Using GPS and LTE

RE: Using GPS and LTE

Martin Lesund — Tue, 18 May 2021 07:13:09 GMT

This is supported in mfw 1.3.0:
https://www.nordicsemi.com/Products/Low-power-cellular-IoT/nRF9160/Download#infotabs

Please make a new ticket if you have any follow up questions since this dz ticket is over 1 year old.

RE: Using GPS and LTE

liteyear — Thu, 13 May 2021 04:46:57 GMT

[quote userid="76760" url="~/f/nordic-q-a/56735/using-gps-and-lte/236807#236807"]After almost 6 weeks I got an answer to issue [2]:
- GPS pulse per second (on COEX1) is not yet implemented
(as of firmware 1.1.1)[/quote]

Oh dear... I assume you mean [1] ?

This is potentially terminal for us. We've invested months into this platform, and didn't think we needed to check whether the GPS supported PPS. After a long, terrible experience getting the basics working, we're now at the point of implementing that part of the design. I'm shocked to find it not supported.

Is there any resolution? Is there any way to access a PPS signal in the nRF9160? In our case, a software interrupt or equivalent would suffice, even if it wasn't on a pin by default.

RE: Using GPS and LTE

Martin — Thu, 27 Feb 2020 11:55:05 GMT

After almost 6 weeks I got an answer to issue [2]:
- GPS pulse per second (on COEX1) is not yet implemented
(as of firmware 1.1.1)

RE: Using GPS and LTE

Martin — Wed, 05 Feb 2020 11:36:06 GMT

Test software coexistence LTE/GPS

I have written a small Zephyr application that should work on all nrf9160 platforms but especially the Thingy.91.
It features some configurable parameters as defines and some pretested settings.

The software consists basically on a task that sends an UDP packet to a time server and gets an UDP packet back. The interval time can be configured.
At the same time during the communication interval it tries to get a GPS fix.
At the end of the number of configured test runs it writes some statistics like RTT of the network packets and number of GPS fixes etc.

devzone.nordicsemi.com/.../LTEwithGPS.zip

RE: Using GPS and LTE

Martin — Mon, 20 Jan 2020 22:09:32 GMT

Some more information to point [3]:
- In France on NB-IOT on network SFR (20810) with the same SIM from Swisscom in roaming the timing is EXCELENT for the first two cycles. Modem goes to sleep within 5s. The RTT is relatively high 2000-3000ms and then the RTT goes down up to 500ms but the modem does not enter any more in power idle and is BUSY almost 100% for the whole cycle of 45s
- CEREG connection event is: +CEREG: 5,"C38E","002090CE",9,,,"00001000","00110100"
- A XMONITOR query shows: %XMONITOR: 5,"","","20810","C38E",9,20,"002090CE",320,6290,90,42,"","00001000","00110100"

RE: Using GPS and LTE

Martin — Mon, 20 Jan 2020 21:46:53 GMT

Some more information to point [3]:
- In France on LTE-M on network Orange (20801) with the same SIM from Swisscom in roaming the timing is MUCH better.
- Same custom hardware, same firmware
- The modem remains in a busy state for about 9-10 seconds with hectic activity on COEX2. Then starts the activity counter for 16 seconds - the activity is now calm with a period a little over one second. This means that after around 25-26 seconds the modem is ready to listen to GPS.
- This is in contrast to the networks activity on the home Swisscom network that keeps hectic for 70 seconds.
- CEREG on connection: +CEREG: 5,"99C0","014BA409",7,,,"00001010","00110101"
- XMONITOR query: %XMONITOR: 5,"Orange F","Orange F","20801","99C0",7,20,"014BA409",383,6400,69,35,"","00001010","00110101"
- packet round time always > 1000ms

RE: Using GPS and LTE

Martin — Mon, 20 Jan 2020 20:06:03 GMT

Some more information to point [3]:
- It seems that other people have the same issue https://devzone.nordicsemi.com/f/nordic-q-a/56680/nrf9160-low-average-power-problem
- The +CREG connection event is: +CEREG: 1,"025E","010EE008",7,,,"00001000","00110101" (active counter at lowest possible 16 seconds and tau at 23 hours)
- A manual query of +CREG afterwards tells me: +CEREG: 5,1,"025E","010EE008",7,,,"00001000","00110101" (illustrates the home/roaming)
- A manual %XMONITOR reports: %XMONITOR: 1,"","","22801","025E",7,20,"010EE008",232,6300,59,36,"","00001000","00110101"
- packet round time about 80-150ms