It was only two days ago where I laid out my master plan for my ultimate show cue remote control system. Now, here I am with a working prototype of Phase One!
It looks like a tangle of wires and microchips… which is exactly what it is at the moment. More importantly it is a functional music player for my magic show.
Music Cue Player
I’ve labelled this mess of wires to help break down the components.
A) The Brains
This is an Adafruit Feather ‘RadioFruit”, and Arduino microprocessor with built in RF (radio frequency) transceiver. I’m able to program it with my own code to do what I want.
B) The DJ
The Adafruit Featherwing Music Maker is an MP3 player chip, which has a slot for a Micro SD card that stores the MP3 music files for my show. It also has a 3.5mm audio jack for headphones, or sending out to a speaker.
C) The Trigger
A hardwired button that can trigger cues. Pressing this button does the same thing as pressing the remote control button. It was mostly there for easy testing during the initial build.
D) The Battery
A 2000mAh Lithium Ion rechargable battery. It charges via a USB cable. In this picture it’s plugged in, hence the bright yellow charging light.
What Went Well…
I’m happy that I was able to get a functional prototype in a couple days. I’ve done this sort of thing before, but I’m by no means an expert. The build-time included lots of whispered swearing.
The Adafruit “Feather” ecosystem plays really well together. Many pieces of the project were already built in to these two chips (SD card, audio out, battery with safe charging, and RF transmission) which saved a lot of time and extra parts.
What Did Not Go Well…
The biggest let-down so far was finding that the Music Maker chip could not play more than one track at a time. That means no potential for layering or cross-fading. That’s not part of the scope for Phase One, so we’re fine for now… but I’ve already ordered a different audio module for later development.
The most challenging struggle was in turning the files on the SD card into a playlist array that could be manipulated by the software. Arduino is based on a language I’m not familiar with (C++) so what I thought would be basic tasks turned out to be very frustrating.
Also, I realized that it will take a very long time to charge this battery. The Feather charges slowly at 100mA, which means it should take 20 hours for a full charge. On the upside, the battery life should also be very long! (we’ll see) I may have to look into a fast-charging system for the future.
The Remote Control
The Remote Control unit is much more simple, but still based on the same “RadioFruit” brain chip as the music player. Other than than it just has a simple push button, a much smaller battery (350mAh), and the little curly pigtail is the antenna.
Getting this unit working was very quick (thanks to the example in the RadioHead code library) and surprisingly it already “feels” (totally subjective) like the most reliable remote unit I’ve used. Testing all day without even a hint of a missed cue. Also, these are both transceiver units, able to send and receive. That means they get real feedback and confirmation that the command was successful. That will be very helpful later on!
Obviously these “naked” parts aren’t very functional for a show, so making some cases for these components will be a high priority.
However, before I get to making a custom fit case I want to finish up phase two of the project, which will incorporate a four character LED display to show me what cue is playing, and what’s ready to play next.