For uno minima, when configuring GPIO with pinMode() function, there is a bug when configured using OUTPUT_OPENDRAIN PinMode. The fix would be to replace line: https://github.com/arduino/ArduinoCore-renesas/blob/4e60678ad7286a8c74caa966e479e64c0c09de09/cores/arduino/digital.cpp#L16 with: ```cpp #if UNO R_IOPORT_PinCfg(NULL, g_pin_cfg[pin].pin, IOPORT_CFG_PORT_DIRECTION_OUTPUT | IOPORT_CFG_NMOS_ENABLE); ```