I made an Android app that communicates with serial port over USB. It sends a string of characters consisting of the start character(x) the switch number(1-27) and the switch to direction(h or s). H stands for home and S stands for switched state. So all together it looks like x18h.
The images above are finished for 4 of the 24 switches on the layout. It takes a lot of time to solder the parts together.Â
This system is currently in progress check back at a later date to see the complete documentation.