nRF9160 DK software update

[SergioT]

I used SES and wrote a printf message at main entrance: when I run in nRF Connect I can see the message that I wrote just after I press the RESET button (OK). Still, as I can't get a connection to NB-IoT, I decided to roll back to the mfw_nrf9160_0.7.0-alpha version: I flashed the board but when I run it I still see my printf message, meaning that still the old code is running.

Can you explain? 

I am still not able to connect although I could before trials with SES...

[MJD093]

mfw is the modem firmware for the nRF9160 radio modem, it is not the same as the application firmware which is written to the partitioned flash memory. Changes to the modem firmware will not change the firmware you have loaded using SES; unless you reflash the flash memory using SES or CLI, nothing will change in that regard.

[SergioT]

So, this is like a Softdevice in the nRF51 family: I wondered already. Thanks.

However, I already found out why the unit doesn't connect: AT%XSYSTEMMODE? returns 1,0,0,0, even I make the sequence below:

AT+CFUN=4
AT%XSYSTEMMODE=0,1,0,2
AT+CFUN=0

After reset and start, I send AT%XSYSTEMOMODE? and I get 1,0,0,0!

If I send:

AT+CFUN=4
AT%XSYSTEMMODE=0,1,0,2
AT+CFUN=1

if I am fast enough and send AT%XSYSTEMMMODE? I get 0,1,0,2 but a few seconds later the system resets and then, after start (AT+CFUN=1) I get 1,0,0,0 if I ask for system mode.

It just doesn't accept 0,1,0,2!

What can I do?

[MJD093]

You do not need to reset the whole device. Only enter the following commands after reseting the Development Kit:

AT+CFUN=4 //ensure the modem is offline

AT%XSYSTEMMODE=0,1,0,0 //set modem to NB-IoT
AT+CFUN=1 //start modem

This will start the modem and it will begin trying to attach to the LTE network for NB-IoT. There is no need to reset the device again after this as this will just place the modem back into CFUN=4 mode and clear the XSYSTEMMODE selection.

I do not have an answer to why the LTE preference is not working but I don't use it in my application, I just specify 0,1,0,0 whenever I need to swap to LTE from GPS mode.

You can now run the command AT+CEREG? to check if the device has been able to connect to the network, be aware this may take a few minutes depending on the network coverage and signal strength.

[SergioT]

Sorry, I can't answer to your comment because I see no REPLY button, so I do it here:

The system crashes the moment a connection is established:

AT+CFUN=1

+CEREG: 2,"CB52","023AAF11",9

OK

+CGEnrf_cloud_connect failed: 22

V: ME PDN ACT 0,0

+CNEC_ESM: 50,0

+CEREG: 5,"CB52","023AAF11",9

+CIND: "service",1

+CIND: "roam",1

AT+COPS=3,2

+CGEV: ME PDN DEACT 0

+CEREG: 0,"CB52","023AAF11",9

+CIND: "service",0

+CIND: "roam",0

+CGEV: ME DETACH

%CESQ: 255,0

%XSIM: 1

%XSIM: 0

OK

AT+CGDCONT?

***** Booting Zephyr OS v1.14.99-ncs1 *****

Flash region(...)

Maybe this trace can help to find identifying the problem...

[MJD093]

What application are you running?

nrf_cloud_connect failed: 22

Unless I am mistaken, this is an error message for the asset_tracker application which handles modem control via lte_lc.c. It is therefore all scripted code and doesn't require manual at commands.

The above at commands are for the at_client application which allows you to manually configure the modem.

EDIT:

I wasn't mistaken, that error is only used in two files in the entire ncs directory, lte_ble_gateway main.c and asset_tracker main.c, you must have one of these, 99% likely it's the asset_tracker

[MJD093]

If you are in fact running the asset_tracker application, please see the following lines in lte_lc.c
https://github.com/NordicPlayground/fw-nrfconnect-nrf/blob/master/drivers/lte_link_control/lte_lc.c#L46-L48
These lines indicate that you need to add an additional line to your prj.conf file to configure the device to NB-IoT in that application. (or any application that directly uses LTE Link Control (lte_lc) to handle modem control)

Try adding into the prj.conf file:

CONFIG_LTE_NETWORK_MODE_NBIOT=y