or-clock, a simple nixie alarm clock

I have been working on and off designing this nixie clock. I was inspired to build an alarm clock with old display tubes after having assembled the Ice tube clock from Adafruit. As a mater of fact I took quite a few design cues from the Ice tube clock. The microcontroller used is a ATmega 328p that has a watch crystal attached to keep time, a pwm output is also used to generate the high voltage necessary for the nixie tubes.

The tubes are old soviet IN-12b nixie tubes an INS-1 neon bulbs. They are the cheapest nixie tubes one can get a hold of on eBay. The guts of the clock consists of 3 PCBs, one for the “brains” of the clock, one just for the nixie tubes and a interconnect board to connect both PCBs together.

The Optibboot bootloader is used on the microcontroller so that it can be easily reprogrammed with the help of a serial breakout board that can be plugged into the header pins on the back side of the clock.


The first prototype of the or-clock

At first the PCBs where designed with Eagle but since then I have used Kicad more extensively. For that reason I converted the project over with the help of a handy collections of scripts available here on github. I had to fix quite a few issues with the converted files but even then it saved me lots of time.


The front pcb of the clock

The back pcb of the clock

The source code and Kicad files for this project are available here: