(SOLVED) Cannot Upload to STM32F103 "BluePill" using ST Link on Nucleo Board

Thank you for that info. I am also powering my STM32 from the lower half of the Nucleo. That target power is a reporting pin (I thought) to report if the target has power before proceeding. Someone told me it was a high-impedance switchable port but I never checked the schematic to confirm. I believe I did test it with my DMM once though and got the same results as you.

I am curious, isn’t OpenOCD used by Arduino IDE? There is a file size and date difference between the two instances of OpenOCD.EXE I found.

Are you using anything special in your platformio.ini file? I would love to see what you have in there. I remember something about build-flags that fixed this for me last time, but I cannot find that info anywhere!!

My ST-LINK appears to be functioning normally with the latest driver.

Serial Driver