I have a thousand and one little projects and project ideas floating around at any given time, but there’s been one thing I’ve always wanted to build: a replica of the ‘Time Circuits’ from the Back to the Future movies.


At their heart, the ‘Time Circuits’ are a clock – three separate displays, displaying the time machine’s present time, destination time, and last departed time. In true ’80s fashion, these are displayed using LEDs: 7-segment and alphanumeric displays, with individual LEDs for the AM/PM indicator and the seconds timer. The displays are controlled by a keypad, where you can input new destination times.

To build a replica, I’m going to need to make three custom LED segment displays in their own casings. I’ll also need to build my own custom keypad, and the supporting circuitry to make everything work and react like it does in the film.

Basic Goals

  • 3 working ‘Time Circuit’ displays
  • 1 working keypad, used to set the display times
  • Match the look of the film as well as I can (within reason)
  • ‘Present’ display keeps track of time

Stretch Goals

If I have the time / energy, I hope to add the following to the setup (in no particular order):

  • Arduino library to easily address each display
  • Sound effects
  • Stopwatch / Timer / Alarm functionality
  • Serial parsing (display text from a computer)
  • CAN bus connection (swap times when a car hits 88 mph)


Here’s a tentative outline for how I think I’ll tackle this:

  1. Proof of Concept (rough prototyping)
  2. Display Design
  3. Keypad Design
  4. Driver Design
  5. Total Assembly

With each design ‘sub-phase’ formed of separate steps:

  1. Planning & Part Sourcing
  2. Breadboard Prototype
  3. PCB Design
  4. Case Design
  5. Assembly
  6. Programming

Obvious the “programming” aspect will be sprinkled throughout, but I want to hold off on doing too much coding until the parts and pins are finalized.


This is a fairly ambitious project, but I think I have the knowledge to build something that does the film justice. As always, I’ll do my best to include my progress on this blog. Only time will tell if I will get it done!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.