Nixie Tube Real Time Clock

Keeping my clock in sync with a battery backup.

Arduino driven OSHW shield from switchmodedesign.

The DS3231 [PDF] is a precision Real Time Clock (RTC) and memory module, with a
battery backup. They are a couple of quid each on eBay.


It uses an internal oscillator and is accurate down to a few minutes per year in extreme temperatures.

Connect SDA (or data) and SCL (or clock). On a Pro-Mini, Arduino Uno or
compatible boards, these pins are A4 – data and A5 – clock. If you’re
using an Arduino Mega the pins are D20 – data and D21 – clock.

Connect VCC to 5V; and GND to GND.


The code should also work with the cheaper DS1307.

Code: uses functions from the tronixstuff tutorial.


I soldered headers on the other end , I don’t use the 32K or SQW pins.

About these ads