Here are my design files for KiCad PC board design, FreeCad mechanical design, and MPLAB-X code development. Feel free to use and share them for your own purposes.
MIDI-Lappi Eurorack Sound Module
This module interfaces the lovely Adafruit VS1053 assembly to eurorack and MIDI signals. The VS1053 chip provides the General MIDI sound set.
PDF schematic for MIDI-LAPPI module:
KiCad PC board file for MIDI-Lappi module electronic board:
KiCad PC board file for MIDI-Lappi faceplate board:
This is my Digi-Key bill of materials for the MIDI-Lappi module. It doesn’t include the Adafruit VS1053 codec board, the two custom PC boards, nor the knobs. There is a mix of thru-hole and surface-mount parts.
Ctrl-Surf Eurorack MIDI Generator Module
PDF schematic for Ctrl-Surf module electronic board:
KiCad PC board file for Ctrl-Surf electronics board:
KiCad schematic file for Ctrl- Surf electronics board:
KiCad PC board file for Ctrl-Surf faceplate board:
This is my Digi-Key bill of materials for the Ctrl-Surf module. It doesn’t include the joystick nor the Microchip PC18F26K22 chip, nor the knobs. All of the parts are thru-hole. There are no surface mount parts on this module.
Mechanical Design Files
This FreeCAD file has both modules. Ultimately I ended up using this 3D model for visualization and generation of the board spacer/wire guide bracket on the MIDI-Lappi, and the translucent, illuminated push button keycaps for the Ctrl-Surf.
I’m retired now, but this kind of stuff provided a good living for over 35 years, and I still enjoy using and sharing the techniques I picked up along the way. It’s too hard to quit cold turkey haha.
Back view screen grab from within FreeCAD:
Front view screen grab from within FreeCAD:
MIDI-Lappi bracket 3d printable .stl file:
Ctrl-Surf key caps 3d printable .stl files:
Notice that the four white Preset caps have slightly different dimensions compared to the twelve chromatic yellow (and blue) keyboard key caps. I printed them all with the same clear translucent filament. The individual key caps are dropped into the Ctrl-Surf faceplate from behind. Then, the Ctrl-Surf electronics board is mated to the back of the faceplate, sandwiching the key caps between the switches and the faceplate.