To keep this ultra slim, a Teensy microcontroller board was used — a standard Arduino wouldn’t fit, not even the headerless Leonardo. After prototyping the full circuit on a breadboard, all the parts were soldered point-to-point and “dead bug” style inside the case. Power is provided by three AA cells in series — a bit under the ideal 5 Volts, but still sufficient to run everything. The cells fit in the “chin” below the three dates. I’d mail-ordered a special battery holder for this, and then in my rush to complete the project I went ahead and made all the case parts based on the holder dimensions on a web site. Naturally then, with the case already cut and glued, the part that arrived was slightly larger than the dimensions posted. The fix was to break off the battery contacts from the ends of the holder and epoxy putty them directly into the case. This eliminated just enough girth for everything to fit. The remaining electronics were delicately folded into the case with copious amounts of hot-melt glue, tape and swearing.
The case was fabricated from laser-cut acrylic and sprayed with faux hammered metal paint. A metal enclosure would have been more authentic (and more work), but a corollary to “Maslow’s hammer” dictates that when you have a laser cutter, every project appears ideally suited to acrylic.
The labels were inkjet printed and made into stickers with a Xyron applicator, trimmed with an X-Acto knife, then painstakingly touched up with a Sharpie marker to hide the white edges. After the labels were applied, the bezels received a thick spray of acrylic sealer, then attached to the front of the case with epoxy.
A classic Dymo labeler (the plastic punched letter kind) might suffice here. In the film trilogy, most of the instruments (including the Flux Capacitor) were labeled that way. But the Time Circuit, being a close-up “hero prop” that required maximum legibility for the audience, had cleanly-printed labels. Sticklers for accuracy might want to take the extra step.
Go for it! If you don’t own a DeLorean, this will still impress your co-workers and look great on your desk. Or maybe you can devise a scheme around Halloween or a cosplay geek-fest like Dragon*Con. Bolt it just below the arc reactor on your Iron Man suit (you do have an Iron Man suit, right?). Or if you have a young son in a stroller, attach the time circuit to the tray, dress junior in mirrored shades and a “life preserver” down vest, while dad dons a Doc Brown getup…you’ll take home all the candy in the neighborhood!
Even if you don’t build this exact item, if it inspires any nifty electronics projects (*cough*Proton Pack*cough*), please share them in the forums, bring them to the Saturday night show-and-tell or document your build on a site like Instructables. Customer projects are frequently showcased on the Adafruit blog!
Here’s the Arduino sketch that runs the show.
Parts from the Adafruit store include:
Additional parts acquired from Digi-Key include: