I’ve been experimenting lately with the SIM7600E MQTT commands and having some difficulty.
I’ve set up an MQTT broker on AWS IoT and downloaded the certificates into the SIM7600E.
I have essentially followed exactly the same steps as outlined in the following blog post: here
Which is basically the same steps as outlined in example 3.4 of the document:
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual_V1.00.pdf,
which is located here: simcom link
I can connect to the AWS IoT broker (the command AT+CMQTTCONNECT? confirms this), and when I publish to a topic
I get the response +CMQTTPUB: 0,0 (i.e., success). However, I don’t see the message appear in the AWS test console.
I can, however, successfully publish to the AWS broker when I use the MQTT.fx PC tool.
To investigate further, I set up a mosquitto MQTT broker on an EC2 linux instance with no SSL certification (so on port 1883).
Again, I can successfully publish to this broker using the MQTT.fx desktop tool from my PC.
This time on the SIM7600E, I can successfully ping the server using AT+CPING, but the AT+CMQTTCONNECT fails. The command
AT+CMQTTCONNECT? returns the following error: +CMQTTCONNECT: 0,26 (socket is closed by server).
Wondering if you have had any luck with the SIM7600E MQTT commands and can perhaps suggest where I’m going wrong?