coospo bc200 - bike computer from aliexpress

spec:

PCB revision: v5.4

• cpu: nrf52840 - cortex-m4 (integrated BLE, USB); 256kb ram; 1mb flash
• external flash: GD25Q127C - qspi 16mb nor flash
• display: BTG-160240D - monochrome, sunreadeble lcd with backlight have 160x240 resolution and based on ST75320 controller
• 4 buttons
• 1300mah lipo battery + charger
• 12mm piezo buzzer
• gps + glonass + beidou module
• hx3203 - light sensor
• qmp6988 - digital barometric pressure sensor

bc200_fw:

test fw based on zephyr os (build instructions)
works:

• lcd display + contrast + backlight + lvgl graphic lib
• buttons
• qspi flash + fatfs + usb mass storage
• fw upgrade via usb usign original image format (pls downgrade fw to 1.5.3 or late first, with 1.5.9 something go wrong). upgrade possible in both direction orig fw <-> zephyr os fw (video of process)
• qspi flash speed fixed by updating nrf sdk

unlock debugging:

jlink connected to SDO and SCLK testpoints
erase all data (exclude qspi flash) and protection, and programm only full flash exclude protection

nrfjprog -f NRF52 --log --recover
nrfjprog -f NRF52 --log --program full_flash.bin

switch NFC antenna pins to GPIOs - used as buttons (first cmd enable write possibility to UICR,second - write needed value)

nrfjprog -f NRF52 --ramwr 0x4001E504 --val 0x00000001
nrfjprog -f NRF52 --ramwr 0x1000120C --val 0xfffffffe

how to make jlink from bluepill:

https://mysensors-rus.github.io/Blue-pill-to-JLink/
https://github.com/GCY/JLINK-ARM-OB
http://forum.easyelectronics.ru/viewtopic.php?p=651817#p651817

how to get full flash:

https://github.com/atc1441/ESP32_nRF52_SWD
https://limitedresults.com/2020/06/nrf52-debug-resurrection-approtect-bypass/

reading qspi flash content:

faketime -f "x0.1" ./nrfjprog --jdll <full path>/JLink_Linux_V752a_x86_64/libjlinkarm.so -f NRF52 --log --qspiini nrfjprog_qspi_gd25q127c.ini --readqspi qspi.bin

faketime -f "x0.1" - need because nrfjprog work with my defective jlink from bluepill continuously only 32sec and this time is not enough for reading qspi flash

usbfw_decode:

util for decrypt and encrypt firmware and font for usb upgrade

original fw:

fw start from 0x31000
spi flash contain font from 0 offset and fatfs disk from 0x380000 offset