AtomDTU NB-IoT

[Felix22]

hello
Have any of you gotten the Atom DTU NB-IoT to work?
I have a SIM from q.beyond/iot-sim.com.
It shows me a provider, but I can't establish a connection or nothing arrives in the q.beyond portal.
With UIFlow it hangs during initialization.
All current C examples do not run (anymore) and abort with error messages when compiling.
The red LED next to the antenna lights up constantly and the blue LED flashes quickly.
Could anyone help me, please.
Best regards
Felix

[felmue]

Hello @Felix22

in UIFlow1 Init NB-IoT DTU block tries a series of AT commands and if one of them is not successful it does not continue and hangs. The AT commands test for proper communication with the modem, then checks that no PIN is set and finally checks if the modem has registered with the provider.

So lets try to break that down and manually setup the serial connection and try one AT command at the time.

Below are some UIFlow1 blocks to simply check if the communication with the modem works.

The result in the terminal should be: b'\r\nOK\r\n' or b'AT\r\r\nOK\r\n'.

Let me know what you get and we go from there.

Thanks
Felix

[Felix22]

thanks
The return is
b'AT\r\r\nOK\r\n'

[felmue]

Hello @Felix22

ok, his means your modem is alive and responding.

Now, please try the following commands (which are the same as are used in Init NB-IoT DTU) block, but we can see the responses of the modem:

You should get something like:

b'\r\nOK\r\n'
b'\r\nOK\r\n'
b'\r\nOK\r\n'
b'\r\n+CPIN: READY\r\n\r\nOK\r\n'
b'\r\n+CGCONTRDP: 1,5,"<YourAPN>","10.100.100.100.255.255.255.0"\r\n\r\nOK\r\n'

Thanks
Felix

[Felix22]

Yesterday i have made the similar with Arduino-C-Code and become as Response the carrier Code 28801 = Swisscom-Network but no response in q.beyond-Control-Panel...

I have tested with a complete new AtomDTU. Flash with v1.13.2

I think, no response :-((

[felmue]

Hello @Felix22

I just read in the q.beyond FAQ says that the SIM card needs to be activated.

I assume you did that already?

Thanks
Felix

[Felix22]

Yes, I have do it. She is activated.
The connection from 17.2.24 comes from a old iPhone

[felmue]

Hello @Felix22

ok, let's see what providers your modem can see.

Note: the last AT command AT+COPS=? can take a couple of minutes as it has to scan through all bands. (in my case it took about 3 minutes.)

Expected output:

b'\r\nOK\r\n'
b'\r\nOK\r\n'
b'\r\n+COPS: 0,2,"22801",9\r\n\r\nOK\r\n'
None
b'\r\n+COPS: (1,"SWISS GSM","SWISS","22801",9),(1,"sunrise","sunrise","22802",9),,(0-4),(0-2)\r\n\r\nOK\r\n'

Thanks
Felix

[Felix22]

:-)

[felmue]

Hello @Felix22

ok, so it seem that the modem is registered with Swisscom, but doesn't get an IP address since AT+COPS? succeeds, but AT+CGCONTRDP fails.

At this point I am not sure what might be the issue. Is there anything in the q.beyond portal, like a log showing some error?

Also since you used your iPhone with that SIM card before there might be some kind of security check not accepting a connection from a different device. On the q.beyond portal, is there a way to reset / clear the data from the previous connection?

Thanks
Felix

[Felix22]

Interesting, this is the response from the DigitalRepublic-SIM-Card how has no NarrowBand.
He see the Network also...

Now, ih have deactivated and new activated the SIM.

Now its a "3" = "Operator forbidden" (?) (Swisscom)
and
1 for sunrise

[felmue]

Hello @Felix22

hmm, strange. Do you know which roaming partner (Swisscom and/or Sunrise) q.beyond has in Switzerland for NB-IoT? Maybe worth checking with q.beyond support.

Thanks
Felix

[Felix22]

Many thanks.

I will write to the support from q.beyond.

If the connection will go on. What are the Code for an MQTT connection ?
If i become an IP-Address, can i use the "normal" MQTT Blockly ??

Regards,
Felix

[felmue]

Hello @Felix22

please refer to the SIM7020 documentation for MQTT commands. You can find the PDFs here - section Related Link.

As soon as the modem gets an IP address the last AT command AT+CGCONTRDP sent by Init NB-IoT DTU block should succeed and then you can use all the other MQTT blocks.

Thanks
Felix

[Felix22]

a.beyond say, she works in Switzerland with Swisscom NB.
How can I explicit connect to Swisscom (AT-Command) ?

[felmue]

Hello @Felix22

AT+COPS=1,2,"22801"

Thanks
Felix

[Felix22]

b'AT+CSQ\r\r\n+CSQ: 18,0\r\n\r\nOK\r\n'
men, i have a signal ?

b'AT+CSTT="iotsim.melita.io","",""\r\r\nOK\r\n'
b'AT+CSTT?\r\r\n+CSTT: "iotsim.melita.io","",""\r\n\r\nOK\r\n'
APN is set correct ?

b'AT+CGREG?\r\r\n+CGREG: 0,5\r\n\r\nOK\r\n'
Registered ?

b'AT+COPS: 1,2,"22801"\r\r\nERROR\r\n'
b'AT+COPS?\r\r\n+COPS: 0,2,"22801",9\r\n\r\nOK\r\n'

b'AT+CGACT?\r\r\n+CGACT: 1,0\r\n\r\nOK\r\n'

If i have a connection, do i become an ip-address ?
with the command AT+CIFSR

[felmue]

Hello @Felix22

it is my understanding that AT+CIFSR returns the local IP address in a TCP or UDP connection. (It's an AT command for compatibility with SIM800.)

See PDF document SIM7020 Series_TCPIP_Application Note_V1.04 - 6.2 TCP Client Connection. You'll find the link to the PDF here.

The way I use to set the APN is described in the same TCP/IP PDF - 3.2 APN Manual Configuration.

Thanks
Felix

[Felix22]

Result:

b'\r\nOK\r\n'
b'\r\nOK\r\n'
b'\r\nOK\r\n'
b'\r\nOK\r\n'
b'\r\nOK\r\n\r\n+CPIN: READY\r\n'
b'\r\n+CGREG: 0,5\r\n\r\nOK\r\n'
b'\r\n+CGCONTRDP: 1,5,"iotsim.melita.io","10.xx.xx.xx.255.255.255.0",,"212.xx.xx.xx","212.xx.xx.xx",,,,,1500\r\n\r\nOK\r\n'

Im a big step wider... now, i have become my ip address... :-)
Now i think... MQTT, next step.

[Felix22]

Juhuuuu !!
It works !
More Information and the solution will follow...

@felmue : many thanks

Felix