nRF9160 1PPS stopping when GPS fix is lost

[jenga]

Hi,

I'm working on a project using the nRF9160 (NCS V1.7.1, V1.3.0 modem firmware) and am utilizing the 1PPS signal.

It is working well, however when the fix is lost the 1PPS signal stops. The manual says it should continue outputting the 1PPS signal. 

Can someone help with this? It is critical that the 1PPS signal is always present after the first fix.

[JONATHAN LL]

Hi,

Make sure you are not using "one-time pulse mode".

Could you test mfw v1.3.1 and see if the you have the same issue?

If the same issue still persists then could you provide a modem trace.

Regards,
Jonathan

[jenga]

Hi,

As far as I know I'm not using 'one-time pulse mode', but there is no mention of it in the documentation.

I would love to upgrade to modem firmware V1.3.1, but unfortunately the V2.0.0 programming utility is broken and gives a 'no matching trait found' error when I try to upgrade the modem firmware. 

[JONATHAN LL]

Hi, 

There does not seem to be an issue with 1PPS in version 1.3.0.  Could you perhaps share some more info on how you measure and setup etc?

If the receiver was configured for one-time pulse mode (by using zero pulse interval), it would output one pulse at first fix, and then no more pulses. Can you confirm that you gett more than one pulse? Just so that we are 100% certain that this is not the issue. 

Regards,
Jonathan

[JONATHAN LL]

Follow up question: Could you provide the source code that you are using. We would be able to check if there is anything suspect going on then.

Note: If you dont want to share it publicly i can make this case private. 

[jenga]

Now that Programmer V2.0.1 has been released I've been able to program modem firmware V1.3.1. I'll do some testing over the next few days and get back to you.