nRF9160 Connectivity issue

[dhandzic]

We have designed a board using the nRF9160 SiP and LWM2M. When testing with poor network connection (~  -118dB) we experience a strange behaviour. From monitoring the current profile it looks like the device is in DRX mode but it is no longer registered at the server. We have eDRX turned of and Registration Lifetime set to 90s. Not sure if this question is for Nordic or Telia, I will ask both.

Best regards

Dirk

[Øyvind]

Hi Dirk, 

Can you provide an output from AT client, which shows more information about the connection? Also, it may be required that you also do modem trace.

Kind regards,
Øyvind

[dhandzic]

Hi Öyvind,

I am running a LWM2M client application. I dont think the AT client will replicate this behaviour. I am not sure how to get a modem trace while using our LWM2M application.

Best regards

Dirk

[dhandzic]

Hi Öyvind,

I have changed the uart in bsd_os.c to uart2 but the problem is still the same. Trace Collector shows "No device available" and after a while the screen turns white. A couple of weeks ago there has been a similar problem with the LTE Link Monitor. I think it is the same bug when the app has to talk to a non DK board. The FTDI cables are usually no problem.

Best regards

Dirk

[Øyvind]

Can you please share your current project with me? 

Thanks!

Kind regards,
Øyvind

[dhandzic]

Q3IoT_zephyr_boards_arm.zip

Q3IoT210121.zip

Hi Öyvind,

here are my board def files and the entire project map.

Best regards

Dirk

[Øyvind]

When connecting to LTE Link Monitor with your device, can you please screenshot what shows in Window? Please screenshot the whole LTE Link Monitor window.

[Øyvind]

Also, can you please provide information from Device Manager regarding the connection? I.e. the COM ports and FTDI cable. Please include VIDs and PIDs

Try the following in the Trace Collector:
Ctrl+Shift+I to enter developer console. Then in the console please enter the following command:

require('serialport').list().then(a => a.forEach(p => console.log(p.path, p.vendorId, p.productId)))

This should output info on the left hand side under "info". The following was outputed in mine:

[dhandzic]