I picked up an Adafruit GPS module while at the Maker Faire. It’s a cool little module. I had a couple of old GPS modules: a Parallax PMB 648 and a Garmin 89, but this one is pretty nifty:

• It is small.
• It is breadboard friendly.
• It has a one pulse per second (1PPS) output for timing applications.
• It can output position/velocity information at up to 10Hz.
• It has a u.FL connector external antennas.
• It can be powered down by pulling an ENABLE pin low.

Lots of good features. I hooked it up tonight. My previous modules had a difficult time getting a lock inside, but this module had no difficulty at all. From a cold start, it had no problem locking. I hooked up the 1PPS output to my oscilloscope. It generates a nice 100ms positive pulse. The specifications say the timing jitter would be around 10ns. Very nice! That should be able to make a nice timebase to test the accuracy of the DS1307 module I was playing with yesterday. Data to come soon.