The last time I did this was in a black box and I bought a half-dozen
arduino clones from Adafruit with 868 mHz radio module breakouts already on the board. I think they called it a Feather or something. Ran neopixel clusters (also from Adafruit) directly from the boards.
Theatre is an off-spec application for most radio. All those cool bluetooth and gigahertz connections and so forth assume you are shooting across a living room; not a hundred feet from booth to
stage (and through a bunch of meat filters that are really good at
blocking gigahertz signal.) I'd gotten XBee to work at an ampitheatre (at Lake Merit) but that was only with the rather more expensive high-power modules, and those seem to have been deprecated since. The mHz 434 and 868 stuff can sometimes make the shot, especially if you add proper whisker antenna to them.
The advantage to me on the last show is the units were mostly doing lamp effects. So the on-board micro was running a lamp flicker program, and the remote controller only had to tell it to go on and off. I could have put
DMX on it but I had a really limited light board on that show, too, and it was safer just to slave them all to one
channel and add a keypad to the transmitter.
I know, sounds like a lot of tech, but since there's libraries for all of this stuff it really was just soldering a handful of connectors and a couple hours programming. I had it running the same day the parts got delivered.
(Another issue I've struggled with is that all that hobby and cosplay and whatnot is usually based around the 15ma
LED standard. Sure, you can stack up a bunch of them...the higher-density
LED strips provide a ton of light...but getting enough light into a crystal ball or similar sized prop so it pushes back against
stage lighting is a real pain. I was taking a clue from the hobby lightsaber people, and the flashlight tinkerers, to make controllers for 3W and up LEDs. Note that a good fighting saber was going for 15W of lighting
power! -- now they tend towards strips so they can do more sophisticated animations. Got to the
point where I had a nice little board that could pop into a prop but feeping creaturitus finally killed the project.)
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Forgot to add the cheap option. Keyfob transmitters. It can take a
bit of searching to find them since there is such a push now for "control everything from your smart phone!" but when you can find them, you can get a matched pair of 315 mHz, four-channel, receiver and keyfob transmitter for under $8 a set. Simplicity itself to use; the receiver has four leads that operate on NO and will drive LEDs,
relay boxes, whatever. The security code is set with solder blobs so you can have multiple units respond to the same
fob. Range is wing-to-stage with decent reliability; I used one in an RC "Robot" prop on Wonka to control the LEDs in the eyes. On another show, I ran it to a sample playback at the sound board; the actor with a gun on
stage pressed the keyfob in his pocket each time he fired!
Adafruit has them. Only reason to go eBay is sometimes they'll sell a bunch of them bulk.