Reader [Kelly Regan] flies large scale RC planes, but would often need someone call out flight sequences while rehearsing. Not wanting to impose on fellow club members, [Kelly] built a sequencer caller from a cheap MP3 player. It just required extending the FWD key to a pin header. Those pins are connected to a custom switch on the back of the controller. Each maneuver is recorded with 30 seconds of padding and then added to a playlist. Once the maneuver is complete, a quick press of the button moves on to the next track. It’s always nice to see people building devices that the consumer electronics industry probably wouldn’t.