Arduino Code Not Executing Command

Are you sending the serial commands via the USB (e.g. Arduino IDE) or are you trying to do it via the Serial1 line (RS485 via the RPi)?

Either way I would recommend testing it via the Arduino IDE first, before hooking it up to the eVOLVER RS485 line. If you are having trouble with the Serial USB commands, it probably is that the code defaults to reading the Serial1 line instead of the USB. For example, the lines to change the code are here for the STIR Arduino code but should be found for all Arduino level code that is communicating via serial commands.

So to change it to read USB commands, update the serialEvent() function to the following:

void serialEvent(int time_wait) {
  for (int n=0; n<time_wait; n++) {
      while (SerialUSB.available()) {
        char inChar = (char)SerialUSB.read();
        inputString += inChar;
        if (inChar == '!') {
          stringComplete = true;
        }
      }
    delay(1);
  }
}

Hope this helps!
Brandon