If you’re at all like me you enjoy listening to music while you work on projects, clean, pretty much while you do everything. Problem is that often leads to the amplifier getting left on for a lot longer than it needs to be. I found this great project on instructables showing how to make an arduino controller idle power sensor that will turn off your amplifier if no sound is detected for 5 mintues. This particular one uses IR and basically does the on/off command that the remote would normally send. Another option would be using a programmed relay setup as well.
Check out the full project link here
