charge-me-up

Custom Firmware / Patches for clone iMax B6 charger (CMS32L051)

SWD Access

In order to get SWD access, you have to dismantle the device.
To do that remove the 4 extremely short screws from one side, then pop the button extensions out with a flat head screwdriver.
Once you have the device in front of you, you will see a obvious unpopulated pinheader on top which has a box drawn around it.
The pinout is: 5v gnd clk dio gnd p51 p50

Connect an STLink 1:1 to it. Use 3.3V instead of 5V and DO NOT PLUG IN POWER

Dumping the flash

Get openocd and read the device memory with
.\openocd.exe -f OpenOCD-20231002-0.12.0\share\openocd\scripts\interface\stlink-dap.cfg -f openocd\dump_flash.cfg
The main flash contents and dataflash will be in their files respectively.
Check those files before continuing.

Erasing the Flash

ACHTUNG, be sure as heck that you have a working dump.
.\openocd.exe -f OpenOCD-20231002-0.12.0\share\openocd\scripts\interface\stlink-dap.cfg -f openocd\erase_flash.cfg

Writing the Flash

Make sure you erased the flash, as to why: find it out and learn something :)
Writes flash_main.bin
.\openocd.exe -f OpenOCD-20231002-0.12.0\share\openocd\scripts\interface\stlink-dap.cfg -f openocd\write_flash.cfg

Dude, Where's my Car? Calibration Menu?

There is no calibration menu in the original firmware.

Schematic

HeHa has already done that here