Note: This program will configure pins 2-7 as pull up inputs and pins 8-13 as outputs with initial values of LOW. This can be modified if you would like a different distribution of inputs and outputs.

This txt file contains a list of all available RS232 serial interface commands implemented in my latest Arduino Leonardo FFB wheel firmware version (you can use this info to make your own control GUI) ...

Arduino and PLCs Hook Up Via RS232 and Modbus There is a thriving online developer community using RS232, Arduinos, and PLCs to build industrial and home automation systems on the familiar serial ...