GPS current consumption abnormal

[Siyou]

Hi

We found abnormal current waveform when running GPS as 120s fix interval and 10s fix retry.

As below pic, the first plus is A-GPS seraching, from second plus is the fix current, but you can see the second fix(third plus) has followed a very wide(it is far beyond 10s fix retry) current plus, what's the reason of this current plus?

[Håkon Alseth]

Hi,

 

The 3 screenshots you posted:

 

This looks like 60 sec, ~20 sec timeout, corresponding to what you set.

This one as well, where it waits until it gets a fix.

  

This also looks spot on per your configuration (120 / 60 sec)

 

The initial current profile does not fully match your settings:

It looks like there is a sequence that is occurring after the 3rd GPS retry.

 

Q1: Can you please share exactly how the firmware is setting up this sequence?

Q2: Which ncs version are you using? and which modem FW is used?

Q3: On the 3rd current pulse, what happens after the GPS socket is started again? Does the firmware do anything towards the modem at this point, like writing to CFUN register?

It would help to see code to get a better overview here.

 

Kind regards,

Håkon

[Siyou]

With further test, we found the unable fix issue is only happened when measuring nRF9160 current(powered by external power supply), there is no issue when it works with on-board power supply. Please close this ticket, thanks!