RealSimControl is a hardware platform for home cockpit builders. It includes firmware code uploaded to the "master board" (Arduino Mega2560), additional firmwares for "slave" boards and interactive I/O configuration tool.
This platform is aimed to save you a lot of time (and money) by allowing you to focus on the cockpit building process without worrying about how to make it work with a simulator. It's a flexible, easy-to-use, yet powerful tool for home flight simulator builders: https://realsimcontrol.com/index.html