This is version 1 of the Bend Matrix (prototype only). The current version is version 2

Circuit Design

[schematic] forthcoming

board layout

Four 4066 quad analog switches provide the 16 switches. In the present form, the switches are wired so that some of the buttons connect glitch points to a “common” (e.g. ground or V+), and other switches connect glitch points to each other. In any wiring configuration, each button goes “high” when pressed, thereby activating one switch on a 4066.

Also, there’s two 8-bit ADC’s (ADC0804 from Analog Devices). Each one inputs a CV from a knob or a photocell, and outputs an 8 bits. The two 8-bit outputs combine to make the 16 bits of the 4×4 button matrix. So by turning the knobs, various switches on the 4066’s are made/broken, thus connecting various glitch points together (and/or to the “common”).

Thus, the Bend Matrix can be used just with the button matrix (each button makes one connection), or just with the knobs (each knob selects zero to 8 of the 16 switches), or with both.

Connecting the host and Bend Matrix

To use the Bend Matrix, we connect contact points on a “host” (10 points, currently) to the Bend Matrix.

Simple Screw-nut connectors are easily made, and allow wires and/or alligator clips to be used for connections. Other methods might be more appropriate (spring clips, banana jacks) depending on the intended use.

Wires from the Bend Matrix could be soldered directly to the host’s circuit board temporarily until the best set of points are found. To make it more permanant, screw-nut connectors (or banana jacks) could be mounted to the host’s casing, and then wired to the board. Then the Bend Matrix would then be connected to the screw-nut/banana jacks on the host using alligator clips or banana plugs.

[diagram coming]

Playing the Matrix

Once the host and Bend Matrix are connected, we can use the matrix to glitch the host. Each button on the matrix represents a connection between two wires. When the connection is made, the button is lit. Organizing which wires are connected when each button is pressed can be done in different ways. Currently, the Bend Matrix is set up to have two common points that connect to each glitch point, as well as connecting some glitch points to each other. There are many possibilities for assigning connections to the buttons, furter discussion is required.

[diagram for current connection set-up]

You can light a button (make a connection) just by pressing it. It will stay lit as long as you hold it.

You can also light a button by turning one of the two control knobs (or photocells). These sweep through every combination of button on/off states. As you turn, buttons flash and flicker, creating and breaking connections with every movement of the knob. With both knobs at 0, all the lights are off (unless you’re pressing one down with your finger!). With both knobs at 10, all lights are on. In between, some are on and some are off. Again, the exact pattern in which the buttons go from off to on can be done in a multitude of ways. Currently, there’s two patterns: one knob makes the half the buttons fill up clockwise in a circle, and the other lights up the other half in a inner-to-outer pattern.

[diagram of two knob patterns]

Sounds

• With Casio SK-1, rhythm “chord” mode: wiki:casiosk1_beats.mp3
• With Casio SK-1, fingering single notes: wiki:casiosk1_bendynote.mp3