3 posts tagged “circuit bending”
I ended up bending 2 of the things I got yesterday for the Circuit Bending Challenge. The driving toy was very straightforward, it had your standard black blob IC inside. I replaced the volume and pitch resistors with pots and added a switch for the 'indicators' sound, since it makes a decent beat. It doesn't sound as good using the 6.5mm output jack, I might need to do something to emulate the speaker better or try a transformer.
The 'black mystery box' was pretty cool to start off with so it didn't need much to take it to the next level. I gave it an RCA out and a switch that puts it into constant burble mode. There were some good pitch up and pitch down points but without re-casing I couldn't use them unless I went for touch contacts and I didn't have anything handy. They way it goes off at random intervals makes it great for doing some dub style bleeps, as I demonstrate below.
I uploaded some .wav files too, but I have to wait for them to make it through the moderation queue before I can link to them.
UPDATE: I finally remembered to post the link to the WAV files.
Circuit Bending Challenge Sample Pack @ The Freesound Project
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 Sequencer
This 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 Sequencer
Atari Punk Console controlled by 8-step Sequencer
Another 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.
