Hello, I have been trying to flash two RAK3172 modules using UART and ST-LINK. I use STM32CubeIDE for programming. Then I use STM32CubeProgrammer to flash RAK3172 in the following situations:
For flashing the module using UART, I can load the program to the module successfully when BOOT0 is connected to 3.3V. However, when I read the MCU to verify the code, it’s not the same. I can’t perform full chip erase (I can do this successfully with my WL55 KIT in the same setup).
When flashing two separate RAK3172 modules using ST-Link debuggers (I used both ST-Link V2 and V3), I got no response, no STM32 target found when I connected BOOT0 to GND or 3.3V (conventionally connected to GND). I tried with all possible configurations on STM32CubeProgrammer: Port SWD, frequency varies from 950k to 12000kHz, mode normal or under reset, reset mode hardware or software, with reset pin connected or disconnected. I even opened up one module to check the connect between SW pins and the MCU, and everything seems correct. I used these pins during the test:
Please let me know if you have any insights on this. My main focus is flashing the module using ST-LINK. Thank you!