nRF9160 DK - Allow program execution to continue without cellular connection

RE: nRF9160 DK - Allow program execution to continue without cellular connection

CoryJPAE — Mon, 06 May 2019 13:32:32 GMT

As a followup, executing the nrfjprog program with flags above fixed the issues I was seeing. I'm thinking most likely the sector erase flag.

I was able to successfully have the lte_ble_gateway sample project work as well. The program now executes without have an LTE connection.

RE: nRF9160 DK - Allow program execution to continue without cellular connection

Martin Lesund — Mon, 06 May 2019 12:02:43 GMT

Hi Cory,

From your log, it does not look like you are running the at_client sample, or at least the application has not started correctly.

I have added a precompiled .hex file which has merged the "at_client" and the "spm" (secure partition manager) (before: secure_boot):at_client.hex

Please flash via the command line: nrfjprog --program at_client.hex -f nrf91 --sectorerase -r --verify

And then connect the board and run the LTE link Monitor.

If you have any issues seeing any logs in the Terminal, please press the reset button on the nRF91 DK so you can see that the nrf91 sends out the logs from the initialization.

I recommend you to update the modem firmware on the custom board to the latest (0.7.0-15): https://www.nordicsemi.com/Products/Low-power-cellular-IoT/nRF9160/Download#infotabs

IMPORTANT NOTE:

There is a bug in the modem firmware version -> "mfw_nrf9160_0.7.0-15.alpha" which makes it start in "nb-iot mode" as default.
To change to the "LTE-M" mode you need to send an AT-Command.
- AT%XSYSTEMMODE=1,0,0,0 and then AT+CFUN=0 to save the changes into the modem flash.

When you restart your device it will now go into the LTE-M mode.

Best Regards,

Martin L.

RE: nRF9160 DK - Allow program execution to continue without cellular connection

CoryJPAE — Mon, 29 Apr 2019 15:20:15 GMT

Hi Martin,

Thank you for the reply.

Sorry about the link. There is no "Copy URL" at the specific page in Chrome or Edge, but here's the path: nRF91 Series -> nRF9160 -> nRF9160 Object Product Specification -> LTE Modem -> Introduction.

I performed the Git checkout procedure for NCS. No changes/updates.

I had already tried the latest modem firmware (mfwm1nrf9160068131alpha) and successfully updated the modem firmware, but I went ahead and perform the update against successfully.

We have tested that we do indeed have an LTE connection in the area (if we go outside...our building is a bit of a Faraday cage so it's easy to simulate LTE connection on/off by going inside/outside).

When I am outside with an LTE connection, I can issue modem AT commands no problem and see expected behavior.

When I am inside, if I issue: AT+CFUN=4 or any AT command for that matter, the nRF9160 via the nRFConnect tool reports a timeout. Note that nRFConnect does report opening a port to the modem.

Debugging via Embbedded Studio (stepping through the assembly code) reveals the nRF9160 DK is "stuck" (stuck isn't the best word but for lack of a better word) in a library function called "interface_socket_wait".

Below is a sample terminal output from nRFConnect while inside (no LTE connection):

Are we thinking that maybe I should try setting AT+CFUN=4 while having an LTE connection on the nRF9160 to enable Airplane mode and that subsequent reset(s) it will work?

Thank you!

RE: nRF9160 DK - Allow program execution to continue without cellular connection

Martin Lesund — Mon, 29 Apr 2019 13:50:52 GMT

Hi Cory,

[quote user=""] It seems the nRF9160 does NOT allow main program execution if there is NO cellular connection.[/quote]

This is not true.

There should not be any issue running the nrf9160 without any network connection. You can set the modem to different power saving modes (sleeping) or even shut it off if you like (AT+CFUN=4) while reading data from sensor etc.

The link you sent is unfortunately "broken", or at least shows the front page of the "nRF9160 DK".
If you want to link to something in "infocenter" please make sure to use the "Copy URL" button to get the correct URL for your selected page:

Please make sure to have the latest version of NCS:

cd ncs/nrf
git checkout master
git pull
west update

So you have all the new features and bug fixes.

Please make sure to have the latest modem firmware version: https://www.nordicsemi.com/Products/Low-power-cellular-IoT/nRF9160/Download#infotabs

This may actually solve the issues you may see, if not please provide the output log from the terminal.

Have you by the way tested with the "at_client" and LTE Link Monitor to confirm that you have network connection in your area?

Best regards,
Martin L.

RE: nRF9160 DK - Allow program execution to continue without cellular connection

CoryJPAE — Fri, 26 Apr 2019 13:17:51 GMT

Any help would be appreciated.

Thank you!