The Mathboard has a new look! 

Since the previous update more than one year ago, I have been working on a fully custom design for the Mathboard. The prototype Mathboard was simply an off-the-shelf 4x4 macropad, which served me well for evaluating the feasability of the project, and for developing the firmware on hardware that I could be confident in. 

Once the prototype was finished and I was confident that what I wanted to build was feasible, I got started on a custom design, the result of which you see above. It has a fully custom PCB and a 3D-printed case. In the spirit of open source hardware, all the design files are available on the project github and the Mathboard can be made with a minimum of tools.

The PCB

The Mathboard uses a custom PCB that I designed in KiCAD and had produced with a rapid PCB prototype manufacturer. Keyboard PCBs are typically simple things, and this is no exception. Just a bunch of key switches, diodes, a status LED, a small 3-way switch, and pin headers for the microcontroller. In the image below you see the bottom of the PCB with the microcontroller already mounted. The microcontroller is Helios, an RP2040 board from 0xCB. I went for this particular microcontroller because of its size, cost, and large flash memory. 

The Case

The case was designed in Fusion 360 and reiterated upon a few times until I arrived at a result I was happy with. The case consists of a bottom part and a lid. The Gateron V2 low profile key switches snaps into place and ensures they are perfectly aligned when soldering them to the PCB.

A small white LED diffuser can be seen in the bottom right corner in the above image. This was simply 3D printed with white PLA and glued onto the blue case with cyanoacrylate glue (aka "super glue").