I have officially gotten my first attempt at the controller to work as designed. Over the weekend I drilled the switch layout and mounted the switches for both of my prototype controllers. I carefully wired and soldered them, for now leaving a long wire bundle for ease of breadboarding.
Wiring on the Bass Synth foot controller.
Wiring on the Percussion foot controller.
As far as actually making a working controller, I started with the easier of the two projects, which is the percussion foot controller. There was much tearing out of hair and cursing under the breath, but I finally got the program to work properly. The microprocessor is the Teensy++ 2.o, which right now is sitting on a standard prototyping breadboard. The other board has a 16 position switch with a binary coded decimal output. This allows me to select which MIDI channel the module broadcasts on. Typically there are 16 available MIDI channels, so this switch is ideal and only takes up 4 inputs on the micro-controller.
The brain behind the MIDI controller, a Teensy++ 2.0. The other board has a 16 position switch with a binary coded decimal output. This allows me to select which MIDI channel the module broadcasts on. Typically there are 16 available channels, so this switch is ideal and only takes up 4 inputs on the micro-controller.
Once I have all the bugs worked out in both controllers I’ll transfer it to a permanently soldered PCB mount. That means I’ll have to buy another, each controller needs one. I have the LED light set to come on whenever a footswitch is activated, which has aided in debugging considerably.
I decided to use an AKAI product as the triggered synth module. It was cheap, has a MIDI input, and can use any percussion samples I want by loading them onto an SD card.
What I didn’t realize about this drum machine, is that the MIDI in jack isn’t a standard MIDI 5 pin DIN connector, they supply a converter and it actually plugs into a standard 1/8″ stereo headphone jack. Once I found this out, I actually like it, now I can just use a small stereo cable to transmit the MIDI data instead of a more expensive MIDI cable. Here is the connector I use on my controller, with the temporary breadboard wires.
Here is my “MIDI” jack and 16 position switch with BCD output.
When I have it all plugged together, I am successfully transmitting the MIDI data from the microcontroller to the AKAI unit. I actually am transmitting over both traditional MIDI as well as the USB port, so either can be used without changing the programming.
Here are the switch layouts of the two controllers, I’ll explain the logic behind them next time. So far so good!
Switch layouts of the Bass Synth and Percussion foot controllers.