My nixie tube clock is up and running! Sure, the software is a mess, the boards are hacked together, and I don't dare leave it running if I'm not in arm's reach of the plug... but it's running!
Considering my starting point was, "I don't really understand how a MOSFET works," this was a lot for me to take on. This forum and it's lovely people were invaluable! I think it's rare to find such a helpful community on the web. Thank you all!
Some bullet points on the project:
- 12 Nixie tubes for date/time
- Each tube has its own driver board with an MCU acting as an I2C client
- Main controller board generates 180V for the nixie supply with a boost converter
- USB PD for power
- Micro OLED and rotary encoder for status display and user input (DST, time zone setting)
- GPS for date/time initialization
- Hardware RTC for precise time-keeping and power-off time-keeping
Honestly, the boost converter was the hardest part. I burned up several MOSFETs and diodes when my control strategy failed to keep the voltage in check.