Bottom right we’ve got a DS1307 RTC connected to a watch crystal and battery connector. An ATmega328p, 16Mhz crystal, hooked up to the RTC over i2c and an LED on digital out 4

I think I’m becoming slightly obsessed with Nixie clocks.

I’m copying my previous clock design here, only this time I’m attempting to do a good job of it and keep it all neat and tidy with everything on one board and not held together with string and tape.

So far so good, Blink runs and I can set and read time on the RTC.

‘MSF’ decoder module

The biggest difference between this and the previous clock, besides the IN-14 vs IN-12 tubes, is the ‘MSF’ radio module which allows this thing to receive the 60kHz longwave time signal broadcast from Cumbria, UK (formerly Rugby until 2007?). Far better than the GPS receiver which would struggle to get a signal indoors? No. This thing is hyper sensitive to interference. Wrong angle, too close to a phone, a monitor or hold your mouth wrong and it fails. Stands to reason it doesn’t like the HV Nixie tubes at all. Bad choice for a Nixie clock then?

First one in