Using GPS on RF9160.

[Alan Hasty]

I want to use the REAL GPS of the RF9160, not the simulated version in the asset tracker demo.
Firstly, is there a demo for the RF9160 that reports actual GPS location that I can reference?

Here is what I have :
Hardware: Dev Kit PCA10090 Version 0.8.2
Booting Zephyr OS v1.13.99-ncs1-1823-g715d2df3dd
Booting Zephyr OS v1.13.99-ncs2
Git repos for nrf is at v0.3.0

After looking at the DK User manual, the schematic and the code for the asset tracker example, here is what I think needs to happen to be able to use the real GPS location.

Code: Remove the references to the gps_sim

Code: Add GPS initialization

Code: Add commands to enable the GPS antenna via the GPS_EN signal and the %XMAGPIO command.
I think the command would look something along the lines of
%XMAGPIO=1,1,1,1574,1577,699,747,748,804,805,850,851,895,896,960,450,451,1710,2200

Questions that I have:
1) In the nRF9160_DK_User_Guide.pdf (V0.7) Section 5.5, there is a note that is highlighted, that this functionality is only available on the modem firmware used in the nRF9160. How do I determine if I have the correct firmware for the GPS function.

2) How do I get the correct firmware if what I have doesn't contain the GPS function.

3) How does the GPS location information get returned to the code? Is it an asynchronous response from the modem?
3b) Is there a command to get the GPS location info returned , and is it possible to control the format of the returned data? In the asset tracker demo the code was returning one of the many GPS format types.

4) For power savings , is it possible to power down the GPS function and only enable it when necessary?

5) Do you have any documentation on how to put the RF9160 to sleep, and have it wake up on an event like an interrupt from an accelerometer?
5a) Is it possible to test this on the dev kit that I have?

Thanks!

[Håkon Alseth]

Hi,

  

Code: Add commands to enable the GPS antenna via the GPS_EN signal and the %XMAGPIO command.
I think the command would look something along the lines of
%XMAGPIO=1,1,1,1574,1577,699,747,748,804,805,850,851,895,896,960,450,451,1710,2200

MAGPIO is a AT command feature that can set your GPIOs based on what band is being used.

That specific command enables all three MAGPIO pins, and sets the GPS band corresponding to all MAGPIO pins set to '0'.

Please see the AT command reference guide for more detailed information about that specific line, as it also includes a truth diagram of the MAGPIOx states vs. LTE bands in use. 

 

Questions that I have:
1) In the nRF9160_DK_User_Guide.pdf (V0.7) Section 5.5, there is a note that is highlighted, that this functionality is only available on the modem firmware used in the nRF9160. How do I determine if I have the correct firmware for the GPS function.

2) How do I get the correct firmware if what I have doesn't contain the GPS function.

3) How does the GPS location information get returned to the code? Is it an asynchronous response from the modem?
3b) Is there a command to get the GPS location info returned , and is it possible to control the format of the returned data? In the asset tracker demo the code was returning one of the many GPS format types.

4) For power savings , is it possible to power down the GPS function and only enable it when necessary?

GPS is not yet available, as per the nRF9160 development status:

https://devzone.nordicsemi.com/b/nrf9160-development-status/posts/nrf9160-development-status

 

Kind regards,

Håkon

[Alan Hasty]

Thank you for the response and the pointer to the blog about the dev status.

I'm understanding that after April, I should be able to use the GPS (once I have the updated firmware) without the need to get a new dev kit , i.e. that the hardware is in place, we're just waiting on the software component. Is that correct?

Regards,

Alan.

[Håkon Alseth]

Hi Alan,

 

The DK versions v0.7 and v0.8.2 may have bad GPS performance, as per the nRF91 DK errata document available here:

https://www.nordicsemi.com/DocLib?Product=nRF9160%20core%20documentation

There's a newer kit version, v0.8.5, where the GPS antenna match is optimized. On this kit version, the software is the component that is currently missing.

 

Kind regards,

Håkon