Okay I have a few remaining things:
- Additionally connect the VTARGET / VREF pin from the JTAG connector to a 3.3V pin on the target
- If the board has a reset button, try holding it down before OpenOCD starts, and then shortly after or before tries to conenct to the chip, release it again
- Instead of the default reset config, try other rest configurations like
reset_config srst_only,reset_config none separate, or the ones listed in STM32 + VS Code + mbed upload issue: Error: libusb_open() failed with LIBUSB_ERROR_ACCESS Error: open failed - #12 by maxgerhardt - Make sure the wiring is correct between Atmel ICE and the target board. This should be given by the used cables and adapters, but it’s better t be sure. The pinout on the Atmel-ICE’s SAM connector can be seen here, with the small arrow on the SAM side indicating pin 1.
If none of these solve the problem, please open an issue in Issues · platformio/platform-atmelsam · GitHub.