RE: Using AT commands to connect to an MQTT broker

Albrecht Markus Schellenberger — Thu, 17 Feb 2022 15:11:43 GMT

Hello Stas,

[quote user=""]1) Could you please indicate the necessary sequence of commands required for the correct configuration and work with MQTT.[/quote]

I have tested this myself with a nRF9160 DK and the Serial LTE modem application in NCS v1.8.0 and it works as expected, see log below:

*** Booting Zephyr OS build v2.7.0-ncs1  ***
Ready
[00:00:00.205,871] <inf> slm: Serial LTE Modem
[00:00:00.234,954] <inf> slm_at_host: at_host init done

AT+CEREG=5
OK

AT+CFUN=1
OK

+CEREG: 2,"76C1","03113C00",7
+CEREG: 1,"76C1","03113C00",7,,,"00001010","11000001"

AT#XMQTTCON=1,"MyMQTT-Client-ID","","","test.mosquitto.org",1883
OK
#XMQTTEVT: 0,0

AT#XMQTTCON=0
#XMQTTEVT: 1,0
OK

[00:01:15.500,396] <err> slm_mqtt: POLLNVAL
[00:01:15.500,427] <inf> slm_mqtt: MQTT thread terminated

Port 1883 of test.mosquitto.org is “MQTT, unencrypted, unauthenticated”, so no username and passwort needed. For more information, see https://test.mosquitto.org/. I’m not sure if “mqtt.mosquitto.org” is a good idea for a client-id, nor if it is accepted by the server.

[quote user=""]2) The SIM card (iBASIS eSIM) used can be deactivated for some reason?[/quote]

I’m not sure if I understand this question. Can you elaborate?

Regards,

Markus