hybridfree/eevblog-posts huggingface dataset:
Bluetooth audio transmitter with selectable input level cut-off - Page 1
Forum section: electronics / projects

author: electr_peter
author_rank: Unknown
timestamp: May 10, 2020, 09:28:11 pm
content: I am looking for solution to bluetooth audio transmitting task. Features needed in BT audio transmitter:maintain BT connection with BT headsetreceive audio input from external source (3.5 mm input)transmit audio via BT only if input audio level is higher than some thresholdCurrently used BT audio transmitter CSR8675 based, similar toRecepteur-Bluetooth-5-0-CSR8675-Adaptateur-USB-audio-de-musique-sans-fil) istoo keen to transmit- it is always transmitting audio, even when audio input is silent or missing.Slightly different BT audio transmitting principle is needed (used with smart phones) - that is, transmitter should maintain BT connection, but stream audio only when audio source is present (music player is on or call is in progress).Can you suggest a better solution (preferably something off the shelf)?
Bluetooth + DAB - Page 1
Forum section: electronics / projects

author: james2k2
author_rank: Contributor
timestamp: March 18, 2015, 12:31:30 am
content: Hi All,I'm interested in building a DAB radio receiver with Bluetooth as it's interface and control method.My idea was to get a simple dab radio that I can tear apart and expose it's lcd, pcb and buttons, then use a bluetooth kit or pcb that exposes the keypress commands (next track, play/pause etc) to outputs that I can then interface to the buttons on the DAB. Oh and also send the audio over the bluetooth link.Sounds simple, but I'm yet to come across a bluetooth kit that offers this.One solution would be to do what I want in software using something like a Raspberry Pi, but I already tried a DAB usb receiver on my phone (for portability during test) and reception was terrible, whereas actual hardware seems to work far better.Any ideas welcome. Thanks very much.

author: james2k2
author_rank: Contributor
timestamp: March 19, 2015, 04:48:28 pm
content: Sorry to bump this, but I've come across the Roving Networks (Now Microchip) RN-52 Bluetooth Module that Sparkfun also sell an adapter board for. It seems to be ideal for my purposes and is relatively cheap.The only issue is that in all examples, it shows it as being the command sender.Here's the data sheet:http://ww1.microchip.com/downloads/en/DeviceDoc/rn-52-ds-1.1r.pdfHas anybody had any experience with this module? The datasheet suggests the GPIO's that are used as button inputs can be configured to be outputs too, but I've not found any code or examples on how to do this.My next idea, was to buy one of those super cheap bluetooth ipod modules (the 30-pin ones) and hook it up to an Arduino with the iPod Serial code module loaded and simply decode the commands being sent and convert them to outputs to then ultimately press the buttons on the DAB.What do people think? Thanks.
Bluetooth device - Page 1
Forum section: electronics / projects

author: LatvianOnJuice
author_rank: Contributor
timestamp: January 19, 2015, 11:12:30 pm
content: Hello, everyone!I decided that I would love to do a project, which includes controlling a home appliance via bluetooth. I am still searching about these kind of projects as I am typing this post, but I wanted to ask you guys, if anyone has done anything that is related to controlling via bluetooth. Ideally, I would love to, for example, turn on an LED by using a self-programmed app on my phone.This is my first time doing anything related to this, so I will really appreciate any kind of webpages, sources, or any information that you would be kind enough to share.Thank you in advance!Cheers!

author: paulie
author_rank: Frequent Contributor
timestamp: January 19, 2015, 11:31:26 pm
content: By far the easiest approach is to program a PIC or AVR to read inputs from a cheap HC05 or HC06 bluetooth module and control the LED or other external devices. The bluetooth module itself does have I/O and can be programed but not as easy. On the other end one of those $1 bluetooth dongles plugged into a PC or Android phone by itself running Blueterm make a great control console. Simple serial protocols make this a cinch. Google is your friend.

author: Richard Crowley
author_rank: Super Contributor
timestamp: January 19, 2015, 11:34:56 pm
content: There are several Bluetooth interface boards ("shields") for Arduino that do exactly that.They let you control things (via the Arduino) from an IOS or Android app.This is just the first hit on Google:http://www.makershed.com/products/bluetooth-low-energy-ble-shield-for-arduino-2-0Quote

author: diegosfb
author_rank: Contributor
timestamp: January 19, 2015, 11:45:39 pm
content: Its really not very hard, those bluetooth modules they are talking about, they just work receiving/transmiting serial commands.You can even test them with a PC instead of a microcontroller (sounds like you know how to program it might be easier to test the modules using a terminal and a max232 board for level conversion if needed (depends on the module used).I have made a Bluetooth RS-232 wireless connection and works like a charm, with that you can control tons of bluetooth devicesThe only concer will be range, keep in mind the range is limited, and it probably wont cover your hole houseGood luck

author: LatvianOnJuice
author_rank: Contributor
timestamp: January 20, 2015, 12:06:36 am
content: Thank you guys for the input! I am still googling and taking notes on pretty much everything I find... This is just a personal future project I would like to do. No rush, no particular desire regarding the end result, however, I want to find & learn everything I can about this, since it seems very intriguing to me!
Bluetooth Devices - Page 1
Forum section: electronics / projects

author: Unknown
author_rank: Unknown
timestamp: July 30, 2010, 02:04:23 pm
content: I am working on a audio project and could use some input:I am using two LM3915 for a VU Meter setup, I am adding a Arduino + SPI FM tuner from sparkfun, I am thinking of adding Bluetooth to the design or wireless 802.11g to stream the audio from my PDA to the device itself.I am also integrating this into headphones; and KOSS might pick this design up in there high end headphones supply chain.What speed do I need to match? as in if Audio is 15KHz using a 430MHz transmitter and receiver would that work fine?Also is there a Bluetooth device that can connect as a Audio Out and have FM already built in?

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 30, 2010, 02:39:53 pm
content: isnt the bluetooth work at 2.4GHz range? i'm not entirely sure what you want to design. i like picture, maybe a sketch of schematic in picture could explain it better.

author: migsantiago
author_rank: Frequent Contributor
timestamp: July 30, 2010, 06:38:30 pm
content: Yeah, a block diagram would come in handy.Bluetooth works on the 2.4GHz range at 1Mbps if there are no other bluetooth devices using this band (or other 2.4GHz devices).

author: joelby
author_rank: Frequent Contributor
timestamp: August 02, 2010, 02:50:55 am
content: If you just want to transmit audio wirelessly, Bluetooth is good. Fortunately, this has already been done!A receiver:http://www.belkin.com/IWCatProductPage.process?Product_Id=508754A transmitter/receiver pair, though I can't tell if it's still available:http://www.amazon.co.uk/Hama-Bluetooth-Audio-Rxtx-Black/dp/B000JFX01MHeadphones that have a built-in Bluetooth receiver:http://www.motorola.com/Consumers/US-EN/Consumer-Product-and-Services/Mobile+Phone+Accessories/Headsets/Bluetooth-Stereo-Music-Headphones/MOTOROKR-S305-Wireless-Stereo-Headphones-US-ENIf your PDA has Bluetooth, it might support the A2DP profile natively so you'd only need the receiver.If you were to do it from scratch, your specifications are a bit unclear - do you want to stream audio data (eg MP3 or PCM) or just the audio? The former may be up to 256 Kbps. If you just want to transmit the audio, an FM transmitter would be the way to go. Fortunately, you can already pick up headphones that have built-in FM radios!
BlueTooth, GPS and similar in presence of high pulse EM fields - Page 1
Forum section: electronics / projects

author: daqq
author_rank: Super Contributor
timestamp: June 02, 2015, 11:53:35 am
content: Hi guys,Assuming a repeating high power pulse signal, is there any reasonable way to use GPS, BlueTooth or similar commercial grade thingies? Is there a chance of them burning out?I'm asking because of the presence of an X band meteoradar very close to one site, where we'd very much like to use a GPS module amongst other things. The other items are fine - everything's shielded, grounded, but the GPS device would present a bit of a problem because it's got a ceramic onboard antenna and I'm worried about what might happen if the beam hits the device.Also, what about BlueTooth, WiFi or similar devices? Would they die in such conditions?Thanks,David
Bluetooth Keyboard - Page 1
Forum section: electronics / projects

author: IconicPCB
author_rank: Super Contributor
timestamp: August 09, 2018, 12:27:09 am
content: Having absolutely no experience with Bluetooth either as a user or developer I wonder whether it is possible to and if so how difficult is it to pair a bluetooth keyboard with a bluetooth enabled phone to make a phone call and disconnect the call via the keyboard. This is to say replace the telephone user interface with a bluetooth keyboard.

author: IconicPCB
author_rank: Super Contributor
timestamp: August 09, 2018, 09:42:19 pm
content: No takers?

author: IconicPCB
author_rank: Super Contributor
timestamp: August 09, 2018, 10:59:20 pm
content: Thank You Blueskull,Is there some online facility where i could go and potentially learn how to write this app?

author: IconicPCB
author_rank: Super Contributor
timestamp: August 10, 2018, 12:03:37 am
content: Thanks Blue,I shall have a look at the two options.
Bluetooth keyboard emulator - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: September 18, 2017, 11:58:07 am
content: I would like to make a circuit (keyboard emulator) with 6 momentary push buttons that will emulate 6 keys on a conventional keyboard. Ideally the device would be bluetooth based running on an AAA battery.This will "connect" with a PC running Windows (7 or later) that is bluetooth enabled.Does anyone know of a suitable IC (keyboard/Bluetooth) interface that would be recognized by Windows as a keyboard so I don't have to provide the windows driver, but simply connect the IC to the 6 switches (or possibly write some simple code for the sending the desired key codes?

author: pigrew
author_rank: Frequent Contributor
timestamp: September 18, 2017, 02:00:10 pm
content: You need a Bluetooth MCU, and various power management circuits.The MCU will need to have a Bluetooth HID implementation. It'll take a reasonable amount of programming to get it working.The ESP32 might be a good platform to look at, because of its popularity and low price. The disadvantage is that it's too powerful, and would drain a battery somewhat more quickly that other simpler MCUs.
Bluetooth keyboard  - Page 1
Forum section: electronics / projects

author: Cloud
author_rank: Regular Contributor
timestamp: March 02, 2016, 09:30:47 pm
content: Recently (about 2 years ago...) I received just a plastic case from ZX spectrum. So I had an idea to build a BT keyboard with it. For switches I was thinking cherry ML (http://cherryswitches.com/product/keymodule-ml/) but for communication with the device I was thinking ATMega and some bluetooth module (I hadn't been working much with them).I also had idea about buying cheap BT keyboard off ebay and just using electronics, but I think it would be too much work with figuring out multiplex in that one.What do you think about this?
Bluetooth LE device FCC pretesting  - Page 1
Forum section: electronics / projects

author: beefplease
author_rank: Newbie
timestamp: July 26, 2019, 02:45:26 pm
content: Hey, I made bluetooth low energy device with FCC/CE certified bluetooth module and I am planning get FCC for whole device. Firstly I want to do emission pretesting to make sure non of the sensors or DC/DC are too "loud". The deal is device consists of few very different modes like "advertising" which is basically power off with few wake ups and real time data transfer while connected to smartphone which of course increases current consumption as well as DC/DC frequency on board. But I cannot find any information how to test emission in this case, I believe I will disturb readings by having smartphone around and I am not sure if I need to test all the modes or just the most power hungry one. Lab doing these pretests is also not helping, they are just doing the measurements and don't care. Any hint would be appreciated.

author: Benta
author_rank: Super Contributor
timestamp: July 26, 2019, 07:19:04 pm
content: Quote from: beefplease on July 26, 2019, 02:45:26 pmFire them and work with a competent test lab. The ones I've worked with on this kind of thing have always been helpful with suggestions, tweaks, knowledge about standards, proposing design changes etc.I cannot recommend any in Lithuania, but I've had very good experience with CEcert GmbH in Wismar, which is still on the Baltic Coast(No affiliation BTW).
Bluetooth LE for Secure Remote Control - Page 1
Forum section: electronics / projects

author: GJS123
author_rank: Newbie
timestamp: December 05, 2019, 06:06:34 pm
content: Hi All,I would like to make a replacement secure RF "key fob" type remote control for an exisiting intruder alarm system. This needs a few functions e.g. arm, disarm, part arm, open garage door etc. Interfacing to the exisiting alarm is no problem.I had an idea to use two Bluetooth LE equipped MCUs e.g. ESP32. I am thingking that once the pairing has taken place, the encrypted data flow between the two MCUs should be pretty secure. I believe that the two devices can be "bonded" which means that no "in the clear" communication takes place as the pairing information is a one time thing only.Does this sound feasible? Or are there securty flaws in my cunning plan?Thanks for any advice.
Bluetooth - led flashing light.  - Page 1
Forum section: electronics / projects

author: lokilukas
author_rank: Newbie
timestamp: May 02, 2013, 01:37:56 am
content: I have a product idea but I'm at a bit of a loss on how to proceed with my project and came across this forum. I've contacted a few electronics companies that build prototypes for customers but they haven't gotten back to me.I have no experience with the making of electroncis and I apologise if I've misused this forum in anyway. Maybe it's a good project for someone here and I'm willing to pay for this service of course.I want to know if someone on this blog can help me a functioning electronic prototype of a product I want to make and whether it is possible to produce considering the size restraints.In order for the product to work I need a device to fit inside a 10mm cube or closest to this size.The image below I found online of a circuit used for pulsating led lights.http://forum.hackedgadgets.com/viewtopic.php?p=6389#6389The primary function I am looking for is to flash one of two led's from a signal via Bluetooth from a mobile phone. If the phone was to ring, it would light up one colour, if the phone receives a text message it lights up another. If multiple LED's were able to fit, or maybe a RGB led.. the ability to manipulate colour via the phone would be good.Obviously it would need it's own power source, maybe watch battery? Rechargeable would be incredible but with the size restraint I imagine it's unrealistic.I have not been involved in the production of electronics before however, the inspiration for this product was a new bluetooth dongle I recently purchased that is incredibly small, protrudes only mm's from the usb port.Can someone help me on who I would approach to help me build this, whether it is even viable or too expensive to produce or if someone here has the ability to give this a shot?
Bluetooth Low engergy SIG Qualification - Page 1
Forum section: electronics / projects

author: wemme
author_rank: Regular Contributor
timestamp: April 10, 2015, 12:22:58 am
content: Hello All,Currently designing a product using the nordic semi nRF51822-QFAA and their LE stack S110 and S120In regard to bluetooth SIG qualification has anyone here done this before?I can leverage a little bit from the stack qualification and have generated a test program but now what?Did anyone work with a local test house in AU or NZ?RegardsBart
Bluetooth module BK8000 documentation. - Page 1
Forum section: electronics / projects

author: Jacek_Paw
author_rank: Contributor
timestamp: November 11, 2016, 01:17:22 pm
content: Hallo,recently I have bought module mentioned in the topic (BK8000). Unfortunately the documentation isn't available or at least I didn't manage to find itAll I found is pdf document, having 10 pages with some brief description. I need programming manual or at least the set of instructions and default UART configuration.Could you be so kind and help me - maybe some one has already got it and could share it with me?Thank you in advance,br,Jacek.
Bluetooth module  for Audio - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 18, 2021, 01:39:48 pm
content: Hi,I want to know which Bluetooth module would you recommend for using in a portable speaker? If it had USB interface for reading from USB Flash it would be nice too.

author: VK3DRB
author_rank: Super Contributor
timestamp: November 21, 2021, 12:13:08 pm
content: Many options here. Consider using classic Bluetooth. If it is cost sensitive, I suggest you could do it on an ESP32, else there is u-Blox, Sierra Wireless, Microchip etc - all good companies, but good luck trying to find what you need during this disastrous Chipageddon. Even so, you might be able to still get eval boards if you cannot get the modules. Also consider Cypress's PSoC Creator range of module - tiny, powerful, and a very good IDE. I just did a medical device project using one of them.Some have USB support. If not, consider a USB interface chip. The ESP32-C3 uses a CP2102N USB to serial port interface chip.Also, stay away from separate antennas to the module, unless you have a VNA and a lot of time messing around and risking getting re-spins done. For the the amount of pain, you are better getting a module with a chip antenna onboard, or a PCB trace as the antenna built in. They cost not much extra.I have been playing with an ES32-C3 with PCB antenna. Small module but not the tiniest. I did the ESP BLE and OLED stuff on an Arduino IDE (the Arduino IDE is pretty crappy but simple enough). I got 55 metres range in a built up area outside. Not bad! If you ever want to use BLE, this is THE book to start with...https://www.novelbits.io/introduction-to-bluetooth-low-energy-book/. Mohammad Afaneh did a great job. But maybe consider the ESP32-WROOM series of modules.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 23, 2021, 07:30:58 am
content: Thanks VK3DRB for the tips, ESP32 seems good candidate, which model has a USB host, I want it to be able to read files from external USB thumb drives too.

author: rpiloverbd
author_rank: Regular Contributor
timestamp: November 29, 2021, 01:24:46 pm
content: You can use RN-52 bluetooth module.
Bluetooth module question? - Page 1
Forum section: electronics / projects

author: docmur
author_rank: Regular Contributor
timestamp: June 28, 2014, 10:53:53 pm
content: HeyHas anyone used this module before:http://www.aliexpress.com/store/product/Free-shipping-NRF51822-Ultra-Low-Power-Bluetooth-4-0-Low-Energy-RF-Module-Fingertip-size/130096_1358212667.htmlI think it is prefect for my current design, I haven't been able to find a datasheet for it yet. I assume I just connect the P0 pins to digital I/O

author: What_NZ
author_rank: Regular Contributor
timestamp: June 29, 2014, 12:54:39 am
content: Quote from: docmur on June 28, 2014, 10:53:53 pmDid you have a look on their website and BBShttp://www.freqchina.com/en/

author: What_NZ
author_rank: Regular Contributor
timestamp: June 29, 2014, 01:04:38 am
content: Actually their Chinese website has more informationwww.freqchina.com/cn/

author: andyturk
author_rank: Frequent Contributor
timestamp: June 29, 2014, 06:36:26 am
content: Quote from: docmur on June 28, 2014, 10:53:53 pmLooks like it does *not* include an antenna. If that's true, you've still got some PCB work to make the thing functional, not to mention FCC certification, if you care about such things. The rest of the datasheet seems to quote Nordic's chip specs. Most likely, they just solder the chip on their PCB, add a crystal, some decoupling caps, and a matching network for the antenna, but you still have to program the chip to make it do anything. That's non-trivial.If you want to start playing with nRF51, maybe this is a better entry point:http://www.rfduino.com/
Bluetooth module with UART data pipe capability. - Page 1
Forum section: electronics / projects

author: Boscoe
author_rank: Frequent Contributor
timestamp: December 21, 2016, 10:06:38 pm
content: Hi all,I think this falls under the microcontroller part of this forum.I wonder if someone has had some experience with a bluetooth module that is easy to use and easily obtainable (farnell or digikey for me). I would like to use it as if it were a UART interface on the PC. Once connected shows up as a serial COM port then I can chuck out ASCII which is output from the module. The lower the cost the better.ThanksPS I don't mind having to program it as long as it's simple and not a project in itself eg writing code for the Cypress modules unless there's an example ready to go. I don't care about the advertising name etc.

author: retrolefty
author_rank: Super Contributor
timestamp: December 21, 2016, 10:45:23 pm
content: Seem to be out of stock again (they were out when I ordered also) but the adafruit device is fully plug and play and even allows PC application to control DTR and receive DSR control signals. It is fully auto-baud rate detection. It just works fine. A little higher price then the direct Asian products but again it's been validated with many buyers for some time now.https://www.adafruit.com/products/1588

author: chicken
author_rank: Frequent Contributor
timestamp: December 21, 2016, 11:20:45 pm
content: Did you already look into HC-05 and HC-06 Bluetooth modules? Widely available on Ebay etc., not sure abot Digi-Key et al.

author: Benta
author_rank: Super Contributor
timestamp: December 21, 2016, 11:27:12 pm
content: Search for "bluetooth serial port module".There are several suppliers, important is, that the module supports SPP through a serial interface.In that case, you can control it using AT commands.
Bluetooth problems. - Page 1
Forum section: electronics / projects

author: David97
author_rank: Contributor
timestamp: December 01, 2015, 10:30:13 pm
content: HI, I was making a couple of bluetooth receivers for my brother for Christmas. I bought a KRC-86B V4.0 and a xs3868. The plan was to use the krc-86B with his hi-fi setup and the xs3868 in his car stereo, I know quality would not be best for cheap Bluetooth, but it would have been adequate.. I've just tested the KRC-86B and realised that range is terrible. At about 3 meters apart if you walk between the module and phone it cuts out. I know Bluetooth is terrible for range, but I would have expected more.I have yet to test the XS3868, but hoping it's going to be better.Anyone have any ideas, is this typical of cheap bluetooth modules? Could I add a antenna? Is there any modules you would recommend? What direction and orentation should I point the squiggly on board antenna?Thanks, David.

author: picitup
author_rank: Regular Contributor
timestamp: December 05, 2015, 11:27:47 am
content: This might help.....http://www.instructables.com/id/Increase-and-extend-the-range-of-a-USB-Bluetooth-d/CheersSteve
Bluetooth RN-52 Audio Link - Page 1
Forum section: electronics / projects

author: 8163jb
author_rank: Contributor
timestamp: September 01, 2013, 10:08:31 pm
content: Hey guys, so I've ordered my first board from OSHPark, it's a device which allows you to play music through bluetooth and it comes out of an AUX 3.5mm jackThought I'd share it and see what you guys think!http://doayee.co.uk/bluetooth-audio-link
Bluetooth Serial Link? cheapest wireless replacement for 115200 BAUD? - Page 1
Forum section: electronics / projects

author: Chendy
author_rank: Contributor
timestamp: March 02, 2017, 01:02:36 pm
content: Hi gangI just want a simple / transparent wireless serial replacement link. Bluetooth chips at booth ends, transporting serial.Doesnt have to be super fast, reliably doing 115200 bidirectional is fine. if faster than great.SERIAL -- BT IC ----- (wireless) ----- BT IC -- SERIALorUSB COM VIRTUAL SERIAL SUPPORTED BT IC ----- (wireless) ----- BT IC -- SERIALWhats the cheapest way / IC for doing this?The Qualcomm CSR101* range seem pretty cheap from checking OctopartAre there any cheap (chinese?) dedicated ICs that do this?what IC is usedherefor example?Cheers gang

author: up8051
author_rank: Frequent Contributor
timestamp: March 02, 2017, 03:33:02 pm
content: Are you looking for chipset or ready modules?Regards,up8051

author: linux-works
author_rank: Super Contributor
timestamp: March 02, 2017, 04:44:28 pm
content: hc-05

author: Sjoertdb
author_rank: Contributor
timestamp: March 08, 2017, 08:49:13 am
content: nRF24?

author: Chendy
author_rank: Contributor
timestamp: March 08, 2017, 04:15:06 pm
content: I guess modules, unless the reference designs dont require certification.cheers gang

author: helius
author_rank: Super Contributor
timestamp: March 08, 2017, 05:27:25 pm
content: LM Technologiesmakes modules, but they aren't that cheap.

author: sagnikbasu
author_rank: Contributor
timestamp: March 08, 2017, 05:31:01 pm
content: go with hc-05/hc-06....they are cheap and efficient for low cost projects....

author: technix
author_rank: Super Contributor
timestamp: March 09, 2017, 12:39:04 am
content: On the device end, HC-05.On the computer end, you can use whatever Bluetooth chipset your computer can accept. Since I am a Mac user I usually use the built in Bluetooth. On my Windows workstation it was the Bluetooth function of my Intel Wireless AC 7260 adapter. And I have an older USB Bluetooth dongle on my Linux workstation.When paired, the HC-05 shows up on the computer as a serial port.
Bluetooth SIG is looking for unlicensed products - Page 1
Forum section: electronics / projects

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: March 20, 2024, 08:31:49 am
content: I have received this email from Bluetooth SIG (of which I am a member.)We do not manufacture any BT devices so I am ignoring it but if someone sells unlicensed BT products they might want to take a note. Make your own mind up.Leo

author: HwAoRrDk
author_rank: Super Contributor
timestamp: March 20, 2024, 10:29:55 am
content: Sounds to me like they're just making sure that SIGmembersare only marketing Bluetooth products that are qualified and licensed, and not hunting downanyproduct made by anyone that uses Bluetooth.If one isn't a member of the SIG and doesn't use their trademarks, I suspect you have nothing to worry about.
Bluetooth UART modules pair? - Page 1
Forum section: electronics / projects

author: abhishekkumar1902
author_rank: Regular Contributor
timestamp: December 26, 2017, 06:23:52 am
content: Unlike bluetooth modules like theHC-06, HM-10,etc which starts up as a bluetooth host access point and then the client (like a bluetooth enabled phone over SPP profile) connects to them whenever they need, are there any module pairs available in the market which comes as a host-client synced pair, sort of a UART bridge which automatically connects to each other and acts a UART bridge which can be used to route to UART endpoints. In a nutshell, I am looking for bluetooth UART modules which comes in host and client pair and the client connects to the host automatically the moment it is powered ON, and routes the UART data sent to them. Thus I do not need to worry about manually connecting the client bluetooth module to the host each time it is powered ON.

author: R.Naresh
author_rank: Contributor
timestamp: December 27, 2017, 03:21:34 am
content: well the hc-05 can be both a slave and a master .... i think thats wat you want to know. cant understand your question tho...but host and client pair and uart bridge idk about that but u can set it up using an arduino
Bluetooth volume stays the same after 20%?  - Page 1
Forum section: electronics / projects

author: lutkeveld
author_rank: Regular Contributor
timestamp: June 13, 2018, 12:27:20 pm
content: I'm working on a PCB with a BM64 bluetooth module. There is one problem that I can't get solved;If I use the line-in (aux) everything works fine. However when I connect a bluetooth device the first 20% of the volume bar accounts for 100% of the actual volume, after that it just stays the same.I have set the BT module to 16 bit output and confirmed that it has a 44.1k sample rate with 2.82Mhz clock.In the attached picture you can see the WS line (top) and data (bottom)What could be the problem? The only thing that looks weird is the last bit which does not go to 0 immediately.Maybe it's not even related to the I2S, but to some settings of the BM64 (which have effect on the I2S signal of course).The amp (TAS5754M) is set to I2S 16 bit and doesn't seem to be the problem.How would I go about solving this problem?
bluetooth wired headphone - Page 1
Forum section: electronics / projects

author: joaopedro007
author_rank: Newbie
timestamp: September 03, 2023, 02:13:46 am
content: Hello, good evening, I'm here to ask for information about a personal project. I want to turn a small wired headphone into a bluetooth headphone, as far as I know, I need a bluetooth transmitter, and a bluetooth receiver, I want both in stereo, one in each earbud. however, the transmitters and receivers I've found are too big to fit in the headset, I've already removed the headset wires. I need to make a small electronic board (PCB) containing only the transmitter and the receiver (one board will receive and send the signal to the other board) so I have no idea what parts I'm going to use on the board (PCB). if you can help me thanks

author: amyk
author_rank: Super Contributor
timestamp: September 03, 2023, 02:49:11 am
content: The "transmitter" is usually in the device that's supplying the audio.Look up "true wireless stereo" or "TWS" for more details on how it's supposed to work. You may be able to salvage the electronics from some cheap TWS earphones as they would definitely be small enough for your needs.

author: joaopedro007
author_rank: Newbie
timestamp: September 03, 2023, 03:14:06 am
content: But what if I don't have the conditions to buy these headphones, what do I do?

author: coromonadalix
author_rank: Super Contributor
timestamp: September 03, 2023, 01:10:39 pm
content: simply find an portable bluetooth transmitter and or the receiver, since you need botha simple google search would have provided all you need at low cost from our excellent chineesium sellers ....
Blurtooth BLE reading  from a sensor using ESP32 - Page 1
Forum section: electronics / projects

author: SPRX
author_rank: Regular Contributor
timestamp: April 06, 2024, 08:19:40 am
content: Has anyone managed to connect to "Smart Life" bluetooth temperature and humidity sensor over BLE using for Eg. ESP32 BLE?This devise looks somewhat similar to the popular Xiaomi bluetooth sensor however serviceUUID and the characteristicUUID looks different.I scanned the service/characteristic UUIDs with nRFConnect on Mobile app but still unable to receive or read the temperature valus using the ESP32. Not sure this is due to the data is formated differently (or ever encripted).
BM1387B datasheet - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: September 21, 2019, 08:13:15 am
content: Hi,I want to know if we have a datasheet for this puppy, or do we have Altium library for it,I want to make a schematic and footprint library for now.Regards
BM235 modifications - Page 1
Forum section: electronics / projects

author: Sceadwian
author_rank: Unknown
timestamp: August 12, 2017, 05:52:06 pm
content: I'd rather ask in a thread here to have all references in one spot if I'm able to go anywhere with this. Has anyone done any modifications to a BM235? I have an ESP32 sitting around not doing anything and I wouldn't mind trying to add Bluetooth functionality to it as a learning project so I gotta get some schematics and chip information to see if it's even possible to grab the screen information to post process it, which might require some interesting bit rangling (which I'm prepared to do) in both software and hardware possibly.Being this is "Dave's meter" this is probably a great place to askI'm sure the bit geeks around here have done something with it.If anyone can post any links to info like schematics or chip PDF links (would be nice) If something like this thread already exists on the forum somewhere that I'm not aware of (I have a lot of catching up to do) could you link the threads in here for me? I'll look up as much of it on my own and drop it in here if anyone is interested but I could use community support on this simply because I'm not very good at reverse engineering and my time on this is limited so whatever anyone can assist with for information would be appreciated.I figure if I can get the chip PDFs and figure out how to grab the data that's being sent to the display (if I have to) or if there's a direct way to get data out of this thing it wouldn't take much more than a weekend or two project to add BT functionality to it. With the functionality of the ESP32 lots of other interesting functions could be added as well. As much of your life you want to spend doing the modding at least

author: floobydust
author_rank: Super Contributor
timestamp: August 13, 2017, 06:39:21 pm
content: There's a wealth of information Dave has provided if you look around the site:Not sure if it was investigated if Pin 20 is TXD on the BTC H200.http://www.kerrywong.com/2016/03/19/hacking-dtm0660l-based-multimeters/

author: Sceadwian
author_rank: Unknown
timestamp: August 13, 2017, 07:39:16 pm
content: Quote from: floobydust on August 13, 2017, 06:39:21 pmThanks, I just wanted this post to collect any references anyone wanted to share in one place. That looks like most of what I'll need
BM3451 to protect a Parkside battery - Page 1
Forum section: electronics / projects

author: Romain
author_rank: Regular Contributor
timestamp: November 02, 2023, 09:44:51 am
content: Hi,I'm using a Parkside 5S 20V battery from LIDL to power a DPS3005 as a portable power station and I'm very happy with it.This is the 3d model I printed:https://cults3d.com/en/3d-model/tool/parkside-x20v-team-rd-dps3005-portable-100w-power-supplyI'm after an under-voltage protection that's normally performed by the power tool, not the battery itself. The battery only includes the balancing circuit.I was hoping I could use an AE module for that. This is what I bought:https://www.aliexpress.com/item/32889959726.htmlUnfortunately since I only have access to the battery 5S 20V output, I cannot tap into the balancing points, which makes the BM3451 unhappy:QuoteSo my question is simple, do you have a suggestion for an under-voltage protection for a 20V battery up to 50A?

author: Chalcogenide
author_rank: Regular Contributor
timestamp: November 02, 2023, 12:38:46 pm
content: You could use a micropower reference and a micropower comparator comparing said reference to a voltage divider from the battery to drive an external MOSFET. TI's TLV6713 includes both the reference and the comparator, although it has an open drain output which might not be what you want.
BMD01 lithium battery charger - Page 1
Forum section: electronics / projects

author: artag
author_rank: Super Contributor
timestamp: April 29, 2025, 10:24:54 am
content: I have some wireless power receivers (aliexpress boards) which include a sot-23-6 device marked LPS BMD01. It seems to be a lithium cell charger but I can't find a datasheet.Does anyone recognise it or the LPS which I presume to be the manufacturer ? Maybe it's LRS.Could be Low Power Semiconductor but their ics usually seem to have numbers starting LP<digits>update : Never mind, I got it. It's an LP2057 with the device code being the BM and D01 the date code.
BMP280 module - does the decoupling caps to BMP280 required - Page 1
Forum section: electronics / projects

author: Nikos A.
author_rank: Regular Contributor
timestamp: December 23, 2022, 04:51:59 pm
content: Hi, this module includes filtering after the LDO and decoupling on the VCC pins of the BMP280 sensor. Since the LDO is close to the sensor, are the decoupling caps C1,C2 required? Could we omit them and instead keep just the C5,C6?https://wiki.seeedstudio.com/Grove-Barometer_Sensor-BMP280/#:~:text=everything%20goes%20well.-,Schematic%20Online%20Viewer,-%C2%B6

author: TimFox
author_rank: Super Contributor
timestamp: December 23, 2022, 05:07:45 pm
content: See "muntzing"https://www.smecc.org/mad_man_muntz!.htmIf you make your own PCB, be sure to include the pads for these capacitors in case you need them.[sorry--I can't get that link to copy properly, even after I tried manually. That ! seems to mess things up.Google "madman muntz capacitors".]

author: Nikos A.
author_rank: Regular Contributor
timestamp: December 23, 2022, 05:17:18 pm
content: Thank you Tim!! Yes, I will design my own module and I will place LDO near to the sensor. So the short answer is that they are not required?

author: TimFox
author_rank: Super Contributor
timestamp: December 23, 2022, 05:22:08 pm
content: No, the short answer is that you remove decoupling capacitors from a circuit at your own risk, and must be able to put them back if the circuit fails to function."Decoupling" means to stop parts of the circuits from interfering with each other."Bypass" means to stop device current variations from interfering with the supply voltage at that circuit.The requirement is quantitative for a given circuit.

author: Siwastaja
author_rank: Super Contributor
timestamp: December 23, 2022, 05:43:20 pm
content: I would also remove C5. The regulator needs 1uF output capacitance. Adding another 100nF in superfluous.Indeed, if the distance is very small, you don't need C1, C2. But be careful, some ICs really need extremely low supply impedance to the point of requiring a separate decoupling cap at every power pin, routed physically close, with good attention to vias going to ground plane.Other option is to keep C1 and C2 but make them 1uF to satisfy the regulator's need for enough capacitance for loop stability, then remove C5,C6. I would consider that one.

author: Nikos A.
author_rank: Regular Contributor
timestamp: December 23, 2022, 05:49:14 pm
content: Thank you Siwastaja!!
BMS: Avoid damage when charger is wrong connected - Page 1
Forum section: electronics / projects

author: Blackgar
author_rank: Contributor
timestamp: April 29, 2022, 04:32:24 pm
content: I am designing a PCB for a low voltage BMS system (<48V).I try to think ways that could prevent damage on BMS or Charger, when Charger is connected wrongly (Charger+ to Pack- etc.). One solution could be a dedicated connector that do not allow the user to do mistake.What else could I add to prevent this case? A diode parallel to the output (Pack+, Pack-) may damage the Charger due to high current.

author: DavidAlfa
author_rank: Super Contributor
timestamp: April 29, 2022, 06:05:33 pm
content: Two beefy p-ch mosfets and a resistor will do the job.For 48V, the bidirectional zener is required to protect the gates, they usually can handle ±20V at very most, 12-15V is a safe value.The voltage drop will be negligible with decent mosfets.What's the charger open-circuit voltage? If not exceeding 48V in any situation, a 55-60V should be enough, but it's always better to leave a larger margin, 75-80V would be perfect.The downside of higher voltages is higher Rds, requiring beefier and more expensive parts.

author: m3vuv
author_rank: Super Contributor
timestamp: April 29, 2022, 06:50:23 pm
content: seems a silly question for a simple task,just use a standard xt connector,one thing i say is tho is to power on the charger before connecting the battery pack to it,on mine it gives a big flash/arc if i dont.p.s the xt connectors only plug in one way so cant get polarity wrong!.
BMS balance connector is unlabeled. Can you figure out which side is B-? - Page 1
Forum section: electronics / projects

author: weinbergerc
author_rank: Contributor
timestamp: January 27, 2019, 11:34:03 pm
content: I ordered this cheap BMS from ebay. It uses a the same balance connector as my battery pack, but the location of B- on the battery's connector and on the BMS's connector extension are opposite! The connector extension has one black lead (this extension shipped with the BMS) which I assume is B-.Since the BMS board is unlabeled, I'm not sure if the lead extension is just wrong, or if the board actually has its B- wire opposite of my pack.=/ What can I do?

author: oPossum
author_rank: Super Contributor
timestamp: January 27, 2019, 11:40:51 pm
content: The harness shown in your last picture looks correct. Pin one of the PCB is designated by a square pad, and on the bottom it goes to some ground plane, so that is most likely to be the B- connection.
BMS circuits as switches, ¿reasonable? - Page 1
Forum section: electronics / projects

author: Barkuti
author_rank: Contributor
timestamp: October 22, 2017, 01:53:09 pm
content: Hi fellows.I am right now tinkering with the idea of overhauling an old Petzl headlamp with a 2S li-ion input driver. I am installing a BMS inside, with additional balance board. Question is, ¿is it 0K to use a small switch over the anode to B+/P+ BMS input as main switch? This way I should be able to switch the thing on/off reliably and efficiently, ¿doesn't it?Thinking in using a couple of these inexpensive boards in parallel (Hycon HY2120 based):Product link:https://www.aliexpress.com/item/-/32673816680.htmlAny experience with these?For reference:http://www.hycontek.com/wp-content/uploads/DS-HY2120_EN.pdfCheers
BMS for 10S lithium pack - Page 1
Forum section: electronics / projects

author: PanSam1986
author_rank: Contributor
timestamp: October 01, 2022, 10:29:44 pm
content: Hi all,I am having trouble finding a BMS for a 10s pack I want to build with a max 5A rating or less. I have 21700 unprotected cells for this project. I was contemplating using 10 1s bms boards + balancing board but I’m not really sure if that would work. The only other solution I can think of is getting a 15A rated 10s bms and connecting a 5A PTC fuse in between. I have never built a lithium pack before so any help would be greatly appreciated.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 01, 2022, 11:25:26 pm
content: Replace the current sense resistor with one of 3x the resistance.

author: tekguy
author_rank: Contributor
timestamp: October 02, 2022, 08:45:32 am
content: dont use an mot transfo type tab welder,i made one with a ssr switched primary and a dual pulse timer,it just cooked the cells never welded the nickel,then got a cheap chinese car battery powered welder,that had the fets short on first use ,did the mods as in this vid,now works great from a 30ah car battery. i got this one

author: PanSam1986
author_rank: Contributor
timestamp: October 02, 2022, 10:54:11 am
content: @NiHaoMike Thanks, makes sense.@tekguy I actually purchased 21700 cells with pre-installed copper tabs just so that I wouldn’t have to do it myself.
BMS for Li-ion cells - Page 1
Forum section: electronics / projects

author: msrinivasan1995
author_rank: Contributor
timestamp: March 18, 2017, 05:25:54 am
content: Hi guys,I wanted to make BMS for my Li-ion battery pack. What I have researched is that BMS basically involves 3 process1. monitoring2.protection3.Balancing.I want to know whether all the three can be done by single TI'ic . I want to know whether which balancing is better active or passive? I'm planning to use Ti76930 ic.(http://www.ti.com/product/Bq76930) . IC provides passive balancing , is it ok or should I go for active balancing. Enlighten more about BMS.
BMS: Proper way to measure the voltage across Pack+ and Pack- - Page 1
Forum section: electronics / projects

author: Blackgar
author_rank: Contributor
timestamp: January 25, 2022, 02:49:21 pm
content: Hello,What is the proper way to measure (with isolation) the voltage across PACK+ and PACK- (voltage across the load) of a BMS? It seems complex since PACK- contactor may open at anytime (due to failure etc.).I was thinking to add a resistor across the terminals and measure the current flow using a current transducer or calculate the Load voltage by summing up 2 different measurements with reference to BAT-.I am not sure which is the best way or what other choices I might have.

author: max_torque
author_rank: Super Contributor
timestamp: January 25, 2022, 07:43:50 pm
content: If this is for any pack above 60Vdc, then be careful, because there are a LOT of rules for packs considered to be "high voltage" (above 60Vdc and below 1KV) These rules include things like leakage currents and capacitiev energy storage etcMost systems use the pack -ve as the reference point, which is fine for internal (ie pack side) voltage sensing of the various Pack+ voltages, but care must be taken for the pack out +ve measurement point, because your resistive divider forms a leakage path around the positive contactor.You don't need galvanic isolation as long as you condsider this leakage path, and most systems simply use a large value resistive divider (typically 4MOhm per leg for example)Take a look at the Isabellenhütte IVT-S series of current and voltage measurement devices for example