Monday, December 30, 2019


4 Squares

I was going to use two sets of 3 Nori PCB's to rebuild the 96 key Ti-Pro keypad. Instead I created 5 tetromino shaped PCB's that can be arranged to fit just about any rectangular shape with a number of switches divisible by 4.

There are five designs. They use the same any direction switch pads that I used on the Polyandry. Individual PCB's can be placed in any orientation.

I arranged the PCB's into a 8x12 grid. I used some steel rulers to hold the pieces tightly together.

Blue painter's tape holds all the pieces in place.

Flipped over, ready for the solder bridges to be soldered.

All pieces held together with solder bridges. Tape removed.

Close up of the solder bridges. Lots of solder.

Test fit in the Ti-Pro. It can be placed either side up, or rotated 180. I had previously de-soldered the original Ti-Pro PCB. These boards have no places for supports. They would only work well with a solid plate to support the switches. The Ti-Pro has a heavy steel plate.

Diodes and jumpers installed. All vertically aligned pads are diodes. Cathode goes to the Square pad, which is sometimes on the top or on the bottom. All horizontal pads are jumpers. These jumpers are 0 ohm resistors. Pieces of wire could be used too, but the resistors were easier to work with.

Close up of the diodes and jumpers. The jumpers are for the Columns, and the diodes are the Rows. This is for a COL2ROW matrix.

PCB installed and switches soldered. A 30awg wire is soldered to each row and column. I mounted the PCB with the diodes hidden on the other side.

I used a wire wrap tool to connect the wires to header pins on the Arduino Micro clone.

Close up of the Arduino Micro clone.

I cut down some color paper and inserted them in the relegendable keycapes. It mimics the colors of the PCB's.

Gerber files on git.