The 6-Digit GPS Clock Display described in last month’s issue of SILICON CHIP was originally conceived as an attachment for the author’s GPS-
Based Frequency Reference (March-May 2007). The idea was that since the NMEA 0183 stream of GPS time, date and navigational data was available from the GPS receiver in the Frequency Reference, we’d provide a “smart” display unit to receive this data stream, extract the time information and display it in either its native UTC form or converted to local time.
However, before the design was published, we realised that it would also be of interest to many more people than those who had built the GPS-Based Frequency Reference. That’s because it could be turned into a fully self-contained GPS Clock simply by building a GPS receiver and display driver module into the same enclosure. And by taking advantage of one of the low-cost GPS receiver modules currently available, this could be done surprisingly cheaply – with the complete clock costing less than $200. Not bad for a clock offering you very close to “atomic time” (and updated every second), wouldn’t you say?
So that’s the story behind the little GPS Clock Driver board described here. Its main application is to convert last month’s 6-Digit Display into a self-contained GPS clock. Alternatively, it can be used to feed the GPS/NMEA 0183 data stream into a PC via a standard serial port. You can then use a freeware software program such as “GPS Clock” to process and display the data – see panel.