I’m trying to connect my Quectel module (using CAT-M1 network) to HiveMQ Cloud via MQTTS (port 8883), but the connection keeps failing with +QMTSTAT: 0,1.
Here’s what I’ve done so far:
1.Verified network connection:
AT+CEREG? → +CEREG: 0,5
AT+QIACT? → +QIACT: 1,1,1,“10.x.x.x”
AT+CSQ → +CSQ: 19,99
2.Uploaded the ISRG Root X1 certificate from Let’s Encrypt:
https://letsencrypt.org/certs/isrgrootx1.pem
Uploaded using:
AT+QFUPL=“cacert.pem”,1939,100
AT+QSSLCFG=“cacert”,0,“cacert.pem”
3.SSL and MQTT Configuration:
AT+QMTCFG=“ssl”,0,0,1
AT+QSSLCFG=“sslversion”,0,4
AT+QSSLCFG=“ciphersuite”,0,0xFFFF
AT+QSSLCFG=“seclevel”,0,1
AT+QSSLCFG=“ignorelocaltime”,0,1
AT+QSSLCFG=“sni”,0,1
4.Open and Connect:
AT+QMTOPEN=0,“xxxxxxxxxxxxxxxxxxxxxxxx.s2.eu.hivemq.cloud”,8883
→ +QMTOPEN: 0,0
AT+QMTCONN=0,“mqtt5”,“user”,“password”
→ +QMTSTAT: 0,1
Despite all of this, the connection is rejected. I’m not using any client certificate or client key, just the CA cert.
Question:
Why is the connection still failing with +QMTSTAT: 0,1 even after uploading the correct ISRG Root X1 certificate?
Is there anything I’m missing, like a required intermediate certificate or extra MQTT setting?
Thanks in advance for any help!
