The full write-up is on Medium:

Lots of additional photos:

The Gerbers are up on OshPark:

The KiCad schematics and PCB layout, as well as Gerbers are up on GitHub:

This project started on a (series of) breadboards

The low-tech LDR-driven PWM adjusting the display brightness uses a 555 timer.

My first real PCB. So much anticipation soldering everything up, hoping I hadn't made any mistakes in the layout.

I created a minimalist 3D-printed wall-mounting frame.

Turns out debugging hardware is a lot more painful and slow than software!

MEMS oscillators don't seem to come in through-hole, so this became my SMT trial-by-fire.


When the crystal circuit proved unreliable I ultimately decided a "patch" was necessary and I created a tiny little addon board with a MEMS oscillator that would slot into the crystal circuit's through holes.

Using the logic analyzer to measure the accuracy.

More details at