BC660K how to use AT-QMTPUB

Hi,

I am trying to connect to Mqtt server through a BC660K. But I get a error when publish by AT+QMTPUB.

For test, I am using a mosquitto mqtt server installed on google cloud.


Sending: AT+CFUN=1
Received: RDY

+CFUN: 1

+CPIN: READY

+IP: 10.42.56.221

+CTZEU: “+8”,1,“2024/09/10,08:52:51”
Sending: AT+CGDCONT=1,“IP”,“iot.1nce.net
Received: OK
Sending: AT+CEREG?
Received: +CEREG: 0,5

OK
Sending: AT+COPS?
Received: +COPS: 0,2,“23820”,9

OK
Sending: AT+CGPADDR?
Received: +CGPADDR: 0,“10.42.56.221”
+CGPADDR: 1

OK
Sending: AT+CSQ
Received: +CSQ: 10,0

OK
Sending: AT+QPING=0,“35.198.185.137” # Mqtt server
Received: OK

+QPING: 569

+QPING: 0,35.198.185.137,32,2829,57

+QPING: 0,35.198.185.137,32,575,57

+QPING: 0,35.198.185.137,32,586,57

+QPING: 0,4,3,1,575,2829,1330
Sending: AT+QMTCFG=“aliauth”,0,“user”,“35.198.185.137”,“password”
Received: OK
Sending: AT+QMTOPEN=0,“35.198.185.137”,1883
Received: OK

+QMTOPEN: 0,0
Sending: AT+QMTCONN=0,“ESP32-S2-001”
Received: OK

+QMTCONN: 0,0,5

+QMTSTAT: 0,4
Sending: AT+QMTPUB=0,0,0,0,“ESP32-S2-001”,9,“Temp: 457”
Received: ERROR

I am struggling to find out how to use AT+QMTPUB.
AT+QMTPUB=? gives +QMTPUB: (0-4),(0-65535),(0-2),(0,1),,(0-1460),

Why do I get the error?

This configuration is only to connect ali cloud, if you connect to other MQTT server, you need to use the clientid, username, password by QMTCONN