kagaimiq
commented
2 months ago From what I could see on the photo, I think you actually have a AC695N chip, specifically the AC6951C chip (as noted by the suffix on the chip). One fact that really gives that out is that there are capacitors that are attached on pins 35, 37 and 38, which are the 'HPVDD', 'VCOM' and 'DACVDD' pins that is related to the audio part of the chip, which is absent on the AC63xx series chips so there wouldn't be any sense in doing that if the board was designed for an AC63xx series chip.
So a correct deciphering would be "AC6951C" instead of "AC635N" (not to mention the latter one might make a false assupmtion that "the rule doesn't always work", like the '-51C8' suffix doesn't mean much in the AC63xx case or something like that...).
Also the possible reason why the log mentions board_ac635n_demo instead of e.g. board_ac695n_demo is that they might've decided to use the AC63xx type SDK for this chip instead of a matching AC69xx SDK, because this is after all a printer, and not a bluetooth speaker, so you don't need all of that audio stuff being in your way, wasting RAM and flash space that could've been used for the printer stuff instead, as well as the SDK architecture itself not fitting this particular application for the same reason.
Uart log pointing its AC635N https://katb.in/azoyavefaqo
Board picture https://imgur.com/a/DaHxXHC
This is out of a Bluetooth label printer (Nelko P21)
Planning on detailing it fully this weekend, but decided to start with this. Thank you so much for this information! It's a massive help so far