Worlds Cheapest MIDI Controller Keypad by mlappy

Last crawled date: 3 years, 4 months ago

Here we have the "Worlds Cheapest MIDI Controller" based on an Arduino Pro Micro and a 4 x 4 Keypad, it can be built for about $6. I wanted something quick, simple and easy to use with a software sampler to trigger stings while recording a podcast. This does the job perfectly, but can also be used as a monophonic keyboard for use with reason, ableton or any software sequencer really.
Requires you to solder 8 pins and 3D print the case, then upload the provided sketch. The sketch uses the MIDIUSB library so make sure you download that first through the arduino library manager. That's it, it couldn't be simpler than that.
Solder pins into the Arduino in holes 2, 3, 4, 5, 6, 7, 8 and 9. Then insert the other end of the pins into the keypad from underneath and solder them to the keypad. There should be an empty hole either side of the keypad connections as can be seen in the photos. Make sure you don't push the keypad down all the way so that there is a gap form the bottom of the keypad to the top of the arduino and then it should line up with the hole in the case for the USB connection.
This was designed to be as simple as possible so everything is a tolerance fit. If you have trouble making things fit in the case or the lid snapping on you might need to look at your printer calibration, or scale up or down slightly. This is perfect for my Prusa MK3S.
Finish it off with a few stick on rubber feet from the local hardware store, I had some lying around, and you can put it all together.
Hardware required:
Keypadhttps://www.aliexpress.com/item/32858408651.html
Arduino:https://www.aliexpress.com/item/32887074671.html