Wednesday, September 16, 2009

A pedal is brewing







So what's going on?

On the breadboard I was trying out different wiring configurations for LDRs, and that's the one I found gives the best expression sweep- two LDRs. Now of course they need to be seeing opposite things- one needs to be in the dark and the other is in the light. I'll be rolling some optoisolaters later.

Up on top of the bench is a collection of old stamps I bought at a flea market. Free art!

And what's with the box?

Well, I'm making a low-frequency-oscillator that you can plug into any pedal with an expression jack with four modes:

1. Sine Wave
2. Square Wave
3. Random Fuck (sample and hold on PCP)
4. Step Sequencer/ Arpeggiator

Controls?

  • rotary switch to choose the mode
  • rotary switch to choose the preset (5 presets total.) Each preset has a default mode it brings you to, but you can switch out of that mode and use that preset's settings in another mode. On top of having memory of all the switch positions, each preset can also store one sequence from the sequencer mode.
  • flip switch to control whether the expression pedal input controls depth (think synth mod-wheel) OR controls center (with depth all the way down, you can use your expression pedal like normal in this mode)
  • center, depth, rate, and shape controls.
  • depth switch that either automatically trims the depth so it doesn't clip past the range limits, or doesn't automatically trim depth so that the wave can clip
  • tap-tempo with ratios
  • step sequencer can go in different patterns, can auto-run, or be stepped through
All of this will be done with a microcontroller, which I'm in the process of programming. I've got most of the code written, I'm just waiting on a debugging cable in the mail so that I can tweak the equations.

This blog will be updated soon with some drilled and painted enclosure pics and other stuff. I'll also make a real header and make a real blog design, and later a website.