I have a custom PCB (based heavily on the Nucleo board) using the STM32F767II. I am using Atollic TrueStudio on Windows 10 and programming it through the ST-LINK on the Nucleo board (header CN6). I have set all the jumpers and connected my PCB to the Nucleo.
I was testing some minor firmware changes and re-programming the board three or four times successfully before I suddenly just got the error "USB communication error". I have double-checked that my wiring is the same as on the previous successful times. I get this error in Atollic TrueStudio and when I try to connect to the board from ST-LINK Utility.
To my knowledge I followed the same procedure for programming the board on all my attempts, so I am confused as to why it suddenly fails now. Are there debug settings or configurations in Atollic TrueStudio that could prevent me from being able to reprogram a chip? Is it possible to recover the chip?
I am also powering my board separately from the programming interface, so would it matter if I connect the Nucleo to the board before I power the board? Could I damage it by doing that?