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# Voltmeter clock
- URL: https://cronoxyd.de/voltmeter-clock/
- Published: 2020-04-07T18:32:00.000Z
- Updated: 2026-08-01T15:04:46.000Z
- Author: Marcel Diskowski
- Tags: Embedded

I saw this project quite a while ago and I just had to build it myself: a desk clock using analog voltmeters to display the time! The build ended up being pretty straightforward; the voltmeters are DC 5V meters that I got on eBay with an Arduino driving them. They respond perfectly to PWM when using a 10 µF capacitor to smooth out the signal.

![](https://cronoxyd.de/content/images/2021/09/DSC_0215_cropped.jpg)

Fully populated PCB of the Voltmeter clock

I got to thinking though when I put together the bill of materials that I didn't want to have a clock that I would need to set all the time. So I decided to use the [DCF77](https://wikipedia.org/wiki/DCF77?ref=cronoxyd.de) radio signal, which has been used to set all sorts of clocks since the early 70s. Thankfully, there are ready-made modules and also Arduino libraries so integrating it into the project was very easy.

![](https://cronoxyd.de/content/images/2021/09/DCF77.jpg)

The finished clock

![](https://cronoxyd.de/content/images/2021/09/Voltmeter-Clock-Iso-Drawing.jpg)

An Iso perspective drawing of the clock

## Code

[![](https://gh-card.dev/repos/cronoxyd/VoltmeterClock.svg?fullname=)](https://github.com/cronoxyd/VoltmeterClock?ref=cronoxyd.de)