Im trying to set up the arduino kina like a car ecu so that when the key is in and on, the bike goes and the lights come on. I would also like to use it as a recording device for speed, location (i have a gps recorder module that im going to try and implement), battery charge level and the likes. The arduino would also record when and what signals and lights were turned on and off. The interrupt allows me to tell the arduino its time to switch the flashing lights on or off and record all data at this time.