This is my first foray into the world of GPS, made possible by the GPS XBee kit.
With Wise Clock 4 offering support for XBee, this little GPS module from seeedstudio seemed like a nice fit. The purpose is, of course, to synchronize the clock with the accurate time received from satellites.
Note: Some time ago I tried the WWVB atomic clock radio receiver module CMMR-6. It comes with a 60mm ferrite rod, pretty inadequate for receiving the Colorado radio signal in Toronto, more than 2200km away. On top of the fact that it is finicky (never worked for me), it is also bulky (the ferrite rod) and fragile (the thin antenna wire).
First, I inserted the module into the XBee adapter from adafruit, which is connected (through the FTDI cable) to a terminal session (9600, 8, N, 1).
Messages started flowing in, right off the bat: wow!
Next, I moved the GPS module onto the Wise Clock 4 and uploaded a sketch that uses TinyGPS library (modified by Justin).
Here is the serial monitor output.
For those who require maximum accuracy on top of the one provided by the DS3231 RTC chip itself, this GPS solution should do it.
Make the "Doomsday clock", like the one by Wyolum team shown in the video below, with Wise Clock 4 and 2 displays.