nRF9160 GNSS periodic mode, every once in a while GNSS will not enter sleep after a fix

[yyang3]

we have a custom board with nRF9160, when using GNSS we configured it to periodic mode with 120 second interval, most time it works fine but every once in a while (like every 20min or so, looks random), the GNSS will not go to sleep after got a fix, it will operating in continuous mode for about 1 minute, then stop output GNSS data, but still no sleep event, and then start next fix at original 120 seconds interval again, this time it will sleep after fix, everything seems back to normal. setting retry time have no impact on this behavior. since we are relaying on sleep event to control the LTE data transfer, when this happens it will block data transfer for 2 minutes, we need a solution.

[dejans]

Hi,

Are there any additional details that you can share about your application?
Do you use A-GNSS or P-GPS in your application?

Best regards,
Dejan

[yyang3]

currently no A-GNSS or P-GNSS, the code is pretty standard, config GNSS, set event handler, start GNSS, the event handler will handle PVT DATA and SLEEP AFTER FIX and WOKE UP event, most time the sleep event will get called right after valid PVT DATA event, but sometime it will just keep calling PVT DATA event with valid data and no SLEEP event for about one minute then stops with no other event, then calling WOKE UP event after 2 minutes.