US maker store Adafruit has just started to release HATs for the Raspberry Pi B+ and A+. The one I’m featuring here is the Ultimate GPS Hat. This sits on top of your B+ or A+ and allows you to receive GPS signal data from the GPS receiver on top of the HAT. Here’s a list of features, taken from the Adafruit site:

• -165 dBm sensitivity, 10 Hz updates, 66 channels
• Only 20mA current draw
• Built in Real Time Clock (RTC) – slot in a CR1220 backup battery for 7-years or more of timekeeping even if the Raspberry Pi is off!
• PPS output on fix, by default connected to pin #4
• We have received reports that it works up to ~32Km altitude (the GPS theoretically does not have a limit until 40Km)
• Internal patch antenna which works quite well when used outdoors + u.FL connector for external active antenna for when used indoors or in locations without a clear sky view
• Fix status LED blinks to let you know when the GPS has determined the current coordinates

The rest of the HAT is dedicated to a small prototyping area and all the non-used pins are broken out for your use. You can read more here and purchase one here.