no, sorry, I don't have such a list. But if the error code is from an AT command you should be able to find its meaning from the AT command document linked on the product page.

Thanks
Felix

sure, here you are:

• Signal Quality: 17
• MQTT-Connection: 0
• Network Registration: 7
• GPRS Network Registration: 5

and when connected to MQTT broker

• MQTT-Connection: 1

Thanks
Felix

I have successfully connected, subscribed and published to the following free MQTT brokers: mqtt.m5stack.com, broker.mqtt.cool, test.mosquitto.org, broker.hivemq.com, broker.emqx.io, and public.mqttserver.eu using below UIFlow:

Thanks
Felix

not exactly; I use an C-Back NB-loT Global version (SIM7020G) which I connected to an M5Atom the same way it is connected in the AtomDTU NB-IoT.

And no, I do not need to add the NB-IoT unit for the Init NB-IoT DTU block to work.

Thanks
Felix

Do you also use the Atom DTU NB-IoT ?

no, I meant in UIFlow1 with M5Atom selected. Then it's under Base - DTU - NB-IoT - MQTT. There even is an MQTT example.

Thanks
Felix

hmm, that's a tricky one. Now that your modem gets an IP address; have you tried the official MQTT blocks?

Thanks
Felix

I see no difference...
The orange part is working and the tree other is not working

• Domainname
• IP-Address
• Dyndns
  not working...
  test.mosquitto.org is working fine.

I am happy to hear you got it working.

Thanks
Felix

@felmue : many thanks

Felix

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.

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

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

AT+COPS=1,2,"22801"

Thanks
Felix

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

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

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

Now, ih have deactivated and new activated the SIM.

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

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

:-)