Datasheet

The breakout is built around the MTK3339 chipset, a no-nonsense, high-quality GPS module that can track up to 22

satellites on 66 channels, has an excellent high-sensitivity receiver (-165 dB tracking!), and a built in antenna. It can do

up to 10 location updates a second for high speed, high sensitivity logging or tracking. Power usage is incredibly low,

only 20 mA during navigation.

Best of all, we added all the extra goodies you could ever want: a ultra-low dropout 3.3V regulator so you can power it

with 3.3-5VDC in, 5V level safe inputs, ENABLE pin so you can turn off the module using any microcontroller pin or

switch, a footprint for optional CR1220 coin cell to keep the RTC running and allow warm starts and a tiny bright red

LED. The LED blinks at about 1Hz while it's searching for satellites and blinks once every 15 seconds when a fix is

found to conserve power. If you want to have an LED on all the time, we also provide the FIX signal out on a pin so you

can put an external LED on.

Two features that really stand out about version 3 MTK3339-based module is the external antenna functionality and

the the built in data-logging capability. The module has a standard ceramic patch antenna that gives it -165 dB

sensitivity, but when you want to have a bigger antenna, you can snap on any 3V active GPS antenna via the uFL

connector. The module will automatically detect the active antenna and switch over! Most GPS antennas use SMA

connectors so you may want to pick up one of our uFL to SMA adapters.

The other cool feature of the new MTK3339-based module (which we have tested with great success) is the built in

datalogging ability. Since there is a microcontroller inside the module, with some empty FLASH memory, the newest

firmware now allows sending commands to do internal logging to that FLASH. The only thing is that you do need to

have a microcontroller send the "Start Logging" command. However, after that message is sent, the microcontroller

can go to sleep and does not need to wake up to talk to the GPS anymore to reduce power consumption. The time,

date, longitude, latitude, and height is logged every 15 seconds and only when there is a fix. The internal FLASH can

store about 16 hours of data, it will automatically append data so you don't have to worry about accidentally losing data

if power is lost. It is not possible to change what is logged and how often, as its hardcoded into the module but we

found that this arrangement covers many of the most common GPS datalogging requirements.