Monday, June 3, 2019


5x6 Split Keyboard

Made a split split keyboard. Each half is made of two identical PCBs. Each PCB is under 100mm, very cheap to have made.

Powered by two Pro Micros, just like my other split keyboards.

TMK firmware and Gerber files on github.

Assembled with a top plate and bottom. Plate mount box switches. TRRS cable connecting the two halves.
The individual PCB. Two of these are connected with solder bridges to create one side of the split keyboard. Shaped to keep the individual PCB size under 100mm x 100mm. Could have done a simpler rectangular 3x6, like the 4x4 PCBs, but this shape is much stronger when assembled.

Side view of the assembled boards. M2 standoffs and screws. There are holes in the plate to access the screw heads.

Left and right halves. They are mirror images of each other. 1N4148 diodes installed. You can see the solder bridges.

Bottom view of the two halves. The TRRS jack is the same as on the foobar. The left half (right in the picture) has the Pro Micro mounted with the component side facing the PCB. The right half (left in picture) has the Pro Micro mounted with the component side facing up.
Bottom plates. The matte black finish really shows scratches.

Close up of the bottom of the right hand side. Peel-a-way sockets for the Pro Micro. 5.2mm surface mount switch connected to RESET.

Switches installed into plate before soldering. The plates are also mirrored for left/right halves. Otherwise the holes won't line up with the screws.

One half assembled. 

An older revision of the board with a different TRRS jack. The jack turned out to be a modified non-standard type so had to be changed back to the original Sparkfun TRRS jack.

The first version of the board. It did not have the 180 degree double switch footprint so half the board would have the switches mounted upside down.