@B_Johnny23 Raspberry 3's GPIO/serial port ? I can see "Using serial port: /dev/ttyUSB20" in your log. It looks like serial through USB. RPI3 GPIO serial port has got some differncies compare with previous RPi2. http://spellfoundry.com/2016/05/29/configuring-gpio-serial-port-raspbian-jessie-including-pi-3/