GPS ClockSun, Apr 23, 2017
For some time I had sought out the ideal clock for the bedroom. Like many I've switched to using my smart phone as an alarm, but I still have the need for a clock to quickly find out the current time. While I've had clock radios that worked well, it proved difficult to find the ideal combination of features. Specifically I was seeking an LED display of twenty four hour time that set itself, eliminating the need to adjust for daylight saving and making the power outages I was experiencing a non-issue. The latter feature of automatic time setting proved especially difficult, as I was living in Fairbanks, Alaska at the time, outside of the signal range of the inexpensively received WWVB atomic clock backed time signal.
Already interested in the growing microcontroller hobbyist market, I looked into what time keeping parts might be possible. I had thought of perhaps having a NTP backed Ethernet or wifi connected device but at the time few components were available offering network interfaces and they required significant work to implement. I ended up going with a GPS receiver, something more frequently used for position information. The GPS system relies on very accurate time keeping, something a small receiver can take advantage of as well. Connected to an Arduino and a large digit display through a breadboard, the clock proved a very useful project that continues to work well to this day.
GPS devices have improved over time and the chip in the clock I ultimately created is able to display accurate, 24 hour time within seconds after being plugged in. I never have gotten around to enclosing the device so it continues to look like a science experiment, many years after it was first put together.