hybridfree/eevblog-posts huggingface dataset:
Modular Smartphone inspired by Phonebloks - Page 1
Forum section: electronics / projects

author: DomesticHacks
author_rank: Regular Contributor
timestamp: October 07, 2013, 10:50:23 pm
content: After reading about the Phonebloks (http://www.phonebloks.com), the Idea of a modular Smartphone haunted me until I gave up and designed a own one.Since i saw major flaws with the Phoneblock approach, I tried to fix those in my design:- Phonebloks has the modules on the outside, so all kind of nasty things (like water or dust) can find their way to the contacts.- The Phonebloks function defines the design, and a possible manufacturer for this platform couldn't produce for example a case with an own design.I printed out my design on my 3D printer and published all models on Thingiverse:http://www.thingiverse.com/thing:161585I also thought about how this could work on the electronics layer and if you can speak German, you can watch this video about my ideas how this could work:It would be nice to get some feedback and if enough people are interested in this project, I could write some informations in English (or make a video).

author: iceisfun
author_rank: Regular Contributor
timestamp: October 08, 2013, 12:25:16 am
content: I thought these types of posts were supposed to wait until April 1'st?

author: ivan747
author_rank: Super Contributor
timestamp: October 08, 2013, 01:32:29 am
content: That actually doesn't seem very bad. I think you are using the press-fit connectors used in PC processor sockets, right?

author: DomesticHacks
author_rank: Regular Contributor
timestamp: October 08, 2013, 05:13:55 am
content: Yes, or something similar with a little dent in the board to give it mor stability.

author: ivan747
author_rank: Super Contributor
timestamp: October 08, 2013, 11:55:58 am
content: Well, it's just a matter of making it cheap and making the connections reliable. You could play with a prototype but be aware that making a cellphone is one of the hardest things a consumer electronics engineer can do.

author: DomesticHacks
author_rank: Regular Contributor
timestamp: October 08, 2013, 12:15:02 pm
content: At this point i'm not planning building the real one.I just want to publish my idea how such a thing could be made.

author: amyk
author_rank: Super Contributor
timestamp: October 08, 2013, 01:08:19 pm
content: Modern phones already have a lot of modularity in their design, mostly for ease of assembly than anything else - things like vibrator, speaker, button, etc. connectors use a lot of spring/press-fit stuff. The mainboard remains one soldered piece because no one has figured out any other cheap and reliable way to connect <1mm pitch BGAs with it....and of course it has to look like an iPhone...

author: DomesticHacks
author_rank: Regular Contributor
timestamp: October 10, 2013, 07:57:27 am
content: Quote from: amyk on October 08, 2013, 01:08:19 pmWhy not?There are two good reasons for that:- The iPhone in my oppinion has the best size. All other similar phones are mostly way too big for me.- It has a simple design, easily printable by a 3D printer.
Modulating 1Mbit data into FSK - Page 1
Forum section: electronics / projects

author: hazuki
author_rank: Contributor
timestamp: March 17, 2021, 09:22:35 pm
content: Hi all. I have a strange application where I want to modulate a 1Mbit data stream into FSK or PSK to send over an optical link. The reason I want to do this is because the optical link has a minimum bandwidth of 20Mbit/s but a maximum bandwidth of 5Gbps. So I was thinking to modulate this 1Mbit data stream into a 100MHz or higher carrier. Any recommendations on how this can be done? I'm looking at frequency synthesizer ICs but they have state transition times on the order of 1us and I'd like something a little faster as to not introduce a large propagation delay to the 1Mbit/s signal.Thanks

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 17, 2021, 09:39:44 pm
content: How about Manchester encoding? Cheap, a clock and a few gates will do the trick. Wasteful, takes something like twice the bandwidth -- but it sounds like you have more than enough available so that won't be a problem.Tim

author: langwadt
author_rank: Super Contributor
timestamp: March 17, 2021, 10:13:58 pm
content: 100MHz clock and an XOR and you have PSK?
Modulating Frequency of Clock Signal - Page 1
Forum section: electronics / projects

author: MarshallPlexi
author_rank: Contributor
timestamp: October 14, 2021, 08:26:28 am
content: Hello All! This is my first time posting here but I've been a member for a while.I'm working on a new project that needs a clock signal (24kHz - 400kHz total range) that will vary +25% / -25% with an applied sine wave. I would use a CD4046 since I can set the clock frequency with the RC combinations and then modulate that clock frequency but I'd prefer to send the clock signal with a Si5351 so my clock can be dead nuts on frequency.It sounds like dead stock FM modulation to me.I've spent the night on Google searching for an IC that will modulate a pre-existing clock frequency but all I can find are PLL examples using 555 timers and the like.Does anyone have a direction I could start looking in for this?Thanks so much for your time!

author: TheMG
author_rank: Frequent Contributor
timestamp: October 14, 2021, 01:27:35 pm
content: Sounds like the sort of thing a DSP would be well suited for.It's going to be quite hard to achieve with discrete circuitry if you need any kind of accuracy, especially over the frequency range you're looking at.
modulation - Page 1
Forum section: electronics / projects

author: R_G_B_
author_rank: Frequent Contributor
timestamp: January 16, 2014, 01:29:25 pm
content: Can anyone explain why it is that when I first modulate two signal using a frequeuncy multiplyer before feeding the result to a high pass filtering to remove the baseband around D.C. so that im left with the image centred around the carrier frequencyAt the reciever the product detection should show twice the carrier with baseband e.g sum and difference frequency they don't seem are not there?At the detector all I see is the carrierThe selected a high pass filter to remove the base band around d.c is correct. I checked the bode plot for the filter design and it does just that and passes anything above the specified cut off.Anyone give an explanation to what's happening?

author: Kremmen
author_rank: Super Contributor
timestamp: January 16, 2014, 03:48:21 pm
content: Quote from: R_G_B_ on January 16, 2014, 01:29:25 pmWell, not from only that explanation because few here have a functional crystal ball. About same as asking why does my car not run...But situation may improve if you provide actual details of what you are doing. So you are saying that your modulator produces the expected result but not your demodulator? The next step is to provide either a circuit diagram or block schema with transfer functions. Then we can start reasoning about your signal processing chain.
Module project - Page 1
Forum section: electronics / projects

author: geot51
author_rank: Newbie
timestamp: June 16, 2017, 06:15:49 am
content: Hello forum.I design a module pcb based on TI's CC1310 but I can't decide yet its antenna output.My first thought was to make it simple and smaller. That means, the antenna region will have only the balun and a trace will be driven directly to a pin. Another thought was to put only UFL connector or UFL besides the antenna's track.And my last thought was to add two antenna types, UFL connector and a chip antenna.I've seen that many relative products incorporate only a UFL connector.What is your opinion?

author: sanwal209
author_rank: Regular Contributor
timestamp: June 16, 2017, 07:46:24 pm
content: You can use simple RF switch IC to switch between chip antenna or UFL connector. Try reading antenna diversity that will help you in this problem.

author: geot51
author_rank: Newbie
timestamp: June 17, 2017, 10:34:53 am
content: Thank you very much for your replies.Quote from: sanwal209 on June 16, 2017, 07:46:24 pmRF switches or antenna diversity topology, apart from the potential increase of pcb size they may increase my final BOM cost.I'd like something cheap and tiny.I've already built a CC1310 module that incorporates only a UFL connector and worked fine.The main issue of course was that I cannot use it without the properly antenna gear (proper 50Ohm cord and an antenna).Now I need something standalone but without losing the "permormance" option that the external antenna gives me.Chip antennae does offer me something more integrated, a completed PCB, in a very tiny size. No need for wires, connectors or the necesity of proper antenna installation.However, I was thinking that if I don't want to loose the performance option of the external antenna I have to add an "antenna option" in the same pcb.And I built a tiny pcb with both options. I kept the UFL connector and just added a chip antenna with a pi filter. I also added a pad to "cut" the traces with zero ohm resistor that takes the role of "antenna selector".During a serching on the internet for other relative or comptetitors of this chip I came accross many modules with CC1310.All of them include only a UFL connector and an option to bring the antenna output to a pad.That fact made me wonder if my design wasn't very conventional and eventualy I ended up to be thinking a more generic version that would have nothing but only a balun which its output would be broughtdirectly to a pad.The main disadvantage of the generic module is that it needs to be soldered to another pcb in which I choose the antenna accordingly to application.My available budget in this subject may should be rised to carry off this approach.The routing of chip antenna has already reviewed by johanson technology.This is the datasheet of the antenna:https://www.johansontechnology.com/datasheets/antennas/0900AT43A0070.pdfI uploaded a photo with my last design.
Module to convert constant voltage power supply into a tunable power supply? - Page 1
Forum section: electronics / projects

author: Plasmateur
author_rank: Regular Contributor
timestamp: August 25, 2019, 03:46:36 am
content: Perhaps I'm not using the right terms when searching for such a device.Let's say I have a 48V 20A power supply and I want to be able to vary the output voltage of this supply through some module which will give readouts of voltage and current.Maybe even be programmable?Does such a device exist?

author: ledtester
author_rank: Super Contributor
timestamp: August 25, 2019, 04:09:04 am
content: Ruideng makes a line of buck converters which work well, e.g.:https://www.banggood.com/RIDEN-DPS5020-Constant-Voltage-Current-Step-Down-Communication-Digital-Power-Supply-Module-p-1181200.htmlTheir official store on Aliexpress:https://rdtech.aliexpress.com/store/923042

author: Plasmateur
author_rank: Regular Contributor
timestamp: August 25, 2019, 05:51:39 am
content: Quote from: ledtester on August 25, 2019, 04:09:04 amWow. This is awesome. Is the negative side ground refferenced? Can these handle inductive loads?I wonder if I can parallel these for my current requirements.

author: ledtester
author_rank: Super Contributor
timestamp: August 25, 2019, 06:21:57 am
content: I have a DPS5015 and the negative input is the same as the negative output.For inductive loads the manual says to limit the max current to, I believe, 5A for my model. It's not exactly clear why you need to derate the current capability and whether an inductive load can damage the device. The only info you get on the matter is presented at the very beginning of this video:https://youtu.be/LyyEOLGm4oAThere is also a warning on that screen about not using the supply in series or parallel with other supplies.
Mofii Keyboard and HC-05 Receiver First Try (SOLVED) - Page 1
Forum section: electronics / projects

author: jpanhalt
author_rank: Super Contributor
timestamp: April 04, 2025, 04:13:04 am
content: My experience setting up RF communication is limited to a ZIGBee pair about 15 years ago.That was not much different that communicating between an MCU and LCD display over copper.Now I want to use a BT keypad (19 keys) to control a readout a few feet away. What's the signal like? Can someone recommend a really simple tutorial, preferably in pdf not YT to help me get started?John

author: jpanhalt
author_rank: Super Contributor
timestamp: April 28, 2025, 03:09:48 pm
content: I paired the Mofii number pad with my laptop (it has built in Bluetooth), and that went fine. I have been unable to get the HC-05 to respond to anything.I installed an FTDI TTL-232R-3V3 serial converter on my Windows 7 PC. I had used it years ago to set up a pair of XBees. Grok says it can be used with the HC-05 and recommends TeraTerm but shows PuTTY as an alternative. Putty is installed, but I have failed to get it to send AT commands with the HC-05 doing its slow blink.I also got a CP2102 USB to TTL converter and also failed to get PuTTY to work with it.I think my problem is getting a terminal emulator to work. Based on Grok's advice, I tried to install Tera Term, but the link went to GetHub, and I couldn't tell exactly what to download.1) Is Tera Term easier to use? Is there a direct link to download its software (i.e., the correct name to install at GitHub).2) PuTTY warns to install from a command prompt. I can get there, but Putty still just shows a black screen with a bright cursor in the upper left. Keyboard entries do nothing. What's the trick, if there is one?
Moisture detection tag/sticker. - Page 1
Forum section: electronics / projects

author: aargee
author_rank: Frequent Contributor
timestamp: June 04, 2015, 05:16:50 am
content: Hi all,I was wondering if anyone knows of any off the shelf tag or sticker that will change colour permanently after coming in contact with water. Like the ones Apple (supposedly?) uses in their phones.Something simple, not electronic, to detect immersion even after the device has been dried out.

author: matseng
author_rank: Frequent Contributor
timestamp: June 04, 2015, 05:47:46 am
content: If ebay is off-the-shelf enough you got some here:http://www.ebay.com/bhp/water-damage-sticker100 pcs for $6 is not too bad....

author: aargee
author_rank: Frequent Contributor
timestamp: June 05, 2015, 03:40:09 am
content: Ah... exactly what I'm looking for. Used the wrong search terms.Thanks very much.
Moisture Sensitive SMD Components, How Much Should I Worry? - Page 1
Forum section: electronics / projects

author: The Doktor
author_rank: Regular Contributor
timestamp: January 03, 2024, 09:13:20 pm
content: In some of my projects, I come across components which come in a sealed bag with a warning that the component needs to be baked for a certain time and temperature if the package is more than a certain age, or if it has been open for more than a certain number of days at a specified humidity. The exact numbers seem to vary based on the component.My question is, just how serious do I have to take this? The main thing I see this on is SMD LEDs, but occasionally also on a larger chip. If the package has been opened for a year or two, what are the chances of me popcorning the device if I just go ahead and try to solder it with the hot air gun? I'm asking just roughly, is it a slight possibility, fairly likely, were almost a guaranteed failure?ThanksEd

author: ataradov
author_rank: Super Contributor
timestamp: January 03, 2024, 09:35:49 pm
content: Quote from: The Doktor on January 03, 2024, 09:13:20 pmNone at all.Those MSL levels only really matter if you are making millions of devices and even 0.1% failure rate is a huge deal.For manual soldering with a hot air gun, you are so far out of the controlled conditions territory that it does not matter.
Moisture Sensitive SMD parts - Page 1
Forum section: electronics / projects

author: timbos
author_rank: Contributor
timestamp: March 23, 2013, 03:27:19 pm
content: Hi,I've collected a box of 'scrap' parts from work which include a few SMD 3v3 regulators that are moisture sensitive. I'm planning to use them in a little project that I'm working on, but they are most certainly outside their floor life. Since I'm going to hand-solder them, are they going to survive the process?Cheers,Tim

author: SeanB
author_rank: Super Contributor
timestamp: March 23, 2013, 04:16:00 pm
content: Tost them for a few hours at low heat in a dry oven to dry them out, then store in a sealed package with a dessicant sachet there as well, preferably one that went through the oven as well to dry it out as well.

author: Ba1tuks
author_rank: Newbie
timestamp: March 23, 2013, 09:28:27 pm
content: I always thought that moisture "sensitiveness" is only if you use these parts in automated process, but this don't bother you if you hand-solder these parts.
MOLEX crimp headers - Page 1
Forum section: electronics / projects

author: daedalus
author_rank: Regular Contributor
timestamp: October 02, 2011, 11:29:11 pm
content: Hi,I use picoblade and duo-clasp molex headers in my current projects, but as a hobbyist i cant afford £200 each to get the right tools. Does anyone know of any 3rd party crimping tools that work on these series, and are more affordable?

author: KJ6EAD
author_rank: Contributor
timestamp: October 03, 2011, 03:42:20 am
content: This hand tool works well for open barrel crimps. It's sold by most large electronics suppliers for about $35.http://www.molex.com/molex/products/datasheet.jsp?part=active/0638111000_APPLICATION_TOOLIN.xml&channel=Products

author: ashley.hughes
author_rank: Regular Contributor
timestamp: October 04, 2011, 09:33:26 am
content: I also use a similar tool to the one linked above it works most of the time. I have found as my tool only has two sizes, don't crimp down to hard and if it is a cable that I am going to unplug a lot I like to apply a bit of solder where the wire is crimped to just add a bit more grip and durability.I mainly use the Molex KK connecters though

author: Unknown
author_rank: Unknown
timestamp: October 04, 2011, 06:04:13 pm
content: Note that soldering wires is not allowed in many high-reliability environments because the solder is wicked into the wire, and stiffens this part. Metal fatigue is likely to occur in the area just past the solder. A good crimp is superior to soldering for wires. Not sure about bad crimp vs solder.

author: daedalus
author_rank: Regular Contributor
timestamp: October 04, 2011, 10:18:41 pm
content: Hi everyone,Thanks for the advice, it turns out I have managed to convince work to buy me a crimp tool for the duo-clasp pins, as its a tool I would be unlikely to ever use again.I have also ordered a cheapie ebay job for the picoblade pins, as have found people online recommending it. Its japanese, PA 09 Crimp tool.I looked at 63811-1000, but its smallest size seems to be 1.4mm, which is too big for both the series I am using. The problem with both types is that at 1mm they are really fiddly to crimp correctly, and all the other molex crimpers I have don't fit well enough to do the job reliably.I have around 300-400 wires to crimp, so need something that has a high success rate or else I will be here forever. The other issue is not having extractor tools for these series, failed crimps cannot easily be removed, so will be a lot of rework if anything fails.
Molex PicoBlade smd FEMALE - Do such connectors exist? - Page 1
Forum section: electronics / projects

author: AndersJ
author_rank: Frequent Contributor
timestamp: November 05, 2019, 03:24:08 am
content: I have a pcb with a Molex Picoblade 1.25 mm male connector.These normally connect via custom cables.I want to eliminate the cable and instead plug the pcb intoanother pcb with a corresponding female connector.Do female PicoBlade connectors exist?

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 05, 2019, 03:29:36 am
content: I don't think so:https://www.molex.com/molex/products/family?key=picoblade&channel=products&chanName=family&pageTitle=Introduction
Molex Picoflex connectors. - Page 1
Forum section: electronics / projects

author: ISmellBurning
author_rank: Newbie
timestamp: July 29, 2013, 03:09:42 pm
content: 'lo all.Anyone familiar with these IDC connectors? The tool to crimp these is priced around at £800. My question is, has anyone used this with a more usual set of IDC crimp tools? Can't believe the price of those crimps! I'd love to use these connectors in my project but there's no way I'd pay £800+ for 'em!Cheers!p.sConnector -http://uk.rs-online.com/web/p/idc-connectors/6702327/Crimp tool -http://uk.rs-online.com/web/p/cable-crimpers/5428093/

author: Short Circuit
author_rank: Frequent Contributor
timestamp: July 29, 2013, 03:43:50 pm
content: Sacrifice a receptable to provide mechanical support for the pins, then you can use a regular IDC crimper like these;http://www.ebay.com/itm/IDC-Flat-Ribbon-Cable-Crimper-Crimping-Tool-Ship-From-USA-/251311312776?pt=LH_DefaultDomain_0&hash=item3a83524f88Used this method alot with the very similar AMP micromatch connectors.

author: ISmellBurning
author_rank: Newbie
timestamp: July 29, 2013, 05:05:34 pm
content: Hiya, yup those were the exact pair of crimp tools i was thinking about getting. But i wanted to know if those picoflex connectors will actually fit in those cheaper crimps. If you see what i mean.Thanks for the suggestion tho, I may well end up having to do that and forget about using picoflex.Anyone actually tried them before?

author: Neilm
author_rank: Super Contributor
timestamp: July 29, 2013, 05:49:06 pm
content: I have used these before - I designed them into some equipment at work. I used them as they were small, and self locate and securely clip in. As far as I remember, there were hard to crimp as each contact has to be pushed through individually. I think I started them with a pair of parallel pliers they pressed them in with the tips of snipe nose pliers.If this is just for a hobby project - I wouldn't bother using it. I only used it on the project I was on as I was space constrained that that was the only one that would fit.Neil

author: Short Circuit
author_rank: Frequent Contributor
timestamp: July 29, 2013, 06:06:20 pm
content: Smallest jaw height of the crimper that I have is 7.1mm. Don't know if that would be small enough.However, the yellow block is easily removed and replaced with something thicker.

author: ISmellBurning
author_rank: Newbie
timestamp: July 29, 2013, 06:40:43 pm
content: Quote from: Neilm on July 29, 2013, 05:49:06 pmAh... that's exactly what i needed to hear! Thanks Neil... I'll look for a different type!Thanks again, you've saved me both cash and time.PS. And thanks to the other that replied, its appreciated guys!
Best way to monitor USB drive traffic? - Page 1
Forum section: electronics / projects

author: sean0118
author_rank: Frequent Contributor
timestamp: June 11, 2017, 02:22:55 pm
content: Hi everyone,The latestAmpHour episodegot me thinking, what is the best way to monitor the traffic of a USB drive?I have a whole bunch of potentially malicious USB drives from tradeshows etc.I guess it's relatively easy to see if there's anything malicious in the storage, but what about the firmware? I would be interested to see what data these USB drives send when first connected, do they install *special drivers*?

author: ^_^
author_rank: Regular Contributor
timestamp: June 11, 2017, 03:05:39 pm
content: There's a device for that "Beagle USB 12 Protocol Analyzer".If you're afraid of malware you can use the stick from VM.Also,AFAIKthe drivers always come from Microsoft database, the device only sends the PID/VID etc.So to actually hack your computer autonomously it would have to exploit USB stack implementation in the OS you are using.

author: sean0118
author_rank: Frequent Contributor
timestamp: June 11, 2017, 04:20:40 pm
content: Quote from: ^_^ on June 11, 2017, 03:05:39 pmThis one?https://www.adafruit.com/product/708Thanks, it looks good, but I think it's probably over-kill (expensive) for what I'm trying to do?The USBProxy (as mentioned in the AmpHour episode) looks interesting as well, but looks like its in an alpha stage still.https://github.com/dominicgs/USBProxyAnyone know of any software options?

author: abyrvalg
author_rank: Frequent Contributor
timestamp: June 11, 2017, 04:38:48 pm
content: There are many. This one for example:https://freeusbanalyzer.com/

author: sean0118
author_rank: Frequent Contributor
timestamp: June 11, 2017, 04:43:41 pm
content: Quote from: abyrvalg on June 11, 2017, 04:38:48 pmThat looks promising thanks!

author: Lukas
author_rank: Frequent Contributor
timestamp: June 11, 2017, 05:52:57 pm
content: Wireshark in conjunction with usbpcap does USB as well.
Monitoring mains voltage with an IC? - Page 1
Forum section: electronics / projects

author: Mark-02660
author_rank: Newbie
timestamp: July 15, 2015, 11:05:18 pm
content: That is what I am looking to do, but I have yet to find someone that has done it.I see a few chips for DMMs but not a lot of them. Ideally I would like the input range to be up to 600Vac RMS The IC needs to feed a value to a micro controller that will do the rest.Any suggestions?(Will be used in remote generator monitoring system)Thanks

author: Mark-02660
author_rank: Newbie
timestamp: July 16, 2015, 02:05:08 am
content: Thanks for the link, I did not think to search Newark for a term, I was asking Google.

author: mjkuwp
author_rank: Unknown
timestamp: July 16, 2015, 10:11:26 am
content: ADE7953 is one example.I have done a project with ithttp://themzlab.tumblr.com/wattmeterit is a really nice ic and can do much more than just give you the mains voltage.
Mono/dual output isolated DC/DC converters - Page 1
Forum section: electronics / projects

author: electr_peter
author_rank: Unknown
timestamp: May 24, 2014, 01:33:37 pm
content: Hi,I am building small current dual rail power supply. I decided to use DC/DC isolated converters to insure isolation independent on power source type. Main goal is to have single DC input and +/0/- isolated DC output.I find 3 general configurations of DC/DC isolated converters:DC in, isolated DC out. Get two modules and connect two outputs in series to get +/0/- railsDC in, two isolated DC pairs out. Connect + and - together (as in 1st case) to get +/0/- railsDC in, dual rail isolated DC out (+/0/-)I am looking for eBay for dual converters as it would be easier with pinout and device size to get dual rail:http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=dc+%28dual%2C+double%29+converter+isolated&_sop=15I read that isolated DC/DC converters are a bit "touchy" and there probably could be problems with 1st case (two separate modules) and maybe less issues with 2nd case (dual isolated outputs). 3rd case probably would be the best (in terms of size and output stability).My question:Are cases 1, 2 and 3 identical in operation for single input and isolated +/0/- output? Can I treat isolated DC/DC converters as "pseudo DC transformers" with different output taps (and connect outputs in any configuration as needed)?
Monome-like Midi controller "Chronome" port - Page 1
Forum section: electronics / projects

author: cavemaneca
author_rank: Newbie
timestamp: July 14, 2015, 04:09:03 am
content: I'm a bit of a new player when it comes to actual EE, but Dave's YT channel really motivated me to jump in head first and worry about the mistakes later.Anyway, as a big fan of music and having made some here and there myself, I've always wanted a Monome midi controller. These are a bit expensive though. Looking around I found a few projects aimed and making open sourced variants, and I quite liked the idea of a controller that also had tri-color LEDs as opposed to the default single color Monome controller.There's a bit more information that I've posted in the CircuitMaker project for this, but I'd also like to see what you guys here think of my project. As well, any tips and ideas would be super helpful.https://workspace.circuitmaker.com/Projects/3B39BD8D-A57C-47E4-A106-7A1FFD52568AFor those who like pretty colors, here's the sample showing the current board layout:

author: cavemaneca
author_rank: Newbie
timestamp: July 24, 2015, 01:58:54 am
content: Hello there.Slight update, received the PCBs for the Arduino shield that this connects to. This could also be considered a small review of the service frommakerstudio.cc. They faithfully recreated the board, including the gerber mishaps with my silkscreen that I never checked...Other than that, took about 2-3 weeks to get the boards from date of purchase. The quality seems to be good, only issue I noticed with magnification was a few holes drilled off-center on some pads. The distance was about 1-5mil off from the actual design.

author: cavemaneca
author_rank: Newbie
timestamp: July 30, 2015, 12:06:24 am
content: For any interested, out of the hundred+ people who viewed this thread, here's a photo of the complete button board.
Monostable flip flop IC with comparator and shootdown - Page 1
Forum section: electronics / projects

author: daqq
author_rank: Super Contributor
timestamp: September 18, 2015, 12:36:07 pm
content: Hi guys,For a project I'd like an IC, or that would do the following function:A rising edge on the TRIGGER would put the OUTPUT into one and start a timeout of about 5us (adjustable, preferably by means of an external voltage). When this timeout had passed, the OUTPUT would revert back to zero. However, if another input (an analog one), connected to an internal comparator, would rise above the determined value (another input), the OUTPUT would also revert back to zero and it would kill the timeout as well, making it ready for another triggering.The setup should only be sensitive to rising edges - as such, no matter how long the TRIGGER stays at one, the OUTPUT will at most be on for the time.The analog input should work close to 0V - the target voltage less than 100mV above ground. This does not bode well for the 555 IC.I could make this out of several ICs, but I was hoping for a single IC solution with a few passives around. The TRIGGER pulse frequency would be anywhere between 0 (totally off) and 100kHz.Does anyone know of such an IC?Thanks,David

author: daqq
author_rank: Super Contributor
timestamp: September 18, 2015, 12:51:51 pm
content: Upon further thinking, it can be done with 2 ICs (http://www.ti.com/lit/ds/symlink/sn74lvc1g123.pdfas the monostable block, with an RC max width setter and some low going comparator as the comparator). I'll do it this way then probably.
Monostable timing components - range of values - Page 1
Forum section: electronics / projects

author: IconicPCB
author_rank: Super Contributor
timestamp: January 18, 2020, 01:30:33 am
content: Please see the attached data sheet - CD4538 CMOS monostable.Data sheet claims ide pulse width range,Wide pulse-width range 1 ms to infinityFurther it states on page 4 under Operating Conditions minimum timing resistance value of 5K whilest maximum value is not specified , how ever it is limited by a clause which explains:"...The maximum usable resistance R X is a function of the leakage of the Capacitor C X , leakage of the CD4538B, and leakage due to board layout, surface resistance, etc. ..."At the same time Cx is not defined at all.What maximum pulse width might be reasonably and repeatably achieved using current technology tantalum capacitors as part of timing circuit?

author: MagicSmoker
author_rank: Super Contributor
timestamp: January 18, 2020, 11:42:32 am
content: Setting aside the kludge factor for trying to get long pulse widths out of any kind of monostable, your main limiting factor is the leakage current spec of the capacitor. If you need to generate pulses more than 10 seconds long then an X7R ceramic is probably going to be a better choice, especially if ambient is >35C (leakage follows the Arrhenius equation, so doubles every 10-11C increase in ambient temp).

author: jfiresto
author_rank: Frequent Contributor
timestamp: January 18, 2020, 12:23:57 pm
content: Quote from: IconicPCB on January 18, 2020, 01:30:33 amSome manufacturers specify a minimum 5 nF Cx value, but I wonder if that is to preserve the simple t = RC timing formula. Most suggest adding a discharge protection diode/resistor if Cx is 500nF or more: to protect the (1)4538's internal ESD network should VDD plummet on powering off.A polyester film capacitor would also be low leakage and I believe would be more stable than an X7R ceramic. I might look at the CD4541 to produce a really long pulse.

author: IconicPCB
author_rank: Super Contributor
timestamp: January 18, 2020, 11:59:31 pm
content: Magic Smoker,Thank You for the comment.I had a look at Tantalum capacitor low leakage specs and came to the same conclusion.Leakage current is is typically specified as some constant * capacitance * voltage.It will be in the low microamps for high value capacitor . The constant in above expression is reduced by operating the capacitor at reduced voltage. Typically 25 to 40% of rated value for a halving in leakage current.Based on the above and the effect of leakage current i estimate 1 Meg and may be up to 20uF night be the largest working combination of timing components where the leffects of leakage current might be acceptable in terms of stability and repeatability of pulse width.jfiresto,A good suggestion; I had seriously considered it. A major problem with CD4541 is that it has"... A setup time equal to the width of the one-shot output is required immediately following initial power up, during which time the output will be high..."If the time in question is in the order of a hundred seconds the powerup set up becomes untenable.
Moog schematics and other drawings - Page 1
Forum section: electronics / projects

author: Rory
author_rank: Frequent Contributor
timestamp: March 14, 2015, 04:43:53 am
content: Some hand drawn by Bob Moog himself. You can almost feel the whiteout on some of them.Lots of current mirrors, UJTs, oscillators, ring modulators and panel layouts.http://moogfoundation.org/schematics/

author: Ericho
author_rank: Regular Contributor
timestamp: March 14, 2015, 06:19:34 am
content: CoolTime to build a few modules.I never buy expencive UJT's, Matched 3904 and matched 3906 Always seems to work fine in Bob's disigns.Out of 100pcs I can get up to 20 pairs matched below 100uV Vbe

author: old gregg
author_rank: Regular Contributor
timestamp: March 14, 2015, 12:12:36 pm
content: Buchla schematics are also very interesting (Buchla himself also is).
More CRO 'scope demos, but with a Microchip DM240013-2 on discount - Page 1
Forum section: electronics / projects

author: Howardlong
author_rank: Super Contributor
timestamp: December 21, 2014, 04:23:14 pm
content: FolksI was looking to do one of the Youscope type demos last week, and in so doing was looking for a microcontroller to fit the bill that wouldn't need many external components like R-2R ladders etc. After a bit of searching, I chose a PIC24FV16KM202, for which there's also a micro demo board, on 35% discount on MicrochipDirect (GBP12.35) and priced at Farnell at GBP11.66. This includes an onboard USB debugger.The chip itself has some interesting features, including dual 8 bit DAC, and will run off 5V if that's what you want.So I wrote some code over the weekend to reinvent the wheel a bit, you don't even need a soldering iron, just an old school CRO with X-Y mode. The code works either with the old MPLAB IDE (8.92) or MPLAB X (v2.26), and will compile and run with the free version of the XC16 compiler.

author: tautech
author_rank: Super Contributor
timestamp: December 21, 2014, 05:06:42 pm
content: Very nice.

author: w2aew
author_rank: Super Contributor
timestamp: December 22, 2014, 04:13:55 am
content: Nice job, and very nice scopes! Two of my favorites!

author: Howardlong
author_rank: Super Contributor
timestamp: December 22, 2014, 05:58:36 am
content: Quote from: w2aew on December 22, 2014, 04:13:55 amDare I suggest that those purchasing decisions may have been slightly swayed by a certain youtube channel you may know?I had a 2465B for some years, but sold it about five years ago, a decision I since regretted, so recently I got hold of a 2467B.

author: Howardlong
author_rank: Super Contributor
timestamp: December 24, 2014, 04:45:13 pm
content: This time, Asteroids (tm) on an HP 1980B CRO and Agilent 54831D MSOhttps://www.youtube.com/watch?v=BXOHyjeLAXM&feature=youtu.be
More diodes that need identification. - Page 1
Forum section: electronics / projects

author: nonsuchpro
author_rank: Contributor
timestamp: July 18, 2020, 09:29:31 am
content: It is inevitable that I receive a lot of diodes that I can't find any information on.These all say MSC which is the only common lettering for the most part. I've found a few online that look like these and have the normal 1NXXXX designation. Unfortunately none of these have that. They all read the same on the multimeter. Anybody know anything about the MSC brand and possibly where to find any information or even a cross reference?Thanks in advance!

author: Labrat101
author_rank: Unknown
timestamp: July 18, 2020, 10:05:11 am
content: Microsemi’s MS8000 series of GaAs Schottky barrier diodesMSC is made by MicrosemiCheck them on a scope
More DRAM questions: vias and trace lengths. - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: December 15, 2017, 06:10:03 pm
content: Background: datasheets and user manuals: SoC isNXP i.MX233 in LQFP128(combined datasheet and user manual,)layout guide here. DRAM isMicron MT46V32M16TG-6T.I am trying to hook up those, and still have some problems with the high speed signals and routing. The pinout on the i.MX233 is intended to be used with the FBGA variant of DDR memory, however most local vendors I searched for carries only the TSSOP version. I have tried to fit the TSOP memory chip with the application processor, but even with byte swapping and bit lane swapping I ended up getting kind of a mess when not using vias - the DQM signals have to loop around the entire DRAM chip... definitely not a good idea even with delay compensation, and the clock signals also have to loop a bit. Do keep in mind that i.MX233 have built-in delay buffers to compensate the trace length mismatches, so length is less important than via count at least according to the layout guide. Questions:* How fast is the rise and fall edges of the DDR-333 SSTL-2 memory bus in the first place? This is linked to the trace length calculation but it is nowhere mentioned in either datasheet.* It seem to me that using 2 vias for all memory bus traces seem to be a good idea here. Is it really?* Is a sharp turning corner at the via going to bite me? (For example, the trace runs up to a via, drops to the bottom layer and immediately goes down.)A few general questions about the design:* In your opinion, which is more important for a DIY tablet/digital picture frame: a microSD card slot, or a network connection? i.MX233 have only two SDIO interfaces, one of which is occupied by the NAND chip through pinmux. (I have industrial-grade NAND chips - see below) Now for the remaining SDIO interface I can either connect it to a microSD card slot or an SDIO Wi-Fi module. Personally I prefer the network connection variant since once the kernel is up it can make use of the network connection to pull data off the cloud and I can SSH into it, but without microSD card slot I may have troubles getting it to boot the first time and load the kernel. Or how do I construct a SDIO mux properly with the kernel in mind?* Am I pushing it with 800x480 resolution through the chip and the EPM240T100C5N CPLD demultiplexing the signal? Or do I need a faster CPLD? Or am I overclocking the i.MX233's LCD interface? (I have heard of people pushing 800x480 from i.MX233 from Olimex, but that uses non-multiplexed RGB LCD interface.)* Since the SoC I bought are industrial grade chips, is it better for me to prefer all other parts to be industrial-grade or better? (My recent grab bag included some automotive-grade parts - are those better than industrial?)
More Fun DS2431 DRM Stuff!!! - Page 1
Forum section: electronics / projects

author: R30Repair71
author_rank: Newbie
timestamp: May 19, 2022, 08:24:19 pm
content: I asked some questions last week about reverse engineering a consumables management chip on a DVD buffing machine. That project has been since abandoned because the boss man went with new machines from a different company... with very similar DRM measures. This time around they use a 1 wire EEPROM, a DS2431 to be exact. The manual says that removing a chip before the 800 minute buffing time is used up renders the chip useless. I have found that powering the machine off before removing the chip circumvents this. I will include dumps of 3 different chips. I used a raspberry pi 4 to dump the contents using a write up i found. When looking at the dumps, the contents of the chip did not change with each buffing cycle. This makes me wonder if the data on the EEPROM is just a key and not something that keeps count of cycles remaining. I am thinking of using a logic analyzer to sniff the traffic between the chip and machine. I do not have a logic analyzer currently, and don't know which model I should go with. I saw a reddit post on a similar topic and the folks in that subreddit said that the people in the eevblog forums eat this type of thing up. THanks for all the help!

author: TheMG
author_rank: Frequent Contributor
timestamp: May 19, 2022, 09:06:23 pm
content: Likely those are just unique keys and the actual time remaining is stored in the machine itself, not written to the EEPROM in the consumable. So probably there is an EEPROM in the machine itself which keeps track of which keys have been used up.Do you have more than one machine of the same model? Try inserting a "spent" chip from one machine into the other and see if it work. If so, then that would prove the theory that the data is actually stored in the machine not in the consumable chip.

author: R30Repair71
author_rank: Newbie
timestamp: May 19, 2022, 09:46:16 pm
content: ooh good idea. im going to try that now

author: DavidAlfa
author_rank: Super Contributor
timestamp: May 19, 2022, 10:41:40 pm
content: I'd open the machine and search for a EEPROM, you might make a dump before and after changing the consumable, It could be as easy as making a reset circuitry that writes the EEPROM with a push button.For the logic analyzer:https://a.aliexpress.com/_vOOJ0n

author: amyk
author_rank: Super Contributor
timestamp: May 21, 2022, 01:52:17 am
content: For a 1-wire bus, the cheapest LA will do.

author: bingo600
author_rank: Super Contributor
timestamp: May 21, 2022, 08:47:19 am
content: When you order a new "Chip" , do they require you to give (or do hey already have) some info , like Unit Serial No or the likes ??/Bingo
More info on old Vectron Crystal Oscillator? - Page 1
Forum section: electronics / projects

author: mstoer
author_rank: Contributor
timestamp: June 02, 2016, 01:46:26 am
content: I salved this Vectron crystal oscillator from some old equipment. Based on the PCB I was able to figure out the pin-out (it had only 4 pins, 2 were ground). It was powered from 5V, but I don't know what range it could accept. The unit is old and Vectron has no info on it anymore they said. It has a frequency adjustment pot (under the tape) and generates a 10 kHz square wave (see screenshot). The DM3058E says it's 10.0000 kHz exactly. Does anyone have any more info on this? Allowable input voltage range, accuracy & precision, etc? A datasheet is probably too much to ask for.

author: Vgkid
author_rank: Super Contributor
timestamp: June 02, 2016, 02:26:53 am
content: Google is useful.http://www.datasheetarchive.com/dlmain/Datasheets-115/DSAP002401.pdf

author: mstoer
author_rank: Contributor
timestamp: June 02, 2016, 02:46:01 am
content: Thanks, I've used google to try and find this for quite some time with no luck. Mind you, I put the actual part number in my search. I am not sure that is the correct part for the following reasons:1. The frequency adjust is on the top, not on the side as in that datasheet. You can see the impression through the foil tape.2. What you cannot see is that the unit in the photo is 0.62" tall, while the one in the datasheet is 0.5".3. The datasheet describes the units have an epoxy base. The base is metal in the one I have.4. That datasheet also does not have the part number 231-2421 listed anywhere I can see.It does appear to be a close relative though.

author: Vgkid
author_rank: Super Contributor
timestamp: June 02, 2016, 02:55:05 am
content: Send them an email. They might have a datasheet on it.

author: edavid
author_rank: Super Contributor
timestamp: June 02, 2016, 03:14:34 am
content: Quote from: mstoer on June 02, 2016, 02:46:01 amHere, check out this page:http://www.datasheetarchive.com/dl/Scans-056/DSAIH000139544.pdfIt shows that the metal can is the CO-231 option C.Quote from: Vgkid on June 02, 2016, 02:55:05 amI guess you missed this:QuoteI have never had any luck getting data out of Vectron either. They can't even find datasheets that are on their own website.

author: mstoer
author_rank: Contributor
timestamp: June 02, 2016, 04:44:05 am
content: So the soldered on metal base adds the extra height. The frequency adjust is still on the wrong side, so maybe this was some custom package job. There is definitely no hole on the side as those datasheets show, but they are likely the best I can find now.Thank you both!

author: Mildi
author_rank: Contributor
timestamp: April 02, 2024, 12:53:24 am
content: Please. Help me find the datasheet for OCXO Vektron.1. Vektron OX-220-0001 30.720MHz2. Vektron 4358270 30M720There is a datasheet for the first position, but it is for newer versions that have different option markings (new OX-220-0-DAE-2580-10M0000000 vs old OX-220-0001 30.720MHz).Thanks in advance for any help.
More novelty for research idea - Page 1
Forum section: electronics / projects

author: saezealbrecht
author_rank: Newbie
timestamp: November 20, 2024, 04:37:30 pm
content: hello everyone!! sooo I'm trying to find a good research topic to work on as a school requirement and all I could think of is this:ESP32-based smart monitoring system with Adafruit IOIt uses the DHT11 sensor and a PIR motion sensor. It also has an MQ2 gas sensor specifically calibrated for smoke and LPG.and like- a graph will be shown in the Adafruit IO dashboard with the relevant info such as temperature/humidity and whatnot. Also, you will be notified via email when the temperature/humidity reaches a certain threshold and if there's a gas leak happening. I'm also planning to add a buzzer when this happens.I've already consulted my research adviser about it and the only comment he gave was that there are already too many of these online and you really can't call it novel anymore.Do you guys have any ideas on how I can make the research idea more unique or novel? I'm new to all this electronics stuff so finding a good topic proved to be quite a difficult task for me.

author: thephil
author_rank: Regular Contributor
timestamp: November 20, 2024, 05:50:42 pm
content: My two cents: What you describe sounds like a niceengineeringproject but notresearch. In order to turn it into research, you would have to add a scientific question that you want to answer with your project. Maybe you could come up with something interesting that you could measure with your setup (or even a sensor solution off the shelf) and do some data analysis on it in order to answer a research question about temperature, humidity, etc. under specific conditions.But before believing me, check the actual requirements of your school...