Tuesday, November 4, 2008

Arduino LED MIDI Controller

It's been a while since I've made a post so I have decided that it was about time I did. This time I'll be talking about my Haunted House I made.

I started with the idea to take a Halloween decoration (small haunted house) and add some LEDs to it and make them blink. What I ended up with was a haunted house with 6 LEDs in it all controlled by MIDI. I used an Arduino to receive MIDI signals from my computer and turn on/off LED lights based on those signals.

Check out the video...

The "MIDI to Arduino Breakout Board" as I call it in the video I designed myself. I used various resources on MIDI around the web and came up with this schematic.

Digikey Part list:

2 x DIN5 - CP-2350-ND
2 x 6N138 - 516-1600-5-ND
1 x diode - 1N914B-ND
2 x 220 ohm resistor
1 x 270 ohm resistor

As you can see it isn't very complicated. The hardest part was finding in DIN5 part numbers at Digikey. The code on the other hand was a bit more complicated. The trick was to decode the MIDI signals without any real debugging tools. The RX/TX ports on the Arduino are being used by the MIDI ports. I had to use blinky LED lights to do the debugging. After fumbling around with it for a while I was able to get it working. The code should easily be expendable to allow for more LED lights. I chose to use the PWM pins on the Arduino so I could adjust the brightness of the LEDs.

I tried to comment the code the best I could. Download it here. Keep in mind that you must disconnect the MIDI breakout board before you program your Arduino or it wont work.

Side Node:

Unfortunately MIDI is meant for instruments and not lights so I wasn't able to really do what I wanted to do. As a future project I would like to implement MIDI show control to allow for more light specific functions. I still have to find a freeware program that supports MIDI show control. I'll keep you posted.