I've been playing with the Arduino a bit more. I bought a couple of PCB-mount RGB LEDs from Jaycar and tried them out with some different example sketches. The most fun has been
this auto-cossfading one by Clay Shirky. It looks quite impressive with a bit of diffusing material and a frosted spherical light fitting sitting on top. Of course, I realize the irony of using a $50 Arduino board and a $4 LED to achieve the same effect as a
40-cent LED from China. However, I can use this set-up for a
DIY Ambient Orb if I want, and those things are worth US$150. At the moment though, I'm thinking about making a
Brain Machine that has a pot to let you dial in any colour you like. I also found a list for what colour matches what brain frequency (ie. green for theta), so I could make a meditation sequence that uses the corresponding colours. Shouldn't be too hard - flog some of the
SLM firmware code by Mitch Altman, flog most of the
pot controlled PWM code and I'm 90% there.
Digging out the breadboard has been good, because it seems to have coincided with a lot of cool CMOS based audio projects appearing online. The coolest I have found so far has been
fun with sea moss by
Sebastian Tomczak. I made up a little shopping list and went and got the bits and pieces I would need to start building some of these 4000 series CMOS based circuits. It's actually fairly fun putting these together, I put together the one in the video below while watching TV. It's sort of like playing with Lego, all the bits just click in to the breadboard sockets.
The 4066 quad-switch in particular is pretty useful - GetLofi has a few
interesting
posts featuring this chip.
Some other interesting circuits I found via YouTube:
Binary Pattern SequencerThis one is particularly nifty as it is going to be used in an Electrofringe workshop this year. I'm definitely going to sign up for that one!
Vactrol Pattern SequencerAtari Punk Console controlled by 8-step SequencerAnother nice idea to look into is using an Arduino > LDR setup via PWM LEDs to create a cheap version of the
Highly Liquid MIDI potentiometer board. With the
right code you can control up to 12 LEDs from an Arduino. So, without figuring out some kind of multiplexing, a 16-step sequencer is out, for now. There are other potential options here though - simultaneous pitch control for 12 circuit-bent toys! Good god, that's more polyphony than most benders will ever need. Think of the racket. The latency of the LDRs should have a nice smoothing effect on the PWM LED output too. Futurlec have some nice and cheap digital pots, which I am planning to order and have a play around with. I'm liking the "Arduino Vactrol" idea right now because it is pretty useful if you happen to have a couple of circuit bent devices with LDRs around, like I do. I actually found a demo of this exact idea on YouTube last night
Arduino controls a resistor.
OK, that's enough rambling for today, here's a video of the first "fun with sea moss" circuit I have built so far. I threw a bit of delay on it inside iMovie to make the squeals and groans a bit more palatable.