This project was one of my friend's ideas in early summer 2018.

The premise of this project is to design a non graphing calculator which incorporates high end switches and keys used in mechanical keyboards. The calculator can also function as a number pad when plugged into a computer using the USB port.

Like many of my other projects, the board is designed in KiCad and the 3d model in openSCAD.

The image on the left is a mockup render of the final design, with screen, keyboard, power switch and other ports. This CAD model does not include the 3D printed case.

In order to simplify the design, almost all of the components were placed on the front side of the board and hidden under the screen.

Since the LEDs under the keys ran on 5v, while the screen, main processor and other components ran on 3.3v, I used a separate micro controller for the lighting. This made the hardware design more difficult since the board now involved two supply voltage levels, but it made the software simpler since one processor was not tasked with delivering smooth lighting animations and simultaneously handling all of the on screen graphics.