Datasheet

Antenna Options

All Ultimate GPS modules have a built in patch antenna - this antenna provides -165 dBm sensitivity and is perfect for

many projects. However, if you want to place your project in a box, it might not be possible to have the antenna

pointing up, or it might be in a metal shield, or you may need more sensitivity. In these cases, you may want to use an

external active antenna. (http://adafru.it/960)

Active antennas draw current, so they do provide more gain but at a power cost. Check the antenna datasheet for

exactly how much current they draw - its usually around 10-20mA. (http://adafru.it/960)

Most GPS antennas use SMA connectors, which are popular and easy to use. However, an SMA connector would be

fairly big on the GPS breakout so we went with a uFL connector - which is lightweight, small and easy to manufacture.

If you don't need an external antenna it wont add significant weight or space but its easy to attach a uFL->SMA adapter

cable (http://adafru.it/851). Then connect the GPS antenna to the cable.

The Ultimate GPS will automagically detect an external active antenna is attached and 'switch over' - you do not need

to send any commands

There is an output sentence that will tell you the status of the antenna. $PGTOP,11,x where x is the status number. If x

is 3 that means it is using the external antenna. If x is 2 it's using the internal antenna and if x is 1 there was an antenna

short or problem.

On newer shields & modules, you'll need to tell the firmware you want to have this report output, you can do that by

adding a gps.sendCommand(PGCMD_ANTENNA) around the same time you set the update rate/sentence output.

uFL connectors are small, delicate and are not rated for strain or tons of connections/disconnections. Once

you attach a uFL adapter use strain relief to avoid ripping off the uFL