I want to set up an interrupt to wait for a button to be pressed on a PiFace Digital, and have found some code here referring to 'Barrier synchronisation':-
https://media.readthedocs.org/pdf/pifac ... italio.pdf
which provides an example... unfortunately, I don't understand it. Can anyone explain/simplify it?
I basically want to wait until one of the tactile switches is pressed, and when it is to switch on one of the LEDs or switch on one of the relays.