Today I have built a Geiger counter with nixie display using EasyNixie module.

The code is quite simple and can be found on https://github.com/allexoK/EasyNixie/tree/main/examples/Geiger_Counter

The better version of a counter that supports correct measurement units(uSv/H) can be built with some symbolic nixies(IN-15A and IN-15B). The IN-15B supports the 'S,' 'V,' and 'H' letters, while the 'u' sign is supported by IN-15A. The '/' sign can be created by rotating the '-' digit if using IN-15A by 45 degrees.