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,
The one in master branch is real GPS yes.

The GPS is turned on when the nrf91 goes in PSM mode. The modem firmware does not support all the low power modes for the GPS yet, but there will be some optimizations in the next releases. (near future)

(a stripped-down sample of this can be found here)