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iot.stackexchange.com

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2016-12-06T17:13:40.417

<p>Honestly, not much really - only the price difference to become a member, better advertising and more power in the organization.</p> <p><a href="https://openconnectivity.org/wp-content/uploads/2016/06/OCF-Diamond-Platinum-Gold-Membership-Agreement-Amended06062016.pdf" rel="noreferrer">The corresponding form to become a member</a> is here. They all must follow the bylaws shown <a href="https://openconnectivity.org/wp-content/uploads/2016/03/Sixth-Amended-Bylaws-Open-Connectivity-Foundation_03142016.pdf" rel="noreferrer">here</a>. </p> <blockquote> <p>SECTION 14.1 DIAMOND MEMBERS</p> <ol> <li>The Corporation shall have Diamond Members. Any applicant qualified under Section 12.2 wishing to become a Diamond Member after the Organizational Meeting must be approved via 3/4 vote of all current Directors appointed by Diamond Members with such vote occurring via electronic means. Following an affirmative vote of the Diamond Members, an applicant for Diamond Membership shall be admitted to membership upon execution of a Diamond membership agreement.</li> <li>Diamond Members who remain in good standing shall be: a. Perpetually eligible to appoint a representative to the Board of Directors of the Corporation in accordance with these Bylaws; b. Eligible to have a representative appointed or elected as an officer of the Corporation; c. Eligible to participate in the Work Groups of the Corporation and have a representative chair the same; and d. Subject to procedures and requirements as may be adopted by the Corporation, eligible to seek certification of the Member’s products and/or services and use the Corporation’s trademarks in connection with the Member’s certified products or services.</li> <li>Diamond Members may be downgraded to Platinum Members (or at their option Gold Members) upon unanimous vote of all Directors appointed by Diamond Members, less one (1), when such Directors determine, after affording the Diamond Member in question the right to be heard on the issue, that the Diamond Member has failed to actively contribute to the work of the Corporation. </li> </ol> <p>SECTION 14.2 PLATINUM MEMBERS</p> <ol> <li>The Corporation shall have Platinum Members. Any applicant qualified under Section 12.2 wishing to become a Platinum Member shall be admitted to membership upon its execution of the appropriate Membership Agreement.</li> <li><p>Platinum Members who remain in good standing shall be: </p> <ul> <li><p>Eligible to have a representative elected to the Board of Directors in accordance with these Bylaws; </p></li> <li><p>Eligible to have a representative appointed or elected as an officer of the Corporation; PAGE - 21 BYLAWS OF OPEN CONNECTIVITY FOUNDATION, INC. PDX\127875\200109\TFH\17626740.1 </p></li> <li><p>Eligible to participate in the Work Groups of the Corporation and have a representative chair the same; and </p></li> <li>Subject to procedures and requirements as may be adopted by the Corporation, eligible to seek certification of the Member’s products and/or services and use the Corporation’s trademarks in connection with the Member’s certified products or services. SECTION</li> </ul></li> </ol> <p>14.3 GOLD MEMBERS</p> <ol> <li>The Corporation shall have Gold Members. Any applicant qualified under Section 12.2 shall be admitted to membership upon its execution of the appropriate Membership Agreement.</li> <li>Gold Members who remain in good standing shall be: a. Eligible to participate in the Work Groups of the Corporation in a non-voting capacity; and b. Subject to procedures and requirements as may be adopted by the Corporation, eligible to seek certification of the Member’s products and/or services and use the Corporation’s trademarks in connection with the Member’s certified products or services.</li> <li>The Corporation may also have Nonprofit/Educational Gold Members. Any entity who qualifies as a nonprofit or educational entity under the laws and regulations of its domicile jurisdiction may apply for Membership as a Nonprofit/Educational Gold Member. The Board of Directors shall review any and all applications for such level of Membership and may, in their sole discretion, accept such application upon a determination that the applicant meets the requirements for this membership subset. a. Noprofit/Educational Members who remain in good standing shall be entitled to all Membership benefits of Gold Members; provided, however, that Nonprofit/Educational Membership benefits (including but not limited to rights under the IPR Policy and the right to receive or review Confidential Information) shall not extend beyond employees of the nonprofit or educational entity. For avoidance of doubt, it is expressly understood that membership rights and benefits do not extend to members or participants in nonprofit entities, their employees or contractors, or to governmental entities other than the educational entity applicant.</li> </ol> </blockquote> <p>It's a lot to process, but pretty much any member must comply with their guideline for devices, but as you go up you get more power to influence what the guidelines of the OCF are.</p> <p>Other than that, between Gold and Platinum, they seem to bump up how much space you get on the membership list.</p>

|ocf|

What are the differences of the Open Connectivity Foundation membership levels?

2

<p>Can someone explain to me the differences between <a href="https://openconnectivity.org/about/membership-list" rel="noreferrer">Diamond, Platinum and Gold membership</a> at the OCF?</p>

2016-12-06T17:51:21.647

<p>Apparently Smart things uses <a href="https://www.smartthings.com/works-with-smartthings" rel="nofollow noreferrer">Z-Wave protocol among others like Philips Hue.</a></p> <p>Maybe you should add your devices near the SmartThings hub for it to recognize them to check if they are compatible.</p> <p>However, be aware of distance, Z-Wave devices tend to always "sleep" and escape the network.</p>

|smart-home|wireless|samsung-smartthings|

Adding Devices to Samsung SmartThings

7

<p>I've got the Samsung SmartThings system installed in my house, but I've encountered a few situations where a new device (e.g. an in-wall outlet) couldn't be found through the SmartThings App on my Android phone. A temporary fix for me was to move one of my plug-in outlets about halfway to serve as a "bridge" between the SmartThings Hub and the new outlet.</p> <p>My question is if there is an alternate way of adding new objects to my smart home? For instance my phone? Alternatively, what wireless technology (e.g. ZigBee, Z-Wave, Bluetooth) is needed to complete these links?</p>

2016-12-06T18:02:11.623

<p>SSH is a reasonable starting point, its essential that you use TLS encryption, and using putty for ssh access is one way to achieve this. A VPN is another. What is really important is that you use strong pasphrases or keys to access the devices within your network, and that you keep the gateway devices up-to-date. </p> <p>Using a non-standard port is kind of sensible, but does nothing to secure your network if you leave your device with a default (or common) password.</p> <p>If you want remote access, you need a port open to forward SSH (or something very similar). If you don't trust the security implementation on the camera (i.e. it's last firmware update was over about 6 months ago), then you need to use a VPN to create an isolated network segment for it. If it has WiFi, and old firmware, it might as well be wide open and public (at least for anyone in physical proximity).</p>

|smart-home|security|raspberry-pi|

What are the best security practices to secure a remote IoT camera?

14

<p>I have done a bit of home automation such as building a remote camera that can be turned on via SSH locally and publishes images on a Raspberry Pi run Linux server.</p> <p>I'm curious, though, as to what protocols are best followed when your security is behind a router. I've used things like Putty and opened ports so that I can tunnel in but I don't imagine these are the most secure methods.</p> <p>I'm wondering what protocols/tools are best used when accessing a home server system remotely. </p>

2016-12-06T18:06:08.170

<p>A little late. I installed one such switch on one of my gas fireplaces in 2017 using Fibaro Home Automation.</p> <p>There was no such regulation in New Zealand. Conditions may vary in other countries. But there are regulations about converting one over for automation.</p> <p>I wanted to do the same to the other gas fireplace which only had a wall switch for the fan. I enquired about converting this. Although the supplier had a kit to do this, he was not allowed to do it because it was for a different model / brand.</p>

|smart-home|wireless|safety|building-code|

Safety of a smart switch on a fireplace

17

<p>Would it be unsafe or considered "bad practice" to replace a gas fireplace switch with an IoT enabled smart switch?</p> <p>I would like to think there would be no issue, but, I want to make sure that it's not going to break any fire safety codes in my house. However, it would nice from a home automation perspective to turn it on as necessary, utilizing other sensors.</p>

2016-12-06T18:08:54.370

<p>If you can have end-to-end TCP, then use <strong>end-to-end TLS</strong> (e.g. with HTTPS).</p> <p>Don't reinvent the wheel, especially when it comes to cryptography — most people get it wrong. Unless the device is too resource-constrained to support TLS, if you get down to the level of AES, <a href="https://www.nccgroup.trust/us/about-us/newsroom-and-events/blog/2009/july/if-youre-typing-the-letters-a-e-s-into-your-code-youre-doing-it-wrong/" rel="noreferrer">you're doing it wrong</a>. #1 mistake is to encrypt and forget to authenticate — if you have an encrypted channel between your server and a man-in-the-middle, instead of an encrypted channel between your server and your device, then encryption hasn't provided any benefit. If you can't use TLS, make sure that whatever protocol you're using <strong>authenticates everything</strong>, and encrypts what needs to be confidential.</p> <p>To use TLS securely, think about what guarantees you need to have, from the point of view of each participant. Generally the device needs to know that it's talking to the legitimate server. That means that it must check the server's certificate. The device must have the X.509 certificate of a certificate authority recorded as trusted; this requires storage that can't be modified by an attacker, but it doesn't require any confidentiality of the storage. Note that you shouldn't hard-code the server's certificate directly, because that wouldn't let you easily replace that certificate if it's compromised. Instead, the device stores the expected <em>identity</em> (host name) of the server, and the certificate of a certificate authority that guarantees that a certain public key belongs to the expected host name. Once again, don't reinvent the wheel, rely on the certificate checking provided by your TLS library or application.</p> <p>If the server needs to know that it's talking to a legitimate client, then each client needs to have its own client certificate. That requires confidential storage on the client. Pass the client certificate to the TLS session opening function from your TLS library, or set it in the application configuration.</p> <p>That takes care of securing the communication between your server and your device. If the mobile application can talk to the device directly (e.g. to allow disconnected operation while it's on the local wifi network), you need to first perform pairing between the smart switch and the mobile phone. Pairing means an exchange of keys, preferably an exchange of public keys if resources permit, otherwise an agreement of secret keys. The goal of this pairing is to ensure that each device knows who it's talking to.</p> <p>You'll need to secure the control channel as well, whether it goes directly from the mobile device to the smart switch or via a server. Think about authorization: are there different levels of access to the switch, e.g. a control level that allows doing reconfiguration and a basic channel that just allows on/off switching? This is generally handled by an authentication step after establishing the secure channel (TLS if possible).</p> <p>Another consideration is firmware updates. That's a tricky one: on the one hand, there's no such thing as absolute security, so you will have security patches to apply now and then. On the other hand, a firmware upgrade mechanism is a complex thing and might itself have bugs. At the very least, make sure that your firmware upgrades are signed. Relying purely on the security of the communication channel for upgrades is dodgy, because the trusted based for a secure channel is larger than for a static security verification, and sometimes you might want to apply firmware updates without a network connection. In addition to verifying the signature, ideally you should have some protection against rollback, so that an adversary can't just push an “update” to version 1 on a system running version 2 and then exploit the security hole that version 2 patched.</p>

|security|bluetooth|mobile-applications|

How do I secure communication between app and IoT device?

19

<p>I am currently working on a project that includes Bluetooth communication between a mobile application (currently using the Ionic platform) and an embedded device. For comparison, our product is similar to a <strong>smart lock</strong>.</p> <p>Security is of utmost concern, and we are looking into ways to ensure our hardware and software are not hackable. What steps should we take to ensure our system is secure?</p> <p>Edit: Yes, we are currently encrypting communications, and using HTTPS when the device communicates with our server.</p>

2016-12-06T18:17:51.117

<p>Use rolling code, similar to what garage doors use now. Here is an <a href="https://www.riyas.org/2015/07/a-simple-rf-remote-with-secure-rolling-code-and-arduino.html" rel="nofollow noreferrer">open source example</a>.</p>

|security|smart-home|raspberry-pi|

Securing 433 MHz wall light switch

25

<p>I'm planning to use a simple light switch, that is placed on the wall. The switch gets power from the battery or piezo and sends unique sequences of data (on on- and on off-events) over 433 MHz to the receiver, that is connected to my SmartHome-RaspberryPI.</p> <p>Since I'm living on the ground floor I have some considerations about the security. Someone could record and replay unique sequences, that the switch sends.</p> <p>Is it possible to improve the security using hardware or software?</p>

2016-12-06T18:22:52.167

<p>Another name for Industry 4.0 is the Industrial Internet of Things(IIoT), the updated version of IoT. IIoT or industry 4.0 is mainly used in the manufacturing industry and its use cases are driving significant operational and financial benefits for this sector. The image represents the following use cases of industry 4.0 in the manufacturing industry. <a href="https://www.kelltontech.com/kellton-tech-blog/top-5-industrial-iot-use-cases-transforming-manufacturing-industry" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4QbGX.png" alt="" /></a></p>

|definitions|industry-4.0|

What is the difference between IoT and "Industry 4.0"?

30

<p>When reading about IoT, I often stumble upon the phrase "Industry 4.0". But what is the exact definition of it? Is "Industry 4.0" just a phrase for an IoT application in an industrial environment?</p>

2016-12-06T18:29:04.690

<blockquote> <p>What is the best approach to partitioning IoT device in the home?</p> <p>I have heard of setting up separate networks, one for IoT devices and one for everything else.</p> <p>Is this approach secure enough?</p> </blockquote> <p>Well, technically, there is no such thing as absolute security. Doing so should be technically safe enough, if we consider that your router doesn't have any vulnerabilities and can separate the network well enough. <strong>Enable</strong> &quot;Client Isolation&quot; (or whatever your router company calls it) if your router supports it (It may be under NAS, Firewall or Wireless menus):</p> <p><a href="https://i.stack.imgur.com/B5Z82.png" rel="noreferrer"><img src="https://i.stack.imgur.com/B5Z82.png" alt="Client Isolation" /></a></p> <blockquote> <p>Are IoT devices a major security risk to have on the same network as my PC?</p> </blockquote> <p>Kinda. While I haven't read of such an attack yet, IoT devices can technically be used to sniff the Internet communications or to make use of vulnerabilities on your operating system or the software you have installed to take it over. This can be a bigger risk if your PC has SSH or Telnet port open, and especially if it uses an insecure password. This was actually abused by the Mirai botnet: It attacked telnet ports of devices and tested common passwords to try to take over the device, to include it in the botnet. But this requires a vulnerability in both the IoT device and your computer, so it's unlikely to happen.</p>

|security|networking|

Secure Home Network Partition for IoT Devices

35

<p>What is the best approach to partitioning IoT devices from non-IoT devices at home? </p> <p>I have heard that setting up separate networks, one for IoT devices and one for everything else, is a good approach. This can be thought of as a three router "Y" network set up. One router connects the home to the outside world and connects to two other routers. One of those routers is for IoT components and one for everything else.</p> <ul> <li>My IoT devices are IP cameras, smart light bulbs, Nest, etc. </li> <li>My non-IoT devices are a PC and a network printer. </li> <li>Users of this network are one experienced computer industry professional and one non-computer savvy user.</li> </ul>

2016-12-06T18:32:38.917

<p>You could try <a href="https://www.hackster.io/krvarma/rpivoice-051857" rel="noreferrer">Raspberry Pi with .NET Core</a>. Microsoft has published decent automation libraries, including speech recognition. This is of course more hands-on, but combine it with other sensors and software, and you could do some pretty cool stuff.</p> <p>Microsoft also utilize their speech recognition libraries in their Bing APIs, so you could potentially use the web service to drive your project. This then relies on basic internet security through authorization and other basic security protocols.</p>

|smart-home|raspberry-pi|voice-recognition|

How to Enhance the Voice Recognition on Raspberry Pi controlling Smart Home Devices

41

<p>I have a Raspberry Pi running <a href="https://github.com/alexylem/jarvis" rel="nofollow noreferrer">Jarvis</a>, a personal IA that I can use with my voice to control my smart home devices.</p> <p>However, the voice recognition is far from perfect. They have a <a href="http://domotiquefacile.fr/jarvis/content/stt" rel="nofollow noreferrer">list of speech-to-text (STT) services</a> that I could use.</p> <p>Should I be worried about privacy if a choose a better service? What can I do to improve the current service I use? Is buying a better microphone a good idea?</p>

2016-12-06T18:34:04.143

<p>why and when to use MQTT:</p> <ol> <li>When you have a server capable to run MQTT Broker/server (obviously). You can install on raspberry pi or compile Erlang MQTT broker on any other SBC with ARM linux.</li> <li>When you are going to make use of the topic wildchars. Explained in Goufalite answer.</li> <li>When you are going to make use of the persistent feature. For example publish with persistent on <code>/device/board_1/should_be_active</code> in <strong>day 1</strong> and nothing published to that topic ever again. When a new device subscribed to that topic on <strong>day 2 or any other day</strong>, he will receive the data that was published on day 1. Even when the broker restarted, that persistent data on that topic will not be lost and will be informed again to the subscribers.</li> </ol> <p>When you don't want to use MQTT</p> <ol> <li><p>You don't really need those above features</p> </li> <li><p>You don't need encryption. For example in a car, not all data is encrypted, especially their data send through <a href="https://en.wikipedia.org/wiki/CAN_bus" rel="nofollow noreferrer">CAN</a>.</p> </li> <li><p>You don't want to spend resource on making an MQTT broker. if you can use microcontroller only why should you.</p> <p>You can use other server like CoAP (explained by Pepe Bellin). <strong><a href="https://nodemcu.readthedocs.io/en/master/modules/coap/" rel="nofollow noreferrer">NodeMCU</a></strong> firmware support <strong>CoAP</strong> server, means you don't need expensive linux powered server.</p> <p>You can use raw socket UDP or TCP-IP and encrypt the data yourself. This way you don't need to use HTTPS.</p> </li> </ol> <p>Years ago i always use MQTT when working on communication between devices. But nowadays in order to be more efficient on resources I always prefer raw socket, even when communicating with Android devices.</p>

|mqtt|protocols|data-transfer|https|

When and why to use MQTT protocol?

44

<p>I am developing a device which measures temperature, humidity and mass. Currently it uses HTTPS to upload data to a remote server. Now I know that there is a protocol called <a href="http://mqtt.org/" rel="noreferrer">MQTT</a> which is claimed to be the "protocol of Internet of Things".</p> <p>In what case and why should I switch from HTTPS to MQTT?</p>

2016-12-06T18:50:25.190

<p>Another factor to consider is radio packet size, which is much smaller for Bluetooth than for WiFi. This means that the collision risk is lower for Bluetooth than for WiFi, and a Bluetooth transmission is more likely to disrupt a WiFi transmission than vice versa.</p>

|smart-home|bluetooth|wifi|

When to use Wi-Fi over Bluetooth or vice versa in an IoT system?

66

<p>Basically when it comes to IoT, the two main communication methods which come to my mind are either Bluetooth or Wi-Fi. I know that there are others as well like ZigBee, Z-Wave but I would like to stay at either Wi-Fi or Bluetooth as they are supported by smart phones and tablets by default.</p> <p><strong>Application overview</strong>, system specifications:</p> <ul> <li>No HD cameras in any device.</li> <li>Purpose is to have connected all the locks, both windows and entrance doors and even dog doors.</li> <li>All light switches should be connected with feedback information about the current state of the particular lamp. (Switches can be controlled remotely and manually as well.)</li> <li>Be able to handle proximity sensors several ones per room.</li> <li>I want the system to be able to handle smart air conditioners (these should be controlled remotely and be able to give feedback about temperature and humidity values.)</li> </ul> <p>In general, I have a lot of devices with low bandwidth requirements and the main goal is to have a system that is as scalable as possible. So if I move to a twice as big house which needs almost twice as much sensors, I want it to be the easiest to install the additional ones.</p> <hr> <p>Now I know the basic advantages and disadvantages of the two compared. It is listed at this site <a href="http://www.diffen.com/difference/Bluetooth_vs_Wifi" rel="noreferrer">Bluetooth vs. Wi-Fi</a> (the image is taken from here as well).</p> <p><a href="https://i.stack.imgur.com/VcRBo.png" rel="noreferrer"><img src="https://i.stack.imgur.com/VcRBo.png" alt="Comparison of BlueTooth and Wi-Fi"></a></p> <p>To highlight: Some Bluetooth is cheap and easier to use. However, Wi-Fi is more secure, has a higher range and bandwidth but, of course, costs more.</p> <hr> <p>So the question is: At the dawn of a project, how can one decide which one will be the more suitable for the task? I consider the scalability as the most important spec.</p> <hr>

2016-12-06T18:53:54.020

<p>Electronics are generally recyclable, that is not something specific to IoT devices. More specifically, your IoT device will typically provide a general purpose MCU.</p> <p>Recycling an MCU is generally feasible. Even if the bootloader is locked down, you may be able to wipe the entire device using JTAG. It is debatable how much value there is in re-using a several year old device, but the hardware should be viable for 5-10 years.</p> <p>Performance, security protocols, wireless protocols etc. would be the factors which would lag behind. You would also be working with a much more physically constrained platform than a small dev-board would provide.</p> <p>Generally, it will not be feasible to re-purpose the original firmware, even if this was open-source derived - there may be missing configuration details or drivers. You should plan on finding or writing the whole stack (but this may be a valuable learning exercise). There may be server-side code which would also not be re-usable.</p>

|hardware|sustainability|upcycling|disposal|

Reusing / recycling a Petzi Treat Camera?

70

<p>A few years ago I helped crowdfund a <a href="https://www.amazon.ca/Petzi-Treat-Cam-Camera-Dispenser/dp/B008U73C46%3FSubscriptionId%3DAKIAILSHYYTFIVPWUY6Q%26tag%3Dduckduckgo-d-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB008U73C46" rel="nofollow noreferrer">Petzi Treat Camera</a> to feed my pet. Due to a broadcast pushed firmware update that I missed, it was rendered unusable. Thankfully, they did however send me a replacement unit but I am now left with a second bricked one. The device by design communicates via Wi-Fi, has a camera and has a motorized trap door to dispense treats. I haven't opened it yet but I was thinking I might try gaining access to it or seeing if its components can be used elsewhere.</p> <p>I'm wondering whether there's a potential to reclaim/salvage parts of my old one and up/downcycle it or, if that's not possible, what would be the most environmental considerate way to dispose of this device?</p>

2016-12-06T19:07:12.187

<p>As a GSM capable device you must switch it to <a href="http://flight%20mode%20of%20GSM%20devices" rel="nofollow noreferrer">Airplane mode</a>. Which means the device RF interface must be completely shut down.</p> <p>Basically what you have described can be any smart phone, and I believe those can be delivered by air post as long as they are in airplane mode. But certainly if they are powered off.</p>

|batteries|gsm|

Can I send my GSM IoT device via airpost?

78

<p>Is legal to send my GSM IoT device which is powered by a ~2000 mAh (3.7 V) lithium polymer (LiPo) battery via air post? (Or even take it with me inside my suitcase?)</p> <p>Also does it make a difference if the device is powered on or off?</p>

2016-12-06T19:21:46.890

<p>In short, standardization and product developments are underway to address this problem. Until then, there are few simple answers that don't require some networking knowledge.</p> <p>My humble suggestion is easy to implement, and will provide your local network with some protection (although it won't protect the Internet at large) without knowing anything about networking other than how to plug in and use a wireless router.</p> <p>Buy a separate wireless router for your home network, and use it just for your IoT devices. This will make it harder for the IoT devices to discover and attack your other devices (such as PCs, Tablets, and Smartphones). Likewise, it will provide your IoTs some protection from compromised computing devices you may have.</p> <p>This solution may break some things, but the solution is perversely helped out by the mostly undesirable reality that today, many Iot devices achieve remote communications through a manufacturer-controlled cloud infrastructure, which will help your Iots to communicate with your computing devices more safely than having them on the same network. It also allows the manufacturer to collect personal information about you, and provide that to third parties.</p>

|security|networking|

Can I monitor my network for rogue IoT device activity?

90

<p>In order to mitigate or manage the risk from having some of the devices on my home network compromised, is it feasible to monitor network traffic so as to detect a compromise? </p> <p>I'm specifically interested in solutions which don't require me to be a networking expert, or to invest in anything more than a cheap single-board computer. Is this a feature that can practically be integrated in a router firewall, or is the problem too difficult to bound to have a simple, easy to configure solution?</p> <p>I'm not asking about Wireshark - I'm asking for a self-contained system which can generate alerts of suspicious activity. Also thinking more focused on practical to setup for a capable amateur rather than a robust production quality solution.</p> <p><em>addendum:</em> I see there is now a kickstarter project <a href="https://www.kickstarter.com/projects/akita/akita-instant-privacy-for-smart-homes" rel="noreferrer">(akita)</a> which seems to offer cloud-based analytics driven from local WiFi sniffing.</p>

2016-12-06T19:32:33.480

<p>The mbed <a href="https://developer.mbed.org/teams/mqtt/wiki/Using-MQTT" rel="noreferrer">mmqt library</a> doesn't seem to document any memory requirements as likely to be limiting, and can reasonably be assumed to be targetted at this sort of small-footprint device as an endpoint. You could fairly trivially import the library into a similar device platform using the online compiler and check the code footprint at least.</p>

|mqtt|microcontrollers|stm32|arm|

How can I implement MQTT on an STM32F030K6T6?

96

<p>The controller in question is an <a href="http://www.st.com/content/st_com/en/products/microcontrollers/stm32-32-bit-arm-cortex-mcus/stm32f0-series/stm32f0x0-value-line/stm32f030k6.html" rel="noreferrer">STM32F030K6T6</a>, which has an ARM® 32-bit Cortex® -M0 low power core, 32 kB Flash memory and 4 kB SRAM. It interfaces an SIM808 for Internet connectivity.</p> <p>The resources are quite limited regarding the memory.</p> <ul> <li><p>Is it possible to implement MQTT on this device?</p></li> <li><p>What requirements should a microcontroller match to be able to use/run MQTT?</p></li> </ul> <p>(I am not asking about a complete protocol stack implementation.)</p>

2016-12-06T19:45:29.950

<blockquote> <p>What classifies a device as an Internet of Things device?</p> </blockquote> <p>As per my understanding, an IoT device:</p> <ol> <li><p>Serves a specific use case, e.g., Amazon Echo, Nest Cam, Belkin WeMo. This is key differentiation from computing devices such computers, smartphones or tablets.</p></li> <li><p>Can connect to a network for purposes of data transmission/reception. Mostly an IP network.</p></li> <li><p>Is designed to be ubiquitous and inconspicuous. These devices are slowly coming up everywhere and serve the purpose without getting in the way of users.</p></li> <li><p>Do have some sort of cloud back end so that they can be reached from anywhere anytime by the users authorized to use the devices.</p></li> </ol>

|definitions|

What classifies a device as IoT?

99

<p>IoT stands for Internet of Things.</p> <p>Would a fitbit or device that connects to a mobile phone or computer through Bluetooth the be considered IoT? What about radio controlled devices?</p> <p>What classifies a device as an Internet of Things device?</p>

2016-12-06T19:45:41.323

<p>Some of the improvements introduced with COAP might become less relevant with the introduction of HTTP/2 and HTTP/3 so will need to wait and see how the protocol war evolve.</p>

|communication|coap|standards|

Is CoAP still used for IoT devices?

100

<p>I did a prototype project for work a few years ago that utilized the <a href="https://www.rfc-editor.org/rfc/rfc7252" rel="nofollow noreferrer">Constrained Application Protocol (CoAP)</a> for communicating with an Arduino board over a mesh network, but we put the brakes on the project due to a serious lack of security in our devices. We ended up abandoning CoAP for our project to move to an in-house protocol that we adapted for our needs.</p> <p>I've done <a href="http://coap.technology/impls.html" rel="nofollow noreferrer">a little digging around</a>, and it looks like there are still a few implementations floating around, but I was curious if anyone is actually using CoAP in any products.</p> <p>Is CoAP still a good protocol to use, or has the industry settled on a de-facto standard?</p>

2016-12-06T20:22:47.717

<p>There is a project <a href="http://elm-chan.org/fsw/ff/00index_e.html" rel="noreferrer">FatFs - Generic FAT File System Module</a> that offers FAT access for microcontrollers.</p> <blockquote> <p>FatFs is a generic FAT/exFAT file system module for small embedded systems. The FatFs module is written in compliance with ANSI C (C89) and completely separated from the disk I/O layer. Therefore it is independent of the platform. It can be incorporated into small microcontrollers with limited resource, such as 8051, PIC, AVR, ARM, Z80, 78K and etc. </p> </blockquote> <p><a href="http://elm-chan.org/fsw/ff/00index_p.html" rel="noreferrer">Petit FatFs</a> is for tiny (8 bit) microcontrollers.</p> <blockquote> <p>Petit FatFs is a sub-set of FatFs module for tiny 8-bit microcontrollers. It is written in compliance with ANSI C and completely separated from the disk I/O layer. It can be incorporated into the tiny microcontrollers with limited memory even if the RAM size is less than sector size. Also full featured FAT file system module is available here.</p> </blockquote> <p>So, <strong>yes</strong>, IoT devices that are based on microcontrollers that could run FatFs or Petit FatFs could access hard-disk drives without a full-blown OS.</p>

|usb|

Can I implement FAT on a microcontroller to access USB/SATA drives?

111

<p>I am interested in connecting a 3.5" hard drive to an IoT device that I am building based on a microcontroller (e.g. an Arduino) which doesn't run a mainstream operating system. </p> <p>As far as I know, to use a 3.5" hard-drive you need a full operating system (such as Linux or Windows) for device drivers to connect a 3.5" hard drive. Is this assumption correct? </p> <p>Is there a way of implementing drivers for SATA/USB and the FAT filesystem, so that I can save files to a USB or hard drive? Are there any pre-existing projects or drivers that I can re-use for this purpose?</p> <p>I would prefer not to use an SD card because the capacity that I want will be more expensive.</p>

2016-12-06T21:43:10.920

<p>A tad late, but adding my experience for completeness and for a 2023 solution.</p> <p>I have a almost fully automated home using the Fibaro system. It uses Zwave. I decided to go with Fibaro</p> <ol> <li>It was a more professional looking system</li> <li>I asked vendors in NZ to show me their last home/install. Only the Fibaro guy came to the party.</li> <li>I have 120+ devices and 100s of scenes to control lights, blinds, AV etc automatically, with a wall mounted tablet, with mobile apps and with Alexa/Google/Siri</li> </ol> <p>Their recent server <code>Home Centre 3</code> now supports Zigbee and other devices as well. So, finally I can communicate to both Zwave and Zigbee and have inter-operable scenes.</p>

|wireless|zwave|zigbee|

Difference Between ZigBee and Z-Wave?

131

<p>I've have installed Z-Wave switches and outlets in a few places around my house. However, I noticed when purchasing the devices that there were a couple of different wireless options available in the brand I was looking at.</p> <p>I'd be curious to know some of the pros/cons between Z-Wave and ZigBee devices. A comparison like <a href="https://iot.stackexchange.com/questions/66/when-to-use-wifi-over-bluetooth-or-vica-versa-in-an-iot-system">this</a> post on when to use WiFi over Bluetooth would be amazing.</p> <p>For instance, I'm curious in information like if one style is potentially more favorable in houses with many walls or if one fairs better in "noisy" wireless homes (eg. many wireless devices/signal types). </p>

2016-12-06T22:33:44.307

<p>You'd track on several levels.</p> <p>You track the truck with GPS, not the products. You track the individual shipments with <a href="https://en.wikipedia.org/wiki/ZigBee" rel="nofollow noreferrer">zigbee</a> or <a href="https://en.wikipedia.org/wiki/Radio-frequency_identification" rel="nofollow noreferrer">RFID</a>. Those technologies are a lot cheaper. Thus, it's affordable to put them in or on less expensive products. Between commercial end points both sides can verify each product by the WPAN technologies on arrival or on packaging the truck.</p>

|communication|gps|tracking-devices|

How reliable is location tracking of shipments?

134

<p>I was reading about the tracking of parcels and other shipments, being a primary example of IoT applications. But I'm wondering about how reliable and precise the positioning would be. I have the impression that those tracking devices would not get any GPS signal in shipping containers, trucks or buildings, where they would be most of the time.</p> <p>Also, I see the same issue regarding the connection to a cellular network or alike, especially in regions with bad network coverage.</p> <p>So, how reliable is location tracking of shipments?</p>

2016-12-06T22:46:38.490

<p>You should differentiate connection and session.</p> <p>Everything is defined by the session. When MQTT connection is authorized to the broker first time, broker creates session for this connection, usually based on client-id connection parameter.</p> <p>In MQTT 3.1.1 protocol (default currently in most clients/brokers) during connection you may specify clean=true or clean=false flag. If clean=true then broker will automatically create new session and close it when connection is broken/closed. If clean=false, broker will maintain session and deliver there events (into some kind of session storage) even when client disconnected. It depends on the brokers implementation if it allow clean=false session at all and what is maximum ttl of such session.</p> <p>In MQTT 5.0 protocol (very fresh, but perspective) it is possible to specify session ttl from client side or even change it after connection has been made. This is extremely useful for unstable WAN connections(IoT mostly) or stateful connections like you described. </p> <p>AFAIK currently MQTT 5.0 protocol from client perspective can be used in python with <a href="https://github.com/wialon/gmqtt" rel="nofollow noreferrer">gmqtt</a> and in javascript with <a href="https://github.com/mqttjs/MQTT.js/pull/827" rel="nofollow noreferrer">mqtt.js</a>.</p>

|mqtt|

Confusion about client-server connection establishment in MQTT

138

<p>According to the <a href="http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html" rel="noreferrer">specifications</a>, it is always the client who should establish connection to a server.</p> <blockquote> <p>Client:</p> <p>A program or device that uses MQTT. <strong>A Client always establishes the Network Connection to the Server</strong>. It can</p> <ul> <li><p>Publish Application Messages that other Clients might be interested in.</p></li> <li><p>Subscribe to request Application Messages that it is interested in receiving.</p></li> <li><p>Unsubscribe to remove a request for Application Messages.</p></li> <li><p>Disconnect from the Server.</p></li> </ul> </blockquote> <p>And if this client subscribes for an Application Message, then the server should forward those messages to this particular client.</p> <blockquote> <p>Server:</p> <p>A program or device that acts as an intermediary between Clients which publish Application Messages and Clients which have made Subscriptions. A Server</p> <ul> <li><p>Accepts Network Connections from Clients.</p></li> <li><p>Accepts Application Messages published by Clients.</p></li> <li><p>Processes Subscribe and Unsubscribe requests from Clients.</p></li> <li><p><strong>Forwards Application Messages that match Client Subscriptions</strong>.</p></li> </ul> </blockquote> <p>Does this mean that if a client subscribes, then it remains connected to the server while the subscription is valid even though there are no data flow in most of the time?</p> <p>I come to this conclusion because if the client disconnects after subscription, then a server cannot forward messages to it because it is the client that should establish connection. But it won't know when to re-establish it.</p>

2016-12-06T22:55:54.177

<p>Generally speaking, an agent is a 'bi-directional' piece of software; i.e., it reads parameters <em>from</em> the device and the communicates the same <em>to</em> cloud or even a gateway. More often than not, an OEM will control the libraries for development of the software to control the parameters of the device. Whereas, the OEM may choose any of the popular communication protocols (MQTT, HTTP, etc.) to publish the values read. Typically, integration of these two is the space where a System Integrator comes in.</p> <p>For example, an agent could be running on a Windows desktop to read the rpm of the fan every 5 seconds. This value is then communicated over to a cloud platform over an agreed protocol.</p> <p>Sample code from Paho MQTT (Python) <a href="https://pypi.python.org/pypi/paho-mqtt/1.2#network-loop" rel="nofollow noreferrer">web site</a>:</p> <pre class="lang-py prettyprint-override"><code>mqttc.connect("iot.eclipse.org") mqttc.loop_start() while True: temperature = sensor.blocking_read() mqttc.publish("paho/temperature", temperature) </code></pre> <p>The above snippet is roughly an agent because there is the 'from device' part in the form of the function <code>sensor.blocking_read()</code> and the 'to cloud' part in the form of a <code>mqttc.publish()</code>.</p> <p>Advanced agents will have mechanisms to handle offline storage, TLS support for communication towards cloud, respond to any updates from cloud (including reboots, if needed) gracefully, etc. And, in the specific case of this question, the agent will handle power constraints too. For example, respond to device level triggers such as sleep, wake-up, etc.</p>

|definitions|

What is an “Embedded Agent” in reference to a Low Powered IoT Edge Device?

143

<p><strong>Question:</strong> What is the underlining design behind an <strong>“Embedded Agent”</strong> in relationship to low powered Internet of Things (IoT) edge devices? </p> <p>Some of the IoT cloud service vendors keep referring to installing an embedded agent on the sensor based edge devices. It appears to be a proprietary piece of software which vendors install on each device connecting to the cloud. Below are two images of software stacks with references to <strong>Agent</strong>. A portion of the of software stack reside in the microcontroller. </p> <p><a href="https://i.stack.imgur.com/zpIDQ.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zpIDQ.jpg" alt="IOT Agent - 1"></a></p> <p><a href="https://i.stack.imgur.com/o2bSz.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/o2bSz.jpg" alt="IOT Agent"></a></p> <p>Also here is very broad explanation Thingworx blog</p> <blockquote> <p>An agent is an embedded program that runs on or near an IoT device and reports the status of some asset or environment. There is always some agent present in an IoT application. Typically the agent reads the status from sensors or local connectivity to an asset, applies some rules or logic about how often the sender has to aggregate the information, and then sends the information over a long-haul communications network to the server. This process can operate in reverse as well.</p> </blockquote> <p>It is my assumption this agent consist of connectivity information such as IP address, server name, SSID type information to aid connectivity. Does these Embedded Agents have other functionality beyond providing connectivity? </p> <p><strong>References:</strong></p> <ul> <li><a href="https://blog.profitbricks.com/top-49-tools-internet-of-things/" rel="nofollow noreferrer">Top 49 Tools For The Internet of Things</a></li> <li><a href="http://www.woodsidecap.com/wp-content/uploads/2015/02/WCP-IOT-M_and_A-REPORT-2015-21.pdf" rel="nofollow noreferrer">The Internet of Things, “Smart” Products Demand a Smart Strategy</a> </li> <li><a href="http://www.oreilly.com/iot/free/foundational-elements-of-an-iot-solution.csp" rel="nofollow noreferrer">Foundational Elements of an IoT Solution,The Edge, The Cloud, and Application Development</a></li> <li><a href="http://www.windriver.com/whitepapers/device-cloud/Wind-River-Helix-Device-Cloud-WP.pdf" rel="nofollow noreferrer">New Life for Embedded Systems in the INTERNET OF THINGS</a></li> <li><a href="http://marketplace.thingworx.com/thingworx/home/developer/iot-guide/the-edge-of-the-iot" rel="nofollow noreferrer">The Edge Of The Iot</a></li> </ul>

2016-12-07T01:39:34.487

<p>To begin with, if there are 'data issues', those issues should be taken up with the data service provider for violation of an agreed SLA. Next, there should be a offline data store option in your solution so that, the requirement of gathering data is taken care. If/when data coverage is available, the older data is republished or after a defined window, etc. As a last resort, the offline data could possibly have been downloaded via USB, etc.</p> <p>Thus, in summary, storing data offline, republishing when online and archival of the collected data is something should be considered in the overall solution.</p>

|mobile-data|

Data connection issues during when working with IoT devices

149

<p>Following my previous question <a href="https://iot.stackexchange.com/questions/137/how-cellular-technologies-benefits-for-iot">here</a>, what are solutions to overcome issues with the data connection (i.e. data out off-quota or I'm out of coverage) during the work with my IoT devices. Especially when working tackling critical issues? </p> <p>This is focused more on mobile connectivity since I don't want this to be broad and off-topic. I asked this since in my country, Malaysia we quite regularly have the lagging issues compared to the US &amp; other western countries.</p>

2016-12-07T07:17:05.313

<p>I don't think there is currently a better option out there. It doesn't even need an app to work since it can provide URLs, it's open-source and more secure than the main competitors due to ephemeral IDs and they provide telemetry.</p> <p><a href="https://blog.beaconstac.com/2016/06/googles-eddystone-vs-apples-ibeacon-who-is-winning-in-the-beacon-space-in-2016/" rel="nofollow noreferrer">This blog</a> lists a lot of reasons why the Eddystone beacons have risen so much in popularity. Between the lines one can even presume that they consider iBeacon dead barring some fundamentally changed successor.</p> <p>The Eddystone beacons just bring more ecosystem, accessibility and flexibility out of the box. So in December 2016, Eddystone seems to be the only sensible protocol choice. (Unless you intend to equip an Apple campus ;))</p> <p>A lot of blog entries I found moved over the year from <em>"let's compare the protocols"</em>, over <em>"oh, Apple didn't even mention theirs in their keynote"</em> to <em>"the reasons why Eddystone won."</em></p>

|protocols|beacons|eddystone|

Connecting Proximity beacon with Mobile App

155

<p>We are planning to implement a proximity beacon network which provides information to the users app based on proximity in the store. Our objective is to cover a radius of 5-7 metres.</p> <p>Which protocol has the better connectivity between the beacon and the iOS/Android app?</p> <p>The Network will be as below,</p> <p><a href="https://i.stack.imgur.com/Kx3aR.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Kx3aR.jpg" alt="process flow of customer using a beacon"></a></p> <p>To clarify, we are focusing on Eddystone over the other protocols because of Google. Considering the current situation in beacon technology, is there a better alternative for communication with mobile applications? If there are any, what is the advantage over Eddystone?</p>

2016-12-07T11:27:43.337

<p>The <a href="http://www.postscapes.com/internet-of-things-hardware/" rel="noreferrer">Postscapes IoT Hardware Guidebook</a> lists quite a few:</p> <ul> <li>BeagleBone</li> <li>C.H.I.P.</li> <li>Dragino</li> <li>Espruino</li> <li>Flutter</li> <li>Hologram Dash</li> <li>Kinoma</li> <li>Libelium Waspmote</li> <li>Marvin</li> <li>Modulo</li> <li>Particle</li> <li>Seeeduino Cloud</li> <li>SODAQ Autonomo</li> <li>Spark Core</li> <li>Tessel 2</li> <li>Thunderboard Sense</li> <li>TinyDuino</li> </ul> <p>Judging by the names, there are a few derivatives of the Arduino. Furthermore, all devices running Linux should be more or less compatible with the Raspberry Pi.</p>

|raspberry-pi|banana-pi|

Are there any IoT devices with fully open source hardware?

176

<p>Raspberry Pi is broadly used for IoT, and there is a lot of software for it. But I would like to know about any completely open source designs, including software and hardware (PCB, not components).</p> <p>I have heard about <a href="http://www.bananapi.org/" rel="nofollow noreferrer">Banana Pi</a> but I'm not sure if it's completely open source or if other alternatives exist.</p> <p>The main requirement is to be fully compatible with any of the broadly existing software platforms (Arduino, Raspberry Pi).</p> <p>Of course, the components used in PCB should be available to anyone. </p>

2016-12-07T15:54:41.350

<p>Give this <a href="https://community.smartthings.com/t/connect-wired-alarm-system-sensors-to-smartthings-with-a-nodemcu-esp8266-deprecated/76010" rel="nofollow noreferrer">one</a> a try.</p> <p>It is talking about connecting your old wired sensor endpoints from the Alarm panel to Smartthings. There might be something that you can get from reading the post. </p>

|samsung-smartthings|sensors|home-security|

Repurpose ADT sensors

191

<p>My wife and I just purchased a new house and the ADT Security sensors were still installed, but no keypad panel. After speaking with a Rep on pricing and logistics, we decided not to continue the service. I asked about the existing hardware and the Rep said that should we decide to continue service we can continue to use the existing hardware, otherwise someone can come and uninstall it. Anyways, I requested them to uninstall the hardware about a month and a half ago with no further response. So, as far as I can tell, I now have 3 Honeywell door sensors and 1 Honeywell Motion Detector (still installed).</p> <p>I'm curious if there is any way to include these sensors with my Samsung SmartThings system? Would it be as simple as adding/changing a wireless component to a compatible signal with ZigBee/Z-Wave/Bluetooth/etc.?</p> <p><strong>Update</strong>:</p> <p>The model number for the entire unit seems to be <strong><em>A 026-0934</em></strong>, however I couldn't find it in the <a href="http://sensing.honeywell.com/" rel="noreferrer">catalogue mentioned in the comments</a>. There are several other model numbers it looks like, <a href="http://sensing.honeywell.com/index.php?ci_id=159835&amp;la_id=1&amp;No=0&amp;Nrpp=50&amp;Ntt=X%20315%20AC&amp;Page=1" rel="noreferrer">mostly referring to what appears to be a safety switch</a> to cut off power when the unit is opened.</p> <ul> <li>The product page is here: <a href="https://www.alarmgrid.com/products/honeywell-5816" rel="noreferrer">Honeywell 5816 Wireless Door Sensor and Window</a> </li> <li><a href="https://iot.stackexchange.com/questions/70/reusing-recycling-a-petzi-treat-camera">Reusing/recycling a Petzi Treat Camera?</a> seems related.</li> </ul>

2016-12-07T21:35:59.250

<p>Currently, it appears that the SDK <a href="https://developer.home-connect.com/" rel="nofollow noreferrer">is still in beta</a>. However, you can apply for it and get a feel for how it will work with their simulator.</p> <p>When it does finally come out, you should be able to do anything with it that you are able to do with the <a href="http://www.home-connect.com/de/en/" rel="nofollow noreferrer">Home Connect</a> application. As a matter of fact, the Home Connect SDK is called (right in their banner) Home Connect for Developers.</p> <p>In other words, anything you are able to do with the Home Connect application, you should also be able to do, with sufficient coding, as a developer with the SDK.</p>

|smart-home|kitchen-appliances|home-connect|

What capabilities does my Home Connect appliance provide in the developer SDK?

196

<p>The smart household appliances that can be controlled via <a href="http://www.home-connect.com/de/en" rel="noreferrer">Home Connect</a> can also be accessed via a developer SDK provided by the Home Connect Service provider. How can I find out what I will be able to do with a prospective oven, e.g. a <a href="http://www.siemens-home.bsh-group.com/uk/productlist/cooking/microwaves/built-in-ovens-with-microwave/CM678G4S6B?breadcrumb=ovens" rel="noreferrer">Siemens iQ700 CM678G4S6B</a>, by using the SDK provided by the developer of the service?</p> <p>I found <a href="https://developer.home-connect.com/?q=docs/oven/supported_programs_and_options" rel="noreferrer">this information in the SDK developer information</a>, detailing that in general I can get information about several heating modes and a pizza mode. Will I be able to use those functions with the oven and how detailed will the information about the oven status be?</p>

2016-12-08T07:29:57.140

<blockquote> <p>But how about actuators?</p> </blockquote> <p>Yes <a href="https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern" rel="noreferrer">pub-sub pattern</a> is applicable to actuators.</p> <blockquote> <p>Is this the way to go with actuators?</p> </blockquote> <p>This is one of the ways to go and this is booming because of many cloud providers like</p> <ul> <li><a href="http://docs.aws.amazon.com/iot/latest/developerguide/protocols.html" rel="noreferrer">AWS IoT</a> as a service support MQTT(over TLS, WebSockets)</li> <li>Google's <a href="https://cloud.google.com/pubsub/docs/overview" rel="noreferrer">Google Cloud pub-sub</a> messaging service</li> <li>Microsoft's <a href="https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-mqtt-support" rel="noreferrer">IoT Hub with MQTT support</a></li> </ul> <p>trying to occupy the IoT space to <strong>move data from sensors</strong> to cloud easily with different approaches and as devices have limited connectivity, power, bandwidth, they need lighter weight protocol like MQTT and such which is pub-sub model based.</p> <p>What my point here is any device that can sense and has data can use pub-sub but the <strong>smart</strong> thing comes from the type of implemnatation they are doing. Suppose if you are not using MQTT over some encrypted mechanism(TLS/SSL) , the data can be sniffed.</p> <blockquote> <p>Is there any smarter solution?</p> </blockquote> <p>It depends on the application and the constraints the problem has and the so called smarter solution varies as time flies. One more thing to note here is that, having a <strong>smarter solution is not the smartest way</strong> to go around, because implementation is what matters the most and not the protocol or method you choose.</p> <blockquote> <p>Is it possible to publish a open door event from anywhere? How easy can it be hacked?</p> </blockquote> <p>Yes, it is possible to open the door from anywhere by publishing an event <strong>but</strong> this all depends on the application and authentication you are providing, for example you can make your application subscribing/publishing to topics is only after authentication.</p> <hr> <p><strong>Real Case Scenario:</strong></p> <p>I know a lot of companies who are using this exact model for actuators, recently I worked for a team which is a part of Solar Tracking systems where the solar panels are controlled, monitored using Wireless technologies. </p> <p>Particularly in that to move/rotate an array of panels according to the sun position and based on different energy optimizing algorithms we use <strong>Linear Actuators</strong>, in this system we also have a provision to control panels manually from web/mobile dashboards in case of emergencies or any maintenance purposes.</p> <p>In the above scenario to control actuators Pub-Sub model with authentication/encrytption is used.</p>

|security|publish-subscriber|actuators|

Is the Subscriber-Publisher pattern applicable also to actuators?

203

<p>There are tons of tutorials on the web, especially with <a href="https://www.rabbitmq.com/" rel="nofollow noreferrer">RabbitMQ</a>, on how to <em>publish</em> sensor data; for example, temperature, humidity, etc. Just publish the value to a message queue and anybody can consume it.</p> <p>So far so good. But how about actuators? </p> <p>Let's take a light switch for example. The light switch publishes the current state of the luminaire to a queue. It also subscribes to a second queue to listen for events. This would allow a bidirectional communication. If someone/something wants to turn on the light, an event has to be published to the message queue the light switch is listening to. </p> <p>I hope you understand the idea. Is this the way to go with actuators? Is there any smarter solution? How about security, thinking on using this for doors for example. Is it possible to publish a open door event from anywhere? How easily can it be hacked?</p>

2016-12-08T10:03:57.357

<p>Mirai attacks embedded linux. You would first need to get command line access to your IoT device. After that you can check the checksums of the read-only filesystem, and compare them to clean firmware versions. Sometimes companies have the original firmware online, or you can contact them for a copy. If you want to understand how firmware is usually packaged, I suggest looking into the program Binwalk. OpenWrt has good documentation about flash memory. When you flash/reflash firmware onto the IoT device, sections of the firmware (kernel, read only root filesystem, writable config section) are stored in MTD partitions on the IoT's flash chip. You can copy/download these partitions (/dev/mtdblock1 is linux example) and compare those to the original firmware, via checksums. If you fear a rootkit and don't trust the command line, you can download &amp; examine the firmware directly off the flash chip with hardware tools, like a Bus Pirate and SOIC8 clip</p>

|security|networking|mirai|

How can I check if my IoT devices are infected with the Mirai worm?

211

<p>I've recently heard about the <a href="https://en.wikipedia.org/wiki/Mirai_(malware)" rel="noreferrer">Mirai worm</a>, which infects vulnerable routers, IoT devices and other internet-connected appliances with insecure passwords. Mirai is suspected of being the cause of some of the <a href="https://www.theguardian.com/technology/2016/oct/26/ddos-attack-dyn-mirai-botnet" rel="noreferrer">largest DDoS attacks in history</a>:</p> <blockquote> <p>Dyn estimated that the attack had involved “100,000 malicious endpoints”, and the company, which is still investigating the attack, said there had been reports of an extraordinary attack strength of 1.2Tbps.</p> </blockquote> <p>The question <em><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></em> provides some useful generic tips for spotting malware on my IoT network, but how can I check if my devices <strong>are</strong> infected with the malware? <a href="https://www.incapsula.com/blog/mirai-scanner-unwitting-mirai-botnet-recruit.html" rel="noreferrer">Incapsula provide a tool</a> to run which can scan for devices vulnerable to Mirai, but is there a way of autonomously checking if any devices on my network are infected (or provide real-time protection) so that I don't have to keep running the tool when I remember? </p>

2016-12-08T13:07:28.870

<ol> <li><p>Many years ago I did analyse difference for using </p> <p><strong>XML</strong> in payment network for payment transaction representation (card_number, date, time, terminal_id, and list of additional elements) in comparation with traditional </p> <p>bit-maped <a href="https://en.wikipedia.org/wiki/ISO_8583" rel="nofollow noreferrer"><strong>ISO8583</strong></a> </p></li> <li><p>XML has huge overhead. If you consider impact in networks with 10000+ nodes each of them sending 10+ messages hourly/daily to the central host then XML goes out and you really need something more efficient.</p></li> </ol>

|communication|networking|xmpp|

Does XMPP have a large overhead for IoT devices sending short, frequent messages?

221

<p>I've been reading about XMPP as a potential communications protocol for IoT devices but, after reading one source, I'm unsure whether it's really an appropriate protocol if you're concerned about overhead for each message.</p> <p><a href="https://exosite.com/embedded-iot-protocols-guide-part-ii-the-old-standards-of-xmpp/" rel="noreferrer">This source</a> states:</p> <blockquote> <p>However, XMPP has a number of problems that make it somewhat undesirable for EMBEDDED IOT PROTOCOLS. As an XML-based protocol, XMPP is very verbose, even more so than HTTP, and has heavy data overhead. A single request/response exchange to send one byte of data from an IOT CONNECTED DEVICE to the server is more than 0.5 kB.</p> <p>There is a draft specification that would compress XMPP using an XML encoding called efficient XML Interchange (EXI). But even with EXI, the same one byte of data gets hundreds of bytes of protocol overhead from XMPP alone. EXI is also a much harder format to process than other options now available. Because of these inherent problems, it is generally recommended to avoid using XMPP in embedded IoT applications.</p> </blockquote> <p>However, XMPP <a href="http://xmpp.org/uses/internet-of-things.html" rel="noreferrer">promotes itself as suitable for IoT applications</a> (although it doesn't specifically say that it's low-overhead), so it seems odd that such a large, seemingly verbose protocol would be recommended/promoted for IoT devices.</p> <p>Is the overhead of XMPP really as large as the source suggests for small amounts of data? For example, how much overhead would there be when sending an 8-byte message? </p> <p>Also, is the overhead so great if <a href="https://en.wikipedia.org/wiki/Efficient_XML_Interchange" rel="noreferrer"><strong>EXI</strong></a> compression is used (as mentioned in the source)? Would this also come with some pitfalls?</p>

2016-12-08T17:02:28.840

<p>In <a href="https://eprint.iacr.org/2014/947.pdf" rel="noreferrer">"The Simon and Speck Block Ciphers on AVR 8-bit Microcontrollers"</a> <em>Beaulieu et al.</em> investigate the implementation of SIMON and SPECK on a low-end 8-bit microcontroller and compare the performance to other cyphers. An Atmel ATmega128 is used with 128 Kbytes of programmable flash memory, 4 Kbytes of SRAM, and thirty-two 8-bit general purpose registers.</p> <p>Three encryption implementations are compared: </p> <ol> <li><em>RAM-minimizing</em> <blockquote> <p>These implementations avoid the use of RAM to store round keys by including the pre-expanded round keys in the flash program memory. No key schedule is included for updating this expanded key, making these implementations suitable for applications where the key is static.</p> </blockquote></li> <li><em>High-throughput/low-energy</em> <blockquote> <p>These implementations include the key schedule and unroll enough copies of the round function in the encryption routine to achieve a throughput within about 3% of a fully- unrolled implementation. The key, stored in flash, is used to generate the round keys which are subsequently stored in RAM.</p> </blockquote></li> <li><em>Flash-minimizing</em> <blockquote> <p>The key schedule is included here. Space limitations mean we can only provide an incomplete description of these implementations. However, it should be noted that the previous two types of implementations already have very modest code sizes.</p> </blockquote></li> </ol> <hr> <p>To compare different cyphers a performance efficiency measure - <em>rank</em> - is used. The rank is proportional to throughput divided by memory usage.</p> <blockquote> <p>SPECK ranks in the top spot for every block and key size which it supports. Except for the 128-bit block size, SIMON ranks second for all block and key sizes. </p> <p>...</p> <p>Not surprisingly, AES-128 has very good performance on this platform, although for the same block and key size, SPECK has about twice the performance. For the same key size but with a 64-bit block size, SIMON and SPECK achieve two and four times better overall performance, respectively, than AES. </p> </blockquote> <p>Comparing SPECK 128/128 to AES-128 the authors find that the memory footprint of SPECK is significantly reduced (460 bytes vs. 970 bytes) while throughput is only slightly decreased (171 cycles/byte vs. 146 cycles/byte). Thus SPECK's performance (in the chosen metric) is higher than AES. Considering that speed is correlated with energy consumption the authors conclude that "AES-128 may be a better choice in energy critical applications than SPECK 128/128 on this platform." The authors however are uncertain whether heavy usage of RAM access (high-speed AES implementations) are more energy efficient than a register-based implementation of SPECK. In either case a significant reduction in flash memory usage can be achieved which might be of relevance on low-end microcontrollers.</p> <blockquote> <p>If an application requires high speed, and memory usage is not a priority, AES has the fastest implementation (using 1912 bytes of flash, 432 bytes RAM) among all block ciphers with a 128-bit block and key that we are aware of, with a cost of just 125 cycles/byte. The closest AES competitor is SPECK 128/128, with a cost of 138 cycles/byte for a fully unrolled implementation. Since speed is correlated with energy consumption, AES-128 may be a better choice in energy critical applications than SPECK 128/128 on this platform. However, if a 128-bit block is not required, as we might expect for many applications on an 8-bit microcontroller, then a more energy effcient solution (using 628 bytes of flash, 108 bytes RAM) is SPECK 64/128 with the same key size as AES-128 and an encryption cost of just 122 cycles/byte, or SPECK 64/96 with a cost of 118 cycles/byte.</p> </blockquote> <hr> <p>Additionally, <a href="http://csrc.nist.gov/groups/ST/lwc-workshop2015/presentations/session1-shors.pdf" rel="noreferrer">this talk</a> has an <em>Enigma</em> figure in it, who could resist a cypher that references <em>Enigma</em>?</p>

|security|simon|speck|

What, exactly, makes SPECK and SIMON particularly suitable for IoT devices?

230

<p>For some IoT devices, the data that needs to be sent is confidential, and hence sending it in plain text is not acceptable. Therefore, I've been considering how to encrypt data sent between IoT devices. An article I recently read on the <a href="http://www.rfidjournal.com/articles/view?13288" rel="noreferrer">RFID Journal</a> website mentions the NSA-developed <strong><a href="https://en.wikipedia.org/wiki/Speck_(cipher)" rel="noreferrer">SPECK</a></strong> and <strong><a href="https://en.wikipedia.org/wiki/Simon_(cipher)" rel="noreferrer">SIMON</a></strong> ciphers as particularly suited to IoT applications:</p> <blockquote> <p>NSA is making the ciphers [...] publicly available at no cost, as part of an effort to ensure security in the Internet of Things (IOT), in which devices are sharing data with others on the Internet.</p> <p>[...]</p> <p>NSA researchers developed SIMON and SPECK as an improvement on block cipher algorithms already in use that were, in most cases, designed for desktop computers or very specialized systems</p> </blockquote> <p>Why should I select a newer algorithm such as SIMON or SPECK for my IoT device, especially for applications where power is constrained (e.g. battery power only)? What are the benefits compared to other encryption systems such as <a href="https://en.wikipedia.org/wiki/Advanced_Encryption_Standard" rel="noreferrer">AES</a>?</p>

2016-12-09T12:28:02.783

<p>Generally speaking you have to adjust the trigger for the motion detection. There's the sensitivity for the actual motion detection and that is as bravokeyl already says despite all technology most efficiently done by trial and error.</p> <p>That might not work the same for all times of day due to low sun, clouds and other factors changing the lighting. Also cats. Motion detection and cats mix badly. Looking at the now provided options of your settings I'd start with deactivating the <em>low light sensitivity</em> box and check the results. At day and night. This might turn the camera useless at night, but that has to be tested with the actual device.</p> <p>There is however another setting that might help you out that is listed in the handbook:</p> <blockquote> <p><strong>Interval</strong> Enter the time in minutes that must pass between motion detection events. Valid values are 0-5, 10, or 15. The default is 2. A value of 0 indicates no delay between events.</p> </blockquote> <p><a href="http://downloads.linksys.com/downloads/userguide/1224639055972/WVC54GCA-EU_V10_UG_A-WEB.pdf" rel="noreferrer">WVC54GCA User guide</a></p> <p>It seems like that setting is set to zero if you get that many mails. Maybe revert it to default or even to five minutes. That should definitely reduce the amount of mails. </p>

|digital-cameras|home-security|surveillance-cameras|

My home monitoring camera sends me thousands of e-mails every day

236

<p>I've got a Linksys Wireless Internet Monitoring Camera (WVC54GCA with the recent firmware), which I've setup at home. I configured it to send me 5 second short videos to my e-mail on any physical movements during my absence. Despite my effort to configure the best settings, I still get the thousands of e-mails every day (one every minute or more) with no movements on them, but only slight contrast changes.</p> <p>Here are examples of three different videos:</p> <p><a href="https://i.stack.imgur.com/GHRjB.gif" rel="noreferrer"><img src="https://i.stack.imgur.com/GHRjB.gif" alt="Video feed: Linksys Wireless Internet Monitoring Camera, WVC54GCA"></a> <a href="https://i.stack.imgur.com/IJEvq.gif" rel="noreferrer"><img src="https://i.stack.imgur.com/IJEvq.gif" alt="Video feed: Linksys Wireless Internet Monitoring Camera, WVC54GCA"></a> <a href="https://i.stack.imgur.com/6F1yK.gif" rel="noreferrer"><img src="https://i.stack.imgur.com/6F1yK.gif" alt="Video feed: Linksys Wireless Internet Monitoring Camera, WVC54GCA"></a></p> <p>Is there anything that I can do about this problem? Or I should buy a better one?</p> <p>To clarify, I want to receive the e-mails, but with valid physical movements on the attached videos.</p> <hr> <p>Here are my configuration settings from /adm/image_fs.htm page:</p> <p><a href="https://i.stack.imgur.com/ILuBpl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ILuBpl.png" alt="Linksys WVC54GCA Wireless Internet Monitoring Camera, image admin configuration page"></a></p> <p>The White Balance options (if relevant) can be selected to: Auto, Indoor (Incandescent), Fluorescent (white light), Fluorescent (yellow light), Outdoor or Black &amp; White.</p> <p>Settings at /adm/event_fs.htm page:</p> <p><a href="https://i.stack.imgur.com/E5Uejl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/E5Uejl.png" alt="Linksys WVC54GCA, image admin configuration page, Motion Detection Settings, Trigger Motion Detection"></a></p>

2016-12-09T12:57:28.410

<p>There's another idea, also from <a href="http://support.thetrackr.com/hc/en-us/articles/205738069-My-TrackR-and-Phone-Randomly-Ring" rel="noreferrer">trackr's support page</a>. Again, it's also a feature that can be enabled/disabled, and that is &quot;Device alert.&quot; Basically, it warns when your phone can no longer make a bluetooth connection with your TrackR devices.</p> <blockquote> <p>If your TrackR device and/or smart phone is sounding off at seemingly random times, you may have device and/or phone alerts enabled. When “Device alert” is enabled your TrackR device will sound off when the bluetooth connection betwen your TrackR and phone is off. Conversely, when &quot;Phone alert&quot; is enabled your phone will begin to ring when bluetooth connection between your TrackR and phone is lost. To remedy this issue you can turn off phone and device alerts from the TrackR app. To turn off the alerts please follow these steps:</p> <ol> <li><p>Open the TrackR app</p> </li> <li><p>Click the icon in the top right corner of the app. This icon will look like 3 blocks stacked on top of each other.</p> </li> <li><p>A menu will slide in with a list of each TrackR device you have connected with. Click the gear cog next to a listed TrackR device.</p> </li> <li><p>Another menu will slide in where you will have the option to turn device and phone alerts on and off. Move them to the off position. Device and Phone separation alert need to be toggled off.</p> </li> <li><p>Repeat the above steps for any other TrackR's you are paired with.</p> </li> </ol> </blockquote> <p>For more information, check out the article referenced.</p>

|gps|tracking-devices|

TrackR keep ringing on its own

238

<p>At the beginning of 2014 I purchased a couple of coin sized <a href="https://thetrackr.com/" rel="nofollow noreferrer">TrackR devices</a> to tag my belongings, so I can easily find them. I use an iPhone to connect to them.</p> <p>My main problem using these devices was that the ringer on these devices keeps on activating on its own at random without any reason, and it keeps ringing constantly until switched off (taking out of the battery from it).</p> <p>Is this kind of problem a common one? How can I avoid this issue? Or has this problem been addressed already in later versions of these devices? Obviously I don't want to buy the new version on the hope that it's going to work this time.</p> <p>To clarify, I didn't use it for the thief-like option to ring when it's separated, I've used only option for the tracking purposes. It was ringing especially when disconnected from the phone, but after some long time. </p>

2016-12-09T13:52:52.440

<p>Okay, turns out he found the solution <a href="http://yourhome.honeywell.com/en/faqs/thermostat/wi-fi/lyric-t5-wi-fi/operation" rel="nofollow noreferrer">here</a>:</p> <blockquote> <p>If your commands are not responding, it means there is a disconnect between the app and Apple HomeKit. To resolve this use the following steps:</p> <ul> <li>Go into Settings on your smartphone and select the Wi-Fi, then scroll down to see thermostat name with the last six digits of the MAC ID .</li> <li>Turn Home Data off.</li> <li>Uninstall and reinstall the Lyric app.</li> <li>Go back into Settings and turn Home Data back on.</li> <li>Make sure that your iOS version is up-to-date.</li> </ul> </blockquote> <p>Apparently, doing this fixed his problem up entirely.</p>

|smart-home|apple-homekit|

Lyric T5 does not respond to commands via Apple Homekit

243

<p>I have a friend who has a <a href="http://www.apple.com/shop/product/HKJU2VC/A/honeywell-lyric-t5-wi-fi-thermostat" rel="nofollow noreferrer">Lyric T5 Wi-Fi thermostat</a> which he was controlling from his iPhone via Apple Homekit. Recently, all commands from his phone stopped reaching his device, demonstrating that they were no longer connecting to each other. Why would this be happening and how could he fix it?</p>

2016-12-09T15:49:48.127

<p>Most smart plugs I have come across are Wi-Fi controlled devices. </p> <p>I expect the regulations would be similar to those imposed on a Wi-Fi router such as Technicolor's <a href="http://www.technicolor.com/sites/default/files/medialib/document/connected_home_certificate/tg582n_dslwbc582pa_conformity.pdf" rel="nofollow noreferrer">TG582n</a>.</p> <blockquote> <ul> <li>RTTE Directive 1999/5/EC: Radio and Telecommunications Terminal Equipment.</li> <li>Commission Regulation (EC) No 1275/2008 implementing Directive 2009/105/EC: Ecodesign requirements for standby and off mode electric power consumption of electrical and electronic household and office equipment.</li> <li>Commission Regulation (EC) No 278/2009 following the provisions of the Energy-related Product directive 2009/105/EC (ecodesign): Ecodesign requirements for no-load condition electric power consumption and average active efficiency of external power supplies. The standards and/or normative documents are as follows: SAFETY</li> <li>EN 60950-1:2006 +Amendment Al 1:2009 + Amendment A12 + Amendment Al :2010 Information technology equipment - Safety Part 1: General requirements. EMC</li> <li>EN 55022:2006 + Amendment Al: 2007 Information technology equipment - Radio disturbance characteristics - Limits and methods of measurement.</li> <li>EN 55024: 1998 + Amendment Al: 2001 + Amendment A2: 2003 Information technology equipment - Immunity characteristics - Limits and methods of measurement.</li> <li>EN 61000-3-2:2006 Electromagnetic compatibility (EMC) - Part 3-2: Limits - Limits for harmonic current emissions (equipment input current up to and including 16A per phase).</li> <li>EN 61000-3-3:2008 electromagnetic compatibility (EMC) - Part 3-3: Limits - Limitation of voltage changes, voltage fluctuation and flicker in public low-voltage supply systems, for equipment with rated current &lt;= 16 A per phase and not subject to conditional connection.</li> <li>EN 301 489-01 VI .8.1 (2008-04) Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 1: Common technical requirements.</li> <li>EN 301 489-17 V2.1.1 (2009-05) Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 17: Specific conditions for Wideband data and HIPERLAN equipment. SPECTRUM</li> <li>EN 300 328 VI .7.1 (2006-10) Electromagnetic compatibility and Radio Spectrum Matters (ERM); Wideband Transmission systems; Data transmission equipment operating in the 2,4 GHz ISM band and using wide band modulation techniques; Harmonized EN covering essential requirements under article 3.2 of the R&amp;TTE Directive. HEALTH</li> <li>European Council Recommendation (1999/519/EC) on the limitation of exposure of general public</li> </ul> </blockquote> <p>It's worth picking up the phone and talking to your local compliance house. I used <a href="http://www.cei.ie/" rel="nofollow noreferrer">CEI</a> previously. It's not cheap but if you are serious and intend to sell your device, you will need to get someone to sign off on your product, otherwise it's a dangerous plug and not a smart plug.</p>

|smart-home|standards|safety|smart-plugs|ac-power|

European Union Regulations for Smart Plugs

250

<p>If I want my smart plug design to be a commercial product in the EU it must surely meet some requirements, regulations or directives.</p> <p>I know about the <a href="https://en.wikipedia.org/wiki/CE_marking" rel="nofollow noreferrer">CE</a> (Conformité Européenne) marking, which is mandatory in the European Economic Area. It means, if I can believe Wikipedia:</p> <blockquote> <p>Most electrical products must comply with the <a href="https://ec.europa.eu/growth/sectors/electrical-engineering/lvd-directive_en" rel="nofollow noreferrer">Low Voltage Directive</a> and the <a href="https://ec.europa.eu/growth/sectors/electrical-engineering/emc-directive_en" rel="nofollow noreferrer">EMC Directive</a>; toys must comply with the Toy Safety Directive</p> </blockquote> <p>I am mainly concerned about the safety, as smart plugs and sockets have direct connection to mains voltage, live wires, which is always dangerous. Proper sealing is needed.</p> <p>I have checked The Low Voltage Directive (LVD) and I think it covers the safety requirements for a smart plug based on the below part.</p> <blockquote> <p>The LVD covers all health and safety risks of electrical equipment operating with a voltage between 50 and 1000 V for alternating current and between 75 and 1500 V for direct current. These voltage ratings refer to the voltage of the electrical input or output, not to voltages that may appear inside the equipment.</p> </blockquote> <p>Now, there are other directives as well. For example <a href="https://en.wikipedia.org/wiki/Measuring_Instruments_Directive" rel="nofollow noreferrer">Measuring Instruments Directive</a>. It also mentions "Active electrical energy meters".</p> <p>There is also a general product safety directive according to this <a href="https://en.wikipedia.org/wiki/List_of_European_Union_directives" rel="nofollow noreferrer">list</a>.</p> <p>All in all which of the above mentioned and not mentioned directives are mandatory for commercial smart plug designs in the European Union? The main concern is safety.</p>

2016-12-09T16:27:00.090

<p>As detailed in my answer to the precision question (<a href="https://iot.stackexchange.com/a/341/78">https://iot.stackexchange.com/a/341/78</a>) the current generation of sdcards doesn't seem to support inherent geo-location capabilities anymore. Furthermore, <a href="http://www.digitaltrends.com/photography/ricoh-eyefi-acquisition-pentax-dslr/" rel="nofollow noreferrer">Eye-Fi was bought by Ricoh</a>. Looking at their product portfolio they seem to prefer to include the GPS function in the camera right away or offer additional GPS modules.</p> <p>Have a look at this <a href="https://havecamerawilltravel.com/photographer/gps-trackers-geotagging-photos" rel="nofollow noreferrer">blog about geo-tagging photos</a>. SD cards aren't even listed there anymore and I couldn't find any decent and recent sdcards with inherent geo-tagging. The trend seems to be different. The new <a href="http://rads.stackoverflow.com/amzn/click/B00O2AHP1Q" rel="nofollow noreferrer">Canon EOS 7D</a> has inbuilt GPS already. </p> <p>How to get your camera back after it's been stolen is of course extremely model based and cannot be answered in general.</p>

|geo-tagging|memory-cards|digital-cameras|

How to track a stolen Canon EOS camera using SDHC memory card?

251

<p>A few years back I've purchased an <a href="https://x2help.eyefi.com/" rel="noreferrer">Eye-Fi Pro X2</a> for my Canon EOS digital camera.</p> <p>Unfortunately, the camera has been stolen and at that time I had my photo sync disabled in <a href="https://center.eye.fi/" rel="noreferrer"><em>Eye-Fi Center</em></a> (which is now deprecated) and I couldn't do anything to activate it back remotely (either to re-activate sync of the photos or track the thief location based on the access point where the card is connected to). Now X2 is End of Life anyway.</p> <p>I'd like to know what I can do in the future to deal with similar situations using the latest version of <a href="http://www.eyefi.com/" rel="noreferrer">Eye-Fi</a> SDHC memory cards.</p> <p>In other words, I'd like to know whether it's possible to track the location of the lost camera remotely (assuming the camera is on with its card intact), or at least re-activating disabled photo sync remotely (assuming the card has been registered correctly). What should I activate or configure in order to prepare for the next potential incident?</p>

2016-12-09T18:01:33.013

<p>Wikipedia's article on <a href="https://en.wikipedia.org/wiki/Weightless_(wireless_communications)#Setting_up_connections" rel="nofollow noreferrer">Weightless</a> states that the base station will determine an appropriate frequency to use by querying a database:</p> <blockquote> <p>In networks using Weightless-W technology a base station queries a database which identifies the channels that are being used for terrestrial television broadcast in its local area. The channels not in use – the so-called white space – can be used by the base station to communicate with terminals using the Weightless-W protocol.</p> </blockquote> <p>To mitigate interference from other IoT networks, Weightless-W <a href="http://www.weightless.org/about/weightlessw" rel="nofollow noreferrer">can perform <em>frequency hopping</em></a>:</p> <blockquote> <p>Operation in unlicensed spectrum requires good interference tolerance. Weightless employs a frequency hopping regime at a frame rate of 2s to avoid interference on congested networks and to limit the impact of interference to a single hop rather than degrading the entire transmission.</p> </blockquote> <p>In the UK, <a href="https://www.ofcom.org.uk/" rel="nofollow noreferrer">Ofcom</a> (the communications regulator) have published <a href="https://tvws-databases.ofcom.org.uk/ofcomweblistspec.pdf" rel="nofollow noreferrer">guidance</a> on how to access approved TV white space databases for use with IoT devices, though this will be different in other countries.</p>

|networking|weightless|

How can I determine TV 'white space' frequencies for use with Weightless-W?

256

<p><a href="http://www.weightless.org/about/weightlessw" rel="noreferrer">Weightless-W</a> promotes itself as a <em>"low power wide area (LPWAN) star network architecture operating in TV white space spectrum"</em>, and seems to suggest that this method of transmission has several favourable characteristics:</p> <blockquote> <p>At the terminal level data rates from 1kbit/s to 10Mbit/s are possible depending on link budget with data packet sizes from 10 bytes and no upper limit with an extremely low overhead - 50 byte packets have less than 20% overhead. [...]</p> <p>An extremely wide range of modulation schemes and spreading factors provides flexibility in network design enabling 5km coverage to indoor terminals.</p> </blockquote> <p>On the <a href="http://www.weightless.org/about/which-weightless-standard" rel="noreferrer">Which Weightless Standard</a> page, it also states:</p> <blockquote> <p>If TV white space spectrum is available in the location where the network will be deployed and an extensive feature set is required, use Weightless-W</p> </blockquote> <p>The problem comes with determining if white space spectrum <strong>is available</strong>; how can I check where white space is open for IoT use with Weightless-W? Is there a tool I can use to determine this or a map? Also, would it be necessary to consider whether <strong>other IoT networks</strong> occupy some of the white space frequencies and the possibility that they could interfere?</p> <p>If it is useful in your answer, you can specifically focus on determining TV white spaces in the UK, although a more general solution would be interesting to read too.</p>

2016-12-09T18:32:35.510

<p>Possibly they fall under the more general, top-level groups of the "Internet of Everything". This groups includes the Internet of things but is more broad and includes devices such as PCs, tablets, industrial computers and so on. A drone is bit more complex than the accepted definition of a thing in the IoT allows for. For IoT think fridges, water heaters, smart meters, etc. For IoE think robots, PCs and all the other more complex devices. </p>

|definitions|drones|

Are drones considered part of the IoT by any officials?

257

<p>To clarify <a href="https://iot.stackexchange.com/q/99/271">what classifies a device as IoT</a> on a specific example, are all flying drones (UAV) part of the Internet of Things? Or there is some minimum requirement to classify it as IoT? What's the stance of the relevant standardization organizations?</p>

2016-12-09T23:16:51.260

<p>I have seen this behaviour when my hub was located next to my wireless router. One of the antenna sleeves on the router came off and disrupted communications to the hub from my lights &amp; dimmer switches.</p> <p>ZigBee and Wi-Fi frequencies overlap on certain channels (2.4 Ghz) so you could try to change the channel in the Hue app, if moving the hue hub further from the router isn't an option.</p>

|philips-hue|

Hue Dimmer Switch frequently "ignored" by the light

265

<p>I've got multiple Hue White bulbs, multiple Dimmer switches and a second generation Hue hub. Sometimes, pressing a dimmer button doesn't result in the bulb reacting in any way. Sometimes I have to press multiple times to switch the light on or off. Sometimes I even have to use the hard switch to get what I need. All 5 dimmers in my house have already (&lt;1 year) exhibited this behaviour at least a couple of times. Some are worse than others.</p> <p>I think I've never seen my lights ignoring the Hue app.</p> <p>I wonder what the reason could be and what troubleshooting I could do. All distances are very reasonable (max distance between 2 nearest bulbs is &lt;5 m). Usually the system works. Sometimes the devices that fail in this way are actually those located the closest to the hub. </p> <p>I would also like to know if the dimmer is actually connected to the bulb directly or via the hub.</p>

2016-12-10T12:11:21.077

<p>The WiFi we know and use now also share the 2.4 GHz frequency range with a lot of other technologies and applications which might interfere. If we have a look on the <a href="https://en.wikipedia.org/wiki/List_of_2.4_GHz_radio_use" rel="nofollow noreferrer">list of 2.4 GHz radio usage</a>, a couple of items are there beside WiFi.</p> <blockquote> <ul> <li><p>Many cordless telephones and baby monitors in the United States and Canada use the 2.4GHz frequency, the same frequency at which Wi-Fi standards 802.11b, 802.11g and 802.11n operate.</p> </li> <li><p>Bluetooth devices intended for use in short-range personal area networks operate from 2.4 to 2.4835 GHz.</p> </li> <li><p>Certain car manufacturers use the 2.4 GHz frequency for their car alarm internal movement sensors. These devices transmit on 2.45 GHz (between channels 8 and 9) at a strength of 500 mW.</p> </li> <li><p>ZigBee</p> </li> <li><p>My wireless mouse and keyboard.</p> </li> </ul> </blockquote> <p>Moreover the 2.4 GHz band has the following <a href="https://en.wikipedia.org/wiki/ISM_band" rel="nofollow noreferrer">licensed users</a>:</p> <blockquote> <p>FIXED, MOBILE, RADIOLOCATION, Amateur &amp; Amateur-satellite service</p> </blockquote> <p>So accepting interference is pretty much the case right now too.</p> <p>From <a href="http://www.theverge.com/2016/1/4/10691400/new-wifi-halow-standard-announced-iot-ces-2016" rel="nofollow noreferrer">The Verge's article, &quot;There's a new type of Wi-Fi, and it's designed to connect your smart home&quot;</a>:</p> <blockquote> <p>It'll be in the 900MHz range, which has better reach and penetration than the 2.4GHz and 5GHz range that existing Wi-Fi operates in. (But, like existing Wi-Fi, it'll be in operating in unlicensed spectrum, so there may be interferences.) There does, of course, have to be a downside. And there is: HaLow isn't going to be as good at quickly transferring data. <strong>This isn't Wi-Fi for browsing the web; it's for transferring small bits of data on infrequent occasions</strong>. Device manufacturers can, to some extent, customize HaLow to their needs to get faster transfers, but that'll happen at the expense of battery life.</p> </blockquote> <p>So as WiFi HaLow is designed for lower bandwidth and for battery saving low-power applications it might a be better solution if we are already talking about interference. As it is intended to transfer less data then original WiFi.</p>

|networking|standards|wifi-halow|

Is Wi-Fi HaLow unsuitable for IoT applications because it operates in unlicensed frequencies?

268

<p>The Wi-Fi Alliance's relatively new <a href="http://www.wi-fi.org/discover-wi-fi/wi-fi-halow" rel="noreferrer">Wi-Fi HaLow</a> (802.11ah) specification seems to be ideal in some characteristics for IoT devices:</p> <blockquote> <p>Wi-Fi HaLow will enable a variety of new power-efficient use cases in the Smart Home, connected car, and digital healthcare, as well as industrial, retail, agriculture, and Smart City environments.</p> <p>Wi-Fi HaLow extends Wi-Fi into the 900 MHz band, enabling the low power connectivity necessary for applications including sensor and wearables. Wi-Fi HaLow’s range is nearly twice that of today’s Wi-Fi, and will not only be capable of transmitting signals further, but also providing a more robust connection in challenging environments where the ability to more easily penetrate walls or other barriers is an important consideration.</p> </blockquote> <p>However, as mentioned in the linked source, HaLow operates in the 900MHz frequency, which, according to <a href="http://www.eweek.com/networking/halow-wifi-standard-brings-its-own-set-of-highs-and-lows-2.html" rel="noreferrer">eWeek</a>, is an unlicensed frequency:</p> <blockquote> <p>Unfortunately, the new HaLow standard doesn't have its frequencies to itself. Because the 900MHz band is shared with other licensed services, the new WiFi band is subject to interference from other users and there is no remedy when that interference happens.</p> <p>For example, if a ham radio operator next door goes on the air with a powerful signal that wipes out your smart thermostat, you're out of luck. Because you're an unlicensed service, you're required to accept that interference.</p> <p>However, if your smart thermostat happens to cause interference to that ham radio operator next door, then you're required to stop doing it. As an unlicensed user, you have few rights to the spectrum if someone else wants to use it.</p> </blockquote> <p>Presumably this is related to the <a href="http://www.ecfr.gov/cgi-bin/text-idx?SID=7b9648f6ec90b7ebfad611bf26c88c34&amp;mc=true&amp;node=pt47.1.15&amp;rgn=div5#se47.1.15_119" rel="noreferrer">FCC rules</a> which are commonly seen on RF products:</p> <blockquote> <p>This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.</p> </blockquote> <p>Does this make HaLow too problematic for use as a communication method, since my transmissions could easily be forced to stop if someone else was transmitting in that frequency? If I wished to design a device using HaLow, how could I avoid interference which would require me to stop broadcasting?</p>

2016-12-10T14:47:02.787

<p>There are two advantages as far I know, here they are:</p> <p>First: Snap packages can bring their own dependencies with them. So no dependency hell.</p> <p>Second: Snap packages can be installed for one user only. So more control of who is running that software.</p> <p>Some quotes (including source links):</p> <p><strong>from <a href="https://insights.ubuntu.com" rel="noreferrer">https://insights.ubuntu.com</a></strong></p> <blockquote> <p>Snaps are isolated from one another to guarantee data security, and can be updated or rolled back automatically, making them perfect for connected devices. Multiple vendors have launched snappy IoT devices, enabling a new class of “smart edge” device with IoT app store. Snappy devices receive automatic updates for the base OS, together with updates to the apps installed on the device. </p> <p>(<a href="https://insights.ubuntu.com/2016/06/14/universal-snap-packages-launch-on-multiple-linux-distros/" rel="noreferrer">source</a>)</p> </blockquote> <p><strong>from <a href="https://developer.ubuntu.com" rel="noreferrer">https://developer.ubuntu.com</a></strong></p> <blockquote> <p>Ubuntu Core is in many ways simply another flavor of Ubuntu (eg, the root filesystem is built from packages from the same Ubuntu archive as other flavors), but it differs in many important ways:</p> <ul> <li>The base system is a very minimal system that consists of three different parts: the kernel, gadget and OS which are all packaged and delivered using the new snap packaging format</li> <li>There is a clean separation between the base system and the applications installed on the system as well as a clean separation between installed applications</li> <li>Ubuntu Core replaces ‘apt’ with the new ‘snap’ command and applications are packaged and delivered as ‘snaps’</li> <li>The root filesystem is read-only</li> <li>Developers may update applications independently of the OS</li> <li>Applications run in a security sandbox by default</li> <li>Ubuntu Core is application-centric instead of distribution archive-centric</li> </ul> <p>The above qualities aim to address many of the challenges inherent in the traditional Linux distribution model and greatly increase reliability, predictability and security. </p> <p>(<a href="https://developer.ubuntu.com/en/snappy/guides/security-whitepaper/" rel="noreferrer">source</a>)</p> </blockquote> <p><strong>from <a href="http://snapcraft.io/" rel="noreferrer">http://snapcraft.io/</a></strong></p> <blockquote> <p>A snap is a fancy zip file containing an application together with its dependencies, and a description of how it should safely be run on your system, especially the different ways it should talk to other software.</p> <p>Most importantly snaps are designed to be secure, sand-boxed, containerized applications isolated from the underlying system and from other applications. Snaps allow the safe installation of apps from any vendor on mission critical devices and desktops. </p> <p>(<a href="http://snapcraft.io/" rel="noreferrer">source</a>)</p> </blockquote>

|ubuntu-core|snappy|package-managers|

What makes Ubuntu Core's "Snaps" better than normal packages for IoT devices?

271

<p><a href="https://www.ubuntu.com/core" rel="noreferrer">Ubuntu Core</a>, Canonical's latest version of Ubuntu for IoT devices, says that its new <a href="https://en.wikipedia.org/wiki/Snappy_(package_manager)" rel="noreferrer">Snappy</a> package manager is ideal for the Internet of Things, and Wikipedia says that:</p> <blockquote> <p>Snappy packaging has been deployed in internet of things environments, ranging from consumer-facing products to enterprise device management gateways</p> </blockquote> <p>However, package managers on Linux aren't a new thing by any means - <a href="https://en.wikipedia.org/wiki/Advanced_Packaging_Tool" rel="noreferrer">APT</a> has been around since mid-1998 - so why is Snappy considered so much better by Canonical for IoT? Are other package managers' security practices unsuitable for IoT or is there another factor that is more important?</p>

2016-12-10T16:29:42.363

<p>After some further investigation, I think the issue in the question is that although the <strong>power</strong> (rate of energy transfer) was reduced, the overall <strong>energy consumption</strong> was increased by using Docker, so there is no benefit in terms of reduced electricity costs.</p> <p>Based on the paper's figures for 100,000 requests, we can calculate the energy usage through the formula:</p> <blockquote> <p>Energy = power x time</p> </blockquote> <p>Given that the native code consumed 2.4893 W of power, and took approximately 170 seconds (see Figure 3, Native 200), we know that the energy used was:</p> <blockquote> <p>2.4893 W * 170 s</p> <p>= 423.181 Ws = 423.181 J (1 watt-second is equivalent to a joule, or, in other words, a watt is a joule per second)</p> </blockquote> <p>For the Docker code, the power usage was 2.3642 W, but the time taken was 220 seconds, so:</p> <blockquote> <p>2.3642 W * 220 s</p> <p>= 520.124 Ws = 520.124 J</p> </blockquote> <p>Hence, the overall energy usage for the example was 96.943 J higher, which is clearly undesirable if energy usage is a concern. However, using Docker does have other advantages for deployment and management, but in <strong>tightly constrained</strong> environments (e.g. battery-only), it would seem that it is best avoided.</p>

|raspberry-pi|docker|power-consumption|linux|

Why does Docker reduce power usage on an Internet of Things device in this benchmark?

277

<p>I've been interested in the applications of Docker on IoT devices such as Raspberry Pis.</p> <p>After reading <a href="https://arxiv.org/ftp/arxiv/papers/1603/1603.02955.pdf" rel="noreferrer"><em>A Performance Evaluation of Container Technologies on Internet of Things Devices</em></a>, I was slightly confused by one of the results. In Table 1, the power consumption shown under <em>Apache 2 Benchmarking (200 clients)</em> shows that using a Docker container <strong>reduced</strong> power consumption, despite the overhead of containerisation using Docker.</p> <p>Why does this occur? Is this reliable enough to be used to slightly reduce power consumption of IoT devices, and would there be any drawbacks?</p>

2016-12-10T21:21:05.620

<p>Well, there is an online scheduling service you could use. <a href="https://ifttt.com/date_and_time" rel="nofollow noreferrer">If this then that</a> offers date time applets that can trigger certain events. They also do have <a href="https://ifttt.com/applets/415943p-fully-open-a-lightwaverf-trv-when-the-temperature-gets-cold" rel="nofollow noreferrer">Lightwave RF heating</a> recipes that prove that IFTTT works with the valve in general.</p> <p>If you are not opposed to writing an IFTTT recipe you might be able to create a recipe there where you can create the schedule - maybe even a configurable schedule - that triggers your valves. The [API of the valve] seems to indicate that the commands should be available in theory.</p> <p>This might be a way. I'll try to detail it a bit more later on.</p>

|smart-home|lightwave-rf|

Schedule for Lightwave RF thermostat

278

<p>I have a LightwaveRF thermostatic radiator valve, and a hub to connect this to the internet. Setting a schedule seems particularly problematic. <a href="http://www.lightwaverf.com/product/922-radiator-wave/" rel="noreferrer">This</a> is the valve in question.</p> <p>I have the option of an Android app, or the website, each seems to have their own problems around the 6am point which is designated as the end of day.</p> <p>If I set a schedule using the web interface, it doesn't seem to be synced across to the mobile view.</p> <p>Is there any reliable way to edit these schedules? I see there are old comments in various places which confirm these are not unique problems. I'd rather not set up a dedicated server for control, but it's an option.</p> <p>I want a profile like this: </p> <pre><code>5am-7:30 20°C 10pm-11pm 20°C 11pm-5am 18°C </code></pre> <p>The design of both UIs appears to insist there are no active settings spanning 6am. It seems very easy to enter parameters which are detected by the web page as conflicting between one day and another. Even setting 5am seems to confuse the system - it gets automatically put in the previous day.</p>

2016-12-11T12:52:57.260

<p>Okay, so this is a bit of a mess, but this is how I did it.</p> <p>First, I tried with my German account to link it and had the same problem with skills. I could use Alexa in English, but not install skills. Frustrating.</p> <p>Next, I created a second Amazon account in the USA and linked my Echo Dots, giving me access to the skills. Of course, I no longer have access to prime music, but the skill library was more important to me than my German Amazon content. So that's a choice you need to make.</p> <p>Even after I installed the skills, some weren't functioning correctly, especially Plex and Harmony with finding my devices. Again, it seems that the German Alexa app (on iPhone) was causing problems, as I would get another language warning from time to time. So I had to switch my iTunes back to the USA store and redownload the Alexa app, so I had the USA version. Now, everything is working perfectly. So if you go this route, there are probably other skills that won't work correctly with the German version of the Alexa app.</p> <p>Hope this helps!</p>

|amazon-echo|alexa|

How to use English Alexa Skills on my German Echo Dot

281

<p>I want to use English Alexa skills on a German Echo Dot. But when I switch to US English to access English skills I get this problem:</p> <blockquote> <p><strong>Die ausgewählte Spracheinstellung stimmt nicht mit den Einstellungen Ihres Amazon-Kontos überein.</strong><br> Daher werden Sie nicht auf Skills zugreifen können.<br> Um auf Skills zuzugreifen und die optimale Spracherfahrung zu nutzen, gehen Sie bitte in den Einstellungen zur Sprachoption, und wählen Sie <strong>Deutsch</strong> aus.</p> </blockquote> <p>Translation:</p> <blockquote> <p><strong>The language you selected does not match your Amazon account settings.</strong><br> As a result, Alexa skills are not available.<br> To get the best Alexa experience, please choose <strong>German</strong> by selecting continue.</p> </blockquote> <p>I switched the account settings but that did not yield in any positive results. How do I use the bigger Alexa skill base that exists for English?</p>

2016-12-11T14:38:28.760

<p>Mesh networks tend to give better local configuration options for an IoT network. Range extension was already mention which the mesh network as each device in the network will help make the network bigger than each device would be alone. Another important aspect is how the messages are routed. While some devices will remain stationary, others may be moved around. This could make routing messages in a typical way difficult, but a mesh network will be able to handle it better as all the nodes will be able to look for the device in question.</p> <p>A practical example of this in work is in a ZWave network you can rediscover all the nodes in your network so the controller and other nodes can figure out the best path for messages and which nodes can talk to which with and without relaying the message on a different device. More information on this can be seen on <a href="http://www.vesternet.com/resources/technology-indepth/understanding-z-wave-networks">this page on the "Mesh and Routing" section</a>.</p>

|networking|topologies|mesh-networks|

Why are mesh networks used more frequently for IoT networks?

286

<p>Many common IoT communication protocols I've researched have adopted a mesh topology (for example <a href="https://en.wikipedia.org/wiki/ZigBee" rel="noreferrer">ZigBee</a>, <a href="https://en.wikipedia.org/wiki/Thread_(network_protocol)" rel="noreferrer">Thread</a> and <a href="https://en.wikipedia.org/wiki/Z-Wave" rel="noreferrer">Z-Wave</a>), which is a significant contrast to the usual star topology of Wi-Fi, where every device connects to one router/hub.</p> <p><a href="http://www.eetimes.com/author.asp?doc_id=1329424" rel="noreferrer">EETimes</a> also state that:</p> <blockquote> <p>Mesh networking is emerging as an ideal design solution for interconnecting a large number of network devices.</p> </blockquote> <p>EETimes suggest that reliability improvements (e.g. self-healing transmissions) are one of the main advantages of a mesh network, though this seems like a small advantage compared to the added complexity of setting up a mesh network.</p> <p>For a home IoT network which is likely to contain about 10-20 networked devices and spread a short range from end-to-end, what makes mesh networks more suitable than a regular star topology? Is the added complexity not as significant as I seem to believe it is?</p>

2016-12-11T17:01:25.687

<p>I think this will be difficult to answer, ask three lawyers get four answers, not to mention that it is something in the future. However, I would argue, that not each device (in the technical sense) would be required to comply with this rule. </p> <p>Consider a use case where smart devices work without an external or cloud-based data service, e.g. a smart home system where IoT devices report to a central node in said home, but not uploading anything. In this case there is simply no <em>data controller</em>.</p> <p>If on the other hand a system uses the data services of a <em>data controller</em> to collect, process, and store user data (e.g. the mentioned FitBit) they shall be required to enable you to take hold of this data and use it with another provider. I argue that the <em>electronic processing system</em> is not necessarily your device (the tracker itself) but the external data service this provider offers. This (to me) also implies that your right to get this data in <em>a structured and commonly used electronic format</em> does not require the first provider to give you the data in the file format of the second provider if their format is proprietary and not <em>commonly used</em>. From a technical standpoint we would expect a common API to allow for this interchange of data but I dare say that we will have to wait for this for some time and quite a number of disputed court decisions.</p> <blockquote> <p>In addition, how will I be expected to comply with this regulation if I design my own IoT device that synchronises with the Internet?</p> </blockquote> <p>If it is DIY and only you use it you'll most likely be fine. If you start turning this into a business plenty of regulations including this one shall hit you.</p>

|standards|data-portability|

Will "smart" devices be required to allow import and export of data under the GDPR?

287

<p>In May 2018, the European Union's <a href="https://en.wikipedia.org/wiki/General_Data_Protection_Regulation" rel="noreferrer">General Data Protection Regulation</a> will come into force, and EU citizens will be given additional rights in regards to their data. As well as this, <em>data controllers</em> (organisations that <em>collect</em> data on users) will have additional obligations placed upon them.</p> <p>Interestingly, one of the new rights given to users is the right to <a href="https://en.wikipedia.org/wiki/General_Data_Protection_Regulation#Data_portability" rel="noreferrer">data portability</a>. Wikipedia defines it like so:</p> <blockquote> <p>A person shall be able to transfer their personal data from one electronic processing system to and into another, without being prevented from doing so by the data controller. In addition, the data must be provided by the controller in a structured and commonly used electronic format. The right to data portability is provided by Article 18 of the GDPR. Legal experts see in the final version of this measure a "new right" created that "reaches beyond the scope of data portability between two controllers as stipulated in Article 18."</p> </blockquote> <p>For the purpose of this question, take the example of a smart health tracker (such as a FitBit). Will I be able to export data from my FitBit tracker and then import the data into a competitor's tracker? </p> <p>In addition, how will I be expected to comply with this regulation if I design my own IoT device that synchronises with the Internet?</p>

2016-12-11T18:15:08.787

<p>According to <a href="https://developer.ubuntu.com/en/snappy/start/gadget-snaps/" rel="noreferrer">developer.ubuntu.com</a>, there are basically <strong>two purposes</strong>:</p> <p><em><strong>- Declare hardware capabilities to the system</strong></em></p> <p>Quoting from <a href="https://docs.ubuntu.com/core/en/guides/build-device/gadget" rel="noreferrer">Ubuntu Documentation</a>:</p> <blockquote> <p>The gadget snap is responsible for defining and manipulating the system properties which are specific to one or more devices that will usually look similar to one another from an implementation perspective. This snap must necessarily be produced and signed by the device brand, which is defined via the model assertion. The brand knows where and how that device will be used, and designs the gadget snap accordingly.</p> <p>For example, the brand may know that the device is actually a special VM to be used on a particular cloud, or it may know that it is going to be manufactured in a particular factory. The gadget snap may encode the mechanisms for device initialization - key generation and identity certification - as well as particular processes for the lifecycle of the device, such as factory resets. It is perfectly possible for different models to share a gadget snap.</p> </blockquote> <p><em><strong>- Pre-allow access to snaps that need to use this hardware</strong></em></p> <p>Also from the <a href="https://docs.ubuntu.com/core/en/guides/build-device/gadget" rel="noreferrer">Ubuntu Documentation</a>:</p> <blockquote> <p>The optional prepare-device <a href="https://docs.ubuntu.com/core/en/guides/build-device/config-hooks" rel="noreferrer">hook</a> is a script that will be called on the gadget at the start of the device initialization process, after the gadget snap has been installed. The hook will also be called if this process is retried later from scratch in case of initialization failures.</p> <p>The device initialization process is for example responsible of setting the serial identification of the device through an exchange with a device service. The prepare-device hook can for example redirect this exchange and dynamically set options relevant to it.</p> </blockquote>

|ubuntu-core|snappy|

What's the purpose of a gadget snap in Ubuntu Core?

288

<p>I've been looking into how to set up Ubuntu Core (the IoT version of Ubuntu) on a Raspberry Pi, and I've read about <a href="https://docs.ubuntu.com/core/en/guides/build-device/gadget" rel="nofollow noreferrer">gadget snaps</a>, which the documentation says is intended to define the device features:</p> <blockquote> <p>The gadget snap is responsible for defining and manipulating the system properties which are specific to one or more devices that will usually look similar to one another from an implementation perspective.</p> </blockquote> <p>What's the motivation for having a gadget snap? Can the information not be obtained through normal system features such as <a href="http://manpages.ubuntu.com/manpages/zesty/man1/lshw.1.html" rel="nofollow noreferrer"><code>lshw</code></a>, or is there another reason for this (perhaps security or a more declarative environment)?</p> <p>The reason I ask is because if I wished to use Ubuntu Core on a different device, the pre-defined gadget snaps won't be suitable, but I'm unsure why I even need a gadget snap in the first place.</p>

2016-12-12T09:07:24.593

<p>Yes.</p> <p>MQTT clients are connected to a broker which can be a cloud or some other device.</p> <p>There is no such thing like creation of topic. They are used as a heading for a message. So if your client has subscribed to a topic and if it publish's something on that topic then the message will be received via the broker to the client again.</p> <p>Examples of good brokers are Mosquitto for running on devices and CloudMqtt for cloud based Broker </p>

|mqtt|

Can an MQTT client subscribe to a topic created by itself?

294

<p>In my understanding, in MQTT a topic is created once a client publishes something with the corresponding topic name.</p> <blockquote> <p>There is no need to configure a topic, publishing on it is enough.</p> </blockquote> <p>From <a href="https://mosquitto.org/man/mqtt-7.html" rel="noreferrer">here</a>.</p> <p>It is possible for a client to subscribe to its own topic, after it published, created it? I could not find any restrictions on it in the <a href="http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html" rel="noreferrer">specifications</a>. It is not listed as possible abnormal behaviour neither:</p> <blockquote> <p><strong>5.4.8 Detecting abnormal behaviors</strong></p> <p>Server implementations might monitor Client behavior to detect potential security incidents. For example:</p> <ul> <li>Repeated connection attempts</li> <li>Repeated authentication attempts</li> <li>Abnormal termination of connections</li> <li>Topic scanning (attempts to send or subscribe to many topics)</li> <li>Sending undeliverable messages (no subscribers to the topics)</li> <li>Clients that connect but do not send data</li> </ul> </blockquote> <p>Based on this, I think it is certainly possible. So I am interested in what are the uses cases of this feature?</p> <p>Why does the standard allow such mechanism, would it be to complicated to track the owner of the topics? So instead it just simply allows clients to subscribe to their own topic.</p> <p>One use case I can think of is that this way a client can verify its published data.</p>

2016-12-12T18:41:55.573

<p>One thing to remember when working with MQTT is that "both subscribers and publishers are considered MQTT clients". </p> <p>As said QoS set while publishing is entirely related to broker(B) not the other clients. So to ensure that subscriber(S) is receiving everything that publisher(P) is publishing, one need to use QoS 1.</p> <p>Let's look at cases: P - sends with QoS 0 which means that every message will be at B atmost once ( one time or zero ). In this case if S subscribes to B with QoS 0 -- there is no guarantee that even when the broker (B) receives a message that is going to finally reach S . QoS 1 -- S will definitely receive QoS 2 -- S won't receive multiple messages while broker can</p> <p>If we do the same with other QoS. We will get to know QoS1 for subscribers works well with all levels as QoS 1 is superset of all.</p> <hr> <p>MQTT does not provide any indication for the same but we can achieve sender's QoS by using QoS 1 while subscribing.</p>

|mqtt|communication|

Is there a way to preserve the MQTT QoS level until it reaches the client?

298

<p>MQTT allows senders to set a <a href="https://dzone.com/articles/internet-things-mqtt-quality" rel="nofollow noreferrer">Quality of Service</a> (QoS) level, which provides certain guarantees about whether a message will be received (and whether duplicates are permitted). This article from <a href="http://www.hivemq.com/blog/mqtt-essentials-part-6-mqtt-quality-of-service-levels" rel="nofollow noreferrer">HiveMQ</a> highlights the problem of <em>downgrading</em>, where a client with a lower QoS level will not receive the message with the guarantees that the sender requested:</p> <blockquote> <p>As already said, the QoS flows between a publishing and subscribing client are two different things as well as the QoS can be different. That means the QoS level can be different from client A, who publishes a message, and client B, who receives the published message. Between the sender and the broker the QoS is defined by the sender. When the broker sends out the message to all subscribers, the QoS of the subscription from client B is used.</p> </blockquote> <p>Does MQTT provide a way of indicating that this downgrade is not acceptable, and that the message <strong>must</strong> be delivered using the original sender's requested QoS? Is the only option to make sure that both the sender and the receiver have the desired QoS setting <strong>before</strong> transmitting the message?</p>

2016-12-12T22:09:41.117

<p>The Harmony Hub creates virtual switches in the SmartThings app. If you authorize these with Google home, you can issue commands like "Turn on Watch TV" or "Turn off Watch TV"</p> <p>The Google home integration can be found under Things -> Voice Control in the SmartThing's Marketplace. </p>

|google-home|samsung-smartthings|logitech-harmony|

How to connect Google Home to Harmony hub through SmartThings

300

<p>I've just got the Google Home, and SmartThings hub. My TV is already controlled with Logitech Harmony Hub (Smart Home Hub).</p> <p>How do I set it up so that saying "Ok Google, Watch TV" would trigger the harmony activity to watch TV?</p> <ul> <li><a href="http://www.bestbuy.ca/en-CA/product/logitech-logitech-harmony-smart-control-915-000195/10242486.aspx" rel="noreferrer">Harmony Smart Control</a> </li> <li><a href="https://shop.smartthings.com/kits/samsung-smartthings-home-monitoring-kit" rel="noreferrer">SmartThings Hub</a> (I understand it's the V2) </li> <li><a href="https://madeby.google.com/home/" rel="noreferrer">Google Home</a> (there is only one version)</li> </ul>

2016-12-12T22:12:08.497

<p>I've tested this out extensively as I really want to be able to verbally initiate one of my Youtube playlist via Google Home.</p> <p>The good news is that can, but only for your Liked videos. I use a Routine to initiate this (because it gives you flexibility that specify a preferred verbal command. Here's how I have set it up in Google Home app on my Android mobile</p> <ol> <li>Open Home app and go to Account/Settings/Assistant/Routines</li> <li>Select 'Add action' for the 'When I say' action and type "My Videos" (or whatever you prefer to say to initiate the routine)</li> <li>Select 'Music' option for the 'My Assistant Should' action, and then select the right hand cog (settings) icon.</li> <li>Enter the following text <em>[your Youtube user name] "Liked videos</em> where it ask 'What music would you like to play?. Just to clarify, here's the exact text I have entered which is between these quotes "Sydney_Robster Liked videos" 5 Use back button to return to the previous page and select the tick at the top of the page to save this Routine.</li> <li>Initiate your Youtube Liked Videos Routine my saying to Google Home/Assistant, "Hey Google, My Videos" (or whatever command you defined). The routine will play your Liked Videos in the order that they have been created in Youtube. If you want to randomise it, then additionally say "Hey Google, shuffle"</li> </ol> <p>Another useful command for the Google Home/Assistant is when you are watching Youtube cast to chrome device, is if you see a new video you like, say "Hey Google, like". The Assistant will reply "I have noted that you like this" and the Assistant will 'like' the video and it will be appended to your list.</p>

|google-home|chromecast|

How to instruct Google Home to play YouTube videos from *my* playlists

301

<p>Everytime I ask Google Home to play a YouTube video, it searches for (seemingly) random playlists that may contain that video... sometimes it doesn't.</p> <p>I have my own playlists, with a specific video.</p> <p>How do I instruct Google Home to play a video from <strong>my</strong> YouTube playlist?</p> <p><em>Edit: Requests I've tried:</em> </p> <p><a href="https://www.youtube.com/watch?v=L0MK7qz13bU" rel="noreferrer">This is the video I want to play</a>. Please note on the web, simply typing "Frozen Let It Go" brings up this video 100% of the times (even in incognito)</p> <ul> <li>Play Frozen Let It Go on TV </li> <li>Play Frozen Let It Go on YouTube on TV </li> <li>Play Let It Go sing-along on TV </li> <li>Play Let It Go sing-along by Disney on TV</li> <li>Play Frozen Let It Go sing-along on TV</li> </ul> <p>Most of the times it brings the <a href="https://www.youtube.com/watch?v=kHue-HaXXzg" rel="noreferrer">Demi Lovato cover</a><br> Other times it loads playlists (again, either with Demi Lovato cover, or others)</p> <p>I have a playlist called "Frozen Sing Along", but I am unable how figure out how to tell Google Home to search within <strong>my</strong> playlists.</p> <p>I've tried "Play Frozen Sing Along on TV", but again, it picks up random playlists, not mine.</p>

2016-12-12T23:29:34.063

<p>I ma using <code>Fibaro Automation</code> with <code>Automation Bridge</code> with Alexa. I can just say</p> <ul> <li>Turn on All Lights or</li> <li>Close All Blinds.</li> </ul> <p>Thats just built in.</p> <p>For further refinement, I have created groups so I can say things like</p> <ul> <li>Turn on Living Room Lights</li> <li>Open Lounge Blinds</li> <li>Turn off Outside Lights</li> </ul> <p>I am not associated with any of the 3 companies. But I would recommend <code>Automation Bridge</code> for anyone that is serious about full control. It interfaces to a range of Automation servers etc and integrates with Siri, Alexa and Google.</p>

|alexa|samsung-smartthings|

How can I use Alexa to turn on/off multiple lights at the same time with SmartThings hub?

303

<p>I have various lights/switches/dimmers on a SmartThings hub. I can control them individually, but would like to say something like "Alexa turn on everything" to turn on all lights, or maybe "turn on movie time" to dim the lights turn off the kitchen lights, etc.</p> <p>Hue has 'scenes' is there something similar for SmartThings? </p>

2016-12-13T05:24:14.113

<p>See these <a href="https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/developing-an-alexa-skill-as-a-lambda-function" rel="nofollow noreferrer">instructions</a>.</p> <p><a href="https://developer.amazon.com" rel="nofollow noreferrer">Create</a> an AWS developer account &amp; AWS account. </p> <p>In the AWS console</p> <ul> <li>Create a lambda function. Include in the lambda function some code that will access the API. This can either be python or java or node.js.</li> </ul> <p>Here is a python script. Change <code>modify_state</code> to be either 1 or 0</p> <pre class="lang-or-tag-here prettyprint-override"><code>import urllib2 def modify_state( port, state, token): url = 'https://us.wio.seeed.io/v1/node/%s/onoff/%s?access_token=%s' % (port, state, token) req = urllib2.Request(url,'') response = urllib2.urlopen(req) def lambda_handler(event, context): modify_state('GroveRelayD0', &lt;STATE:0:1&gt;, '&lt;APIKEY') # TODO implement return { 'version': '1.0', 'sessionAttributes': {}, 'response': { 'outputSpeech': { 'type': 'PlainText', 'text': '&lt;whatever whitty remark alexa should say&gt;' }, 'card': { 'type': 'Simple', 'title': "SessionSpeechlet - foo", 'content': "SessionSpeechlet - bar" }, 'reprompt': { 'outputSpeech': { 'type': 'PlainText', 'text': 'I know right' } }, 'shouldEndSession': True } } </code></pre> <ul> <li>Make sure to publish new version (copy the ARN in the top right, you'll need it later)</li> </ul> <p><a href="https://i.stack.imgur.com/URaP7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/URaP7.png" alt="aws lambda code"></a></p> <ul> <li>Set the 'trigger' to alexa skills</li> </ul> <p><a href="https://i.stack.imgur.com/OlqYe.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OlqYe.png" alt="aws trigger configuration"></a></p> <hr> <p>In the developer console </p> <ul> <li><p>Create a skill <a href="https://i.stack.imgur.com/EMCLm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EMCLm.png" alt="create a skill dialog"></a></p></li> <li><p>Create an Interaction Model with an intent, and a sample utterance <a href="https://i.stack.imgur.com/1bSNm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1bSNm.png" alt="intent schema dialog"></a></p></li> <li>Link the endpoint</li> </ul> <p><a href="https://i.stack.imgur.com/UJry3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UJry3.png" alt="endpoint configuration dialog"></a></p> <p>You can skip the last 2 steps. The skill will run in development mode and only you will be able to access it. Complete the last 2 steps only if you want to share your skill with anyone in the world. </p>

|alexa|amazon-echo|voice-recognition|

How do I configure Alexa to access a REST API?

306

<p>I have several lights connected to relays which are connected to a <a href="https://www.seeedstudio.com/Wio-Link-p-2604.html">wiolink</a> </p> <p>I can turn the lights on and off through the REST API, like so:</p> <pre><code>curl https://us.wio.seeed.io/v1/node/GroveRelayD0/onoff/[onoff]?access_token=xxxxx </code></pre> <p>How can I access this REST API through Alexa with an Echo Dot?</p>

2016-12-13T17:52:50.617

<p><strong>Yes, Mosquitto does support multiple brokers.</strong></p> <p>Mosquitto uses <a href="https://mosquitto.org/man/mosquitto-conf-5.html">MQTT Bridges</a> to connect multiple brokers thus routing messages between these mosquitto brokers. This way a bridge between your primary broker to a fallback system can be established. Avoid creating loops though. If both brokers run your clients publish to the primary broker which then publishes the topic to each and any subscriber including the bridged secondary broker. If the primary fails your clients will note (Connection Refused, Server unavailable) and can fallback to directly publish to the secondary. (I am not yet sure how to fix it the other way round.) As you're not expecting the client to disconnect ungracefully I think that "Last Will and Testament" do not apply here (it would be used to have the broker notify on behalf of a disconnected client).</p> <p>This <a href="https://www.quora.com/How-does-the-MQTT-mosquitto-work-with-multiple-brokers">post</a> however lists the drawbacks of this approach especially with respect to scalability and availability:</p> <blockquote> <ul> <li>The bridge routing mechanisms don’t scale well if you forward all messages to the other bridges</li> <li>The communication overhead between bridges is significant if you’re using QoS 2 between bridges (which you need to do if you want to propagate messages between clients that are connected to different bridges)</li> <li>There is no failover and high availability. If a broker bridge crashes, messages may get lost</li> <li>MQTT clients cannot be migrated to other bridge nodes. MQTT sessions are not replicated across bridges, so you will lose all your queued messages and subscriptions if you’re using MQTT persistent sessions.</li> </ul> </blockquote>

|networking|mqtt|mosquitto|

Can Mosquitto support multiple brokers?

318

<p>I've been considering <a href="https://mosquitto.org/">Mosquitto</a> for a MQTT message broker for a home IoT network, but I'm concerned that the broker could be a single point of failure which could bring down my whole network if it failed, since all messages have to go through the broker and no messages can be transmitted at all if the broker goes offline for any reason (e.g. accidental unplugging, hardware failure, etc.)</p> <p>Would be possible to use multiple brokers with Mosquitto installed to improve the reliability of the network? If it is possible, are there any disadvantages/significant overheads to using multiple brokers?</p>

2016-12-14T07:51:18.677

<p>You should be able to do this now with Alexa's <a href="https://developer.amazon.com/docs/custom-skills/understand-name-free-interaction-for-custom-skills.html" rel="noreferrer">name free interaction</a>.</p> <blockquote> <p>To make your skill more discoverable for name-free interaction, you can implement the the CanFulfillIntentRequest interface in your skill</p> </blockquote>

|smart-home|alexa|

How to write custom Alexa Skills without 'Ask xxxx'

323

<p>I am currently using fauxmo to send custom commands to various devices to turn them on/off (For instance I have a WiFi to IR converter to control my Tuner &amp; TV) and I can turn the tv on/off with this.</p> <p>I also have Kodi integration setup, so I can say:</p> <pre><code>Alexa, Ask Kodi to set volume to 50% </code></pre> <p>But I'd like to be able to say:</p> <pre><code>Alexa, Set tuner volume to 50% Alexa, Play Bluray </code></pre> <p>I.e. I want to be able to control devices without needing an <code>Ask xxxx</code> as part of my request.</p> <p>Ideally I want to do this without a cloud-based service (i.e. SmartThings or Wink).</p> <p>I like the solution used by fauxmo (emulate an existing UPNP service), but it is limited to on/off (and 'dim' if you use the Hue enabled patch) and not really flexible enough.</p>

2016-12-14T16:06:03.037

<p>According the <a href="http://www.eng.auburn.edu/~wilambm/pap/2008/A%20Neural%20Network%20Implementation%20on%20an%20Inexpensive%20Eight%20Bit%20Microcontroller.pdf" rel="nofollow noreferrer">first paper</a>, running is not a problem. That was the purpose. Only there is a limitation on the maximum weights:</p> <blockquote> <p>Currently the limitation on the architecture embedded in this microcontroller is limited only by the number of weights needed. The neural network is currently limited to 256 weights. However for most embedded applications this 256 weight should not limit the system.</p> </blockquote> <hr> <p>As for training, as far as I understand the implementation described, the PIC controller receives parameters from an external source.</p> <blockquote> <p>The neural network forward calculations are written so that each neuron is calculated individually in a series of nested loops. The number of calculations for each loop and values for each node are all stored in a simple array in memory.</p> <p>[...]</p> <p>These arrays contain the architecture and the weights of the network. Currently, for demonstration purposes, these arrays are preloaded at the time the chip is programmed, but in the final version this would not be necessary. The microcontroller could easily be modified to contain a simple boot loader that makes use of the onboard RS232 serial port which would receive the data for the weights and topography from a remote location. This would allow for the weights or even the entire network to be modified while the chip is in the field. </p> </blockquote> <p>I suspect that the training is performed externally as well.</p> <p>The paper also gives references for Neural Network Trainers which were probably used to determine the values preprogrammed into the PIC's memory.</p> <ul> <li><a href="http://www.eng.auburn.edu/~wilambm/pap/2007/Neural%20Network%20Trainer%20with%20Second%20Order%20Learning%20Algorithms.PDF" rel="nofollow noreferrer">Wilamowski, B. M.; Cotton, N.; Hewlett, J.; Kaynak, O., "Neural Network Trainer with Second Order Learning Algorithms,"</a> </li> <li>Wilamowski, B. M.; Cotton, N. J.; Kaynak, O.; Dundar, G.,<br> "Method of computing gradient vector and Jacobean matrix in arbitrarily connected neural networks,"</li> </ul> <p>Now, I have looked into the first one which describes network architectures and algorithms to use with them. But the Neural Network Trainer software used here is implemented in MATLAB.</p> <blockquote> <p>Currently, there is very little neural network training software available that will train fully connected networks. Thus a package with a graphical user interface has been developed in MATLAB for that purpose. This software allows the user to easily enter very complex architectures as well as initial weights, training parameters, data sets, and the choice of several powerful algorithms.</p> </blockquote> <p>I have to mention that the fully connected networks has lower weights number for a same task than a layer by layer architecture. That makes it more suitable for microcontrollers.</p> <p>I am not a neural network expert and it is quite complex so I can be wrong, but based on these papers I would say that Cotton, Wilamowski and Dündar's approach requires an external, more powerful platform to perform the training.</p> <hr> <p>About running a neural network on a microcontroller, ST Microelectronics just announced a toolkit <a href="https://blog.st.com/stm32cubeai-neural-networks/?fbclid=IwAR3iWyFIDLSk6FufU9spDyTQPF1G8Ngkoozsv1f0eDT8hLCEWnQst900GDU" rel="nofollow noreferrer">STM32Cube.AI: Convert Neural Networks into Optimized Code for STM32</a> to convert <strong>pre-trained</strong> neural networks from popular libraries to most of their STM32 MCUs.</p>

|smart-home|microcontrollers|machine-learning|

Is it possible to run and train a neural network on an 8-bit microcontroller?

327

<p>I've recently read about neural networks in constrained environments (in particular, <a href="http://www.eng.auburn.edu/~wilambm/pap/2008/A%20Neural%20Network%20Implementation%20on%20an%20Inexpensive%20Eight%20Bit%20Microcontroller.pdf" rel="nofollow noreferrer">A Neural Network Implementation on an Inexpensive Eight Bit Microcontroller</a>) and their applications to IoT devices (e.g. regression for predicting things based on sensor inputs, etc).</p> <p>This seems ideal for simple applications where processing is not time-critical, and the data to process will be relatively infrequent. However, further research suggests that training a neural network in a resource-constrained environment is a poor idea (see the answer to <a href="https://robotics.stackexchange.com/a/569">Is it possible to run a neural network on a microcontroller</a>).</p> <p>Does this still apply for Cotton, Wilamowski and Dündar's approach that I linked? Would it be necessary to train a network designed for low resource usage on a more powerful device in my IoT network?</p> <p>For context, if I had a sensor transmitting the heat setting, I am considering a neural network as described in the paper to predict the desired boiler setting based on that and the time of day, etc. Training would be useful to change the neural network's outputs based on more data provided by the user. <a href="https://www.quora.com/What-machine-learning-algorithms-are-used-in-Nest-thermostat" rel="nofollow noreferrer">This Quora question</a> describes a similar scenario well, and discusses the implementation details for a neural network, but my question is more focused on whether running the network on the actuator itself would work.</p>

2016-12-14T20:02:23.297

<p><strong><em>What does it actually monitor?</em></strong> </p> <p>From the company's web site:</p> <blockquote> <p>Lively pillbox activity sensors monitor daily medication activity and create an alert whenever anything is missed</p> </blockquote> <p>They also have a web based dashboard, which relatives or carers can check.</p> <blockquote> <p>Lively's safety watch features a pedometer to keep track of steps throughout the day.</p> </blockquote> <p><br></p> <blockquote> <p>Coming soon!<br> Clip for auto fall detection </p> </blockquote> <p><br></p> <blockquote> <p>Turn on/off vibration for reminders, alerts Turn on/off medication reminders</p> </blockquote> <p>From a USA Today review</p> <blockquote> <p>When you're out of range, the watch reminds the person to call 911 </p> </blockquote> <p><strong><em>Specifically I would like to know, does it check the vulnerable person's pulse or neural activity, or is it just checking for various motions/actions throughout the day?</em></strong></p> <blockquote> <p>How do we measure daily activity patterns?</p> <ul> <li>Medication</li> </ul> <p>Attach a sensor to any pillbox to keep track of when medication is taken.</p> <ul> <li>Food &amp; Drink</li> </ul> <p>Attach a sensor to the refrigerator and other kitchen objects to infer when food is prepared or consumed.</p> <ul> <li>Custom</li> </ul> <p>Attach a sensor to a movable object that is part of the daily routine patterns of older adults to log more detail (e.g., bathroom door or favorite chair) in order to log more detail.</p> </blockquote> <p>To answer your question:</p> <p>from the <a href="http://www.usatoday.com/story/tech/columnist/baig/2015/02/05/review-lively-safety-watch-isnt-perfect-but-it-could-save-a-life/22925659/" rel="nofollow noreferrer">USA Today article</a>:</p> <blockquote> <p>It doesn't monitor sleep or measure heart rate or other vitals.<br> The step counter isn't the most accurate. What is being measured is the movement of the watch, so my steps tally climbed even when I lay in bed.</p> </blockquote> <p>Also, Googling for <code>+"Lively Medical Alert Watch" +pulse</code> returned zero hits.</p> <p>When the company says</p> <blockquote> <p><strong><em>infer</em></strong> when food is prepared or consumed</p> </blockquote> <p>it doesn't fill me with confidence. </p> <p>I also quibble with "keep track of when medication is taken", and say that they can <strong><em>infer</em></strong> that pills have been taken form a pill box, but not that they have been ingested.</p> <p>Does this answer your question? It took me 5 minutes Googling, although, in your place, I would have emailed the manufacturer directly.</p>

|sensors|monitoring|lively-medical-alert|

What does the Lively Medical Alert Watch Monitor?

329

<p>According to <a href="http://www.makeuseof.com/tag/internet-things-10-useful-products-must-try-2016/" rel="nofollow noreferrer">MakeUseOf.com</a>, the Lively Medical Alert Watch...</p> <blockquote> <p>... allows remote health monitoring of your loved ones. The smartwatch can track steps taken as well as other kinds of daily activities, plus it provides an emergency assist button that alerts Lively to call in and check that everything is alright.</p> </blockquote> <p>What does it actually monitor? Specifically I would like to know, does it check the vulnerable person's pulse or neural activity, or is it just checking for various motions/actions throughout the day?</p>

2016-12-14T23:40:40.147

<p>Turns out there is no broker running on the Arch system whereas installing <code>mosquitto</code> on Raspbian automatically starts it. Simply enable and start the broker.</p> <p>Start the systemd service.</p> <pre><code>systemctl start mosquitto </code></pre> <p>Enable the systemd service to run on boot.</p> <pre><code>systemctl enable mosquitto </code></pre>

|mqtt|raspberry-pi|mosquitto|linux|

mosquitto_sub "connection refused" on Arch Linux

332

<p>So I installed <code>mosquitto</code> and <code>mosquitto-client</code> on a Raspberry Pi running Raspbian Jessie through <code>apt-get</code> as well as <code>mosquitto</code> on another Pi running Arch Linux through <code>pacman</code>. On Arch the client utils do not need to be installed separately.</p> <p>Testing simple subscription/publishing on Raspbian worked out of the box. </p> <pre><code>mosquitto_sub –d –t blub mosquitto_pub –d –t blub –m “test” </code></pre> <p>Publishing from the Arch box works as well: </p> <pre><code>mosquitto_pub -h &lt;IP-Raspbian&gt; -t blub -m "test" </code></pre> <p>Subscribing a topic on the Arch system however gets me just:</p> <pre><code>mosquitto_sub –d –t blub Error: Connection refused </code></pre> <p>Now that is pretty generic. What's wrong here?</p>

2016-12-15T01:50:27.427

<p>I think it is important to consider that there are many different use cases for MQTT brokers, as with any piece of software.</p> <p>Handling chat messages for a billion users (many users, relatively low message rate per user) is different to a system with few clients but a high message rate, and they are both different to a home automation system (few clients, low message rate).</p> <p>HiveMQ are thinking about the very high client/message rate applications - in which case the capability of the broker almost certainly far exceeds that of a client.</p> <p>If you want to subscribe to <code>#</code> in your home automation system then it's really unlikely to cause problems. You can check and see if the broker is using excessive CPU in any case.</p> <p>As in the other answers, subscribing to <code>#</code> will give you all 'normal' topics, that is anything that doesn't start with a <code>$</code>. I interpret the spec as saying that each topic beginning with <code>$</code> is a whole separate tree in itself, so you'd have to subscribe to <code>$SYS/#</code>, <code>$whatever/#</code> to get <em>everything</em>. You most likely don't want to do that anyway for a normal application.</p>

|mqtt|mosquitto|

Don’t subscribe to # - so how to dump all messages to database with Mosquitto?

334

<p><a href="http://www.hivemq.com/blog/mqtt-essentials-part-5-mqtt-topics-best-practices" rel="noreferrer">HiveMQ's blog</a> lists under "best practices" not to subscribe to the multi level wildcard when attempting to dump all messages to a database. They claim that the subscribing client may not be able to keep up with a high load of messages and propose to use a broker plugin to directly hook into the stream of messages instead. </p> <blockquote> <p>Sometimes it is necessary to subscribe to all messages, which are transferred over the broker, for example when persisting all of them into a database. This should not be done by using a MQTT client and subscribing to the multi level wildcard. The reason is that often the subscribing client is not able to process the load of messages that is coming its way. Especially if you have a massive throughput. Our recommended solution is to implement an extension in the MQTT broker, for example the plugin system of HiveMQ allows you to hook into the behavior of HiveMQ and add a asynchronous routine to process each incoming message and persist it to a database.</p> </blockquote> <p>Is there either</p> <ul> <li>a similar system (extension/plugin) for the mosquitto broker,</li> <li>another recommended method that works with mosquitto, or</li> <li>reasonable evidence that this approach is unnecessary at all, i.e. that a client subscribing to <code>#</code> can do just fine? </li> </ul> <hr> <p>^{<a href="https://stackoverflow.com/q/31584613/3984613">https://stackoverflow.com/q/31584613/3984613</a> does not address this question exhaustively.}</p>

2016-12-15T17:20:02.280

<p>As you say, it depends on the server implementation, especially the QoS of the transmitted message if it is "at least once".</p> <p>IMHO MQTT is a broadcasting system, not a end-to-end protocol between two machines so we don't absolutely need a subscriber every time we create a subject. </p> <p>I can post anything (temperature,...) and two months later implement something that will read it, or even remove it and think of something else while my sensor still publishes data.</p>

|mqtt|

What happens when there is not any subscriber to a topic in MQTT?

347

<p>The situation is the following:</p> <p>There is a client, a publisher, it is not subscribed to any topic. This client <strong>has a single topic</strong> of its own, and publishes data reguraly to it. But <strong>there are not any other clients</strong> that are subscribed to this topic.</p> <p>So this poor and lonely client might be considered as abnormal (<a href="http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718028" rel="nofollow noreferrer">Chapter 5.4.8</a>).</p> <blockquote> <p>Server implementations might monitor Client behavior to detect potential security incidents. For example:</p> <ul> <li><p>[...]</p> </li> <li><p>Sending undeliverable messages (no subscribers to the topics)</p> </li> </ul> </blockquote> <p>It has <a href="https://stackoverflow.com/questions/32431489/must-a-mqtt-client-publish-to-topics-if-there-are-no-subscribers">no idea about how many clients have subscribed</a> to its topic. So it does not know that it might be considered a client with abnormal behavior.</p> <p>So what happens with such a client will depend on the server implementation? What are the practices, it should be simply disconnected, but won't it try to reconnect then?</p>

2016-12-15T19:15:28.667

<p><strong>Yes and no.</strong></p> <p>Both technologies are concerning different levels of providing connectivity. Usually mesh networking is provided by level 3 or 4 or even both of the <a href="https://en.wikipedia.org/wiki/OSI_model#Description_of_OSI_layers" rel="nofollow noreferrer">ISO OSI model</a>, depending on the extend of implementation. The network and transport layers provide the basic reliability of the mesh network. That reliability is usually not impeded when a node drops off.</p> <p>MQTT and AMQP are application layer protocols on level 7. Therefore these protocols are dependent on the reliability of the lower levels as far as the basic model goes. However it's always the prerogative of higher OSI levels to implement safeguards to cope with failures of the lower levels. For example the application can switch to a completely different network, like from Wi-Fi to 4G for example if it detects network failure. Smartphones do it all the time when we enter or leave a place with a configured Wi-Fi.</p> <p>There are also possibilities for the lower levels to accommodate for failures in upper levels. OSI level 4 load balancing for example can accommodate for failing nodes behind it. Of course, that requires that each nodes that can be addressed for <a href="https://en.wikipedia.org/wiki/Load_balancing_(computing)" rel="nofollow noreferrer">load balancing</a> and or failover solutions can provide the same service. Also obviously you need the <em>central component</em> at least twice. Since <a href="https://en.wikipedia.org/wiki/MQTT" rel="nofollow noreferrer">MQTT</a> is basically application level routing based on topics that should be possible by simple duplication. This is <a href="http://www.hivemq.com/blog/building-a-high-availability-mqtt-cluster" rel="nofollow noreferrer">an example of an MQTT cluster solution</a> with the HiveMQ implementation.</p> <p>With that in mind it can be concluded that, <strong>no</strong>, <em>the reliability on the network and transport levels cannot be negated by the choice of any higher level protocols.</em> However that does not apply to the user experience. For the user the lower level protocols are just vehicles. Using an application layer protocol that has a single point of failure still means, that if that node is broken, then <strong>yes</strong>, <em>the functionality is broken even though my network is still working.</em></p> <p>Anyhow, the application layer and above are responsible to provide the reliability to the user. Mesh networks can only deliver the basics. </p> <p><em>There is one final thing to consider. Unless one has redundancies for every component, there are always use cases that have single points of failure. It's most likely the node the user actually interacts with. In home automation for example every failing node very likely means that one just lost a use case.</em></p>

|publish-subscriber|mesh-networks|thread|

Do protocols based on the publish-subscribe pattern negate the benefits of mesh networks?

348

<p>Protocols that are modelled on the <a href="https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern" rel="noreferrer">publish-subscribe pattern</a> such as <a href="https://en.wikipedia.org/wiki/MQTT" rel="noreferrer">MQTT</a> and <a href="https://en.wikipedia.org/wiki/Advanced_Message_Queuing_Protocol" rel="noreferrer">AMQP</a> require a centralised message broker to co-ordinate messages being sent and received. This does not pose much of a problem when your IoT network is based on a star topology, where all messages have to go through a central hub anyway, however I've been thinking about the benefits of mesh networks and how these may be affected by protocol choice.</p> <p>The <a href="http://threadgroup.org/portals/0/documents/events/ThreadIntro.pdf" rel="noreferrer">Thread Introduction</a> presentation outlines several benefits of Thread's mesh network in particular (however these should apply generally):</p> <blockquote> <p>✔ No single point of failure</p> <p>✔ Self-healing</p> <p>✔ Interference robustness</p> <p>✔ Self-extending</p> <p>✔ Reliable enough for critical infrastructure</p> </blockquote> <p>Although I can't imagine the latter four points being affected by protocol choice, I'm curious as to whether using a message-brokered protocol would cancel out any advantages of the mesh network's &quot;no single point of failure&quot;.</p> <p>Does using a publish-subscribe based protocol introduce an inevitable single point of failure in general, and is this why the <a href="http://threadgroup.org/portals/0/documents/events/ThreadIntro.pdf" rel="noreferrer">Thread Introduction</a> presentation suggests CoAP instead as a potential protocol to use?</p> <hr /> <p>^{I've <a href="https://iot.stackexchange.com/questions/318/can-mosquitto-support-multiple-brokers">already asked</a> about Mosquitto supporting multiple brokers to remove the single point of failure, but I'm asking this to question whether this is a fundamental conflict between mesh networks and publish-subscribe protocols.}</p>

2016-12-16T05:30:25.000

<p>Another area to consider is corrosion in electrical signal paths, particularly in tropical climates close to the ocean. If the metal electrical connections are expose to the elements the conductive medium starts deteriorating cause a change in electrical signal. Therefore good mechanical packaging might be something to consider. </p> <p>Alternatively, in Tropical climates Liquid Petroleum Gas (LPG) is mostly used for cooking. Also the LPG cylinder tends to be placed close to the stove. So if you can monitor use of the stove in relationship to LPG cylinder pressure, it might be possible to monitor and notify if there is a LP gas leak using something like IFTTT. Example if stove not in use and LP Gas pressure is dropping then there might be a leak and alert interested parties. </p> <p>Deviating outside the scope of the question, additional services can be created to notify users when LP gas is running low or even monitor usage patterns to help manage LP Gas usage. It is common in under develop countries to carry a secondary small backup gas cylinders to supplement until a availability of a refill. Providing a monitoring capabilities can help eliminate the secondary LP gas cylinder. </p> <p><strong>References:</strong></p> <ul> <li><a href="https://www.nde-ed.org/EducationResources/CommunityCollege/Materials/Physical_Chemical/Corrosion.htm" rel="nofollow noreferrer">Corrosion</a></li> <li><a href="https://ifttt.com/" rel="nofollow noreferrer">IFTTT</a></li> </ul>

|smart-home|safety|sensors|

Using LP Gas Sensor in a Smart Home Safety System

351

<p>We are making a smart home safety system for a small academic project (Yes. I am a newbie for this). We need a <em>Gas Sensor (LP Gas)</em> for the project, but there are a few questions that I have.</p> <p>I found the <a href="https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-6.pdf" rel="noreferrer">MQ-6 Sensor</a> that can be used for sensing the LP gas leakage. But the problem is, how far can it go ?</p> <p>I live in a tropical country, where there is always high temperature and humidity. </p> <ol> <li>How can these weather conditions effect the sensor ?</li> <li>What happens if we keep it in a large room ? Will it still be able to sense the gas ?</li> <li>How much closer do I have to place the sensor to the cylinder ?</li> </ol> <p>Any ideas will be helpful. Thanks in advance.</p>

2016-12-16T17:05:08.647

<blockquote> <blockquote> <p>By saying a key phrase Amazon calls a “wake word” the Echo comes to life and begins listening for commands. By default, the wake word is Alexa.</p> <p>If you reread that last sentence it may not make sense, especially if you are in the security field. According to Amazon, the Echo only listens for commands once it hears its wake word. How does it know when you have said the wake word if it wasn’t already listening?</p> </blockquote> </blockquote> <p>Echo listens actively for the <strong>keyword</strong> and takes the words spoken after keyword for NLU processing. Here is my understanding how echo achieves this neat feat.</p> <p>Echo is built on <a href="http://www.ti.com/lit/ds/symlink/dm3725.pdf" rel="noreferrer">Texas Instruments DM3725</a> Digital Media Processor.</p> <p>This TI SoC has two key pieces inside, first is ARM Cortex-A8 MPU, and the second one is TMS320DM64x+ DSP. The ARM core should be running Linux and the DSP is running firmware. </p> <p>When idling, the ARM core is taken to lowest possible power state and Linux is completely suspended. At this time the DSP and 64KB On-Chip RAM are active. The DSP firmware processes noise coming in from the mics and attempts to identify if a keyword (e.g., Alexa) is spoken. As soon as it identifies there's a keyword, DSP sends an interrupt to wake up the ARM core which in turn resumes Linux. But, remember, while Linux is waking up the human who said Alexa would have continued speaking (as in, <strong>“Alexa, what time is it?“</strong>). The DSP buffers the <strong>"what time is it?"</strong> part on the on chip RAM. And when Linux is resumed Linux fetches the buffered speech and uses Natural Language Processing (partly local, partly cloud) capability to understand what Human said.</p> <p>As you see the design is totally created to be least power hungry one and to avoid need of including cloud for keyword detection and initial buffering. As a matter of fact keeping the ARM core at lowest powers state ensures that the silicon heats the least when idling thus in a way bringing long life to your device.</p> <p>I am leaving out discussion of attempts to hack echo as the question was following:</p> <blockquote> <p>the wake word recognition is indeed done locally.</p> </blockquote>

|amazon-echo|privacy|

Is the Amazon Echo 'always listening' and sending data to the cloud?

357

<p>Several news sources such as <a href="https://www.intellihub.com/amazon-echo-is-the-ultimate-spy-device/" rel="noreferrer">Intellihub</a> and <a href="http://www.cepro.com/article/amazon_echo_always_listening_feature_worries_security_experts" rel="noreferrer">CEPro</a> seem to suggest that Amazon's Echo home assistant constantly listens to conversations and sends them via the Internet to Amazon's servers. CEPro states that:</p> <blockquote> <p>By saying a key phrase Amazon calls a “wake word” the Echo comes to life and begins listening for commands. By default, the wake word is Alexa.</p> <p>If you reread that last sentence it may not make sense, especially if you are in the security field. According to Amazon, the Echo only listens for commands once it hears its wake word. How does it know when you have said the wake word if it wasn’t already listening?</p> </blockquote> <p>Intellihub's article is similar in its sentiment:</p> <blockquote> <p>The “Amazon Echo” device, a constantly-listening Bluetooth speaker that connects to music streaming services like Pandora and Spotify at the sound of a person’s voice, can be easily hacked and used by government agencies like the FBI to listen in on conversations.</p> </blockquote> <p>(Note that I'm not particularly focused on exploring the hacking aspect of this question, since that would probably be too much for one question. My main focus is the always-on aspect and whether this sends data <strong>all the time</strong>.)</p> <p>Neither article seems particularly keen to disclose a source for its claims, which suggests to me that they are unproven at best, or clickbait at worst.</p> <p>Is the Echo always recording and sending data to the cloud, or are the above claims unsubstantiated? How does the Amazon Echo process data if it's not always sending data to servers in the cloud?</p>

2016-12-17T10:04:23.207

<p>I would either go with RS485 or CAN because with long buses a lot of noise can be picked up. These are the most noise resistant as both of them use differential, twisted data lines.</p> <p><a href="http://www.rs485.com/rs485spec.html" rel="nofollow noreferrer">RS485 supports</a> distances up to ~1,200 meters with a guaranteed speed of 100 Kb/s. Max 10 Mb/s with smaller distances. It is a multi point bus with up to 32 drivers and 32 receivers. (One active driver at a time.)</p> <p>CAN is usable over 20 meters as well. From this <a href="http://www.ti.com/lit/an/slla270/slla270.pdf" rel="nofollow noreferrer">Controller Area Network Physical Layer Requirements</a>.</p> <blockquote> <p><a href="https://i.stack.imgur.com/KNEKh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KNEKh.png" alt="cable length vs signaling rate table" /></a></p> </blockquote> <p>To repeat my comment, I2C is out of question because of the long distances. The bus capacitance would be too high. It is designed for short on-board distances.</p> <p>As for SPI here is another document about <a href="http://www.ti.com/lit/an/slyt441/slyt441.pdf" rel="nofollow noreferrer">Extending the SPI bus for long-distance communication</a> but it might be complicated. So I would stay with CAN or RS485.</p> <p>Both of them are pretty common, so finding sensors would not be a problem IMO.</p> <ul> <li><a href="http://www.hw-group.com/products/sensors/Temp-485_en.html" rel="nofollow noreferrer">RS485 temperature sensor</a></li> <li><a href="http://www.hw-group.com/products/sensors/HTemp-485_en.html" rel="nofollow noreferrer">RS485 humidity and temperature sensor</a></li> </ul> <p>There are sensors with CAN interface as well, but RS485 is more common, so maybe that would be the cheapest and the easiest.</p>

|protocols|sensors|wired|

Wired sensor protocol for buildings monitoring sensors?

360

<p>Assuming I cannot use wireless technologies such as <a href="https://www.lora-alliance.org/" rel="noreferrer">LoRa</a>, <a href="https://www.thefastmode.com/wiki-networking/5432-lte-for-m2m-lte-m" rel="noreferrer">LTE-M</a> or <a href="https://en.wikipedia.org/wiki/Sigfox" rel="noreferrer">SigFox</a> in the environment for the install, I must use a wired sensor protocol to communicate with the gateway installed remotely in a building.</p> <p>The cable runs can be up to 20m from the gateway and ideally I will be purchasing a reliable solution that is not overly expensive. It would be excellent if the sensor was CE compliant but there doesn't seem to be a low cost option (&lt;£20), e.g. <a href="https://www.leveldevelopments.com/products/inclinometers/inclinometer-sensors/solar-360-1-rs485-inclinometer-sensor-single-axis-180-rs485-interface/" rel="noreferrer">solar</a>.</p> <p>So, the requirements are:</p> <ul> <li>Can connect to 10 or more devices</li> <li>Maximum distance at least 20m</li> <li>Price less than £20 for temperature/ humidity/ lux (luminosity) sensor(s)</li> </ul> <p>There are many options such as SPI, I2C, RS485, Onewire and CAN. The protocol we select will determine the sensor we select. </p> <p>The Onewire protocol from <a href="https://www.maximintegrated.com/en/products/digital/one-wire.html" rel="noreferrer">Maxim</a> (Dallas) looks ideal but there are as yet a limited range of sensors, (in saying this we could use the maxim <a href="https://www.maximintegrated.com/en/products/interface/controllers-expanders/DS28E17.html" rel="noreferrer">bridge</a>)</p> <p>What is the best wired protocol for the requirements listed above? </p>

2016-12-17T19:45:47.387

<p>The linked article is a little misleading. The interface provided by IFTTT is not completely open, it requires a key in the request. Since the request is made using HTTPS, the secret is not directly observable (provided your client always reliably connects to IFTTT, not a mitm proxy).</p> <p>From the <a href="https://maker.ifttt.com/use/my-secret-key-here" rel="nofollow noreferrer">maker channel information page</a> (user specific)</p> <blockquote> <p>To trigger an Event Make a POST or GET web request to:</p> <pre><code>https://maker.ifttt.com/trigger/{event}/with/key/my-secret-key </code></pre> <p>With an optional JSON body of:</p> <pre><code>{ &quot;value1&quot; : &quot;&quot;, &quot;value2&quot; : &quot;&quot;, &quot;value3&quot; : &quot;&quot; } </code></pre> <p>The data is completely optional, and you can also pass value1, value2, and value3 as query parameters or form variables. This content will be passed on to the Action in your Recipe.</p> <p>You can also try it with curl from a command line.</p> <pre><code>curl -X POST https://maker.ifttt.com/trigger/{event}/with/key/my-secret-key </code></pre> </blockquote> <p>Now the key is only low entropy so could potentially be reversed from monitoring your requests (unless you pad them with high quality noise), but the request for per-session security is in this case satisfied by TLS which handles the setup of the HTTPS channel.</p> <p>To make the communication significantly more secure would require IFTTT to specifically support endpoint authentication, but this appears to exceed the security which is applied to the other service-side links. This means that your maker channel to IFTTT is currently equally secure as the IFTTT channel to your in-home appliances.</p>

|security|ifttt|one-time-password|

How do I generate a Time-based One-time Password with IFTTT?

374

<p>I recently registered with <a href="https://ifttt.com/discover" rel="nofollow noreferrer">IFTTT</a>, which seems like a fantastic service to chain events together in order to create a smart home or automate various services.</p> <p>I've just found the <a href="http://makezine.com/2015/06/26/ifttt-adds-new-channel-makers/" rel="nofollow noreferrer"><strong>Maker channel</strong></a> which allows you to make simple HTTP requests (e.g. GET and POST), and I'm hoping to use this to securely send a message to a Raspberry Pi I have running that is waiting for any API request on a certain route (let's say, for example, <code>POST /foo</code>).</p> <p>The <a href="http://makezine.com/2015/06/26/ifttt-adds-new-channel-makers/" rel="nofollow noreferrer">Makezine article</a> I linked suggests this method for security:</p> <blockquote> <p>Now what I did above was horribly insecure, I basically exposed to the world a script — a web application in other words — that could toggle a switch controlling a light in my house on and off. This is obviously not something you want to do, but that’s why IFTTT’s services provides the capabilities to pass more information to the remote service.</p> <p>It wouldn’t be difficult to set up a <a href="https://www.rfc-editor.org/rfc/rfc6238" rel="nofollow noreferrer">TOTP</a> authenticated link between the two for instance, or a token or key exchange — and to protect your IFTTT account itself? They’ve just added two-factor authentication.</p> </blockquote> <p>I read more about <a href="https://en.wikipedia.org/wiki/Time-based_One-time_Password_Algorithm" rel="nofollow noreferrer">Time-based One-time Passwords</a> on Wikipedia, which seems to suggest that there is an element of computation involved in order to generate the one-time password.</p> <p>Since IFTTT does not support chaining of tasks or any scripting, how do I generate the TOTP as suggested in the article? Is it possible at all to do this, since some calculations are required and there doesn't seem to be a way to do these?</p>

2016-12-17T23:09:56.763

<blockquote> <p>Is it possible to automatically switch my TV, my home cinema system and FireTV on and set all of them to the proper input modes when they booted?</p> </blockquote> <p>Yes, this is a standard activity. Here are two sample activities:</p> <ul> <li><strong>Watch Roku</strong> - Receiver power on, Receiver input set to HDMI1, TV power on, TV input set to HDMI1 (note: no commands to Roku since it is always on)</li> <li><strong>Watch TV</strong> - Receiver power on, Receiver input set to Optical In, TV power on, TV input set to ANT</li> </ul> <p>There is some info here: <a href="https://support.myharmony.com/en-us/understanding-harmony-activities" rel="nofollow noreferrer">Understanding Harmony Activities</a></p> <p>You can also bind different buttons to different commands for different activities.</p>

|logitech-harmony|

What can I actually do with a Harmony Hub?

379

<p>I am considering getting a <a href="https://secure.logitech.com/en-us/product/harmony-hub?crid=60" rel="nofollow noreferrer">Logitech Harmony Hub</a>. It's my understanding that I can define activities which can entail using certain commands of the compatible devices. However, I am unable to find what kind of actions I can use within these activities and if these activities can contain several actions for the same device.</p> <p>Is it possible to automatically switch my TV, my home cinema system and Fire TV on, and set all of them to the proper input modes when they have booted? Is there a list somewhere of the things I can and cannot do with the Harmony Hub?</p>

2016-12-18T01:46:59.720

<p><strong>Yes, apparently that's possible.</strong></p> <p>In <a href="http://www.smarterhomeautomation.com/reviews/wink-hub-review-nest-google-echo/wink-hub-review-nest-google-echo-7/" rel="nofollow noreferrer">this blog</a> some possibilities of connecting Nest with Wink robots are described.</p> <blockquote> <p>The first Robot, I named “Someone’s Home’. I simply chose the robot to activate when Nest Away, detects someone is home. I set the time period to anytime. Then as a result, I set the robot to alert me via email.</p> </blockquote> <br> <blockquote> <p>My second Robot was not as diabolical. . When Nest detects we are away. Wink will wait 10 minutes, then lock the door!</p> </blockquote> <p>Thus, the Wink Hub can react to that away state of Nest.</p>

|nest-thermostat|wink-hub|

Can the Wink Hub 2 "listen" for away status from the Nest Thermostat v3?

380

<p>I know that I can control a Nest thermostat from a Wink Hub (and app) by "pushing" commands to the thermostat (e.g. "turn up the temperature"). However can the Wink hub be notified when the Nest thermostat detects that I'm away? I want to use the away status as a trigger for a Wink Robot (e.g. "When I'm away, turn off the lights.")</p>

2016-12-18T12:20:17.227

<p>IFTTT have now launched a <a href="https://ifttt.com/blog/2017/05/calling-all-makers" rel="nofollow noreferrer">maker platform</a> which appears to support filters and chaining. I've not yet worked out if it has timers and cloud side variables/storage. </p>

|ifttt|connector-services|

Can triggers be chained with IFTTT?

387

<p>When using IFTTT, it's trivial to connect one trigger (<em>if this</em>) to one event/output (<em>then that</em>). However, I'm interested in using IFTTT for a slightly more complex query, along the lines of <em>"if this happens 3 times, do that"</em>.</p> <p>A <a href="https://www.quora.com/Can-you-use-two-or-more-triggers-and-actions-on-IFTTT-How-can-I-do-that/answer/Hans-Andersson-1" rel="noreferrer">Quora question</a> discusses this and suggests Numerous as a channel which can be used for more complex triggers, but it turns out that Numerous <a href="http://blog.numerousapp.com/2016/02/02/numerous-shutting-down-on-may-1.html" rel="noreferrer">had to shut down due to lack of funding</a> several months ago.</p> <p>A similar question <a href="https://www.reddit.com/r/ifttt/comments/43wpwo/are_there_any_good_alternatives_to_numerous_for/" rel="noreferrer">was asked on Reddit</a> with no satisfying answer, so I'm asking here in the hope that there is a better solution to my problem: <strong>How can I chain triggers in more complex queries with IFTTT?</strong> Is this even possible now that Numerous has shut down, or will I have to use an alternative service?</p>

2016-12-18T18:41:59.190

<p>A lot of people have struggled with this. No charter appears to be forthcoming, because the interests of the cloud providers lies in locking their hardware users in, based on the potential future profits to be made from subscribers. The more dependent you are upon their cloud, the more you'll be theoretically willing to pay for continued service (note that payment already includes non-monetary transactions such as targeted advertising and data collection.) So don't expect any of the cloud-based solutions to champion an exit strategy.</p> <p>So for now, you can overcome your reluctance by taking matters into your own hands. Your best defense is to purchase independent items that comply with standards (open or proprietary), as opposed to being run by proprietary clouds. </p> <p>Let's look at three examples: cloud-based, proprietary network, open network.</p> <h2>Cloud-based</h2> <p>AssureLink is a proprietary wireless network that uses a home hub to connect to a cloud-based service to provide remote access to one brand of garage door openers. When these openers were released on the market, a subscription to AssureLink cost $19.00 per year, and there were few sales. The company dropped charging for the service so they haven't gone away, but there is always concern that once they've saturated the market, the company will have no reason to continue the service, at which point the devices would become useless. </p> <p>This concern is not without merit.</p> <p>Pebble's recent acquisition by Fitbit has thrust them into the spotlight, but Revolv was the previous poster child for IoT devices being bricked by their parent company. The Revolv home hub connected to a proprietary cloud service. Google bought Nest, and then bought Revolv to get some of the people. They saw Revolv as splintering the home automation market away from Nest so they shut it down, bricking every Revolv home controller.</p> <p>Is this true for all cloud-based hardware? Apple, Google, and Amazon are all as stable as any provider can be. But Revolv sure looked good when Google first bought them; Nest is reportedly in disarray internally (and Google's new hub is pitted directly against Nest's philosophy), and you only have to look as far as Microsoft's Zune or Phone to see that being big doesn't mean that a centralized service will remain successful over the life of your devices. </p> <h2>Proprietary P2P network standard</h2> <p>Z-Wave is an example of a proprietary mesh network technology. Z-Wave devices can talk to each other, but each device requires a communications chip licensed by a single company. Development and per-chip licenses are ridiculously expensive, so the price of the devices will never come down until the patents expire, and even then only if someone else enters the market to compete with them. However, once you have a Z-Wave device, it will continue to work with new and old Z-Wave devices.</p> <h2>Open P2P network</h2> <p>WiFi based cameras are a good example of devices based on open network technology. Apps for smart phones can connect directly to the camera, no cloud required, no expensive licensed technology. However, these have drawbacks. In order to use these devices without a cloud, the installer has to configure their router/firewall to enable remote access. And as we've seen with the Mirai botnet, these devices are responsible for their own security but not all do a good job of it, and they even put the rest of your network at risk.</p> <h2>The future with Open Source</h2> <p>The open source answer to this are projects like OpenHab, Domoticz, mosquitto, and others. Instead of a proprietary cloud, you run the P2P devices from your own server. Only the server is exposed to the internet, and for the most part these are positioned to be better hardened. At this point this approach is still very much in its infancy, and all the solutions so far require some technical skills to set up and maintain a home network.</p> <p>However, by focusing on P2P devices today, whether they use an open or closed protocol, you are at least investing in building your own infrastructure that will work free of the dependency on proprietary external services. You can even get started with a proprietary home hub, as long as the devices are communicating via a P2P standard that exists beyond a single company. The open source solutions can't get any worse than they are right now, and are rapidly improving.</p>

|standards|sustainability|open-source|

Are there any initiatives to prevent IoT obsolescence?

395

<p>I've been reluctant to invest in many IoT devices, especially externally managed/subscription based devices because of issues having to deal with the closure of management services due to issues like planned obsolescence and corporate take-overs of parent companies, for example like what's happening with <a href="https://www.techdirt.com/articles/20161211/22012636251/how-dmca-cfaa-are-preventing-people-saving-their-soon-to-be-broken-pebble-watches.shtml" rel="noreferrer">Pebble watches</a>.</p> <p>I'm curious to know if there are any initiatives in active development (such as charters or legal frameworks) to devolve management rights of IoT devices or "Opening" the source code in the event of an end of product service.</p> <p>I've looked around a little bit on GitHub and the Free Software Foundation but haven't found anything like that. I'm wondering if there are any licenses or charters in development that imply the release of IoT source code once a service ends. </p>

2016-12-19T15:11:44.747

<p>According to <a href="https://support.smartthings.com/hc/en-us/articles/204733384-Does-SmartThings-work-with-Nest-" rel="noreferrer">SmartThings's Support Page</a>:</p> <blockquote> <p>SmartThings doesn’t officially support Nest at this time, but many users instead utilize a custom integration created by a developer in the SmartThings Developer Community. This integration reportedly works well, and you can set it up through the <a href="http://ide.smartthings.com/" rel="noreferrer">SmartThings IDE</a> by <a href="https://community.smartthings.com/t/release-nest-manager-4-0/60052" rel="noreferrer">following the steps here</a>.</p> </blockquote> <p>In other words, it isn't officially supported, but it appears that it can work. <a href="https://ifttt.com/connect/nest_thermostat/smartthings" rel="noreferrer">Ifttt.com</a> claims to have designed an applet which connects these two.</p>

|samsung-smartthings|nest-thermostat|

SmartThings Hub and Nest Thermostat

400

<p>Is it currently possible to link a Nest thermostat with the Samsung SmartThings Hub?</p> <p>The Nest is not available in the list of thermostats to add, within the SmartThings App. However, is there at least a SmartApp that allow a bit more automation?</p> <p>If not, is there a newsletter or RSS feed to let me know when Nest might be supported?</p>

2016-12-19T20:56:30.947

<p>The question here appears to be "should I use MQTT over TCP, or use MQTT over websockets (which also goes over TCP)?" In other words, is "encapsulating MQTT in the websockets protocol a good idea?"</p> <p>This is (almost) entirely down to your application and whether you need websockets support - probably for consuming messages in a browser or for firewall reasons. If you can't have your server be accessible on port 1883 or better 8883 for pure MQTT, then websockets may be your best option.</p> <p>Websockets does require extra bandwidth, but whether that is important to you is something only you can answer.</p> <p>It's also worth noting that in current versions of Mosquitto, websockets don't work as well as they could so there can be extra latency when sending/receiving websockets messages. That is something that will not be an issue in future versions though.</p>

|mqtt|mosquitto|web-sockets|

Should I use Mosquitto's web sockets or connect clients directly?

405

<p>According to <a href="http://jpmens.net/2014/07/03/the-mosquitto-mqtt-broker-gets-websockets-support/" rel="noreferrer">this blog</a>, Mosquitto (the MQTT broker) now supports connecting to clients over web sockets. The blog article seems to hint that web sockets are more useful for browser applications, since web browsers don't support proper TCP sockets (yet), although the web socket protocol <strong>is</strong> supported by the majority of modern browsers.</p> <p>If I just have various clients in a network (e.g. sensors and actuators based on microcontrollers such as Raspberry Pis), will there be any advantage to using web sockets over direct TCP connections? Is the overhead of the web socket protocol only worth it when you are communicating with a browser?</p>

2016-12-20T16:56:18.117

<p>Apparently not. <a href="http://www.zdnet.com/article/alexa-times-two-can-two-amazon-echos-find-love-and-happiness-in-one-home/" rel="noreferrer">This blog discusses the current impossibility of the synchronized alarms.</a> I couldn't find any information that suggests that they changed it by now. However as the blog discusses, it means that you can set one alarm and one timer per Echo, which multiplies your available timers and alarms. Alas, that's not your goal.</p> <p>I checked the usual suspects, but IFTTT does not offer the <em>that-branch</em> for Alexa. It also seems to be incapable of just playing your voice back and thus making the voice output of the one Alexa the input of the other one. However that would mean a delay for a timer, since timers are relative times. Moreover, this would only work with different wake words, since otherwise the Echos don't react both (cf. <a href="http://www.howtogeek.com/262664/what-you-can-and-cant-do-with-multiple-amazon-echos/" rel="noreferrer">This blog</a>). Only the nearest will respond. That also eliminates the possibility to just speak somewhere where all Echos can hear you.</p> <blockquote> <p>If you have more than one device using the same wake word, <em><strong>Alexa responds intelligently from the Echo you're closest to with ESP (Echo Spatial Perception)</strong></em>, and performs the requested task.</p> </blockquote> <p>(<a href="https://www.amazon.com/gp/help/customer/display.html?nodeId=202013740" rel="noreferrer">Amazon Documentation</a>, emphasis mine)</p> <p>The page also confirms that the alarms are device specific.</p> <blockquote> <p>Some content is not common between devices on the same account, including:</p> <ul> <li>Alarms and timers</li> <li>Sounds</li> <li>Bluetooth connections</li> </ul> </blockquote> <p>The following solidifies even more that there is no off-the-shelf solution for the dual alarms.</p> <blockquote> <p><strong>Note:</strong> You cannot connect multiple Alexa devices to each other and play the same requested audio at the same time.</p> </blockquote> <hr /> <p>Of course you can use the app to set the alarm from wherever you are and can set it for each Echo. Still, that means setting the alarm twice. Currently, I see no option to easily set the alarm automatically on both (or all) Echos.</p> <p>(Update: you can select which echo to set the alarm or timer on by selecting it in your voice command and do not need to use the app.)</p> <p>For example: &quot;Alexa, set a timer to go off in an hour in the kitchen.&quot; Would effectively set the timer to only go off in the kitchen.</p>

|alexa|amazon-echo|

Will alarms set on one Amazon Echo be shared with all other devices in the same home?

411

<p>With the Amazon Echo, it's easy to set an alarm that will be triggered on the same device that the alarm was created, however it isn't always useful if you're not going to remain in the same room when you expect the alarm to fire (e.g. if you set an alarm in the kitchen to wake you up in the morning).</p> <p>The Amazon documentation seems to suggest <a href="https://www.amazon.co.uk/gp/help/customer/display.html?nodeId=201549770" rel="noreferrer">that alarms are independent of each device</a>:</p> <blockquote> <p>Ask Alexa to set multiple countdown timers or alarms using your voice.</p> <p>Each Alexa device has its own timers and alarms. You can set the timer or alarm up to 24 hours ahead.</p> </blockquote> <p>Can these alarms be synchronised or shared in some way, or will I have to go to the room where I want the alarm to be set?</p>

2016-12-21T15:29:08.313

<p><strong><em>No, it doesn't at the moment.</em></strong> The only <em>this</em> block that supports custom entries is the trigger block you cited yourself already. That function block does not support any special characters to be entered that would be necessary to define IFTTT variables.</p> <p>So yes, you do have to create a recipe manually for every phrase Alexa is supposed to react to via IFTTT. Hopefully they will add a more flexible <em>this</em> block as well. We can see on the Google channel that they have basically four different <em>this</em> blocks, <em>"simple phrase", "with number", "with text" and "with both"</em>. The Alexa channel only supports <em>simple phrases</em> up until now. Hopefully they catch up.</p>

|alexa|ifttt|

Does IFTTT's Alexa channel support 'text ingredients'?

431

<p>IFTTT has support for Amazon Echo (and the Alexa assistant) through the <a href="https://ifttt.com/amazon_alexa" rel="noreferrer">Amazon Alexa</a> channel. Some channels allow you to specify variables, known as <em>ingredients</em>, from a trigger which will be passed into the output event.</p> <p>The <a href="https://ifttt.com/google_assistant" rel="noreferrer">Google Assistant</a> channel supports recognising a phrase with a text ingredient (see the &quot;Google Assistant triggers and actions&quot; at the bottom of the page):</p> <blockquote> <h2>Say a phrase with a text ingredient</h2> <p>This trigger fires when you say “Ok Google” to the Google Assistant followed by a phrase like “Post a tweet saying ‘New high score.’” **Use the $ symbol to specify where you'll say the text ingredient</p> </blockquote> <p>Alexa's trigger does not seem to mention anything about text ingredients:</p> <blockquote> <h2>Say a specific phrase</h2> <p>This trigger fires every time you say &quot;Alexa trigger&quot; + the phrase that you have defined. For instance, if you set &quot;party time&quot; as the phrase, you can say &quot;Alexa trigger party time&quot; to have your lights loop colors. Please use lower-case only. Neither German characters (Umlaute/Eszet) nor their long-form equivalents (ae, oe, etc.) are currently supported — support is coming soon.</p> </blockquote> <p>Does the Alexa channel support <em>ingredients</em> at all, or must I preprogram every possible input I want?</p>

2016-12-22T10:08:33.430

<p>Although decentralised networks often look appealing as a solution, there are a few compelling advantages of centralised networks which make them far more popular at the minute.</p> <h2>Design Overhead</h2> <p>Understanding, programming and setting up a decentralised network is often much more challenging than a traditional centralised (client-server) model in the majority of cases. Take, for example, a <a href="https://en.wikipedia.org/wiki/Mesh_networking" rel="noreferrer">mesh network</a> (the topology used by ZigBee, Z-Wave and Thread), which tends to be structured like so:</p> <p><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/97/NetworkTopology-Mesh.svg/592px-NetworkTopology-Mesh.svg.png" alt="Mesh network"></p> <p>(image from <a href="https://en.wikipedia.org/wiki/Mesh_networking#/media/File:NetworkTopology-Mesh.svg" rel="noreferrer">Wikipedia</a>, in the public domain)</p> <p>Nodes in the network must be capable of sending messages for themselves, but they must also be able to <strong>route messages across the network</strong>, which is more more complex, since each node must be able to calculate a route to the destination. The <a href="https://www.ietf.org/proceedings/64/slides/6lowpan-3.pdf" rel="noreferrer">IETF</a> has a rather interesting presentation on the routing protocols used in <a href="https://en.wikipedia.org/wiki/6LoWPAN" rel="noreferrer">6LoWPAN</a>, a mesh network protocol that uses IPv6. As you can see, the design is far more involved than a traditional star network connected to a Wi-Fi router, and of course each node will need more computational power to handle the additional processing steps needed to participate in the mesh network.</p> <p>The main problem of all of this is that each node will require more processing power, and hence cost more. A <a href="http://searchitchannel.techtarget.com/tip/Introduction-to-network-centralization-and-decentralization" rel="noreferrer">TechTarget article</a> addresses this more generally:</p> <blockquote> <p>Centralization is an attempt to improve efficiency by taking advantage of potential economies of scale: improving the average; it may also improve reliability by minimizing opportunities for error. Decentralization is an attempt to improve speed and flexibility by reorganizing to increase local control and execution of a service: improving the best case. </p> </blockquote> <p>The other side effect will be that the increased computation will lead to a higher power consumption (although this tradeoff may not be <em>that</em> significant compared to long-range transmissions which would otherwise be necessary).</p> <h2>Security</h2> <p>Unless security is built-in to the design of the decentralised protocol, it can easily pose a big problem. Since nodes will be passing data between each other, it's difficult to guarantee the integrity of each packet, since one router node could easily replace one packet with another, and the receiver would never be able to tell the difference. A <a href="http://smallbusiness.chron.com/security-issues-wireless-mesh-networks-46553.html" rel="noreferrer">Chron article</a> describes this issue well:</p> <blockquote> <p>If a computer becomes infected or malicious computer enters a mesh network, it can pretend to be a trusted member of that network and then modify sent data and disrupt how the network passes information. In a black hole attack, information passing through the infected computer will not continue through the network, blocking the flow of data. In gray hole attacks, some data may be blocked, while other data is allowed, making it seem like the computer is still a working part of the network. Wormhole attacks are harder to detect: They tunnel into a network computer from the outside and pretend to be other nodes in the network, essentially becoming invisible nodes. They can then monitor network traffic as it passes from one node to the next.</p> </blockquote> <h2>Economies of Scale</h2> <p>Large cloud platforms such as <a href="https://aws.amazon.com/?nc2=h_lg" rel="noreferrer">AWS</a> or <a href="https://azure.microsoft.com/en-gb/" rel="noreferrer">Azure</a> allow you to set up a centralised server for a price that is <em>dirt cheap</em> - Amazon and Microsoft have the benefit of running truly immense server farms which allows them to provide server space for a very low price. Have a play with the <a href="https://azure.microsoft.com/en-gb/pricing/calculator/" rel="noreferrer">Azure pricing calculator</a> to see what I mean - you can run a function 1 million times in a month, using 128MB of RAM and taking 5 seconds per execution for £2.20/month, and scaling up the capacity is trivially easy.</p> <p>On the other hand, scaling up a decentralised network requires adding more and more nodes, and I expect that you would start to see <em>diseconomies of scale</em>, since the nodes would need to spend more and more time routing data rather than performing useful computation.</p> <p>In summary, although decentralised networks looks like a perfect solution, they <strong>do</strong> have significant disadvantages, which is why many IoT developers still favour centralised solutions.</p>

|security|networking|

Disadvantages of decentralized peer-to-peer networks in IoT

434

<p>I have recently read an <a href="https://techcrunch.com/2016/06/28/decentralizing-iot-networks-through-blockchain/" rel="noreferrer">article</a> about why IoT should switch from the now dominant centralized (server - client) model to a decentralized peer-to-peer solution.</p> <p>Reasons against centralization:</p> <blockquote> <p>Connection between devices <strong>will have to exclusively go through the internet</strong>, even if they happen to be a few feet apart.</p> <p>[...]</p> <p>it <strong>will not be able to respond</strong> to the growing needs of the huge IoT ecosystems of tomorrow</p> <p>[...]</p> <p><strong>Existing IoT solutions are expensive</strong> because of the high infrastructure and maintenance cost associated with centralized clouds, large server farms and networking equipment. The sheer amount of communications that will have to be handled when IoT devices grow to the tens of billions will increase those costs substantially.</p> <p>[...]</p> <p>Even if the unprecedented economical and engineering challenges are overcome, <strong>cloud servers will remain a bottleneck</strong> and point of failure that can disrupt the entire network. This is especially important as more critical tasks such as human health and life will become dependent on IoT.</p> </blockquote> <p>Instead the article suggests a decentralized approach to IoT networking using peer-to-peer communication. But:</p> <blockquote> <p>However, establishing peer-to-peer communications will present its own set of challenges, <strong>chief among them the issue of security</strong>.</p> </blockquote> <p>Other source, like <a href="https://www.hackable.io/blog/how-p2p-becoming-iot-nightmare" rel="noreferrer">How Is P2P Becoming the IoT Nightmare?</a> also mentions security as a problem.</p> <blockquote> <p>It seems that the P2P (peer-to-peer) communication capabilities embedded into some Internet of Things devices turns into a security headache for users.</p> </blockquote> <p>So security is clearly an issue to be solved, but what else should I care about when choosing to use a decentralized P2P network?</p> <p>I am interested in general limitations, risks, and issues that can be used as points of comparison when I want to decide between centralized and decentralized network.</p>

2016-12-22T18:17:24.193

<p>Great question! I found an article from <a href="http://www.radio-electronics.com/articles/wireless-technology/thread-wireless-networking-for-the-iot-160" rel="noreferrer">radio-electronics.com</a> which really helps explain in some more detail how Thread works. Basically, the first eligible router node self-designates as the leader.</p> <p>In other words, when a node is added, if it is unable to find a leader in the system, it will automatically designate itself as the leader. Otherwise, it will fall into line under the existing leader node. I quote from the article referenced above:</p> <blockquote> <p>Router Eligible nodes become routers if they are needed to support the mesh. The first Router Eligible node to form the network will be autonomously designated a router as well as the Leader. A Leader performs additional network management tasks and makes decisions on behalf of the network. Other Router Eligible nodes in the network can assume the role of a Leader, but there is only one Leader per network at a given time.</p> </blockquote> <p>In other words, it's a one <s>man</s> machine election. Not very democratic, but in computers, it works.</p>

|thread|

How does Thread elect a Leader device?

439

<p>Thread have produced a document about their protocol, <a href="http://threadgroup.org/Portals/0/documents/whitepapers/Thread%20Stack%20Fundamentals_v2_public.pdf" rel="noreferrer"><em>Thread Stack Fundamentals</em></a>, which I've been reading to try and understand more about how Thread works.</p> <p>On page 5, the document explains that despite having no single point of failure, a <em>Leader</em> is needed to make decisions for the network:</p> <blockquote> <p>A Router or Border Router can assume a Leader role for certain functions in the Thread Network. This Leader is required to make decisions within the network. For example, the Leader assigns Router addresses and allows new Router requests. The Leader role is elected and if the Leader fails, another Router or Border Router assumes the Leader role. It is this autonomous operation that ensures there is no single point of failure. </p> </blockquote> <p>How is the Leader elected by the devices in the Thread network? Is there a set of criteria that are evaluated when the devices 'vote' for or select the Leader?</p>

2016-12-23T17:48:03.313

<p>The reason you see such a difference between ANT and BLE is the use case is very different for ANT. Sports use cases are looking for data from a "UDP" type of view where they just want the most recent information and don't need to send much information but they need to send it often. </p> <p>For example, BLE can behave similar to a message based system (as is Zigbee) where you only transmit if you have something to say, ANT does not do that. ANT transmits on period, and if you have nothing new to send, then the radio will send the last message again. </p> <p>Therefore I would recommend using the radio that best suits your use-case to get the best power consumption.</p> <p>Note: also ANT+ is simply an application layer overtop of ANT and has little to no effect on power consumption except for defining channel configuration.</p>

|wireless|power-consumption|ant|

Power consumption of ANT/ANT+ compared to other wireless sensor network technologies

447

<p>ANT/ANT+ is a proprietary but open access multicast wireless sensor network technology. It's data rate and the resulting application throughput of 20 to 60 kBit/s is significantly reduced compared to its competitors, i.e. Bluetooth and ZigBee. For applications that get along with that restriction and a physical range that is comparable to other wireless network systems it might well be an interesting alternative. It would seem that it is primarily used by sports and fitness sensors by a number of manufacturers. </p> <p>This <a href="https://de.wikipedia.org/wiki/ANT_(Netzwerk)" rel="noreferrer">Wikipedia page</a> states that:</p> <blockquote> <p>Geräte benötigen beim Empfang oder Senden weniger als 50 mW Leistung. Da sie die meiste Zeit im Sleep-Mode verharren, ist die Gesamtstromaufnahme gering.</p> </blockquote> <p>Which roughly translates to:</p> <blockquote> <p>Devices require less than 50 mW of power when receiving or transmitting. Since they remain in sleep mode for most of the time, the total current consumption is low.</p> </blockquote> <p>It focuses on ANT being specifically well suited for low power sensor networks with less than 50 mW of power consumption during transmissions and being in sleep mode most of the time. </p> <p>However, one would expect any battery powered appliance (and even more so devices powered by energy harvesting) making heavy use of deep sleep modes during times of inactivity. I wonder how a "real life" sensor network using ANT would compete against other technologies such as Bluetooth low energy in terms of power consumption?</p>

2016-12-23T17:50:13.340

<blockquote> <p>Can it suspend its network connection and act as a Sleepy End Device, or does the networking component need to be on all the time?</p> </blockquote> <p>They can be sleepy end devices! but, <code>the Network device is still ON.</code></p> <p>According to the definition <code>"Sleepy end devices are host devices. They communicate only through their Parent Router and cannot forward messages for other devices"</code> i.e, their network device is not off!</p> <p>Sleepy end devices will be communicating with their parent router.</p>

|thread|

Can Router-eligible End Devices sleep in Thread networks?

450

<p>In <a href="http://threadgroup.org/Portals/0/documents/whitepapers/Thread%20Stack%20Fundamentals_v2_public.pdf" rel="noreferrer"><em>Thread Stack Fundamentals</em></a>, the four types of devices in a <a href="http://threadgroup.org/" rel="noreferrer">Thread</a> network are outlined on page 5/6:</p> <ul> <li>Border Routers</li> <li>Routers</li> <li>Router-eligible End Devices (REEDs)</li> <li>Sleepy End Devices</li> </ul> <p>It is implied by the document that Routers must be able to constantly supply themselves with electricity (hence REEDs must also be able to run constantly if they are upgraded to Routers). However, can REEDs save power and sleep if they aren't currently being used as routers, or must they always be on in case they are needed?</p> <p>Take, for example, a smart TV supporting Thread, currently acting as a REED. Since no other devices depend on it while it is a REED, can it suspend its network connection and act as a Sleepy End Device, or does the networking component need to be on all the time?</p>

2016-12-24T10:49:17.220

<p>Some ideas - I've not covered all combinations of with/without username/TLS, hopefully you can see where they are missing.</p> <p>Can a client connect anonymously, no TLS?</p> <pre><code>mosquitto_sub -t test/topic -h &lt;broker address&gt; </code></pre> <p>Can a client connect if it provides a username but no password, no TLS?</p> <pre><code>mosquitto_sub -t test/topic -u &lt;username&gt; -h &lt;broker address&gt; </code></pre> <p>Can a client connect if it provides a username and a password (correct or not), no TLS?</p> <pre><code>mosquitto_sub -t test/topic -u &lt;username&gt; -P &lt;password&gt; -h &lt;broker address&gt; </code></pre> <p>Can a client subscribe to the <code>$SYS</code> topic and see information about the broker?</p> <pre><code>mosquitto_sub -t '$SYS/#' -v -h &lt;broker address&gt; </code></pre> <p>Can a client connect using TLS?</p> <pre><code>mosquitto_sub -t test/topic -h &lt;broker address&gt; -p 8883 --capath /etc/ssl/certs </code></pre> <p>Can a client subscribe to all topics? What does it see?</p> <pre><code>mosquitto_sub -t '#' -v </code></pre> <p>Repeat all the above when publishing as well.</p>

|security|mqtt|mosquitto|testing|

What simple security tests can I perform on my MQTT network?

452

<p>I am about to set up an MQTT network at home. I want to build up some knowledge by practical exercises. It would be a small network with the broker hosted on my laptop (Windows 7) and some Raspberry Pi powered client. Also I am thinking about making a client on my phone (Android).</p> <p>My goal is to have a simple network on which I can experiment and I want to perform some security testing, experimenting first.</p> <p>I have found an <a href="http://www.codenomicon.com/products/defensics/datasheets/mqtt-server.html" rel="nofollow noreferrer">MQTT Server Test Suite</a> which is designed to act as a malicious MQTT client. It is pretty promising to start with.</p> <blockquote> <p>Test tool general features</p> <ul> <li>Fully automated black-box negative testing</li> <li>Ready-made test cases</li> <li>Written in Java(tm)</li> <li>GUI, command line, remote interface modes</li> <li>Instrumentation (health-check) capability</li> <li>Support and maintenance</li> <li>Comprehensive user documentation</li> <li>Results reporting and analysis</li> </ul> </blockquote> <p>I am also interested in some more simple practices I can use to verify MQTT security features. What are the simplest ways for a beginner to perform some basic security verification on an MQTT network?</p>

2016-12-26T17:57:22.777

<p>I'm a few hundred kilometers away from my Echo, so unfortunately I can't test anything. I found no way to deactivate the sound altogether. If I recall correctly however that waking <em>hello</em> is tied to the usual volume levels one sets. </p> <p>Fortunately that volume level is different from the timer and alarm volume levels. So one could at least over night set the speech volume level to zero and still be woken up by a reasonably volume level for the alarm clock. However you'd have to reset the speech volume level back up in the morning, manually—well, by voice. </p> <p>Of course, that's only necessary if the Echo is the alarm clock. If not, one could always have the echo on a timed power plug shutting its power off completely over night. Maybe one could even connect the echo power supply to the alarm clock, but that'd be a different question.</p>

|amazon-echo|

How do I stop an Amazon Echo from making a sound after restarting?

458

<p>When booting, the Amazon Echo plays a sound and says 'hello', which is usually not a problem, but I'm concerned that if I have a power failure in the night, the Echo might reboot and play a loud sound, waking me up.</p> <p>One user seems to have experienced a similar problem on the <a href="https://www.amazon.com/forum/amazon%20discussions%20feedback?_encoding=UTF8&amp;cdForum=FxLCMW9UN2N6QR&amp;cdThread=Tx3L1M4NTPBJI8X" rel="noreferrer">Amazon forum</a>:</p> <blockquote> <p>[OP]: I'd prefer Echo didn't make a startup sound and say "hello" after a power outage. Is there a way to disable the startup sounds?</p> <p>[reply]: Do you really have so many power outages that this is a significant problem? I've only had one power outage in the past two years.</p> <p>[OP]: Yes. Construction-related. Likely to continue for at least a year.</p> </blockquote> <p>Understandably, in a situation such as this, it is not at all desirable for the sound to be playing frequently at night. One reply suggested an uninterruptible power supply (UPS), but I would like to avoid this if possible because they are quite expensive.</p> <p>How can I stop my Echo from playing the startup greeting? Is it supported at all (or is there a suitable workaround)? </p>

2016-12-26T19:41:54.513

<p>On the <a href="https://myactivity.google.com/myactivity?product=29" rel="noreferrer">Voice &amp; Audio</a> section of the Google My Activity page, you can see your history. The recordings it keeps are only after triggering it to wake up with the wake word (OK Google). It also has the ability to delete your history.</p>

|google-home|privacy|google-assistant|

Does the Google Home record conversations to target advertisements?

459

<p>Google states that the Google Assistant (the personal assistant that runs on the Google Home, Pixel and the Allo app) uses 'conversation history' for targeted advertising:</p> <blockquote> <h2>Does Google use my conversation history to personalize the ads I see?</h2> <p>If you interact with the Google Assistant, we treat this similarly to searching on Google and may use these interactions to deliver more useful ads. You can delete past interactions with your Assistant at any time.</p> </blockquote> <p>What exactly is Google using when it says 'conversation history' - is Google Home listening to <strong>everything</strong> so it can target advertisements or are my queries only stored <em>after</em> saying 'OK Google'?</p> <p>Some sources suggest that the Google Home might even be recording what I listen to on the TV:</p> <blockquote> <p>"That microphone will be a witness to every verbal interaction in the home. It will also know what you watch on TV, what you listen to, and, obviously, when there's no one home."</p> <p><strong><em>- <a href="http://www.computerworld.com/article/3128791/data-privacy/how-google-homes-always-on-will-affect-privacy.html" rel="noreferrer">Computerworld</a></em></strong></p> </blockquote>

2016-12-26T20:08:51.040

<p>First, the quote seems to have been about securing mobile devices, not about "an IoT network of diverse sensors", but some lessons can perhaps still be drawn.</p> <p>Unlike with a mobile device, an "IoT network" of sensors tends to imply that they aren't all in the same place, so a user likely can't be expected to qualify in the judgement of all of them at once. This means that a system would need to be very provisional about the authenticity of the user - in effect:</p> <blockquote> <p>You walk like Joe and know Joe's password, so maybe you are Joe, and I'll let you do Joe's less critical things unless I start suspecting you aren't Joe, but to do something more critical you're going to have to go here and do this, and go there and stare into that, and repeate the following phrase, and...</p> </blockquote> <p>But as critically, and in common with the mobile device case, such a scheme <em>only secures the front door</em>. It offers no protection against <em>at least three</em> other types of vulnerability.</p> <ul> <li><p>Many exploits against modern systems come not from a malicious user, but rather from malicious data delivered via a network, USB stick or similar, either in the form of unsolicited traffic, or undesired payloads catching a ride on things that the user does want. Typically such data exploits a security failure in the design - either an insecure optional feature that shouldn't be there (windows autorun files) or a classic mistake-data-for-code bug like a buffer overflow.</p></li> <li><p>Both IoT systems and mobile phones tend to be heavily integrated with network servers, with the latter often given a high degree of access to the same data or the capabilities the mobile system's security is trying to protect. Absent things like end-to-end encryption and authentication tokens <em>not known to the server infrastructure</em>, a successful attack or misuse of the server infrastructure can often accomplish most of what bypassing the device's security could.</p></li> <li><p>IoT systems, likely even more so than mobile devices, may be quite vulnerable to physical attack. Phones may attempt to secure the keys used to encrypt a user's data against ready access with a JTAG debugger, but what an IoT system holds <em>locally</em> is often not so much data, as the ability to do various things. It effectively matters not a bit to a local attacker how secure the computer part of an IoT device is, if they can simply pop off the cover and use a clip lead to activate the output relay - or for that matter, cut the wires going to the actuator and touch them to their own battery. Or an attacker may create false conditions at the site of the IoT device's sensors (candle under the heat sensor, wet sponge on the moisture, etc), and cause it to uplink or act on erroneous readings.</p></li> </ul>

|security|sensors|machine-learning|biometrics|

Will multiple simultaneous biometric sensors create unbreakable security for devices?

460

<p><a href="http://www.eetimes.com/document.asp?doc_id=1330938" rel="nofollow noreferrer">This article</a> quotes the CEO of Image Ware, </p> <blockquote> <p>[The solution] according to Miller, is multi-modal biometrics which he claims makes it virtually impossible for the wrong person to access computer systems.</p> </blockquote> <p>His company uses existing hardware and platforms, connecting physical feature recognition algorithms (finger, palm, hand and prints, and face, eye, iris ) with other algorithms employing common biometric data sensors found on today's mobile devices.</p> <p>My gut feeling is that he has overstated this somehow, but I can not put my finger on why this rings untrue. It seems to me that if a multi-sensor approach was truly effective we would see hardware and software for such strategies everywhere by now.</p> <p>Can an IoT network of diverse sensors be an efficient and effective security strategy? (Is the multi-sensor approach effective? )</p> <p>What are the pitfalls? </p>

2016-12-26T20:58:24.230

<p>What <a href="http://internetofeverything.cisco.com/sites/default/files/docs/en/ioe-value-index_Whitepaper.pdf" rel="noreferrer">Internet of Everything</a>'s aim is:</p> <blockquote> <p>connecting the unconnected — people-to-people (P2P), machine-to-people (M2P), and machine-to-machine (M2M) — via the Internet of Everything (IoE).</p> </blockquote> <p>So basically it seems to be a broader term, the next generation of IoT <a href="http://www.cisco.com/c/dam/en_us/about/ac79/docs/innov/IoE_Economy.pdf" rel="noreferrer">according to Cisco</a>.</p> <p><strong>The point is that all devices will have direct connection to the Internet</strong>, while in IoT the devices are members of an Internet-Like-Network but not necessarily the Internet itself.</p> <p><a href="http://www.cisco.com/c/dam/en_us/about/ac79/docs/innov/IoE_Economy.pdf" rel="noreferrer">What makes it possible</a> is the IPv6 which will allow countless devices to have its own IP address.</p> <blockquote> <p>Second, barriers to connectedness continue to drop. For example, IPv6 overcomes the IPv4 limit by allowing for <strong>340,282,366,920,938,463,463,374,607,431,768,211,456</strong> more people, processes, data, and things to be connected to the Internet. Amazingly, IPv6 creates enough address capacity for every star in the known universe to have 4.8 trillion addresses.</p> </blockquote> <p>So IoE emphasizes TCP/IP connection and larger, more comprehensive networks.</p> <p>But all in all there are not much differences at all. Using only TCP/IP in IoE exclude a lot of IoT platforms and devices but the concept does not change much.</p> <p>Also the targeted connection of M2M, P2P, M2P does not make a significant difference either. </p>

|definitions|

What is the difference between the Internet of Things and the Internet of Everything?

463

<p>As the title says: What is the difference between the Internet of Things and the Internet of Everything and should I care?</p> <p>I came cross two concepts the <em>Internet of</em> <strong>Things</strong> and the <em>Internet of</em> <strong>Everything</strong>. Can anyone help me understand: How do the two topics differ from each other?</p> <p>If you have time to watch a 20 minute video, this is where I first got the topic from: <a href="https://www.youtube.com/watch?v=iCzQNTL4-Rs" rel="nofollow noreferrer">Introduction to the Internet of Everything by Eli the Computer Guy</a>.</p>

2016-12-27T14:37:44.390

<p>The <a href="https://datatracker.ietf.org/doc/html/draft-ietf-6lowpan-hc-15#section-3" rel="nofollow noreferrer">RFC draft</a> explains a bit better how the header compression works. What is described as <em>arbitrary prefixes</em> in the abstract is essentially a bunch of information that is assumed to be in a certain range or having a specific value. Thus, making transmitting those information unnecessary.</p> <blockquote> <p>To enable effective compression LOWPAN_IPHC relies on information pertaining to the entire 6LoWPAN.</p> </blockquote> <p>This assumption goes for the <em>entire 6LoWPAN</em>, breaking down the next sentence we have six information that are assumed to be known or in a considerably smaller range of values.</p> <blockquote> <ul> <li>Version is 6;</li> </ul> </blockquote> <ul> <li>Traffic Class and Flow Label are both zero;</li> <li>Payload Length can be inferred from lower layers from either the 6LoWPAN Fragmentation header or the IEEE 802.15.4 header;</li> <li>Hop Limit will be set to a well-known value by the source;</li> <li>addresses assigned to 6LoWPAN interfaces will be formed using the link-local prefix or a small set of routable prefixes assigned to the entire 6LoWPAN;</li> <li>addresses assigned to 6LoWPAN interfaces are formed with an IID derived directly from either the 64-bit extended or 16-bit short IEEE 802.15.4 addresses.</li> </ul> <p>(Bullet points by me, otherwise continuing section three of the draft.)</p> <p>This also explains why this compression is not used by devices like your PC. Your PC has to be able to address the whole world basically. However the compression as described above is only really effective if used in a sufficiently constrained environment—the <em>entire 6LoWPAN</em>—and not the world.</p> <blockquote> <p>In the best case, the LOWPAN_IPHC can compress the IPv6 header down to two octets (the dispatch octet and the LOWPAN_IPHC encoding) with link-local communication.</p> </blockquote> <p>(Still same draft section)</p> <p>As described in the RFC draft the compression gets even better when it's in a more constricted environment. For <a href="https://en.wikipedia.org/wiki/Link-local_address" rel="nofollow noreferrer">link local</a> only it's down to two octets. Of course, we want our usual computers and end devices to be able to address everything else instead. However, if we want to be able to change all those values this compression takes as granted it doesn't work anymore. We'd have a mismatch between what we mean and what every other network participant thinks we mean, because the compression takes values for granted.</p> <p><em>Thus, the compression severely limits the vast possibilities of IPv6 to reach smaller headers and gain efficiency in time and energy <strong>in a very well defined small environment.</strong></em></p>

|networking|6lowpan|compression|

Why does 6LoWPAN use additional header compression?

480

<p>I've been reading about the <a href="https://en.wikipedia.org/wiki/6LoWPAN" rel="nofollow noreferrer">6LoWPAN</a> protocol (which is used by Thread, among other network protocols), and it seems to be highly useful for networking, and has the advantage of allowing each device to easily be addressable.</p> <p>Wikipedia says that 6LoWPAN uses a form of header compression to reduce transmission size (hence saving time and energy):</p> <blockquote> <p>The target for IP networking for low-power radio communication is applications that need wireless internet connectivity at lower data rates for devices with very limited form factor. An example is automation and entertainment applications in home, office and factory environments. The header compression mechanisms standardized in RFC6282 can be used to provide header compression of IPv6 packets over such networks.</p> </blockquote> <p>It refers to <a href="https://www.rfc-editor.org/rfc/rfc6282" rel="nofollow noreferrer">RFC 6282</a> as the compression format used. The abstract is rather brief in <em>how</em> it works:</p> <blockquote> <p>The compression format relies on shared context to allow compression of arbitrary prefixes. How the information is maintained in that shared context is out of scope.</p> </blockquote> <p>As far as I can tell, 'shared context' is used to elide some header fields and save space. How, exactly, is this 'shared context' managed, and why doesn't every IPv6 device (e.g. my computer) use this compression?</p>

2016-12-27T20:41:07.707

<p>To achieve 2FA in MQTT network I have created following services for authentication which are connected to Broker.</p> <ol> <li>ID verifier</li> <li>Token Generator</li> <li>Token Verifier</li> </ol> <p>When MQTT client connects to broker over SSL/TLS, it first publishes its own ID to <em>device_id</em> topic, the ID Verifier verifies that it is the authentic client and then Token Generator is invoked which generates a token and publishes the token on locked topic <em>device_token</em>.</p> <p>The client device gets this token and further publishes it to a topic <em>verify_token</em>. As soon as the topic is published on <em>verify_token</em> the token verifier compares the values at topic <em>device_token</em> and <em>verify_token</em> if it matches it add the device's id to verified device pool and allow the device publish data. This improves security because the only verified devices gets connected to the topics to publish data. </p> <p>I have also used MQTT_KEEPALIVE configuration option to keep the client active when no data is being sent or received to keep the client device alive in device pool and prevent it from being verified again once it is added to device pool. however for security purpose I froce the device to 2FA every 24 hours.</p>

|security|mqtt|authentication|

How can I use 2FA in an MQTT network?

496

<p>How can I use 2FA (two factor authentication) when I connect a new device to the broker, if it is even possible?</p> <p>Because it seems easier, the second factor can be a software solution first but I would welcome ideas on how to introduce hard tokens (RFID maybe).</p> <p>It would make sense if the devices should authenticate only at the first connection and server would remember "old" clients.</p> <p>The idea maybe unusual or unsuitable - if it is a bad idea, please give me the reasons why.</p>

2016-12-28T04:25:34.443

<p>The Nest Protect seems to have three self-testing mechanisms:</p> <ul> <li><p>The <a href="https://nest.com/support/article/What-is-Self-Monitoring" rel="nofollow noreferrer">Self Test</a>, which runs every <strong>200 seconds</strong>, and tests power, smoke/CO sensors and Wi-Fi</p></li> <li><p>The monthly <a href="https://nest.com/support/article/Learn-more-about-Sound-Check" rel="nofollow noreferrer">Sound Check</a>, which verifies that the speaker, horn and light ring work as expected</p></li> <li><p>The on-demand <a href="https://nest.com/support/article/How-and-when-should-I-test-my-Nest-Protect" rel="nofollow noreferrer">Safety Checkup</a>, which tests all of the above components.</p></li> </ul> <p>The automatic testing mechanisms <strong>cannot be disabled</strong>:</p> <blockquote> <p>Self Test helps ensure that your Nest Protect is working to keep you safe, and gives you essential information when you need it, so it can't be disabled. </p> </blockquote> <p>All of the test results are collected into the <a href="https://nest.com/support/article/What-is-Nightly-Promise" rel="nofollow noreferrer"><em>Nightly Promise</em></a>, which verifies that there are no problems with your smoke/CO detectors before you sleep. If the Nest Protect glows yellow at night, this indicates a problem that requires attention (e.g. battery needs replacing, fault with sensors). You can view this in the app to see the exact problem.</p> <p>The Nightly Promise automatically shows as soon as you dim the lights at night - no button is required for it to display.</p> <p>In regards to answering <em>how</em> the detector self-tests, it's a little harder to say. Naturally, the detector can't just burn something to test if it's working or not, so I can only assume that the test procedure functions similarly to a normal smoke alarm.</p> <p>The Nest Protect <a href="http://www.safelincs.co.uk/blog/2016/03/01/safelincs-introduces-the-nest-protect/" rel="nofollow noreferrer">uses an optical detector</a>, so it may be worth following the advice at <a href="https://diy.stackexchange.com/questions/37091/how-can-i-safely-test-my-optical-smoke-alarm?noredirect=1&amp;lq=1"><em>How can I safely test my (optical) smoke alarm?</em></a> on Home Improvement Stack Exchange if you want to test the device's reaction to actual smoke.</p>

|smart-home|testing|nest-protect|

How does the Nest Protect autotest?

498

<p>I've been reading about Nest's various devices, and one particularly useful device has come to my notice: <a href="https://nest.com/smoke-co-alarm/meet-nest-protect/" rel="noreferrer">Nest Protect</a>. However, one thing still puzzles me. It says on their web page that: </p> <blockquote> <p>The new Nest Protect has been redesigned from the inside out. It has an industrial-grade smoke sensor, tests itself automatically, and lasts up to a decade.</p> </blockquote> <p>How does the alarm auto test? Is this just a battery check or is this actually testing whether the alarm will go off in a smoky environment? Being an IoT device, I would naturally <em>assume</em> that it is measure more than just a simple battery level, but what and how?</p>

2016-12-28T10:48:46.470

<p>You may be interested in the <a href="http://www.skein-hash.info/" rel="noreferrer">Skein</a> family of cryptographic hash functions, which are designed to be efficiently implemented on a wide variety of small and large processors. You can trade RAM for speed, or vice versa. The hash can be implemented with as few as 100 bytes of state. The Skein primitive is the basis for both hashing and encryption.</p> <p>The home page has a post offering a freely available PIC implementation; although I didn't find the link, you can probably search online for it.</p>

|security|microcontrollers|pic|cryptography|

Cryptographic algorithms for PIC16 microcontrollers

499

<p>I'm planning to implement my own home automation system. In will contain the central Raspberry PI server and a number of sensors and switches based on 8-bit PIC16 microcontrollers which are communicating to the central Raspberry PI over the radio (using nRF24L01, 2.4GHz).</p> <p>As an example consider <a href="http://www.microchip.com/wwwproducts/en/PIC16F1705" rel="noreferrer">PIC16F1705</a> with 16k ROM and 1k RAM.</p> <p>In order to secure the system I need some cryptographic algorithms, like</p> <ul> <li>Hash functions</li> <li>Block ciphers</li> <li>Random number generators</li> </ul> <p>Now my questions are:</p> <ul> <li><em>Which cryptographic algorithms are available for PIC16?</em></li> <li><em>Which algorithms can be ported or implemented?</em></li> </ul> <p>For example, Advanced Encryption Standard (AES) in my understanding can't be implemented due to the RAM restriction.</p>

2016-12-28T14:58:17.327

<p>15 minutes after ringing my Ring doorbell (notifications from the Ring app come literally instantly) my lights (also instant from the app) blink.</p> <p>20 seconds after pressing a Amazon AWS Dash button, the function is executed.</p> <p>Point is: The delay can be anywhere from 5 seconds, to 50 minutes. Do <strong>not</strong> rely on IFTTT.</p>

|ifttt|

How delayed can IFTTT triggers be?

503

<p>I've been using IFTTT for various tasks, and it works relatively well, but for the triggers I've been using (RSS feed updates) the update time is quite slow (up to 15 minutes of delay after the feed is updated. For high-frequency feeds, 15 minutes is a severe delay, but in my use case this is manageable, so I'm not too concerned.</p> <p>For other triggers and recipes I want to create, I need to be able to respond more quickly to an event. For example, if I receive an email, I'd like IFTTT to perform an action much more quickly (within 5 minutes at most). </p> <p>Ignoring any issues with IFTTT being down, how can I determine how quickly a trigger will fire? Is the time to react based on the applet (I assume some applets might have push triggers, so IFTTT will be able to respond more quickly)?</p>

2016-12-28T20:11:52.857

<p>If the <code>clientid</code> is the same, in MQTT, the spec says you must consider them to be the same client! Probably Y should be connected using the <code>Id</code> and <code>X</code> should be disconnected.</p> <p>This part is from the documentation:</p> <blockquote> <p>If validation is successful the Server performs the following steps.</p> <ol> <li><p>If the ClientId represents a Client already connected to the Server then the Server MUST disconnect the existing Client [MQTT-3.1.4-2].</p></li> <li><p>The Server MUST perform the processing of CleanSession that is described in section 3.1.2.4 [MQTT-3.1.4-3].</p></li> <li><p>The Server MUST acknowledge the CONNECT Packet with a CONNACK Packet containing a zero return code [MQTT-3.1.4-4].</p></li> <li><p>Start message delivery and keep alive monitoring.</p></li> </ol> </blockquote> <p>Look <a href="http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718032" rel="nofollow noreferrer">this documentation</a> for more details.</p>

|mqtt|

What will be the result of the following connection scenario in an MQTT network?

504

<p>In MQTT it is the client who initiates the connection with a CONNECT message.</p> <p><a href="https://i.stack.imgur.com/UAIFW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UAIFW.png" alt="MQTT Connect Package parameters"></a></p> <p>The first field of the packet is the <code>clientId</code>:</p> <blockquote> <p>The client identifier (short ClientId) is an identifier of each MQTT client connecting to a MQTT broker. As the word identifier already suggests, it should be unique per broker. The broker uses it for identifying the client and the current state of the client. (Image and quote are taken from from <a href="http://www.hivemq.com/blog/mqtt-essentials-part-3-client-broker-connection-establishment" rel="nofollow noreferrer">here</a>.)</p> </blockquote> <p>Now let's say I have two clients, client X and Y in the following situation.</p> <ol> <li>Broker launched, no clients yet.</li> <li>X succesfully connects to the broker with <code>client-1</code> id, username is <code>X</code>.</li> <li>Now, Y tries to connect using <code>client-1</code> as id, username is <code>Y</code>.</li> </ol> <p>What will happen?</p> <ol> <li>Based on the clientId, the broker will think that X performs a <strong>repeated connection attempt</strong> which is <a href="http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718123" rel="nofollow noreferrer">abnormal behavior</a>.</li> <li>Nothing extraordinary will happen. Y connects successfully as it <strong>uses a different username</strong>.</li> <li>Nothing extraordinary will happen. The <strong>broker will reject Y</strong> connection attempt as the given clientId is already in use.</li> </ol>

2016-12-29T13:40:07.297

<p>Having used X10 and now Zwave for complete home automation (I mean everything, doors, blinds, lights, towel rails, water pump, hot water, heat pumps etc), I would sit on the fence.</p> <p>You may need a server (or PC) running all the time, and a UPS for it too. Each light is controlled by a device which is running all the time. Some have physical relays in them, which consume power when activated.</p> <p>Yes, you are saving power by turning LED lights off when not needed, but this shortens their lifespan drastically. On the face of it they are rated for 30,000 to 50,000 hours, but no one mentions that there are a limited number of switching cycles. Within 7 years, 10% of my LEDs have failed. The ones that have failed are the ones that are switched on/off based on motion and the one on dimmers.</p> <p>The rated cycles can be as low as 20,000. If you turn each light on and off 5 times day, it gives you a life of 11 years.</p> <p>In my case, I am using sealed LED downlights, so I have to replace the whole fitting, which blows teh saving out of the water.</p>

|smart-home|power-consumption|

Do Internet-connected lighting systems save energy overall?

512

<p>Many manufacturers of 'smart lighting' systems claim that connecting your lights to the Internet of Things will save energy. For example, Samsung SmartThings use energy savings as <a href="https://www.smartthings.com/uses/lighting-energy" rel="noreferrer">a key selling point</a>, and have a <a href="http://blog.smartthings.com/stories/part-2-the-aftermath-the-future/" rel="noreferrer">case study</a> that promises large savings:</p> <blockquote> <p>All in all, after one season of using SmartThings, our home utility bill was $78 less than it was the season before.</p> </blockquote> <p>Philips Hue also <a href="http://www2.meethue.com/en-gb/about-hue/" rel="noreferrer">call their bulbs 'energy-efficient'</a>, although it isn't such a selling point for the Hue compared to how much SmartThings promote energy savings.</p> <p>I would have thought that the majority of energy savings from turning off the lights would be negated by the extra energy used by the processing hubs and wireless radios in every device, as well as the energy requirements of any motion sensors you install.</p> <p>Is it true that energy can be saved (in a typical home situation, assuming the same number and type of bulbs before/after) by using 'smart lighting' such as SmartThings or Hue, or are the benefits exaggerated in terms of energy consumption?</p>

2016-12-30T18:30:39.377

<p>Very old question, but still active, so it deserves an updated answer.</p> <p>Yes, OpenHAB 3 is fully integrated with Google Assistant via their myopenHAB.org cloud bridge.</p> <p><a href="https://www.openhab.org/docs/ecosystem/google-assistant/#google-assistant-action" rel="nofollow noreferrer">https://www.openhab.org/docs/ecosystem/google-assistant/#google-assistant-action</a></p>

|google-assistant|openhab|

Does openHAB support the Google Assistant?

526

<p>I've been considering using <a href="http://www.openhab.org/" rel="noreferrer">openHAB</a> recently as my home automation system, but I'd like to connect a Google Home to it so I can control the system with my voice.</p> <p>It looks like openHAB <a href="https://github.com/openhab/openhab-alexa" rel="noreferrer">support Amazon Alexa through the <code>openhab-alexa</code> skill</a>, so with an Echo I could issue voice commands and receive simple voice messages, but I'd like to use a Google Home instead.</p> <p>I've checked the <a href="http://www.openhab.org/features/supported-technologies.html" rel="noreferrer">Supported Technologies</a> page on the openHAB website, but it looks like there's nothing there for the Google Home/Assistant. <strong>Is it possible to connect my Google Home to openHAB?</strong> If possible, I'd like to connect directly, but I would be happy with connecting it through a different service if necessary.</p>

2016-12-31T14:39:51.280

<p>I finally succeeded in finding the correct command on this <a href="https://www.kepware.com/support/knowledge-base/default.asp?solution=/_ui/selfservice/pkb/PublicKnowledgeSolution/d?&amp;id=50133000000f9YF" rel="noreferrer">site</a>. It is:</p> <pre><code>net start mosquitto </code></pre> <p>It can be run from any directory. If you receive the following error:</p> <pre><code>D:\..\MQTT\mosquitto&gt;net start mosquitto System error 5 has occurred. Access is denied. </code></pre> <p>then you need to run the command prompt as an administrator. In case of success the following response will be shown.</p> <pre><code>D:\..\MQTT\mosquitto&gt;net start mosquitto The Mosquitto Broker service is starting. The Mosquitto Broker service was started successfully. </code></pre>

|mqtt|mosquitto|microsoft-windows|

How to start Mosquitto broker service on Windows 7 from command prompt?

528

<p>I have set up <a href="https://mosquitto.org/" rel="noreferrer">Mosquitto MQTT</a> on my Windows 7 laptop. I have performed the installation process according to this step by step <a href="https://sivatechworld.wordpress.com/2015/06/11/step-by-step-installing-and-configuring-mosquitto-with-windows-7/" rel="noreferrer">guide</a>.</p> <p>Installation was alright and I could start the Mosquitto Broker's service by using <code>C:\Windows\system32\services</code>.</p> <p><a href="https://i.stack.imgur.com/lmK2e.png" rel="noreferrer"><img src="https://i.stack.imgur.com/lmK2e.png" alt="windows service overview showing mosquitto broker service"></a></p> <hr> <p>Now what I want is to be able to launch the service from Windows 7 command prompt. In everycase I tried to run the commands from the install directory of Mosquitto (<code>D:\..\MQTT\mosquitto&gt;</code>).</p> <ol> <li><p>First I have tried the following command according to the <a href="https://mosquitto.org/man/mosquitto-8.html" rel="noreferrer">documentation</a>:</p> <pre><code>mosquitto -d </code></pre> <blockquote> <p>-d, --daemon</p> <p>Run mosquitto in the background as a daemon. All other behaviour remains the same.</p> </blockquote> <p>Turned out that I cannot do this on Windows.</p> <pre><code>1483193297: Warning: Can't start in daemon mode in Windows. </code></pre></li> <li><p>After, I have tried a command shared on this <a href="http://www.embedded101.com/Develop-M2M-IoT-Devices-Ebook/DevelopM2MIoTDevicesContent/articleid/237?dnnprintmode=true&amp;mid=948&amp;SkinSrc=%5BG%5DSkins%2F_default%2FNo%20Skin&amp;ContainerSrc=%5BG%5DContainers%2F_default%2FNo%20Container" rel="noreferrer">site</a>.</p> <pre><code>mosquitto –p 1883 –v </code></pre> <p>This one started the broker but not the background service. I have checked the service among the Windows services, and Mosquitto Broker was not started.</p></li> </ol> <hr> <p>Does anyone know the proper way of starting Mosquitto broker's service from Windows 7 command prompt?</p>

2016-12-31T15:09:40.377

<p>I know you wrote that you would rather not purchase additional hardware, yet at least this is an option. You can easily use the Harmony hub, here is how to do it: <a href="http://www.voicedesigned.com/?q=content/controlling-your-entertainment-system-alexa-and-harmony-hub" rel="noreferrer">Controlling Your Entertainment System with Alexa and the Harmony Hub @ VoiceDesigned.com</a></p>

|alexa|wake-on-lan|microsoft-xbox|

How can I boot an Xbox One remotely using Amazon Alexa?

530

<p>I've been researching how to control an Xbox One through Alexa, but I can't find a straightforward way to achieve this. A <a href="https://www.reddit.com/r/amazonecho/comments/4c1prj/alexa_and_xbox_one_integration_possible/d1elbk4/" rel="noreferrer">reddit thread</a> suggests using the Blumoo remote, but I'd rather not pay for <em>more</em> hardware if I can avoid it.</p> <p><a href="http://www.insidegamer.net/2014/07/18/xbox-one-august-update-brings-wake-lan-kind/" rel="noreferrer">This article</a> from InsideGamer suggests that there is <em>some</em> sort of remote control ability:</p> <blockquote> <p>Microsoft’s August Xbox One update brings with it a long awaited feature for Xbox owners, the ability to wake your console to automatically download games, addons and DLC when you aren’t in proximity to it.</p> </blockquote> <p>Is there some form of <a href="https://en.wikipedia.org/wiki/Wake-on-LAN" rel="noreferrer">Wake-on-LAN</a> I can use, perhaps? I'd be happy with any method to turn it on wirelessly though, even if I have to use something like <a href="https://ifttt.com/" rel="noreferrer">IFTTT</a> to trigger it.</p>

2017-01-01T19:05:42.300

<p>What it looks like they're trying to do is establish semantic definitions for messages and rules that can be interpreted or processed at any layer, and that the layers can be migrated up or down. So yes, a home hub could be a fog node, but only if it supports the fog behaviors and messages.</p> <p>Think of a typical home automation architecture:</p> <pre><code>Remote -&lt;Z-wave&gt;- light switch -&lt;Z-wave&gt;- home hub -&lt;Ethernet&gt;- cloud server -&lt;GSM&gt;- phone </code></pre> <p>You trigger the remote and it sends a Z-wave message to the switch, which turns on the light. You can configure your home hub to send a message to the switch based on other rules (the garage door is opened.) And your watch can talk to your phone which can contact the company's cloud, which sends the message to your home hub, which sends it to your light switch.</p> <p>Today, you can do the first part of this by setting up a scene in your light switch that is triggered by a paired remote. Using Z-wave, no home hub is needed. You can add a home hub and set up a new scene to trigger the light switch if the remote's button is pressed, but you better delete the scene in the light switch first. You can use a cloud interface to configure your hub's behavior, perhaps triggering your hub via IFTTT. And you can also use your phone to contact a web interface on the cloud and have it turn on the switch.</p> <p>What OpenFog is aiming to do is to have those device definitions be universal, the rules be platform independent, and the messages be transport independent. They'll share common security and authentication methods. That means you set it up once, no matter where you are, and the definitions and rules are migrated up and down the architecture. </p> <p>From your phone you could view your devices, which would include the light switch and remote control, and say "I want button 1 on the remote to toggle the light switch". The rules might be created right there in your phone, then transported to the cloud server. The cloud server could examine the inputs and decide "All the responsibility for lights and remotes belongs at a lower level", and push the rules down to the home hub. The home hub could say "hey, Z-wave knows how to run a scene in this model of light switch, so I will push these rules to the light switch and remote." Next time you push the button on the remote, the signal will be caught by the light switch and the light will turn on. This would provide the fastest possible response time (no hub needed). And by having the rules backed up at a cloud level, if you have to replace a defective light switch, none of the rules need to change. They'd just be pushed back down to the replacement switch.</p> <p>OpenFog also will provide for elastic scale. Let's say you place 1000 light switches in an office building, using a network technology that has a latency that goes up exponentially based on the number of nodes. It could scale communications such that the 1000 nodes are split into 10 networks, so that no network ever has a latency longer than 200 milliseconds. </p> <p>It also specifies scalability of control. If you've ever worked with systems built for GUI control you get used to instructions like these: "right click on the node, pick 'settings', then set intensity to '75%', then 'OK'". Such instructions are worse than useless when it comes to managing 60,000 nodes. OpenFog should enable automated groupings of nodes allowing scalable control. "For all nodes in Eastern Standard Time zone, set intensity to 75%," or "For all nodes in profit center 12, set intensity to 65%."</p> <p>It also specifies autonomy where possible. If the Peoria, Illinois branch replaces a furnace vent duct control, it shouldn't require an HQ person to delete the old control unit ID, then add the replacement ID. The local maintenance person should be able to do that herself. The security still has to ensure that the furnace repair person doesn't have the authority to disable the burglar alarm sensors on the back door. </p> <p>Now, place all of this behind open standards so that a Honeywell burglar alarm and a Trane heating system all interoperate in the same logical network as your Philips light bulbs, Leviton Z-wave switches, and your Fitbit scale.</p> <p>So, is your SmartThings hub an OpenFog node? Not today, and it won't be unless and until it implements and interoperates with these standards. But a future home hub certainly could be an OpenFog node.</p>

|definitions|fog-computing|openfog|

What would a "fog node" consist of in OpenFog?

543

<p>The <a href="https://www.openfogconsortium.org/" rel="noreferrer">OpenFog Consortium</a>, a group that is working on an open <em>fog computing</em> specification, has published a <a href="https://www.openfogconsortium.org/wp-content/uploads/OpenFog-Architecture-Overview-WP-2-2016.pdf" rel="noreferrer">white paper about their architecture</a>.</p> <p>They define a <em>fog node</em> as:</p> <blockquote> <p>The physical and logical network element that implements fog computing services. It is somewhat analogous to a server in cloud computing.</p> </blockquote> <p>However, I'm having a bit of trouble intuitively understanding what a fog node would <em>be</em>. Would it just be a server or hub device hosted locally on your own network, rather than in a massive server farm? Would a smart home hub (like a SmartThings Hub) be a very simple example of a fog node under the OpenFog definition?</p>

2017-01-02T00:22:15.090

<p>My experience at least with Outlook Calendar events. If I set the event to give me a reminder at a certain time prior to the event, my echo device will give me a voice prompts the time. For instance, I have an event tomorrow at 6PM. I set the event in Outlook Calendars to remind me 24 hours prior. My Echo just reminded me of this event today at 6PM. In short, this capability is driven by your calendar program. </p>

|alexa|amazon-echo|

Can you setup Alexa to remind you about calendar events?

546

<p>Is it possible to configure an Amazon Echo so that Alexa will tell you about upcoming events (e.g. from Google Calendar) an hour before each of them by waking itself up and reminding you about them?</p>

2017-01-02T11:57:42.960

<p>I've just tried it with mine but she says I don't have any books in my Audible account. I do have books in my kindle account so I guess it is not rolled out in the UK yet.</p> <p>I wasn't trying to use Audible as I don't have an Audible account. I've now tried the keyword "Listen to a Kindle book" with a book name I have in my Kindle account. Alexa says she can't find the book. I've been into the Amazon UK website and tried to "deliver" the book to my Echo or Echo Dot but those options are currently greyed out unlike my Kindle reader devices </p> <p>Reading a <a href="https://www.groovypost.com/howto/how-to-find-kindle-ebooks-alexa-can-read-to-you/" rel="nofollow noreferrer">blog post</a> today it seems that you need to have books that Alexa can read aloud</p>

|alexa|amazon-echo|united-kingdom|

Can Alexa read Kindle books in the United Kingdom?

549

<p>Is there any way to make Alexa read Kindle books in the UK? I couldn't find any options to do that. </p>

2017-01-02T12:35:09.203

<p>It is possible to enable any skill by voice, provided you already know the name of the skill.</p> <p>The <a href="https://www.amazon.co.uk/gp/help/customer/display.html?nodeId=201848700" rel="noreferrer">Amazon documentation</a> for adding skills is relatively straightforward:</p> <blockquote> <p>If you know the exact name of the skill you want, <strong>you can say, &quot;Enable [skill name] skill&quot;.</strong> Some skills may require you to link to an existing account and a separate subscription in order to use the skill.</p> </blockquote> <p>However, this requires you to know the name of the skill beforehand, which may not be particularly useful. To get around this, you can take advantage of the Amazon-developed <a href="https://www.amazon.co.uk/Amazon-Skill-Finder/dp/B01GGW79U4" rel="noreferrer">Skill Finder</a> skill. This allows you to search through skills by voice with the following commands:</p> <blockquote> <p>Alexa, tell Skill Finder to give me the Skill of the Day</p> <p>Alexa, tell Skill Finder to give me the newest skills</p> <p>Alexa, tell Skill Finder to give me top skills</p> <p>Alexa, tell Skill Finder to list categories</p> <p>Alexa, tell Skill Finder to list the newest skills in the education category</p> <p>Alexa, tell Skill Finder to list the top skills in the games category</p> </blockquote> <p>You can enable this skill with <em>&quot;Alexa, enable Skill Finder skill&quot;</em>, and then the above commands will be supported.</p>

|alexa|amazon-echo|

Can you teach Alexa a new skill by voice?

551

<p>Can you enable a new skill in Amazon Echo by voice?</p> <p>Ideally, I'd like to ask Alexa which skills they offer related to a specific category (like dictionary), then I'd like to enable one.</p> <p>Is this possible?</p>

2017-01-02T20:50:35.890

<p>In addition to other answers, if the data is sent in plaintext it can be modified. </p> <p>Apart from mentioned problems faking data can cause (turning heat to the max due to lying thermometer in the middle of hot summer might lead to fire hazard, for example) manipulating data can lead to compromise of IoT device, and everything that accesses it (for example, you notebook might be checking temperature, but HTML page showing temperature could be replaced in-transit with computer virus designed to infect your internal network, or JSON data might be modified to break into application reading malformed data etc).</p> <p>Not that implementing security is without its risks, especially in IoT world. Security is hard, and implementation of it usually vastly increases codebase, and with it number of bugs (and thus possible attack vectors / exploit opportunities). IoTs rarely get firmware upgrades, so when a IoT device without auto-update has a problem, it is almost guaranteed to provide <a href="https://en.wikipedia.org/wiki/Botnet" rel="noreferrer">Botnets</a> with extra zombie machines.</p> <p>And yes, auto-upgrade itself is not without issues - from privacy issues to possibility that evildoers will take control of it if not implemented properly; but it should be lower risk than hoping your first firmware will be without any security bugs allowing attackers to increase their zombie ranks.</p>

|security|sensors|privacy|cryptography|

Is there any advantage in encrypting sensor data that is not private?

554

<p>Some sites, such as <a href="https://www.helpnetsecurity.com/2015/09/07/end-to-end-encryption-is-key-for-securing-the-internet-of-things/">this article on end-to-end encryption for IoT</a>, suggest that <strong>all</strong> traffic sent across the IoT network should be encrypted, saying:</p> <blockquote> <p>Enterprises, government agencies and other organizations should take adopt [sic] an “encrypt-everything” strategy to protect against IoT-enabled breaches.</p> </blockquote> <p>I can understand the need to encrypt any data that could be confidential, such as the commands to lock/unlock a 'smart lock' device, but is it really necessary to encrypt <em>everything</em>, such as the sensor that reports the current thermostat reading? </p> <p>Is it simply the case that "encrypt everything" stops people from forgetting to encrypt data that really ought to be encrypted, or is there a real benefit from using cryptography, despite the extra power, time and cost of it?</p>

2017-01-03T18:00:18.233

<p>When the bulbs have an integral role in contributing the look, feel &amp; mood of the room, the switches make sure to set on/off primarily &amp; also consider the energy management of the home.</p> <p>So while these two distinct products advance, obviously the impact will be on their respective purposes only. I mean to say a smart bulb has just come up with its expected outcome only, like giving an more than hundreds of color variations &amp; the user liberty to change/modify based on the situations.</p> <p>On the other hand, smart switches have taken a great leap in controlling the entire home appliances from a 40 watt (existing bulb) to high amps AC, washing machine, iron box. Instead of smartifying the individual electronic products by their respective companies &amp; coming up with lots of individual apps, I would say smart switches are ahead of all these. </p> <p>My conclusion is, there's no point in mixing up these smart bulbs &amp; smart switches. When you install smart switches, the entire home would be automated &amp; then buy a smart bulb for your needed rooms. Even if you control the dimming or color variation using a smart switch, it can be at least switched off from anywhere which is what its destined to do.</p> <p>For smart bulbs, I guess Philips is the best &amp; for smart switches Curiousfly has come up with a complete home solution:</p> <p><a href="https://www.youtube.com/watch?v=TmFBNNAAFc0&amp;t=6s" rel="nofollow noreferrer">https://www.youtube.com/watch?v=TmFBNNAAFc0&amp;t=6s</a> </p>

|smart-home|

Is it better to control smart lights or smart light switches/fixtures?

568

<p>IoT enabled light bulbs have been on the market for a while now. The Philips Hue is probably the best known. But I think controlling bulbs directly is a rule-maintenance disaster waiting to happen. If a bulb goes out (and yes, LED bulbs do fail), you have to replace the bulb, and remember to update any scenes or other rules that control the bulb (or are triggered by the bulb.) Or if you move a bulb from fixture A in the kitchen to fixture B in the bedroom, (perhaps while cleaning), the rule that says "Turn on kitchen lights" will now illuminate the bedroom.</p> <p>That may not seem like a big problem today for those of us who understand the configurations of our home automation systems intimately, but imagine a home automation system set up by a professional integrator for a typical customer. The homeowner may not know how to change the rules, so replacing a lightbulb could cost them not only the price of the smart bulb, but an additional service call charge from the integration company. A smart switch or fixture solves this problem because the switch doesn't move with typical maintenance. (The switch offers the same problem of configuration if it fails and needs to be replaced, of course, but switches typically have better life expectancies than bulbs, which are generally considered consumables.)</p> <p>On the other hand, an IoT enabled light switch can't fully control every aspect of lighting the same way a smart light bulb can. A switch can do simple dimming for certain technologies of bulbs, but it can't control the color of the Hue bulb. </p> <p>Much worse, smart switches use different types of electronic circuitry to perform dimming, and must be carefully matched to the technology of the bulbs they are controlling. A typical older dimmer can dim only incandescent bulbs and not CFL or LED bulbs; some dimmers can dim both incandescent and CFL but not LED bulbs; some dimmers can control incandescent bulbs and LED bulbs, but not CFLs; and some dimmers can control inductive loads like halogen transformers, but not CFLs or LEDs! With incandescent bulbs being replaced because they're such energy wasters, this has been a real problem, too.</p> <p>So what's the most practical approach? Buy expensive bulbs that are directly controllable and expensive smart switches to control them, or buy cheap bulbs and just expensive smart switches, and give up on the idea of controllable color lighting? </p>

2017-01-04T14:03:10.023

<p>The good news for you is that the choice of fan-speed and lighting control is often independent of the actual ceiling fan itself. Most lighted ceiling fans operate using two independent circuits; the wall switch will have one hot wire that delivers power to the fan motor, and a separate hot wire that delivers power to the light fixture. (This is not counting any ground wires or neutral wires. This also may not be true for some digitally controlled fans, so you'd have to inspect the wiring in your wall switch to confirm. You should consult a qualified electrician before continuing.)</p> <p>Once you've confirmed that you have two separate wires leading from your wall switch to control your fan and lights, you can start the task of replacing your broken controller. Unfortunately, buying a light dimming switch has gotten kind of complex with the introduction of new lighting technologies.</p> <p>The light fixture circuit can be controlled using a dimmer switch that is rated for the type of lamps you have. Incandescent light bulbs are very simple &quot;resistive loads&quot;, and can be dimmed using virtually any of the common technologies. LED light bulbs are electronic circuits, and often require a special dimmer switch designed to work with LED bulbs. Low voltage halogen bulbs use a transformer to lower the voltage; to dim these requires a dimmer switch capable of controlling an &quot;inductive load&quot; (the transformer is an inductor.)</p> <p>Most fan manufacturers recommend not using an ordinary dimmer switch, but instead state that the fan motor should be controlled by a &quot;fan motor controller&quot;. That's because most fan motors are &quot;inductive motors&quot; and require a speed controller that is designed for inductive loads - the same kind of load controller that halogen lighting requires. The Qubino site says it is designed to control all kinds of loads, including low-voltage halogen lighting transformers, so their controller should work with your fan motor. (I recommend asking their support people to confirm that it would work with your model of fan.)</p> <p>As a plus, if you put in a dimmer, you will have a truly variable speed fan. You won't be limited to the three speeds the manufacturer's controller provided.</p> <p>UPDATE: I just (Sept 2020) purchased an Inovelli Fan &amp; Light Switch (LZW36). It contains a wall switch with two separate buttons (one for fan, one for lighting), and an electronic fan/light controller module that is to be mounted in the ceiling at the fan. It's fully Z-wave enabled, and the wall switch nicely fits in the existing single-gang box (which I can't change due to the wall's construction.) According to reviews posted on their site, some customers are reporting success replacing existing poor quality remotes and controllers. Unfortunately, the company is brand new and I think they are selling only 120VAC products at this time.</p>

|smart-home|hardware|

UK-compatible (240VAC) receiver/controller for ceiling fan with dimmable lights

585

<p>I have a 3-speed ceiling fan with integrated dimmable lights which when installed prior to my owning the house was fitted with an infrared wireless receiver.</p> <p>For a long time the remote did not work (poor quality construction) and after repairing it and having a few months of use have since found the receiver now isn't working (I've tried all the jumper combinations).</p> <p>So I now seek to replace the wireless receiver with one that supports a home automation system rather than just another infrared like-for-like replacement. My existing remote control looks like this:</p> <p><a href="https://i.stack.imgur.com/oAFrG.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oAFrG.jpg" alt="Infra-red remote control"></a></p> <p>Has anyone come across a home-automation system with wireless receiver (ideally compatible with at least one of the major brand solutions such as Z-wave, ZigBee, LightwaveRF, Smartwares etc, but honestly I'd consider anything) for a <strong>3-speed ceiling fan</strong> with integrated dimmable lights? </p> <p>I've seen an <a href="http://www.insteon.com/ceiling-fan-controller/" rel="nofollow noreferrer">Insteon Ceiling Fan and Light Controller</a> module available for U.S. ceiling fans running on 120V AC but they don't seem to have a product for 240V AC as required for UK models.</p> <p>I've also seen a <a href="http://qubino.com/products/flush-dimmer/" rel="nofollow noreferrer">Qubino Flush Dimmer</a> which could control the dimmable lights and their website says a second unit of the same would also be suitable for controlling the fan but I'm not certain of this aspect since it is a 3-speed fan (i.e. off, slow, medium, fast), not just variable speed (I can't set it to 62% speed for example). </p> <p>What I don't know however is whether this 3-speed setup is a limitation of the current wireless infra-red receiver/controller or of the fan unit itself, and this is where I find myself a bit out of my depth. The ceiling fan unit looks similar to this, except with no pull-cords for operation:</p> <p><a href="https://i.stack.imgur.com/Asgdg.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Asgdg.jpg" alt="Ceiling fan with lights"></a> </p> <p>I'm really trying to establish here whether such a part even exists, or how else I might be able to integrate the unit with a combination of parts.</p> <p>Any help appreciated thank you.</p> <p>For further clarification: This model has a wireless-only controller, there is no wall-mounted controller in addition to the remote control. The wall switch is just a fused spur, then the wiring from the fused spur to the ceiling fan unit is just standard UK shielded twin and earth. There are no controls for the lights or fan except for on the remote control. The remote control is a Hampton Bay UC7080T.</p>

2017-01-04T16:03:04.280

<p>It doesn't have an open telnet port. I still come across lots of residential / off-the-shelf wifi routers with open telnet ports. The firmware is usually available online too, with backdoor accounts. If you are renting your wifi router from your ISP provider, it probably has an open telnet port. Wifi routers usually have weak security and their firmwares are available online too, which can easily be examined with binwalk. If you have a Netgear router, have fun googling "netgear geardog"</p>

|smart-home|security|routers|norton-core|

How does the Norton Core increase the security of a "smart home"?

593

<p>Symantec is releasing a new router, the <a href="https://us.norton.com/core" rel="nofollow noreferrer">Norton Core</a>, which they describe as <em>"The secure router for your connected home."</em></p> <p>I found out about this while reading an article on <a href="https://www.engadget.com/2017/01/03/symantec-norton-core/" rel="nofollow noreferrer">Engadget</a>, but their description of what the device actually does and how it's better than a normal router isn't particularly great.</p> <p>What advantages does the Norton Core have over a regular router as far as improving the security of a simple smart home setup?</p>