hybridfree/eevblog-posts huggingface dataset:
Blown LED driver, what happened? - Page 1
Forum section: electronics / beginners

author: varias
author_rank: Newbie
timestamp: June 13, 2023, 12:56:16 pm
content: Hi, everyone. This is my first post. I have very basic experience with electronics and some soldering experience. A few days ago I had a LED ceiling light start flickering and the next day it flickered again and went off. I've opened the LED driver and there's visible damage to an IC package I can't identify. The driver was connected to a 230V AC mains that it's a bit old (solid copper wire) so I don't know if it's got something to do. What happened to the LED driver? How can I diagnose the problem? Is there a way to identify the IC package? Is it an easy repair or should I just get an off-the-shelf LED driver to replace it and call it a day? I've attached photos of the LED driver. Thanks for any help.

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2023, 01:31:00 pm
content: The IC that has a crater in its top is a SMPSU controller. These has fail due to deterioration in associated capacitors or through a mains spike. Sometimes they fail for no obvious reason ….. there is a switching transistor inside the package that literally explodes creating the hole in the top of the package. I have repaired similar power supplies by purchasing the correct IC and fitting new capacitors. Sometimes a protection resistor gets fried as well. It is often easier to just buy a replacement power supply if they are not too expensive.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2023, 01:36:46 pm
content: The TNY266 is an example of a similar SMPSU IC but it is NOT necessarily the one used in your power supply! The data sheet gives you an idea of how these small switching chips work though.https://datasheetspdf.com/datasheet/TNY266.htmlFraser

author: varias
author_rank: Newbie
timestamp: June 13, 2023, 01:47:32 pm
content: Thank you so much for your replies, Fraser. The light was relatively new (a year old at most). I don't have experience with SMD components so I don't know if I'll try repairing it. If anything, I'll take this as a learning opportunity.
Blown mosfet? - Page 1
Forum section: electronics / beginners

author: fthebest
author_rank: Newbie
timestamp: February 05, 2013, 12:28:08 am
content: Hi everybodyI'm new on the forum and I have one question.I'm trying to repair an hp printer power adapter (0957-2271) I opened it and I saw a blown resistor. I replaced the resistor and, of course, it blew up when I power the thing on. So I started locking at other possible blown component and I found a strange thing on the power mosfet (SPP07N65C3), all of the three terminals where shorted out measuring them with my DMM (I measured it both on the pcb and stand alone).The question is: is this mos blown? Or I've to do other measures? According to what I know about mosfets I don't think that a short between gate and source or drain is normal but I want to be sure before replacing it.Thank you

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: February 05, 2013, 01:03:31 am
content: You're right, it's blown, semi conductors mostly fail short.Check other nearby components, visually and with a meter, they could have caused the fet to blow.

author: Psi
author_rank: Super Contributor
timestamp: February 05, 2013, 03:22:58 am
content: Trace the gate connection back and check that whatever's driving it is ok.When mosfets go short on all 3 pins they can take out the mosfet driver as well due to the gate being shorted to supply rails.Sometimes you can power up the device with no mosfet and check with a scope that there is a signal on the gate pad/TH.

author: amyk
author_rank: Super Contributor
timestamp: February 05, 2013, 12:24:10 pm
content: Always test out of circuit unless it's obvious there shouldn't be continuity between the two points.Depending on what your definition of "shorted" is, if you test in circuit you're essentially driving voltage through other components too and if they happen to be in parallel and have a low enough resistance then you could be identifying the wrong culprit.

author: WBB
author_rank: Regular Contributor
timestamp: February 05, 2013, 02:43:24 pm
content: There should be 1 or more diodes near the mosfet that should be checked as well. They are often shorted and will blow up the new mosfet.

author: fthebest
author_rank: Newbie
timestamp: February 06, 2013, 08:55:53 am
content: Thanks to everybody.There are others component gone and there is a short on a power rail I'll try to fix this in better day now I'm quite busy cause I'm preparing an exam.I'll keep you updated.ByeP.S.maybe I should change topic's title
Blue Pill Schematic in Upverter - Page 1
Forum section: electronics / beginners

author: Hugondon
author_rank: Newbie
timestamp: July 03, 2020, 10:48:31 pm
content: Hi!I've been working with a Blue Pill developing board for some weeks now and I want to keep track of some designs that I've done. I found out about this Upverter platform and I wanted to create a Schematic Diagram of a system I'm currently working on, but I can't seem to find a module that already considers everything that this board has and I don't want to only put the STM32F103C8T6 microcontroller.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 04, 2020, 03:52:47 pm
content: A simple search like below finds all kind of stuff:https://html.duckduckgo.com/html?q=KiCad+%22blue+pill%22+schematic
Blue tooth to NFC - Page 1
Forum section: electronics / beginners

author: tanzim01
author_rank: Newbie
timestamp: May 06, 2015, 02:38:07 am
content: I need to create a circuit that can receive information through bluetooth and write it to a NFC chip, any tips on where to begin?

author: generic_username
author_rank: Regular Contributor
timestamp: May 07, 2015, 11:26:48 am
content: This months Elektor has a NFC Project in it.http://www.elektor.com/elektor-magazine-en-may-june-2015They use a NXP Chip that has I2C that is connected to an Atmel Microcontroller.So you can read and write the tag via I2C then connect bluetooth via I2C to that chip and that should do what you want.
Bluetooth audio, a2dp, questions - Page 1
Forum section: electronics / beginners

author: djspoko
author_rank: Newbie
timestamp: November 19, 2014, 10:54:26 pm
content: Hi,I have to make university project with microcontroller and I have a few questions. I want to make something like 'my own bluetooth audio receiver'. I thought that it will contain: bluetooth, atmega8(20Mhz) (or sth with more power) and DAC. First part which is generate sound from atmega using DAC, i did. But I have question about bluetooth connection. My first idea was buying bluetooth like hc-05 and setting headset profile and transmit data via UART (but I was reading about it and it is probably impossible).My second idea was buying bluetooth with A2DP, connect with atmega, get music data (UART isn't too slow?) and generate sound from this data.I know that it doesn't make any sense but it is for fun, learning and university project.I want to know yours opinions. Is it possible to do? Do you have any helpful ideas?Thanks

author: aveekbh
author_rank: Regular Contributor
timestamp: November 20, 2014, 06:15:34 pm
content: Hello djspokoI am not familiar with the HC-05 type modules. Does it give you the raw data from Bluetooth, or is it emulating a serial port?The maximum data rate is 3 Mbps, so you need UART of 3 Mbps to ensure you get all the raw data out. If you're looking at A2DP, it will generate about 1 Mbps. But, you'll also need a stack that encodes and decodes the A2DP data being sent over the air. There are some chips available with an embedded stack, but I am not sure how easy they are to buy in small quantities. I would certainly look at that first.I hope I haven't discouraged you too much. Think up a good idea, and I am sure you will get enough help (from me and others).- A

author: Dave
author_rank: Super Contributor
timestamp: November 21, 2014, 05:30:28 am
content: I'm currently designing a bluetooth audio receiver for my car.I'm using Microchip's (ex Roving Network) RN52 module. It offers A2DP, among others, and has direct differential audio output, as well as I2S and S/PDIF.It doesn't get much easier than this.

author: Rasz
author_rank: Super Contributor
timestamp: November 21, 2014, 07:21:16 am
content: I dont get ithttp://www.ebay.com/itm/Favored-1PC-A2DP-3-5mm-Stereo-Bluetooth-Music-Receiver-Audio-Dongle-Adapter-/201158542346what exactly is it that you want to achieve?

author: jeremynguyen
author_rank: Newbie
timestamp: November 21, 2014, 08:26:45 am
content: fasdsa
Bluetooth audio receiver: digital non-DAC output? Limitations in receiver IC? - Page 1
Forum section: electronics / beginners

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: September 07, 2023, 02:56:54 pm
content: Are there bluetooth receiver IC's that don't have a built in DAC, so it outputs a digital signal like an S/PDIF or some other standard digital audio signal?And then codec support and things like that wouldn't be of no concern with the actual receiver IC right? It just needs to be able to connect and receive data. Are there speed limitations that need to be considered with the receiver for high bitrate audio?Also is there a name for DAC-Less bluetooth receivers? All the ones I find are "one chip solutions"... I want to have a DAC-Less one because if I'll have a DAC anyway, I'd rather use a single DAC for both a digital wired and bluetooth input, also the sound quality would depend on 1 DAC that's used for everything, instead of depending on a bluetooth receiver IC

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 07, 2023, 03:20:57 pm
content: Some can be modified to output is audio, I did this with a CSR64215 board,Bluesuite software,BlueMagic, atxs0108E shifter to talk to the 1.8v logic, and dump the SPI flash using a ch341.It was a PITA, these modules are extremely easy to brick, so the SPI flash backup is a must.I mainly used it to fix distortion, the soc EQ had +6dB amplification, causes the output to clip over 60% volume.While doing so I tried interfacing a PCM5102A I2S DAC, it worked, and that was all, I reverted to analog output.Then Qualcomm bought CSR (Cambridge Silicon Radio), renames the devices to QCxxxx, made all the docs and tools pretty NDA, though you might still find them.Search for I2S bluetooth receiver, for sure you'll find something

author: tooki
author_rank: Super Contributor
timestamp: September 07, 2023, 06:37:57 pm
content: Quote from: ELS122 on September 07, 2023, 02:56:54 pmTry the Microchip BM83:https://www.microchip.com/en-us/product/BM83The BM83 comes with a few default firmware options (though any can be reflashed to another), and you can configure the audio output from analog to digital I2S using the config tool. (Unlike many competing products, the entire toolchain is publicly available.)It's a fairly complex beast, so I'd definitely recommend getting a dev kit to play with. (It took us a while to get it up and running.)You can also use the BM83's I2Sinputto use it as your system DAC. (It also contains a microcontroller of its own, if you feel like having it run the show entirely.)I strongly suspect that many competing Bluetooth audio modules which have onboard DACs can similarly be configured to output I2S audio instead of analog.Or use an ESP32 with corresponding firmware. Take a look at the LyraT dev board (which only costs around $20).
Bluetooth Audio Receiver Module Recommendations - Page 1
Forum section: electronics / beginners

author: AntiProtonBoy
author_rank: Frequent Contributor
timestamp: February 11, 2019, 12:53:10 pm
content: Thinking of modding my old analogue amp and retrofit Bluetooth audio receiver module so I can play music from my mobile devices.There are few candidates on this page:https://wonderfulengineering.com/10-best-bluetooth-audio-stereo-module-for-your-project/Not sure what would be a good choice, to be honest, as reviews and perf specs on these modules are somewhat lacking. If anyone did a similar project before, drop me a few notes and recommendations.edit: Just realised this topic would be more suitable in the "Projects, Designs, and Technical Stuff". Sorry mods, feel free to move this thread.

author: Bratster
author_rank: Frequent Contributor
timestamp: February 11, 2019, 06:26:26 pm
content: Do you have to use a module / circuit board?There are plenty of Bluetooth receivers on Amazon with reviews and specs.Some of those are still pretty small even with the case and everything.I have a Logitech one and it's only about 2in by 2in by 3/4 inch.Sent from my Fi Moto x4 using Tapatalk

author: Gyro
author_rank: Super Contributor
timestamp: February 11, 2019, 10:19:30 pm
content: Quote from: Bratster on February 11, 2019, 06:26:26 pmIf not, then the Arcam miniBlink is a very nice sounding but not audiophool price option.P.S. You'd need to provide a bluetooth pairing button and accessible antenna anyway, so it's a lot less effort.

author: AntiProtonBoy
author_rank: Frequent Contributor
timestamp: February 11, 2019, 11:23:33 pm
content: Quote from: Bratster on February 11, 2019, 06:26:26 pmPreferable, as I would like to conceal it inside the amp chassis.edit:I might get one of these dudes and have play around:https://www.amazon.com/Module-CSR8645-Bluetooth-Receiver-Amplifier/dp/B07G3DLPD9

author: ArthurDent
author_rank: Super Contributor
timestamp: February 12, 2019, 01:24:10 am
content: Someone else had asked this question in another thread and this was one I found.https://youtu.be/Jmo4KWAUpAc
Bluetooth audio - Page 1
Forum section: electronics / beginners

author: paulca
author_rank: Super Contributor
timestamp: February 11, 2018, 11:02:06 am
content: Can anyone give me the cliff notes version of how to handle bluetooth audio?My research suggests the following:All in one boards which have the full BT receiver chip, MCU, DAC and DSP with audio in and out, plus control switch inputs on the board.However, if I wanted to go down a level the bluetooth ICs all seem to just stream serial data vua UART or SPI. How complex is interfacing that with a DAC on one side and how complex is getting it to work with, say, an Android device as an audio player? Is it worth attempting over just using one of the full, all in one, boards?Has anyone any experience of these boards that could suggest one they know works well? Ideally I would like to live without the connector hardware being on the board. ie. a bare board without 3.5mm jacks etc.

author: kripton2035
author_rank: Super Contributor
timestamp: February 11, 2018, 11:06:12 am
content: you have boards of all kind, and they output : uart, analog audio, digital audio or even spdif.sometimes, they CAN output digital signals, but you need to enable these outputs on the board, with a dedicated programming interface and software.just read carefully the board description for what you need, and you can find one ready made.
Bluetooth Beacon Project Help - Page 1
Forum section: electronics / beginners

author: BTZ93
author_rank: Newbie
timestamp: June 07, 2022, 12:56:37 am
content: Hello everyone!Let me start by saying that I am completely new here, so excuse me for my rookieness, but hopefully some kind souls here will be willing to help me!I have a BLE Beacon project that I want to start, and potentially produce down the road, which has led me to beginning my study/learning process in this field for the first time in my entire life lol. I've always enjoyed electronics but have never studied how they work but will hopefully be able to learn from you all in the coming months and years!Anyways, to get to the point...What I'm looking to build/create is a really simple BLE beacon device with solid signal strength and reliable connectivity. The kicker is that I'm looking to make this in the smallest form factor possible.Ideally I'm looking to create a footprint roughly the same as the "Tile Sticker" product, or potentially even smaller, but certainly no larger than a CR2032 battery. I'm also looking for it to be powered by a coin cell battery like a CR2032.I know I may not be able to create a perfect product, and probably won't be close the first time, but I want to at least know I'm heading in the right direction, and if I can get pretty close to the final product on the first try then fantastic! I know nothing, but It doesn't seem that it could get much more simple than a BLE beacon. Maybe I'm delusionalSO MY QUESTIONS ARE THIS:Am I being crazy? Is building such a beacon reasonable? Why or why not?What would I need to do to build this on such a small footprint? What am I looking at as far as materials? PCB? Components? Programming?I know that is a lot to read so thank you all for your time and potential help and answers on this topic!- Connor
Bluetooth computer headset design - Page 1
Forum section: electronics / beginners

author: Mike Mair
author_rank: Newbie
timestamp: July 16, 2018, 12:25:22 pm
content: Hi all,I want to design a Bluetooth headset module using the CSR 8635 chip.Where do I start? Is the chip available in a pre-programmed version for this application that just works or must I learn to program it?Please help as I am new to this technology.

author: tooki
author_rank: Super Contributor
timestamp: July 16, 2018, 06:40:05 pm
content: If I google “CSR 8635”, the search results include a long discussion on these forums, ready-to-buy modules, etc. Have you done any research yourself? Cuz we aren’t here to do your basic homework for you. Why don’t you research on your own and then come back with concrete questions?

author: Mike Mair
author_rank: Newbie
timestamp: July 17, 2018, 07:55:19 am
content: I looked at the information before posting but could not work out the programming side of things as I am a beginner with this.I made a USB adapter with a chip that did not require any programming which is why I asked the question.I was hoping to find someone who has done this before and could simply say yes or no to the programming question.Sorry that you feel that I am trying to get you to do this for me, not my intention at all.

author: Buriedcode
author_rank: Super Contributor
timestamp: July 17, 2018, 01:02:09 pm
content: As tooki suggested, by far teh easiest and cheapest way to go aobut this - if you really want to make one yourself and not buy one for $10 - is to buy a "module" from amazon or ebay.These often come on breakout boards making prototyping easier, and just require a microphone, speaker, and power supply, perhaps a couple of buttons. I assume your "USB adapter" is the CSR-SPI type made with a FT232R - that can indeed be used with csr8635 modules to change the configuration (which is stored on the module in EEPROM), the chip itself isn't programmable, they are generally ROM's.
Bluetooth design - Page 1
Forum section: electronics / beginners

author: rexxar
author_rank: Frequent Contributor
timestamp: May 15, 2015, 02:22:38 am
content: Hey guys, I've been tasked with designing a board based on the RFDuino BLE module. In the datasheet, it recommends a 1" strip of copper coming off the ground pins (to form a dipole antenna?). I've never done RF stuff before, so I'd like your input.Since my board has a ground fill, I put a route keepout line to isolate that section, and left a small strip at the end for an electrical connection to ground. Is this the correct thing to do? I also put the same thing on the top and bottom layers. Although, thinking about it, it's probably best to just have one on the top layer, yes?I'll attach some pictures of my layout, please tell me if I've done something wrong. (ignore the USB connector, it wasn't my idea)
Bluetooth Headphones Battery Question - Page 1
Forum section: electronics / beginners

author: FallenAngelDraco
author_rank: Newbie
timestamp: October 07, 2016, 04:55:18 pm
content: I have an old pair of headphones that I would like to turn into Bluetooth Headphones. To do this I am planning to follow this instructable(http://www.instructables.com/id/DIY-Bluetooth-Headphones-Sony-MDR-V6-wireless-mod/). However, I would like to make one change which is the addition of a USB power bank in order to prolong the time of usage. The power bank will be plugged into the receiver for as long as I am using it which ranges form 3 to 8+ hours a day.My question is will the power bank being constantly plugged into the receiver cause the power bank to deteriorate and not be able to hold as much charge as it would have when new. (I had a laptop that was constantly charging and now it runs out of charge in half an hour rather than the advertised 8 hour life.)

author: Audioguru
author_rank: Super Contributor
timestamp: October 08, 2016, 01:16:05 am
content: A good battery should last a long time. But a cheap battery probably fails soon because it has too much rice in it.I bought a new bicycle made in China to replace my old one made in Canada, the same manufacturer. The brake cable broke after 2 days because its steel had too much rice in it.
Bluetooth- MIT App Inventor and Arduino Code  - Page 1
Forum section: electronics / beginners

author: Brown
author_rank: Contributor
timestamp: January 10, 2014, 08:39:14 pm
content: So, I maked Bluetooth app with App inventer Linkand I found some Arduino code online and was wondering if it's correct thanks---Arduino code---// This program shown how to control arduino from PC Via Bluetooth// Connect ...// arduino>>bluetooth// D11 >>> Rx// D10 >>> Tx//Written By Mohannad Rawashdeh//forhttp://www.genotronex.com/// you will need arduino 1.0.1 or higher to run this sketch#include <SoftwareSerial.h>// import the serial librarySoftwareSerial Genotronex(10, 11); // RX, TXint ledpin=13; // led on D13 will show blink on / offint BluetoothData; // the data given from Computervoid setup() {// put your setup code here, to run once:Genotronex.begin(9600);Genotronex.println("Bluetooth On please press 1 or 0 blink LED ..");pinMode(ledpin,OUTPUT);}void loop() {// put your main code here, to run repeatedly:if (Genotronex.available()){BluetoothData=Genotronex.read();if(BluetoothData=='1'){ // if number 1 pressed ....digitalWrite(ledpin,1);Genotronex.println("LED On D13 ON ! ");}if (BluetoothData=='0'){// if number 0 pressed ....digitalWrite(ledpin,0);Genotronex.println("LED On D13 Off ! ");}}delay(100);// prepare for next data ...}
bluetooth rs232 password - Page 1
Forum section: electronics / beginners

author: RobbieB
author_rank: Newbie
timestamp: August 01, 2012, 06:23:12 pm
content: I'm a total newb. I have an project idea that is driving me into electronics. My question is about a common bluetooth module rs232 thats available all over the place.I know with a lot of commercial bt devices the password is typically 0000 or 1234. But I was wondering on a device like that if you could change the password using something like a 4 way dip switch.Thanks in advance

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 01, 2012, 06:45:26 pm
content: Quote from: RobbieB on August 01, 2012, 06:23:12 pmIf you have a module in mind, care to share which one it is or are you speaking in general?QuoteA common dip switch would not give you the ability to change a lot, but there are these little 0-9 rotary print switches. 4 of them would make it possible to set anything from 0000-9999.

author: SeanB
author_rank: Super Contributor
timestamp: August 01, 2012, 06:59:20 pm
content: Most have the code preset in the bluetooth stack, and to change it you need to either recompile the code with a new one, or you might find it is set in eeprom on board the microcontroller. A little hard to change on the fly, and not really used much.

author: Chet T16
author_rank: Frequent Contributor
timestamp: August 01, 2012, 07:03:23 pm
content: Is it these ones?http://www.dealextreme.com/p/jy-mcu-arduino-bluetooth-wireless-serial-port-module-104299?item=2You can change the code on them by sending an AT command

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 01, 2012, 07:21:09 pm
content: Yeah, that's what I was thinking: AT+PSWD="4321"

author: RobbieB
author_rank: Newbie
timestamp: August 01, 2012, 07:29:41 pm
content: I know I'm in way over my head at the moment. So I will need to do a lot of homework.I guess really i need to work on a prototype anyway before I concern my self with changing a password.Thanks guys.

author: Unknown
author_rank: Unknown
timestamp: August 02, 2012, 09:32:02 am
content: I'm using the same or similar module in my little widget; I haven't used the password feature; instead I make the PC client send a unique binary code to the module to start each communication packet. I used a PIC16f877A @4mhz and bit-banging to send/receive at 9600. I found the module very solid and stable.
Bluetooth speaker module (spk md blk-b)  - Page 1
Forum section: electronics / beginners

author: Lee_horner93
author_rank: Newbie
timestamp: June 13, 2018, 06:39:37 am
content: Hi folks! I've been working on a a small Bluetooth project, creating a set of Bluetooth headphones, using the Bluetooth speaker module spk md blk-b that I purchased a few weeks ago from somewhere in China. Unfortunately I can't find any proper wiring diagrams or schematics for this specific chip, I will attach a few pictures. The problem is I can't seem to power the chip up no mater what I try, and I have tried with two separate modules.I have seen diagrams of similar modules that feature a multi function button (mfb) that requires a long press (3sec) from the power supply to power it up. If anybody has any information on the chip that I have or know off any other methods to try and power it up that would be great!

author: Buriedcode
author_rank: Super Contributor
timestamp: June 13, 2018, 12:18:23 pm
content: Depending on which diagram you provided is your module, you need to pull the "Vreg" or "MFB" line high - to Vbatt via a 10k resistor will do. MFB = multifunction button and is usually the "pairing/power on/off" button on bluetooth audio devices. It is also sometimes referred to as Vreg, even though it is an input. It is essentially what powers up/down the internal 1.8V regulator which powered the chip.I assume you mean this module:https://www.elecfreaks.com/wiki/index.php?title=BLK-MD-SPK-B

author: Lee_horner93
author_rank: Newbie
timestamp: June 13, 2018, 01:10:26 pm
content: Thanks for the response! Apologies the top image is the board I have, with the charging pins across the bottom. I will try this later. You wouldnt happen to know if the 1.8v circuit earths on the same pins as the 3.3v circuit?Sent from my SM-G935F using Tapatalk

author: Buriedcode
author_rank: Super Contributor
timestamp: June 13, 2018, 01:20:15 pm
content: Yes, all the grounds should be connected. The 1.8V comes frm the module (on-board voltage regulator) but the 3.3V is supplied externally. It is designed to run from a lithium polymer battery so 3.3-4.2V on Vbatt. So for your module, Vbat is 3.3V in, and "Vreg" should be connected to Vbat by a 10k resistor.

author: Lee_horner93
author_rank: Newbie
timestamp: June 13, 2018, 05:33:23 pm
content: Just tried tried pulling the Vreg pin high and it works perfectly! Thanks very much!Sent from my SM-G935F using Tapatalk

author: suraj
author_rank: Newbie
timestamp: August 28, 2018, 06:23:02 am
content: need a help to design a low cost bluetooth speaker. It will be very helpful if you provide me a refrence circuit daigram
Bluetooth streaming help - Page 1
Forum section: electronics / beginners

author: Dane1
author_rank: Newbie
timestamp: July 26, 2020, 05:42:23 pm
content: (first the summary: need bluetooth ic formp3 or for making cellphone calls ( using sara u201))Hi,so I'm working on a project that involves streaming audio (music, ...) throught bluetooth, basically a bluetooth mp3.The mcu I'm using is an stm32, some bluetooth ic/modules are cyw___,csr___,bm__,cc256__.The rn 52 and the cc2564 look like could work but the first one looks expensive and for the secons looks like a need a bsd sofftware (can't comercialize it, for the moment I dont care);The problem is that I don't find any bluetooth ic for this I think I need a bluetooth 5 ic but everytime i find someting it follows this path.Phone or pc (with their own bluetooth ------>speaker(with the bluetooth ic implemented)The simplified diagram of the product would be (no audio codecs tc)stm32 (with the bluetooth ic implemented)----->speaker(with his own bluetooth)I'm not really good at explaining myself sorry
BM235 Gone Bad? - Page 1
Forum section: electronics / beginners

author: clansd99
author_rank: Contributor
timestamp: January 21, 2023, 04:15:41 am
content: Hi all,I noticed a while back that my BM235 multimeter was giving odd measurements, and seemed to keep shutting on and off with larger caps.Just today I compared resistance measurements with a different device, and realized my BM235 is off by a good 10 percent!Tried to take it apart but seems like some screws are inaccessible behind soldered in PCB elements...Doesn't seem like any blown elements as far as I can tell.Any ideas?Seems like my warranty is out (bought years back), so don't think I have any warranty/repair options.What is a good replacement meter in a similar price range?

author: bidrohini
author_rank: Regular Contributor
timestamp: January 21, 2023, 07:33:28 am
content: You can consider Mastech multimeter as a replacement.

author: golden_labels
author_rank: Super Contributor
timestamp: January 21, 2023, 09:02:41 am
content: Looking at 6:35 in YouTube/YM--cxT6X3k(VIDEO1)andlygte-info’s BM235 reviewthere is a single screw in the middle of the connectors daughterboard and two wires to desolder. There are a few board-to-board connectors to be careful with.(VIDEO1)

author: wraper
author_rank: Unknown
timestamp: January 21, 2023, 09:11:08 am
content: Are you sure batteries are not discharged?Quote from: bidrohini on January 21, 2023, 07:33:28 amSuggesting buying garbage instead of a good multimeter.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 22, 2023, 10:01:20 pm
content: I'm actually considering replacing my BM257s with a BM235. There's nothing wrong with the BM257s, just a couple things that bug me (like the short duration backlight and inability to light up LEDs).I think if I were you I'd probably get another BM235 if the previous suggestions (check the batteries and give the inside an inspection) don't pan out. If another BM235 isn't what you want, the BM257s costs only a bit more than the BM235. If your experience has soured you on Brymen altogether, the Uni-T UT161D or UT61D+ has a similar feature set as the BM235 for similar to less money (note that the protection on the UT61D+ isn't in the same ballpark as the Brymen meters, but the UT161D should be in the neighborhood). The Uni-T meters mentioned don't have as good specs as the Brymens, but might still be good enough. The Uni-T's are not as compact as the BM235.
BM869s lower screw holes: wrong screws or too tight? - Page 1
Forum section: electronics / beginners

author: ChrisG
author_rank: Unknown
timestamp: January 19, 2017, 01:08:31 pm
content: Hi, being a happy owner of the BM869s since 9 months or so. However when wanting to check the inside, as so many of us do, I noticed afterwards that the screw holes are not designed well or somebody made a mistake. Now I'm not sure if those DMM's are delivered by the factory with Batteries installed, I for sure did not put them in. So it might be that I tightened them to fast and messed up the small plastic ring around the screw but I'm not sure if it was me. Anyways I believe it's not a good design of either screw hole or screw it self.

author: Lightages
author_rank: Unknown
timestamp: January 19, 2017, 07:12:06 pm
content: This happened to my first BM869. I believe it is from not aligning the battery cover carefully enough before tightening down the cover screws. Since I have been careful with my other meters this has not reoccurred.

author: ChrisG
author_rank: Unknown
timestamp: January 20, 2017, 09:03:28 am
content: Hi Lightages,That perhaps might have been and then things became worse since you want to feel-tighten the screws. Anyways I still feel it's a bad design because screwing those too tight will equally break those flimsy plastic side walls. Hope that Brymen is taking notice of it and will adjust their mouldings.
BMA400 SDA/SCL Spacing, Via Size, Battery Charger Concerns - Page 1
Forum section: electronics / beginners

author: aidbucha
author_rank: Newbie
timestamp: August 06, 2025, 03:29:16 pm
content: Hello,I’m a beginner in PCB design and would greatly appreciate some feedback on my board. I’m particularly concerned about a few design choices and would love input from more experienced designers. I previously made a very similar board (2-layer) that powered up, but I was unable to upload code because I only routed USB and had not broken out UART1 or provided an STMLink header.SDA/SCL Routing: I’m connecting a BMA400 accelerometer via I2C. I’m worried the SDA and SCL lines might be routed too closely together, or that having one directly under the other on different layers might cause interference. I'm unsure if this fear is unjustified, it is just something I read about when doing researchVia Sizes: I’m unsure if my power vias are large enough to handle the total current draw from all the components. The board is powered from a 3.3V power plane, and I’d like to ensure the vias can carry enough current to power everythingBattery Charging Circuit: This version includes a battery charging IC, which I’ve not used before. I'm not sure if it’s correctly implemented, so I’d really appreciate if someone could check over that part of the schematic/layout.For the crystal, decoupling caps, and USB circuitry, I followed a STM32 tutorial, but the rest (BMA400, battery charging, layout choices) were based on datasheet recommendations only.If you’re willing to take a look, I’ve attached my schematic and PCB layout screenshots/files. Any feedback is welcome!Thanks in advance!
BMS boards for Li-Pol cells and charger requirements. Basic question. - Page 1
Forum section: electronics / beginners

author: castingflame
author_rank: Regular Contributor
timestamp: August 12, 2018, 08:23:36 am
content: I have a requirement to build a charge system for Li-Pol cells as part of my project. I have built the voltage and current monitoring sections of my project and I am now looking at charging/discharging of the cell 'pack' that I will make. My pack will be 2 cells in parallel, with those in series with a total of 7 cells giving me 25.9(ish) volts at the correct mAh.I have seen the following type of battery management system 'protection' boards ...https://www.ebay.co.uk/itm/173030613442?var=472039673542My question is this; Are these boards a charging solution as well as protection, so I just provide the correct voltage and current, or will I still need to supply the correct charging curve, deta V etc ? I think it is the latter.Thanks for any help.
BMS cell multiplexer - Page 1
Forum section: electronics / beginners

author: chota.sanjiv
author_rank: Contributor
timestamp: January 04, 2019, 02:22:40 pm
content: Hi Guy,I am trying to create a mosfet based multiplexer controlled via opto-isolated MCU control, the object is to connect any li-ion Cell out of a series pack to a CC load whenever required. I got it working by using diodes to stop the reverse current (as +tive of one cell becomes -tive of the other) but I want to eliminate the use of diode and used mosfet based circuit only (can load more current and also less voltage drop).I would appreciate any suggestions.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 04, 2019, 02:42:45 pm
content: Maybe photo-fets could work. This are opto-couplers with a FET output part.

author: chota.sanjiv
author_rank: Contributor
timestamp: January 06, 2019, 07:29:14 pm
content: they might, but looking for a cheap soln which can handle 10A of current per cell.

author: jonroger
author_rank: Regular Contributor
timestamp: February 25, 2019, 12:38:55 am
content: The EMB1428Q provides all the gate drivers you need for mosfets to connect any one of a series string of batteries to a single connection.
BMS output cut-off function works only part way. - Page 1
Forum section: electronics / beginners

author: MrBond
author_rank: Contributor
timestamp: December 25, 2023, 10:35:48 pm
content: Hello everyone, in posting in hopes someone has an answer to my problem. I built a ebike battery, 13s 7p, the problem is that the bms, which has a switch option, cutting power to the output doesn't function properly. The battery sits at 51.8V and when switched off the output of the bms still shows 43V. Im about to put a load on it and see if it isolates but this isn't my 1st build and it never happened before.Update: I did a load test, nothing goes trough, however im still confused about why the voltage is shown.

author: ArdWar
author_rank: Frequent Contributor
timestamp: December 26, 2023, 02:15:59 am
content: That's okay. Just the MOSFET's leakage current. Should be okay as long as it's small (less than 1 mA(?)).

author: MrBond
author_rank: Contributor
timestamp: December 26, 2023, 02:17:55 am
content: My multimeter shows 0, it's a 4 decimal.
BMS problem - BQ79616 not responding to read commands - Page 1
Forum section: electronics / beginners

author: Dias52
author_rank: Newbie
timestamp: October 18, 2024, 03:58:43 pm
content: Hi,I am currently designing a modular BMS with a master-slave topology. The master PCB has a microcontroller and a BQ79600 and the slave PCB has two BQ79616s to monitor and balance 22 series of cells. The PCBs are connected via the daisy chain pins of the BQs.However, I have successfully communicated with the slave before, now I can only wake the slaves and then communication fails when I send a read command. I can communicate with the TI BQ79616 evaluation module (EVM) using my master board and the same software.In the attachment there are two photos with the COMMH+ and COMMH- of the slave board and the EVM, the voltage in my slave board is slightly lower, is this difference relevant for it not to work?Also attached is the schematic of the slave board, which is based on the schematic of the evaluation board.Does anyone know where the problem might be coming from?Best regards.
BMS questions - Page 1
Forum section: electronics / beginners

author: jerryk
author_rank: Regular Contributor
timestamp: April 27, 2020, 08:18:21 pm
content: I'm trying to learn the functions of a bms for an LFP battery that I was given as defective out of the box. Something that I cannot understand is the mosfet arrangement for discharge/charge. All similar battery bms's that I have looked at use the same mosfets in this common drain configuration.Is there an reason why four different mosfets were used on this bms?The links to their datasheets:auirfs8408-7p,IPB180N04S4,IPB180N10S4,IPB180N08S4Another observation is that the typical mosfet arrangement I have seen uses only two pins from the mcu to control the gates of the mosfet configuration. One pin controls the charge side gates and the other pin controls the discharge side. On this board there are four pins used. Two pins for each side of the common drain. I'm not sure why you would want to partially open either side.There is a component in the third picture attached that I have yet to source. It's marking code is HUHJ. I know it's a 3.3V linear regulator. Just wondering the specific identification.I am also looking for advice on how to trouble shoot a board like this. I made a voltage divider from 4 - 20k trim pots to mimic each cell on the bms balance inputs and power it with my lab power supply. Is there a better way to simulate a 4S lifepo4 battery. The goal is to see what the mcu does when I throw the cells out of balance or where the various cut off limit are.Any help/ideas are appreciated.Jerry
Bnc caps for my Ds2072a - Page 1
Forum section: electronics / beginners

author: Emi
author_rank: Contributor
timestamp: November 04, 2016, 03:45:32 pm
content: Hi .. i know its a bitquestion but should i plug something into all unused Rigol bnc inputs to obtain better dust and emi protection ?I know there's a lot of bnc caps around but some are 50/75 ohm, others has shorted pin to gnd and again others are simply dust covers but not in short..What is better for ch inputs, ext trigger and trigger out?

author: BravoV
author_rank: Super Contributor
timestamp: November 04, 2016, 06:04:33 pm
content: https://goo.gl/tZMGv5

author: Gary350z
author_rank: Regular Contributor
timestamp: November 05, 2016, 02:13:03 pm
content: Look here:https://www.eevblog.com/forum/testgear/how-do-you-keep-your-bnc-malefemale-clean-on-your-test-equipemnt/
BNC token replacement - Page 1
Forum section: electronics / beginners

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: May 06, 2024, 03:13:32 pm
content: Hello, I need to replace the male plug of my rigo ds1054z oscilloscope sanda and I wanted to know if this is the right one?https://es.aliexpress.com/item/4001077529958.html?spm=a2g0o.cart.0.0.6e5e7a9dqfEpLH&mp=1&gatewayAdapt=glo2esp

author: tooki
author_rank: Super Contributor
timestamp: May 06, 2024, 06:33:01 pm
content: Sorry, what is it you’re trying to fix?“Sanda” isn’t an electronics-related word, and “token” in the title makes no sense.The link is for a BNC plug to go on a cable. To attach that, you need the appropriate crimp tool. And the plug needs to CLOSELY fit the cable, and the crimp tool needs to match that specific connector type.If it’s the plug on the probe, whether you can replace it at all depends on where the compensation trimmer is; if it’s in the plug, forget it. (Rigolhas had a few probe models. On mine, the trimmer is in the handle, but I don’t know where the others have it.)In any case, buying a crimp tool, even a cheap one, costs more than a new probe.

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: May 06, 2024, 08:46:31 pm
content: Is the male plug of a probe correct, I can get the tools, it's just knowing if that BNC male plug would work well?

author: tooki
author_rank: Super Contributor
timestamp: May 07, 2024, 01:10:40 pm
content: Quote from: Adrian_Arg. on May 06, 2024, 08:46:31 pmThanks for the reply.In that case, no, that plug won’t work. It’s for RG58, which is substantially larger coax than the probe lead. Look for a plug designed for RG174, that’ll be a lot closer in dimensions.The center conductor of the scope probe wire is extremely thin, much thinner than normal thin coax, so you may need to fold it over a few times to crimp, if you’re crimping the center conductor. I also don’t know whether the center conductor wire is solderable or not. (It’s some kind of resistance wire, not copper.)
Board connectors - Page 1
Forum section: electronics / beginners

author: codedninja
author_rank: Newbie
timestamp: November 10, 2014, 08:30:42 am
content: I been trying to design a board for almost a year now and I am still having problems thinking about how to design the board.The board is less then a square inch and it needs to have a connector to send over the settings. It needs to be user friendly as I want to sell it to non technical people. Any ideas?

author: Jeroen3
author_rank: Super Contributor
timestamp: November 10, 2014, 11:52:48 am
content: You can get 1.27 mm pitched pinheaders?
Board Routing and Layout - Page 1
Forum section: electronics / beginners

author: ashley.hughes
author_rank: Regular Contributor
timestamp: January 07, 2013, 10:34:20 am
content: Hey all,I am having trouble working out how the best way to approach laying out a components on a board and then the routing of the parts.I use Eagle but the principles would be the same across most design packages I would think.I am currently working on a LM317 board needs to be single sided as its going to be a test for a CNC milled board (Not ready for double side boards).I knocked that up quickly. What is the approach you guys use in you layouts and routing

author: crispus
author_rank: Regular Contributor
timestamp: January 07, 2013, 10:48:19 am
content: You can check Dave's pcb tutorial:http://alternatezone.com/electronics/pcbdesign.htm

author: ashley.hughes
author_rank: Regular Contributor
timestamp: January 08, 2013, 07:42:33 am
content: Thanks I knew there was a video out there some where. I will watch it when I have some spare time.Got a exam to study for

author: ElektroQuark
author_rank: Unknown
timestamp: January 08, 2013, 08:22:07 am
content: It's not a video, it's a text.

author: AndyC_772
author_rank: Super Contributor
timestamp: January 08, 2013, 08:30:29 am
content: Your 240R resistor wants to connect to the ADJ pin, not ground.

author: Kremmen
author_rank: Super Contributor
timestamp: January 08, 2013, 08:41:02 am
content: Just tiny note on one specific detail: when using trimmers or pots as adjustable resistors like R2 in this schematic, it is a good practice to connect the slider to one end of the resistor instead of leaving the end floating. Doing so guarantees that you will not get an open circuit if the slider should fail to make contact with the element inside for any reason. Some circuits really don't appreciate the connection breaking and this is an easy way to guard against that.

author: EEVblog
author_rank: Unknown
timestamp: January 08, 2013, 11:27:03 am
content: Quote from: EdoNork on January 08, 2013, 08:22:07 amI have a real-time PCB layout video here.Not a tutorial, but might be useful.Dave.
Board to Board connector for an external module - Page 1
Forum section: electronics / beginners

author: Saimoun
author_rank: Frequent Contributor
timestamp: October 02, 2022, 09:54:29 am
content: Hello everybodyI have a (almost) finished project with a metal case. I intend to design an external module for it which will be plastic, and will have plastic clips to be fermly attached to it.What would you recommend to connect the module to the main device? There should only be 4 lines only: VCC, GND, and UART TX/RX.Because the module is attached and not "dangling" there should not be any strain on the cable. So I was thinking using simple pin headers, maybe with a clip to make sure the cable is set the correct way and fermly attached? (i.e. won't come off)Thanks!Simon

author: Whales
author_rank: Super Contributor
timestamp: October 02, 2022, 10:49:28 am
content: I was thinking panel-mount M10 style connectors, they come with different pin counts and you only need a round hole in your metal cases (easy to drill).https://lcsc.com/product-detail/Circular-Connectors-Cable-Connectors_Liansheng-HKT-00006_C2876034.htmlhttps://lcsc.com/product-detail/Circular-Connectors-Cable-Connectors_Liansheng-HKT-00003_C2876035.htmlIf you want to use a cable: that'll work.If you want to skip the cable and mate box directly to box: one gender is normally not panel mount, but two nuts will probably fix that. Sadly I think they'll unscrew their nuts if someone uses the two cases for leverage. If you don't line them up perfectly rotationally in every unit then this will be a problem.

author: tooki
author_rank: Super Contributor
timestamp: October 02, 2022, 01:40:54 pm
content: You could skip the (external) cable entirely and use “blind mating” connectors (often denoted as “BMI”, for “blind mating interface”). They self-align so you can, for example, screw on an external case and the plug on the case plugs directly on the jack on the main unit.

author: Saimoun
author_rank: Frequent Contributor
timestamp: October 03, 2022, 08:29:34 am
content: Thanks guysI was thinking of maybe something a bit smallerMy idea was to have a connector inside the box, so that the users will actually need to open the box to connect the module.And yes I love the mating solution but then the pins will be exposed (so they will need ESD protection, and make sure nobody shorts 5V and GND together)

author: Saimoun
author_rank: Frequent Contributor
timestamp: October 03, 2022, 08:33:40 am
content: Quote from: tooki on October 02, 2022, 01:40:54 pmOk I googled that a bit and it does look really awesome. My problem (the ones I found at least) is still the size, I mean if no module is attached I want the device to still look decent, without a massive plug on the side