In this project I created a nixie wristwatch, with 3D-printed case and a custom PCB.
It is based on four IN-17 tubes, witch require 170V to operate. The tubes are driven by discrete transistors rather than a driver IC, to make the design a compact as possible.
The MCU Atmega328P is used for RTC, HV PSU and display driver.
The current draw from the singel cell LiPo battery is around 80mA at 3.7V when active. In sleep mode it's abount 30uA.
The accelerometer is sampling at 100Hz both in active and sleep mode, to detect hand movements. A simple twist of the wrist activates the nixie display. By tapping the watch, battery info etc is shown.
A micro USB-port on the bottom of the watch is used for charging and programming.