Code from here and tried to adapt to platformio https://github.com/Ebiroll/RAK811_BreakBoard.git
It compiles and flashes but when I got blinky to run the speed was way to low,
Edit rak811.json as the linker script is an absolute path. cp rak811.json .platformio/platforms/ststm32/boards/rak811.json
pio run
In stm32flash_src there is code to flash the device ./stm32flash -w .pioenvs/rak811/firmware.bin /dev/ttyUSB0 To reset and start after download, try ./stm32flash -w .pioenvs/rak811/firmware.bin -v -g 0x0 /dev/ttyUSB0
It does not apear to tun correctly. :-( in src/main there is also a blinky main that can be used for debugging. I was able to run it once, then I made some change that made it unusable
The startup code should have been these, https://github.com/RAKWireless/RAK811_BreakBoard/tree/master/src/boards/RAK811BreakBoard/cmsis/arm-gcc
boards/RAK811BreakBoard/cmsis/startup_stm32l151xb.s
But instead .platformio/packages/framework-cmsis/variants/stm32l1/stm32l151xba/startup_stm32l151xba.S is used,
Only difference is /bl __libc_init_array/ /* PlatformIO note: Will work without -nostartfiles */