Above is a shot of my DIY USB foot-switch. The construction is relatively simple for those who just want a simple box with some buttons.
For starters, you will need a project box…
You can buy these at electronics shops and hardware stores, but I recommend searching online and potentially getting a better deal.
The above shot is of a momentary (push on/off) switch. These can also be purchased at electronics shops / hardware stores (but I, likewise, recommend searching for them online (RIP RadioShack)). Keep in mind, these switches should be mounted to the top of the project box before soldering any connections.
Next, you will need an old (but still functional) USB QWERTY keyboard from which to extract the circuit board.
Remove the keyboard’s plastic casing by simply popping off the keys and removing the screws. Unscrew the board from within. You will need a mini-screwdriver set for this. I also recommend mounting the board onto a piece of cardboard with electrical tape. This provides extra surface stability during the soldering portion of the project.
Secure this apparatus to the backing plate of the project box.
You can now test for whether or not two pins will complete a circuit, thereby producing a character. Take a small piece of wire and press each end to two different pins. I recommend ribbon wire as it is very fine and, therefore, easy to manipulate.
Do this while the board is connected to your computer via the USB port and a word processing application is running. If you make a successful connection, it will show within the word document as a singular character. This can be tedious as the process of elimination through trial and error can prove to be lengthy.
Once you’ve determined which pins produce the desired characters, the soldering can begin. Prepare your lengths of wire. Strip the rubber casing from the wire lengths, exposing about a 1/2” of the copper thread on each end.
Solder two lengths of wire (one for each pin) to each of the switches.
That being done, the free ends of each wire can be soldered to their respective pins on the board. Be sure the board is not plugged into your computer before attempting to solder.
Taping the excess lengths of wire down to the cardboard backing will help maintain what visual clarity you can. It will also help maintain the connections after you’ve fixed the backing plate to the top of the box.
You will end up with a beautiful mess, like this.
Notice this small hole in the side of the box is there so the USB cable is not inhibited by the plastic casing in any way. Also, the numbers and logos were painted on with white out and then smoothed out with a black marker. Decorating your box in any way will definitely add a presentably fun dimension to it. Show the world that you actually respect yourself by taking the time to “pretty your MIDI.”
I’ve used this box with Ableton Live to control several loopers within the session (one button per looper, one looper per track).
In a typical performance, I will use this to capture and loop sounds from a bass guitar (amongst other instruments) and then remix and manipulate these loops with MIDI controlled effects.
The box can have many other performance applications with your DAW so long as your software can utilize keystrokes for parameter modulation.
Duane