The UNIX Epoch Clock

From DIY to finished product

Origin

The UNIX Epoch clock project started out as an idea for a Christmas gift to a friend after hearing them mention about how cool it would be to have a UNIX time piece. Searching through the standard shopping sites and even some of the more esoteric ones, I was disappointed with what was available on the market. My idea of the perfect UNIX Epoch clock was one that was simple in operation and elegant in design. Any extra bells or whistles were unnecessary and would detract from such a unique clock. Even after an exhaustive search I could not find anything that matched my strict criteria for the perfect UNIX clock. I decided that if I couldn’t find what I was looking for, I would just make it myself. And so I did. The original UNIX Epoch clock was made using standard off-the-shelf parts and modules. A couple of seven segment display modules, an Arduino nano micro-controller, a real time clock, and some prototyping PCBs were all that were needed to get the clock made. A hand made enclosure using tinted acrylic and two-part epoxy held everything together. It was a bit rough around the edges (literally and figuratively) but the gift was well received and greatly appreciated. There was an issue though; It was such an interesting time piece that I wanted one for myself. To my surprise, a few other people expressed sincere interest in having one as well. It was at that point that I decided to turn the DIY project into a real product.

Design

The goal of the project was to create a clock that matched my initial vision of what a UNIX Epoch clock should be: Simple and elegant. The simplicity in the final design is twofold. The clock is simple to use because no user input is required, other than plugging in, and no extra clutter or useless information occupy the real estate of the display. To facilitate this simplicity, the clock needs to be accurate. The UNIX Epoch clock uses a Maxim Integrated DS3231 temperature compensated real-time-clock (RTC) and backup battery for precise timekeeping. This RTC is automatically adjusted using a small GPS antenna located inside the clock. This means that you never need to worry about having to set the time yourself. The physical construction of the clock was made as an homage to the classic 1970s electronics design language. The electronics are housed in a custom made two part clam-shell enclosure that was typical for industrial and scientific electronics equipment of the era. The display is made up of bright red seven segment LED digits behind a dark acrylic screen which contributes to the retro look. On the back is a micro USB port for powering the clock.

Operation

To use, simply plug in a micro USB cable powered from a high quality USB wall charger. Apple chargers work great for this. The clock is not designed to be powered from USB battery power banks. The clock will automatically adjust the time using its built in GPS antennae. If the clock is showing an erroneous time and hasn’t corrected itself in half an hour, unplug the clock and move it near a window to make sure that there is adequate GPS reception. Once set, the clock may be moved to an area with poor GPS reception. The RTC will maintain an accuracy of ±3.5ppm.