RADIX16 Laptop Touchpad Matrix MIDI Controller


The RADIX16 is a custom MIDI controller I built in early 2014.

The controller is fashioned from 16 surplus laptop touchpads arranged in a 4x4 matrix. Each touchpad transmits:

  • Note on / note off when tapped
  • 0-127 MIDI CC for touch pressure
  • 0-127 MIDI CC for X axis position
  • 0-127 MIDI CC for Y axis position

For a total of 16 notes and 48 control change values available at the fingertips.

4-step 4017 Sequencer

This weeks project is a simple 4-step sequencer based around a 4017 decade counter chip. The basic schematic is based on this circuit, using a 555 timer as a clock source:

Led chaser

I changed it a bit by having the 4017 outputs drive transistors that switch current to the pitch pots (instead of turning on LEDS). Also, I triggered the chips RESET on step 4 instead of using all ten steps.

Simple 555 Synth

I'm starting a new project that will hopefully get me motivated to make some tracks. It's called 'One Instrument a Week', and it's exactly what it sounds like! I'll be building one simple music instrument or effect a week for the next year, and using them in my experimental Year of the Duck project.

Here's the first entry, a simple synth I built over a weekend based on a 555 timer IC. I used this schematic as a starting point:

555 Synth