GPS Navigation mode vs Power Save Mode

[Panagiotis Galiatsatos]

Hi,

reading through the gnss socket configuration parameters it came a question to my mind regarding the Power Save Modes.

Is the PSM configuration applied when the GPS is configured for Periodic Navigation (Fix interval set to 60)?

In other words, if I measure the current while keeping the fix interval to 60 sec and rerunning the test for PSM settings 0,1,2,

will the PSM setting, make any difference to the current measurement?

Thanks in advanced,

Panagiotis.

[Martin Lesund]

Hi Panagiotis.

Here you can see what you should expect when measuring the different modes.


Please also see this devzone thread that discusses the same topic.

[Panagiotis Galiatsatos]

Hi Martin,

thank you for your reply! 

I am aware of the info and the thread you mentioned on your post.

But what is unclear to me is if I set position fix interval to 60 sec, would I expect to see any affect on the measured current when switching among the available PSM modes (0,1,2).

As far as I can understand here the current measured with position fix interval set to 1 sec. Am I right?

Please correct me if I am wrong.

Thank you in advance.

Kind regards,

Panagiotis.

[Martin Lesund]

Hi Panagiotis

"The fix interval parameter determines the mode of navigation. There are three different navigation modes available: single-fix, continuous, and periodic."

So when selecting 60sec you basically select the "Single-fix" mode.

And if you select 120sec you can expect ~2,5mA based on the PS data.

[Panagiotis Galiatsatos]

Hi Martin, 

thank you for the clarification.

The question is how the "NRF_SO_GNSS_POWER_SAVE_MODE" affects the current measured when the "Single-fix" mode is selected (fix interval 120sec)?

Thank you for your time and your support.

Probably there is something I haven't understood correctly and I need to make it crystal clear.

Kind regards,

Panagiotis.

[Martin Lesund]

Hi Panagiotis

So when you select the fix interval of 120sec (single shot, one fix every 120sec), that means the socket option, NRF_SO_GNSS_POWER_SAVE_MODE is using the default NRF_GNSS_PSM_DISABLED value.

Since:

• NRF_GNSS_PSM_DUTY_CYCLING_PERFORMANCE is continuous tracking, the received GNSS signal has no gaps. Best performance is achieved with continuous tracking.
• NRF_GNSS_PSM_DUTY_CYCLING_POWER is duty-cycled tracking, the GNSS receiver operates in on-and-off cycles consisting of tracking and sleeping. The received GNSS signal has therefore short gaps during the sleep periods. This type of tracking reduces the power consumption at the expense of performance.
• NRF_GNSS_PSM_DISABLED is Single shot

[Panagiotis Galiatsatos]

Good morning Martin,

thank you very much for your response!!! Now, things gets clear!!

So according to my understanding, is of no sense setting the NRF_SO_GNSS_POWER_SAVE_MODE to anything else than NRF_GNSS_PSM_DISABLED when we configure the GPS for Single Shot (120 sec interval). 

In the following picture line 206 will override the setting of line 185. Is that true?

Thank you for your support!!!!!

Kind regards,

Panos.

[Martin Lesund]

Hi Panagiotis,

Your understanding is correct.

Best regards,

Martin L.