AtomDTU NB-IoT

[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

[felmue]

Hello @Felix22

I am happy to hear you got it working.

Thanks
Felix

[Felix22]

now, i have a new problem.
The mqtt broker test.mosquitto.test is working with my Blockly but my own Broker on my Server at home in a Docker container is not available from AtomDTU. But with a Internet Test Tool, it is working ( https://testclient-cloud.mqtt.cool/ )

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.

[felmue]

Hello @Felix22

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

Thanks
Felix

[Felix22]

you mean the blocks at "Fortgeschritten" / MQTT ?
over there it connects over Wlan/Wifi...
Is there a MQTT-Block how i can say the RX and TX pin ?

[felmue]

Hello @Felix22

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

[Felix22]

this hangs by the "Init NB-IoT DTU" Blockly if you have not Load the Unit NB-IoT.
But with the NB-IoT-Unit and the correct RX/TX Pin's it works fine.

Do you also use the Atom DTU NB-IoT ?

[felmue]

Hello @Felix22

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

[felmue]

Hello @Felix22

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

[Felix22]

Do you have a list with the Status Codes ?
Signal Qualität: 16
MQTT-Connection: 0
Network-Registration: 7
GPRS network registration

[felmue]

Hello @Felix22

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

[Felix22]

Hello Felix
By the error code I meant what the individual numbers mean.
Each code 0 to x
Do you have a code list ?
Greeting
Felix

[felmue]

Hello @Felix22

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