I am looking for a type of digital watch where hours and minutes would show as binary, e.g. with an LED on for a 1 and off for a 0. So 12:30 would show as:


(since 12 = 1*8 + 1*4 + 0*2 + 0, and 30 = 0*32 + 1*16 + 1*8 + 1*4 + 1*2 + 0*1). With lights, it would give:

**  : **** 

It would both be fun and useful training for finding patterns and reading in binary. Ideally it would switch from endian-ness, big or little.

I have found items advertised as "binary digital watch" which have an LED next to an hour or a minute, but I want a watch only in binary.

I imagine it would be feasible with a microcontroller like a microbit or Arduino Nano and addressable LEDs.

Does it already exist, or has anyone built something similar?

1 Answer 1


There are a number of binary clock designs on Instructables, as well as a few binary watch models. Due to a sign-on requirement for searches, the above link now goes only to Instructables. Use "binary watch" in the search box for the same results, or go to the instructable with this result:

binary wrist watch

One great aspect of Instructables is that you can begin with a post you like and modify it to meet your requirements.

  • Your link sends me to a login page.
    – jaskij
    Feb 20, 2020 at 22:16
  • Apparently, in order to commit a search, one must sign in. You can go to www.instructables.com and search for binary watch to get the results from the link. I'll change the link appropriately.
    – fred_dot_u
    Feb 20, 2020 at 22:41
  • This is exactly what I wanted. From the expression "Binary digital watch" I happened to find a video with that title that explained the operation of the binary digital watch, then found several similar products with that name at online retailers. I like this one the best because it's geeky and stylish. Feb 21, 2020 at 8:58

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