Simple Binary Watch Uses A PCB Body

There are many ways to tell the time, from using analog dials to 7-segment displays. Hackers tend to enjoy binary watches, if only for their association with the digital machines that seem to make the world turn these days. [Vishal Soni] decided to build one of their own.

It’s a straightforward design, that uses six bits to show the time. A red light is illuminated at the top of the watch to indicate the watch is showing minutes, and these are displayed in binary on the six blue LEDs below. Then, the watch indicates it is showing hours, and again uses the six blue LEDs to show the relevant number.

[Vishal] refers to this as a binary coded decimal (BCD) watch, but BCD involves using binary to directly refer to numbers from 0-9. Instead, it appears to be a regular binary watch using 6-bit notation.

The heart of the watch is an ATtiny85, It also features a TP4056 for charging and maintaining the lithium battery used to power the watch. Charging is via a USB-C port. It’s all built on a custom PCB which is designed to act as the watch body, with the straps directly attached to the PCB itself. The only thing that appears missing is a 32.768 KHz crystal or real-time clock for accurate timekeeping.

Overall, it’s a fun build that would have taught [Vishal] plenty of useful design skills. We imagine those will serve [Vishal] well in future projects. If you’re digging the binary watch, consider some of the other great builds we’ve seen over the years. Video after the break.