Am Arduino sketch which posts data to the serial port & a Max for Live patch which crunches the data into a number for use in patches.
A simple boilerplate to start creating physical Arduino devices to control & manipulate Ableton via Max.
1 - Plugin board, upload Sketch and let it run.
2 - Quit the Arduino editor.
3 - Open Ableton and load up Max patch.
4 - Check the serial object is listening to correct port by clicking 'print'
5 - Toggle metro & get creative.