Audio Amplifier bluetooth chip identification help

Thread Starter

PaolaEngineer

Joined Apr 1, 2021
3
Hello everyone.

I'm new here and this is my first post. I'm a junior in high school and currently learning electronics on my own. I recently purchased a 200w audio amp that I really want to improve. I have managed to change the connections from RCA to Speakon and they work perfect. What I want to do now is get into firmware programming and flashing. I have been able to do simple Arduino stuff, but I want to get deeper into Nordic, STmicro

What I want to do is identify the BLE chip on this device. I think the vendor scraped the id info for safety reasons, but I have been reading that I can either flash it and install the default firmware, or I can change the chip for a new one.

Can you guys please advice me on what steps to take? I have added pictures of the board.

Thank you for taking the time to read this and I'm hoping this project fries my brain and teaches me good stuff. Im buying a Hakko desoldering station so that I can remove the chip if necessary.
 

Attachments

Thread Starter

PaolaEngineer

Joined Apr 1, 2021
3
Not really improve, but have my own bluetooth name display istead of the factory default. So far I have managed to change the output connectors for a more robust one. I think using the banana/screw plugs are too flimsy compared to the speakon i upgraded to.

I'm sure that by picking experienced engineers brains on a challenging task like this will prepare me before getting into the uni.

Hope you can help me.
 

Papabravo

Joined Feb 24, 2006
18,806
Not really improve, but have my own bluetooth name display istead of the factory default. So far I have managed to change the output connectors for a more robust one. I think using the banana/screw plugs are too flimsy compared to the speakon i upgraded to.

I'm sure that by picking experienced engineers brains on a challenging task like this will prepare me before getting into the uni.

Hope you can help me.
As I see it there are a couple of things you can do:
  1. Lean the assembly language for the processor of interest. This may or may not be of immediate tangible benefit, but it will be useful in debugging and troubleshooting down the line. Trust me on this.
  2. Find a compiler and development environment for this processor. I'm assuming that your budget will be limited for the time being so free and open source software is the way to go.
  3. Acquire the programming hardware and a development board for the processor of your choice. You do not wan to turn your amplifier into a brick while you are learning the ins and outs of the process.
  4. From these assembled pieces see if you can determine if there is an appropriate connector you can use to dump and make a copy of the existing firmware and any non-volatile memory. If not you may have to hack your amplifier. Swallow hard before attempting this.
  5. Maybe buy a backup amp in case you screw the first one up.
 

Papabravo

Joined Feb 24, 2006
18,806
I think I found the schematic and chip model number. can you help me confirm its okay?

https://www.microchip.com/en-us/development-tool/BM-23-EVB
It would be nice if you can find a datasheet for this part. The #1 hit is from alldatasheet.com which usually means the manufacturer no longer makes or supports this chip. On top of that it looks like a custom part with an inhouse designation and it likely has been copy protected. None of this is certain, but the signs are not encouraging.
 
Last edited:

bassbindevil

Joined Jan 23, 2014
461
If it has a legitimate FCC ID, the FCC site should have a bunch of information including schematics or data sheets.

A place to start might be to hook up a serial terminal to test points and see what the chip says when it boots. You'll need something like an FTDI 3.3V serial to USB adapter.

Sometimes you get lucky and find a lot of info, like I did with a bluetooth audio receiver I bought on ebay:
https://www.instructables.com/id/Change-Bluetooth-HeadsetSpeakerAdapters-Name-or-Ot/
https://kovo-blog.blogspot.com/2016/01/ovc3860-how-to-change-name.html
 

Papabravo

Joined Feb 24, 2006
18,806
If it has a legitimate FCC ID, the FCC site should have a bunch of information including schematics or data sheets.

A place to start might be to hook up a serial terminal to test points and see what the chip says when it boots. You'll need something like an FTDI 3.3V serial to USB adapter.

Sometimes you get lucky and find a lot of info, like I did with a bluetooth audio receiver I bought on ebay:
https://www.instructables.com/id/Change-Bluetooth-HeadsetSpeakerAdapters-Name-or-Ot/
https://kovo-blog.blogspot.com/2016/01/ovc3860-how-to-change-name.html
AFAIK there is not a single schematic on the FCC website. Where did you get that notion?
 

bassbindevil

Joined Jan 23, 2014
461
The information resource for all wireless device applications filed with the FCC.
https://fccid.io/
Many of the schematics may be confidential and not available to view, but the manuals frequently reveal technical details and pinouts.
Here's the manual for a WiFi module I rescued from a sidewalk Blu-ray player; no schematic, but it has the USB pinout.
https://fccid.io/RAXWN8122A65/User-Manual/User-Manual-1494802
And here are actual schematics for a USB ATSC TV tuner:
https://fccid.io/XY310001/Schematics/Schematics-1217020
 
Last edited:
Top