- 94 BOOT0
- no 3.3V on PCB. I guess connect to WCH-Link 3V3?
boot to high pin => seems to enable USB even with SWD plugged in
ID 4348:55e0 WinChipHead
This is USB bootloader mode
Document at https://raw.githubusercontent.com/openwch/ch32v307/main/EVT/PUB/CH32V30xEVT%20Evaluation%20Board%20Manual.pdf indicates that for USB bootloader mode: "(1) BOOT0 to VCC, BOOT1 to the ground, connect to PC via serial port or USB"
WCHISPStudio/WCHISPTool (the separate programming tool, accessible via Tools->WCH In-System Programmer in the IDE) sees the device when jumpered this way. The IDE doesn't, so it might be necessary to use this tool to do the programming.
Sample flow for Linux doing LED blink
In theory we have all firmware (system ROM, bootloader, main firmware) and should be able to unbrick devices. However, I was unable to restore my devices
Theory: unrick issue is firmware is not at correct .hex location. Things that didn't seem to work to get firmware .hex file:
objcopy --input-target=binary --output-target=ihex --set-start 0x08000000 t48_bootrom_2022-06-30.bin t48_bootrom_2022-06-30.hex
objcopy --input-target=binary --output-target=ihex --change-addresses 0x08000000 t48_bootrom_2022-06-30.bin t48_bootrom_2022-06-30.hex
objcopy --input-target=binary --output-target=ihex t48_bootrom_2022-06-30.bin temp.hex objcopy --change-addresses 0x08000000 temp.hex t48_bootrom_2022-06-30.hex