https://forum.arduino.cc/t/max232-only-support-one-serial-port/351169
MAX232 only support one Serial Port? - General Electronics - Arduino Forum
Dec 7, 2015 - Greetings to all! Recently I'm building a project that requires 2 serial ports. I'm using arduino mini pro for this project. One port only receives data, and...
serial portgeneral electronicssupportonearduino