Nixie clock - Millivolt Meter Hack
After finding an old Nixie Millivolt Meter on some pile of disposed electronics, [Jimmy] was wondering how to make a clock out of it but still preserve the original voltage measuring functionality.
This instrument shows voltages in 0-99.99mV range (0-0.0XXXXV) on Nixie tubes so [Jimmy] had a great idea to generate the appropriate voltage on its input pin that will correspond to current time. For example, to show time at 12:15 he must generate exactly 12.15mV. Voltage generation is done with PWM signal from an Arduino AVR microcontroller.
[ Source: Jimmy H. ]