>I am reviewing potential candidates for IoT position. The position in a industrial factory setting requires the candidate to contribute to the 4 stages of an IoT infrastructure as defined in the article: <a href="https://techbeacon.com/4-stages-iot-architecture" rel="noreferrer">How to design an IoT ready-infrastructure:The 4-stage architecture </a></p> <p><a href="https://i.stack.imgur.com/DzxcQ.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/DzxcQ.jpg" alt="4-stage architecture"></a></p> <p>Since IoT is a relatively new field, some of the candidates only talk about what they learned from building PCs. For example candidate A <strong>learned</strong> from building <em>audio workstations</em>: </p> <blockquote> <p>Faster processors with more cache are preferable to higher core counts which can adversely affect system performance. Chipsets handles all aspects of the communications between system components: low latencies and high data throughput for hard disks and audio/DSP cards make chipset/motherboard choices paramount. Maximizing data throughput with higher HD rotational speeds or employing a separation-of-concerns HD partitioning strategy positively affect system performance; as does the HD cache size. RAM size is directly proportional to system performance. The audio card’s driver-ASIO compatible-is a vital component to attain low latency. Graphics cards need to support OpenGL 2.0 or higher. 64-bit OS is preferred.</p> </blockquote> <p>Essentially I am trying to derive IoT qualifications for this architecture from a PC building skill set.</p> <p>It seems obvious that stage 3 is where the candidates could have an impact —given the quote — but are there opportunities in stages 1,2,4 where the candidate could contribute using solely the experiences listed above? </p> <p>Where would I draw direct lines from the experiential statements to the implied tasks in the 4-stage architecture?</p>

2017-06-29T14:04:07.987

<p>I think that <a href="https://www.particle.io/products/hardware/electron-cellular-dev-kit" rel="nofollow noreferrer">Electron</a> by Particle may be something what you are looking for. Electron allows you to build device that can connect to 2G or 3G mobile wireless network.</p> <p>In one of the previous comments you mentioned that your data usage probably will not exceed a megabyte of data per month. With Electron you are charged monthly for the base rate which is <a href="https://www.particle.io/pricing#cellular-data" rel="nofollow noreferrer">$2.99 (includes first megabyte) and then $0.99 per any additional MB</a>.</p> <p>From technical point of view, Electron is connected to Particle's cloud and exchanges messages with it. Then you can control Electron through your web-app by sending HTTP requests from your web-app to Particle's cloud. Electron has GPIO pins (also for Serial/UART communication) so depends on your needs you can connect it with your Raspberry Pi - for more information go <a href="https://docs.particle.io/datasheets/electron-datasheet/" rel="nofollow noreferrer">here</a>.</p> <p>In a general scenario communication between you and Electron should look like that:</p> <ol> <li>write a function which handles command on Electron:</li> </ol> <pre class="lang-c prettyprint-override"><code>int callRaspberry(String command) { //handle communication here } </code></pre> <ol start="2"> <li>register previous function during setup:</li> </ol> <pre class="lang-c prettyprint-override"><code>void setup() { Particle.function(&quot;callRaspberry&quot;,callRaspberry); } </code></pre> <ol start="3"> <li>make a request to Particle's cloud, to call the function on Electron:</li> </ol> <pre class="lang-bash prettyprint-override"><code>curl https://api.particle.io/v1/devices/&lt;DEVICE_ID&gt;/callRaspberry \ -d access_token=&lt;YOUR_ACCESS_TOKEN&gt; \ -d arg=&lt;COMMAND_VALUE&gt; </code></pre> <p>More code examples can be found <a href="https://docs.particle.io/guide/getting-started/examples/electron/" rel="nofollow noreferrer">here</a>.</p> <p>I've also seen that <a href="https://hologram.io" rel="nofollow noreferrer">Hologram</a> provides similar devices to Electron and their service price is also cheaper. You can find some comparison <a href="https://community.hologram.io/t/how-do-you-compare-vs-the-particle-electron/320" rel="nofollow noreferrer">here</a>.</p>

|networking|

Connecting your Pi to the internet when mobile

1783

<p>So I am working on a project where I have torn away all the RC related parts of an older 1/10 scale Racing Buggy I had as a kid and replacing said parts with some Arduinos and a GPS to create a super rudimentary autonomous vehicle. I want to add in the Raspberry Pi Zero W as an on board base station for data logging and network control through a web app I'll design later on with my server.</p> <p>My concern is that short of getting some kind of data-box from Verizon or AT&amp;T and paying a terribly large monthly bill on a contract I don't want, I'm not sure of any other cheap options.</p> <p>So what options do I have available to get the Pi on the cellular network that won't cost me an arm and a leg?</p>

2017-07-10T17:54:36.887

<p>The presence of a commercial product which has reviews of varying quality should be a good sign that building something like this from scratch is a non-trivial undertaking. Doing IoT well is hard.</p> <p>Doing it yourself brings some advantages - you can tune the installation for a specific location, implement your own configuration strategy (most likely cli based), associate with just your home router, etc.</p> <p>There is no clear answer to which approach is better. Why are you doing this, what skills you you have already, what are you prepared to learn, is security important or can you rely on an ad-hoc implementation providing security through obscurity?</p> <p>Start by defining your requirements. <strong>Lighting, Motion detection, video capture</strong>. Look at the commercial product you rejected, and decide which aspects of it you need to improve on (this is subjective).</p> <p>List out some alternative implementations. This could be:</p> <ul> <li>MCU on each node, handling each aspect with network connection between them</li> <li>Raspberry Pi as a central controller with each part connected through (long?) wires.</li> <li>Commercial camera, commercial motion detection</li> <li>Commercial camera, MCU for motion detection</li> </ul> <p>Trade off the time/cost/performance of these options, and go with whichever <em>you</em> prefer. You might find that some of the more low-level approaches are harder but are better documented (since the off-the-shelf components are unlikely to be documented, and will rarely be designed with extensions in mind).</p> <p>Fundamentally, any working commercial product which satisfies your spec (even if it's got some flaws), will be far easier. Far more research is needed.</p>

|amazon-echo|digital-cameras|lighting|surveillance-cameras|

Ring Floodlight - Simple alternative by combining camera and floodlight?

1786

<p>The Ring Floodlight looked pretty nice, until FakeSpot warned that most of the positive reviews seem to be bogus, so I've decided to not pursue the commercial product and try to figure out how to get the same functionality otherwise.</p> <p>Is there a smart motion detection flood light that could IFTTT trigger a camera to start recording?</p> <p>Or would it be better to keep them separate? For example a night vision motion detecting camera doing its thing, and a separate dumb motion detecting flood light that just turns on when someone walks past?</p> <p>(Have just an Amazon Echo but don't think this helps me much).</p> <p>Ring Camera and Flood Light: <a href="http://rads.stackoverflow.com/amzn/click/B0722R3WV5" rel="nofollow noreferrer">https://amazon.com/Ring-Floodlight-Camera-Motion-Activated-Security/dp/B0722R3WV5</a></p> <p>FakeSpot Analysis: <a href="http://fakespot.com/product/ring-floodlight-camera-motion-activated-hd-security-cam-with-floodlights-two-way-talk-and-siren-alarm-black" rel="nofollow noreferrer">http://fakespot.com/product/ring-floodlight-camera-motion-activated-hd-security-cam-with-floodlights-two-way-talk-and-siren-alarm-black</a></p>

2017-07-11T10:24:21.623

<p>In 2024, Alexa asks for more than wake words.</p> <ul> <li>My son an I had accounts linked to it. After using it for a few months, all of a sudden it chimed up and asked me which one I was and then asked me to say a few things so that it could tell us apart.</li> <li>I also asked it to recognise my wife's voice even though she doesn't have an account.</li> </ul> <p>One of the ways to retrain it is</p> <ul> <li>Open Alex App</li> <li>Press on <code>More</code></li> <li>Press on <code>Settings</code></li> <li>Press on <code>Your Profile &amp; Family</code></li> <li>Press on <code>Voice ID</code></li> <li>Press on <code>Delete Voice ID</code></li> <li>Set it up again.</li> </ul>

|google-home|google-assistant|voice-recognition|smart-assistants|

Is it possible to train the "Google Home" device for different styles of pronunciation?

1788

<p>My English pronunciation and accent is different from how American or British English is spoken. I suspect this is contributing to misses for the <em>Google Home</em> device.</p> <p>Is there a way that I can train the <em>Google home</em> device generally or specifically for the words that I know it has tendency to miss?</p>

2017-07-12T12:49:07.070

<p>No, because there is no information about who published the message included in the message header, only the topic and any retained flags.</p> <p>The bridge between the 2 brokers is exactly the same sort of connection as between the a normal client and the broker, it looks to the remote broker just like any other client connection.</p>

|mqtt|mosquitto|

Traffic Shaping and MQTT

1794

<p>There are two MQTT Brokers, the connection between them should enable traffic shaping. Broker A has multiple clients who publish data, Broker B has multiple subscriptions.</p> <p>Is there a possibility to enable traffic shaping on the connection to ensure that very publisher hast a minimum of granted bandwidth on the connection to broker B?</p> <p>This scenario is implemented using the Mosquitto MQTT broker with the broker-bridge feature to ensure every MQTT message will be send only once over the connection between broker A and B.</p>

2017-07-13T15:26:08.500

<p>Quite a biased article about IoT and energy saving.</p> <p>From article:</p> <blockquote> <p>the addition of ceiling fans meant that the company could increase the canteen thermostat from 24.5°C to around 26°C and the feedback from diners remained positive.</p> </blockquote> <p>They knew they can set the target temperature of cooler machine to higher (warmer) value when they adjusted the system using user feedback and IoT system data and algorithms. Using less effort on pushing cool air they saved money. Instead they used more fans.</p> <p>Putting more fans, less cooling power and collecting feedback would have worked without IoT by wise guessing, but IoT proved its use on desicion making once again.</p> <p>Why did I say biased? </p> <p>By using IoT once a short period they came up an idea to save energy, nobody told adjusting temperature with IoT technology would save more than keeping fans all time on, at least nothing in that direction was said.</p>

|hvac|

How does the IoT reduce Bosch cooling costs?

1799

<p>I read <a href="https://internetofbusiness.com/bosch-canteen-singapore-iot-control-aircon/" rel="nofollow noreferrer">an article</a> recently from InternetOfBusiness.com which outlines how Bosch has been implementing remote controlling of their A/C systems. One thing, however, I fail to see in the article, and that is how <em>the IoT aspect <strong>in particular</strong></em> helps save energy. The article says,</p> <blockquote> <p>The engineers also set up a feedback panel at the canteen entrance to see if the IoT system was working; users could rate whether the temperature was too cold or hot for their liking.</p> <p>“Since we wanted to create a better experience for diners and lower energy consumption, we needed to check they were happy with the result.” He said.</p> <p>He added that results back from the system and the addition of ceiling fans meant that the company could increase the canteen thermostat from 24.5°C to around 26°C and the feedback from diners remained positive.</p> <p>“This temperature change almost halved the canteen’s cooling demands. We estimate that this will not only save around 4,000 Singapore dollars annually but reduce carbon dioxide emissions by more than eight tonnes,” said Staudacher.</p> </blockquote> <p>How does the IoT make the air conditioning any more efficient? Is it just that the people in the building can adjust it themselves, making the temperature not get as cold, consequently saving on energy, or what?</p>

2017-07-17T14:49:06.780

<p>I see at least 3 choices to make in your system design.</p> <p><strong>RF Protocol</strong> WiFi is not very energy efficient. You can mitigate this by only <em>sending</em> readings infrequently (measure at 1 min, transmit at 20 min). BLE or similar might be better, but you need to trade range and parts cost if you opt for something a little less commodity. If its personal domestic use, much over 2 years is probably not worth much extra optimisation.</p> <p><strong>Inside Unit</strong> You probably have different power constraints for this unit, but you don't specify. Critically, it doesn't need to be the same platform as the outdoor unit, but it doesn't sound like you <em>need</em> an SBC running linux here. How you want to develop your stack is maybe the driving factor here (as well as familiarity).</p> <p><strong>Outdoor Unit</strong> Currently you have a low feature requirement - just a digital interface to your thermometer. You might want a resolution of 0.25 °C or better to allow some scope in how you use it. Certainly you need a sleep mode, but the choice is quite wide. Development environment and ease of use might be as important a factor as price. You have no compute payload worth worrying about over the communication protocol, so a low clock frequency makes sense.</p> <p>Other factors you might want to consider are how likely you are to expand this in the future, this might affect your choice of board (for example if you want to add a display/control unit indoors).</p> <p>It's fairly clear that the only important choice here is that the outdoor/battery unit should be a micro-controller with sleep (and RF), rather than a full linux platform. Newer platforms are likely to offer better energy efficiency, but might be sufficiently expensive as to offset the benefit in this use case.</p>

|raspberry-pi|

Which IoT platform should I use for low-energy temperature sensors to be powered by battery?

1812

<p>I'd like to setup two temperature detectors: one outside and one inside my house, in order to compare temperature and act on the difference (opening/closing the window for example).</p> <p>The issue I'm facing is which platform to take. My initial thought was to go with the <a href="https://store.particle.io/collections/photon" rel="noreferrer">Photon</a>, but the price is quite high when I can go for a Raspberry Pi Zero for way much. On the other hand, the Pi Zero requires a lot of power, and since I plan to place one sensor outside, I was hoping to "place it and forget it" at least for a few months, with some AA batteries (one? two?) on it.</p> <p>So I'm asking for your help. I'm open to other platform to implement my plan. Here's what I'm looking for in this platform:</p> <ol> <li>Wi-Fi capable (or some transmission for the outside remove, and Wi-Fi for the inside)</li> <li>Can live weeks, months using simple AAs</li> <li>Not expensive. It's just a small side project.</li> </ol>

2017-07-19T01:05:34.097

<p>AFAIK you cannot do that. Thinking of Bluetooth as a quite complex protocol of approximately 1k pages of documentation the power electronics to build such circuit would be overly sized. </p> <p>Think of your PC, it inputs 110 or 220 and still there is the power unit that lowers the voltage to low DC as in every micro circuit you see nowadays. </p>

|smart-home|bluetooth|

Bluetooth chipset high voltage

1819

<p>I understand we usually use relay to do controlled switch, but I'm wondering if the Bluetooth protocol could work on high voltage I mean 110-220v. So is it theoretically possible to design a Bluetooth chipset running directly on such voltage? If yes what are the cons not to do it ? From my little knowledge, I guess it's mainly consumption problems.</p> <p>Hope I'm clear enough; thanks for any input.</p>

2017-07-19T22:06:42.440

<p>Google Home can be set Up and used in other countries. This <a href="https://beebom.com/how-set-up-use-google-home-outside-us/" rel="nofollow noreferrer">Beebom article</a> provides a step-by-step guide of doing so.</p> <p>During setup you'll see popup:</p> <blockquote> <p>You may see a warning telling you that the Google Home was manufactured for a different country, and may not work with your WiFi network.</p> </blockquote> <p><strong>"May not work with your WiFi network"</strong> could happen if your 2.4 GHz WiFi router is set to use one of the channels beyond channel-11, so that is one aspect.</p> <p>Now coming to services, users have reported on forums that music services like Pandora, Youtube Red and Spotify do not work for them. But, that is due to these services not being geographically supported in all countries.</p> <p>I guess maximum number of services may be blocked in China due to government policies. Even searches may be affected.</p>

|google-home|

Can I use Google Home in countries where it is not officially available?

1828

<p>I want to know if it works in countries where it's not sold. It's the same Internet, so it should work. Right?</p>

2017-07-26T19:33:26.967

<p>A Raspberry Pi 3 is a pretty serious bit of kit when you think about it</p> <ul> <li>Quad core Arm Cortex</li> <li>1gb of RAM </li> <li>a onboard GPU</li> </ul> <p>That is a huge amount of memory, easily more than enough to run a MQTT broker and something like Node-RED to interface between a LoRa radio and the broker.</p> <p>We have a commercial gateway (MultiTech MultiConnect Conduit) in the office which is a very similarly <a href="https://www.multitech.com/documents/publications/data-sheets/86002170.pdf" rel="noreferrer">spec</a>'d bit of kit and if you google loRawan gateway most of the first page is all about how to build one with a pi.</p>

|mqtt|hardware|raspberry-pi|lorawan|

Would RPI 3 serve as IoT server with MQTT?

1858

<p>I answered to the below linked question and started to think, what are the hardware specs for running an IoT stack of for example MQTT over LoraWan? Would Raspberry PI 3 survive or not?</p> <p>I do not care how RPI connects LoraWan, mainly about RAM and storage use. </p> <p><a href="https://iot.stackexchange.com/questions/388/how-to-select-simple-light-weight-iot-server-for-development/1856#1856">How to select simple light weight IoT server for development?</a></p>

2017-07-29T05:44:21.993

<p>There are 4 standard SDA ratings that I'm aware of: 2, 4, 6, and 10. Basically, the number corresponds to the minimum write speed in MB/s that the card is capable. So for instance, a Class 4 would have a minimum write speed of 4 MB/s, whereas a Class 10 would have a minimum write speed of 10 MB/s.</p> <p>As Helmar mentioned, this means that the Class 4 will be slower. If you're running well under the 4 MB/s limit, however, as Helmar said, you could be better with the Class 4. <em>That being said,</em> if you're running close to the 4 MB/s limit, one problem I have had when videotaping to SD cards is that the card will start heating up, which can cause damage to the card. Frequently, upgrading the card will resolve that issue.</p>

|microcontrollers|linux|microsoft-windows-iot|intel-galileo|

What will happen if I use Class 4 SD card, instead of recommended Class 10 for Intel Galileo?

1874

<p>I could not find any relevant information on this, sites just recommended class 10. I want to know if it is okay to use Class 4, 8 GB SD card, for making a bootable Linux drive for Intel Galileo, or even installing Windows. Are there any consequences of doing so?</p>

2017-08-06T11:55:17.473

<p>IF you would like to located indooer, rfid and bluetooth would be best choice. It has UHF and HF for rfid requency, respectively 860-960MHz and 13.56Mhz. And UHF divided into 902-928 MHz(USA) 865-868 MHz(EU). The passive rfid is better option than active if space not too big. I would recommend the <a href="https://www.seikorfid.com" rel="nofollow noreferrer">SEIKO RFID</a> for you, you will find more required information from the site.</p>

|wireless|rfid|tracking-devices|

Wireless communication technologies for indoor location-tracking

1891

<p>I need to develop a solution for determining whether an object/tag exists within a defined perimeter. The perimeter would be located indoors so GPS isn't an option. It would be an approx 10 metres x 10 metres rectangle. The 'tag' needs to fit in a person's pocket (however it could be battery powered), and I would need to know:</p> <ol> <li>When the tag leaves the perimeter (doesn't have to be exact and I don't care where it is located within the perimeter)</li> <li>Identify the tag left the perimeter (as there will be 10-20 objects in the perimeter that need to be tracked)</li> </ol> <p>Would an active RFID system be the way forward? I'm thinking that I'd need 3-4 receivers spaced around the perimeter so that I can combine the readings from them to estimate the position.</p> <p>Really appreciate any advice or suggestions.</p>

2017-08-07T15:00:18.663

<p>Maybe the following links can help you:</p> <p><strong>Basic client example:</strong> <a href="https://docs.python.org/2/library/asyncore.html#asyncore-example-basic-http-client" rel="nofollow noreferrer">https://docs.python.org/2/library/asyncore.html#asyncore-example-basic-http-client</a></p> <p><strong>Basic echo server example:</strong> <a href="https://docs.python.org/2/library/asyncore.html#asyncore-example-basic-echo-server" rel="nofollow noreferrer">https://docs.python.org/2/library/asyncore.html#asyncore-example-basic-echo-server</a></p> <p>Also, have you thought about using UDP protocol? it may be better...</p> <p>And I would advice about HTTP/1.0, as far as I know, is not mandatory in its implementation, to keep connections alive, that was defined in HTTP/1.1; anyway it depends on the implementation, it can have or it can't.</p> <hr> <pre class="lang-py prettyprint-override"><code>import asyncore, socket class HTTPClient(asyncore.dispatcher): def __init__(self, host, path): asyncore.dispatcher.__init__(self) self.create_socket(socket.AF_INET, socket.SOCK_STREAM) self.connect( (host, 80) ) self.buffer = 'GET %s HTTP/1.0\r\n\r\n' % path def handle_connect(self): pass def handle_close(self): self.close() def handle_read(self): print self.recv(8192) def writable(self): return (len(self.buffer) &gt; 0) def handle_write(self): sent = self.send(self.buffer) self.buffer = self.buffer[sent:] client = HTTPClient('www.python.org', '/') asyncore.loop() </code></pre> <hr> <pre class="lang-py prettyprint-override"><code>import asyncore import socket class EchoHandler(asyncore.dispatcher_with_send): def handle_read(self): data = self.recv(8192) if data: self.send(data) class EchoServer(asyncore.dispatcher): def __init__(self, host, port): asyncore.dispatcher.__init__(self) self.create_socket(socket.AF_INET, socket.SOCK_STREAM) self.set_reuse_addr() self.bind((host, port)) self.listen(5) def handle_accept(self): pair = self.accept() if pair is not None: sock, addr = pair print 'Incoming connection from %s' % repr(addr) handler = EchoHandler(sock) server = EchoServer('localhost', 8080) asyncore.loop() </code></pre>

|networking|wireless|software|

Creating an HTTP GET polling service on a Raspberry Pi Client

1897

<p>I have the following hardware:</p> <ol> <li><p>3 x <a href="https://store.particle.io/#photon" rel="nofollow noreferrer">Particle Photons</a>. Each serve as an HTTP Server</p> </li> <li><p>1 x <strong>Raspberry Pi 3</strong> which will serve as an HTTP Client</p> </li> </ol> <p>Upon requesting an <strong>HTTP GET</strong> to any of the the Photons, the API returns:</p> <pre class="lang-json prettyprint-override"><code>{ node: 1, uptime: 1234556, location: 'back', sensor: { Eu: {// Euler Angles from IMU h: 0, p: 0, r: 0 }, La: {// linear Acceleration values from IMU x: 0, y: 0, z: 0 } } } </code></pre> <p>I want to create a Polling scheme where the Raspberry Pi client performs an HTTP GET every <strong>0.1 Second</strong> on each of the the 3 Servers.</p> <p>I am not sure whether there is something like <em>HTTP Polling</em> and whether <em>Asynchronous</em> Libraries like <a href="https://twistedmatrix.com" rel="nofollow noreferrer">Twisted by Python</a> should be the one to be used.</p> <p>I would like to gain some advice on how will a <strong>Multiple Server - Single Client</strong> model would function w.r.t. HTTP?</p> <h3>Reference</h3> <p>Each Particle Photon has the above mentioned <strong>JSON</strong> response to a HTTP GET Request.</p> <p>The Raspberry Pi would serve as an HTTP Client, trying to get requests from each and every Particle Photons. <a href="https://i.stack.imgur.com/vnw4g.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vnw4g.png" alt="component picture with the Pi and three photons and direction of rest calls" /></a></p>

2017-08-07T23:15:51.360

<p>It sounds like you should be looking for a complete IoT device management platform - there are too many complicated aspects of scalability, security, provisioning and firmware update for this to be a sensible thing to try and develop in house from scratch. Make sure you pick a platform which uses open standards.</p> <p>To answer your question more directly, each endpoint generally opens a TLS secured connection to a cloud server (using something like CoAP, LWM2M or MQTT depending on the purpose of the connection), so connections are almost always initiated from the endpoint. Only with IPv6 or particularly specicfic use cases are you likely to have the cloud initiating the connection without any assistance from the endpoint.</p>

|remote-access|

Remote access for multiple IoT project units

1901

<p>We are in the early stages of planning an IoT project.</p> <p>One issue we are struggling with is how our Internet based server can access each unit of our IoT project and deploy code updates, messages ... etc.</p> <p>I'm concerned about this because, of course, each IoT unit is within it's own WiFi network which is closed by design. </p> <p><strong>How does our server, an essential part of our setup, call all it's 'children' within their respective closed networks?</strong></p>

2017-08-09T18:54:31.590

<p><strong>No, CoAP is an application layer protocol it's not dependent</strong></p> <p>Basically that's the beauty behind the OSI layers. If correctly implemented you can mostly stack them however you want. As with every thing that starts with <em>if correctly implemented</em> that's mostly academic and some protocols fit better together with others than others do. More or less the only restriction is to be able to transfer the data of an upper layer with the lower level protocol.</p> <p>In the case of CoAP it runs great on UDP which is kind of the intended protocol on the next lower OSI level, the transport level. </p> <blockquote> <p>Instead of a complex transport stack, it gets by with UDP on IP. — <a href="http://coap.technology/" rel="noreferrer">CoAP Website</a></p> </blockquote> <p>From our daily Wi-Fi / smart phone experience we all know that IP runs great on 802.11 &amp; LTE/5G.</p> <p>Bluetooth and it's low energy variant however are actually protocol stacks that go up to the presentation layer. I'm not sure how good the match of CoAP is there directly. It may be easy, but I just don't now.</p> <p>However with Bluetooth 4.2 they included the IPSP. Basically allowing you to tunnel IPv6 over Bluetooth enabling you to use the <em>standard internet protocol suite</em> from thereon upwards.</p> <blockquote> <p>The Internet Protocol Support Profile (IPSP) allows devices to discover and communicate to other devices that support IPSP. The communication between the devices that support IPSP is done using IPv6 packets over the Bluetooth Low Energy transport. — <em>Bluetooth 4.2 Specification</em></p> </blockquote>

|networking|wifi|protocols|bluetooth|coap|

Does CoAP depend on IEEE 802.15.4?

1908

<p>In the CoAP specification, it is implied that IEEE 802.15.4 can be used in conjunction with CoAP. Is this a requirement or can CoAP also be used with other OSI layer 1, 2 protocols such as IEEE 802.11, BLE or LTE/5G/etc?</p>

2017-08-11T01:03:21.387

<p><strong>EDIT</strong>: Since having a physical remote seems to be a must, you can check the <a href="https://www.itead.cc/wiki/Sonoff_RF" rel="nofollow noreferrer">Sonoff RF</a> that uses a remote to turn the lights on and off. But, RF are low security and does poor filtering of bad signals, so, it might be attacked. I'll go with wifi if possibe.</p> <p>First of all, I don't have any partnership with this brand, just sharing my experience as a maker and electronics enthusiastic.</p> <p>I have a couple of sonoff s20 at my place. It cost me about 12€ a month ago (buying in China), but you can find it up to 20$.</p> <p>It came with an app that works pretty well. You can set up scenes and it haves ifttt integration. The phone (android or ios) doesn't need to be on the same network as the sonoff to work.</p> <p>Also, the sonoff s20 it's easy to hack and it's possible to replace the firmware with a custom one.</p> <p>It's a nice way to get started with home automation.</p>

|lighting|

What is the easiest to install smart switch that has a remote control?

1910

<p>I want to install a light switch at my church that has a remote control. Similar to the <a href="http://www.lutron.com/en-US/Products/Pages/SingleRoomControls/CasetaWireless/Overview.aspx" rel="nofollow noreferrer">Lutron Caseta</a>. The only requirement is that it has a remote control. Prefer <strong>not</strong> to have a dimmer. I would like to have as few accessories as possible. Are there any solutions that have the switch, the remote and nothing else (i.e. a hub etc)?</p> <p>I was thinking about Z-Wave or Wi-Fi, but it doesn't matter, as long as it's reliable and easy to use.</p>