GPS Sample code works, but how do you reduce power?

[stevenminnick]

I got this project to compile and work: https://github.com/NordicPlayground/fw-nrfconnect-nrf/tree/master/samples/nrf9160/gps

I have the latest radio firmware at this time: 0.7.0_29.  I'm actually using a DK 0.8.2 which required an external antenna, but when I use one it works fine.

I measure constant current around 30mA when doing this. 

According to this, there seems to be 2 lower power modes below what this sample is using: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf9160%2F_tmp%2Falta.nRF9160%2Fautodita%2FCURRENT%2Fparameters.id_current_gps.html&resultof=%22%67%70%73%22%20%22%67%70%22%20

Also some information on lower power modes here: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf9160%2Fgps.html&resultof=%22%67%70%73%22%20%22%67%70%22%20

Is there any guidance on getting the radio into these lower power modes?  Are these modes implemented in the radio firmware at this time?

[Martin Lesund]

Hi Steven,

I am sorry for the confusion this older link to the PR may have caused. There was made another PR that added GPS which is now merged with master branch in NCS.

I highly recommend you to update to master branch to test out the real GPS which is added in the asset_tracker sample.

cd ncs/nrf
git checkout master
git pull
west update

cd applications/asset_tracker
west build -b nrf9160_pca10090ns -d build_gps
nrfjprog -e
west flash -d build_gps

Then you can push down the "button_1" for 10 seconds and you will turn on the GPS functionality.

[stevenminnick]

Does that add "real" GPS instead of the circle around Nordic's headquarters?  What about the low power modes for GPS?  I've tested "real" GPS and that works, but I was looking at testing the low power modes.