gnss sample failing

RE: gnss sample failing

Kazi Afroza Sultana — Mon, 29 Aug 2022 13:33:34 GMT

Hello,

Have you tested other samples than GNSS ? Does LTE work fine? looking at these pin description , can not make a concreted comment. It would be helpful if we could look at schematic design.

Thanks.

Best Regards,

Kazi Afroza Sultana

RE: gnss sample failing

okwestern — Wed, 24 Aug 2022 14:04:38 GMT

Hello!

Yes, newest firmware 1.3.2.

The only change directly relating to the nRF9160 is (except almost all signals have been routed to other more convenient pins, but that shouldn't interfere?):

-a 100k pulldown on COEX2 (although we didn't connect COEX2, so the resistor will be removed)

-connecting COEX0 to a nRF52840 and a LNA with a 1M pull-down.

-connected sim card detect pin to the socket. But problem persists both with and without sim card inserted.

I don't know if pulling any of the below pins will interfere at boot / modem init, but we have physical pullups on:

-P0.08 (4.7k)

-P0.09 (4.7k)

-P0.12 (47k)

-P0.13 (47k)

-P0.18 (100k)

-P0.23 (100k)

-P0.26 (10k)

-P0.30 (10k)

MAGPIO0/1/2, COEX1, SCLK/SDATA are all floating.

It's a very big and complex schematic (9 pages), so i would avoid it (or I have to clean it up good first).

I don't see how the matching and SAW filters could prevent the modem for initialize, unless it has some internal mechanism for disabling modem at antenna disconnect?

It's been confirmed to not work on the both prototypes we've assembled so far, so I doubt it is assembly.

RE: gnss sample failing

Kazi Afroza Sultana — Wed, 24 Aug 2022 13:45:54 GMT

Hello,

Thanks for your queries.

I can see an error like ''gnss_sample: Failed to initialize modem'' . Have you updated the modem firmware?

'Rewamped the matching and added SAW filters. '' I would like to know more about this. After doing this change, GNSS sample does not work on second prototype? You may send the schematic design of your prototype.

Best Regards,

kazi Afroza Sultana