Lightning Semi LN8825B ELM327 OBDII Scanner PCB Text and Baud Rate Details

Another wifi ELM327 OBDII car code scanner/reader that links my current obsession with a previous one, the Lightning Semi LN8825B.



PCB text:
K413-8825
K408_S2_V1.0



and from B7 at 921600 baud:



I can connect SWD OK using J-Flash to A1/A4 but am getting stuck on this point with any J-Flash version and config variation I can think of, so no factory flash backup to post yet.



Hopefully I can add more as I progress.

You will never stop shopping new gadgets, won't you ?
Good luck!

max4elektroda wrote:

You will never stop shopping new gadgets, won't you ?

😂 Not for the foreseeable future anyway 😳🤓

Onsemi MC34063A - Inverting Regulator - buck, boost, switching - datasheet attached
Chipsmi QBD1044 - High-speed CAN transceiver - datasheet attached

I've been playing a little

I have a working backup of the OBDII firmware, taken from A1/A4 SWD using JLink, but it does not seem to want to boot when flashed back with JFlash.

I have however turned the device into a kind of dev board. This is my second device after making a mess of the first. There's still room for improvement. The idea with this is to route usable LN8825B pads to unused OBDII connector pins. This way the device can be put back into the case and only the OBD connector pins need to be touched for flashing.



edit: add cleaned-up image


I was careless with the A1 pad and sadly it was lost

Also, the choice of B8_RXD route means that B7 and B6 for the other UARTs is hard to access - a bit of blow because checking log out now can't be done with the case closed and I don't think I can attach anything to those without upsetting the soldering of B8



And it works. I have flashed it quite a few times now with the LN Serial Downloader for LN8825x (A10 grounded for UART download mode).



Flashing the OBDII backup back over UART results in a bootable device and AP broadcast. I've tried several MQLinks AT test firmwares and they all boot. The original Tuya LEDcontroller backups I took do not boot, however much I fiddle with the binary.

I started to look into the more complete SDK referenced here.

It took a while to get going. For one, the sdk\tools\scripts folder appeared to be missing entirely. The LN882H script folders seems to contain at least one of the files this SDK needed.


After installing the pre-reqs laid out in the attached SDK doc, Python can be used to get the build files generated


then Ninja is run on those file to compile the binary

sadly they all fail to complete - build-wifi_mcu_basic_example hangs here on step 127.


so that's where I'm at at the moment.

patience is a virtue. Wait longer and this one finishes




sadly it doesn't boot

Added after 25 [minutes]:

here's the SDK with scripts folder present and I think mkimage needed to be in a different place.

hmmm