Thursday 12 July 2007
Musical interfaces
After a good deal of poking and prodding, I got my Arduino board to speak MIDI! The current program reads a potentiometer and sends pitch bend messages down the pipe.
Had a bit of worry when it just sat there doing nothing, but it turned out that I just had the signal and +5V leads reversed. Bonus: if your computer isn’t talking to it via USB, it’s just fine with being plugged into USB and MIDI at the same time. Makes for much, much easier programming.
Invaluable resources in this effort: circuits and code from Tom Igoe, of the Interactive Telecommunications Program at NYU, and Sebastian Tomczak’s blog little-scale, which includes news of his Arduino / MIDI projects.
The more I think over that guitar string ribbon controller idea, the less it strikes me as a permanent solution. I like that it’s quick and cheap, but it’s going to rub the oxide off the tape (or whatever I use as a resistance). So the design will have to take replacement of the tape into consideration. The guitar string method may be useful for building multiple controls - I’d love to have something you could play like the fingerboard of a bass. No rush there, though.
A capacitive position sensor would be a better alternative - that’s what computer touchpads / trackpads use, and among other advantages, they can be placed inside a case so you never have to touch the actual sensor element. Durable is good, especially where musical instruments are concerned. And they generally feature serial output, which I can feed to the Arduino.
Cirque make some promising-looking devices, including some standalone models. Of course, most of the ones I’m interested in are OEM and hard to come by for someone who’s not designing laptops for a manufacturer.
But why buy new when they’re going for scrap all over? A quick search on eBay turns up masses of laptop frames - just the panel that goes around the keyboard, and including the touchpad. I’ll have to hit some local surplus and computer stores too.
Code and sounds to come.