Wednesday, September 13, 2017

6lit

Split 6 key macropads

I wanted to make a 6 key macropad that would fit within the 100mm x 100mm PCB size. Since I have been making split keyboards lately I added the same circuitry to this. I can't think of a practical use for a split macropad, but it works. It can be used singly as a regular 6 key macropad as well.

Other than the size the construction is the same as the foobar and the 16mm Split 40% keyboards. The modified firmware is on github as are the gerber files.

The PCB is smaller than 100mm x 100mm so you can get it made at a discount at EasyEDA or JLCPCB.

I am running low on the Sparkfun PRT-12639 TRRS jacks. I instead used the PJ-320D-A from LCSC.com. These have smaller plastic registration pins so need to be held in place while soldering. The Sparkfun jacks feel sturdier and I have ordered more of them.

The TRRS jacks are on the side. A cable with right angle plugs works best.
Keycaps are leftover Semiotic G20 from PMK. The rest of the keycaps are on this Gherkin.

The PCB is snapped in half for the top and bottom pieces. The rough edges need to be sanded smooth with sand paper.
All of the unused pins as well as VCC and Ground are broken out to pads.

PCB mount switches are required as there is no plate.

The bottom pieces.

6mm M2 spacers and screws. You may need thicker spacers. I used an extremely low profile socket for the right hand side.

Size comparison. Let's Split, foobar, 6lit.