As part of an experimental music project, I need help designing/building a set of simple and inexpensive battery-powered audio boxes that will each play a single mp3 file loaded into memory. Two watts audio output to the speaker should be enough power.
There’s one other requirement that makes this something of a challenge: I need to simultaneously trigger playback in ALL the boxes with a radio transmitter, up to distances of about 300 feet (to activate every unit within a concert hall). A model airplane radio transmitter and receivers might work, but since these are usually designed for proportional control of servos, I’m not sure this is the best way to proceed. I do have a design budget, and would appreciate hearing from anyone interested in working with me on this project.
Some of the R/C transmitters have an output function that can turn on a discrete output on the receiver. It’s often used to drop “bombs” from R/C aircraft. I don’t have any product references, but I’m sure if you browse the hobby radio control sites, you’ll find what I’m describing.
You could DIY, but this stuff is fairly cheap already off the shelf.