Tiny IN-16 Nixie driver

This project was heavily inspired by cnlohr’s cnixxi project. (github link) After watching his video on how he designed this very compact driver board for driving IN-12 nixie’s, with some very cheap parts like the CH32V003 microcontroller I was determined to make a version for the IN-16 nixie tubes I bought.

Different Nixie type design choices

I managed to snatch up 6 beatiful IN-16 Nixies on Ebay, these are quite a different style then the IN-12 tubes cnlohr used in his project.

Due to the much smaller board footprint of an IN-16 Nixie, I decided to opt for a dual-PCB stack solution. The top PCB will be the “break-out board”, converting the difficult to work with circular pattern of pins into 2 rows of standard 0.1" headers. The bottom PCB will contain all the driving circuitry and a CH32V003 microntroller.

I decided not to include the High-Voltage power supply on the boards due to the limited space, and instead opted to break-out the HV pins to one end of the board. Then all modules can be supplied with one HV-supply unit.

Requirements

• CH32V003 microcontroller
• All digits individually fadable
• Standard spacing so it plugs into a breadboard
• I2C plus single-wire SWD pins

Parts selection