GNAP! with numpad
Combined a set of GNAP 4x4 PCBs with a regular 4x4x4x4x4 PCB. The GNAP 4x4 has the same modular circuit layout as the 4x4x4x4x4 and the 4x4x4x4x4 PCB can be attached to either side. The Arduino Micro has to be on the left most PCB.With random left over DSA keycaps. The firmware is the same as for the 4x4x4x4x4.
Assembled without any keycaps. You can see the solder bridges connecting the individual PCBs.
The PCBs are connected to a 3x12.375" 1/8th inch thick 5052 aluminum plate I got from eBay. M2 spacers and screws.
The assembled PCB with diodes. Solder bridges on the top side.
Bottom of the assembled PCBs.