Cant establish connection MQTT - BC66-NA

Technical Subjects
1

Hi! Im using a qectel bc66-NA chip and I have tried several times to follow the example in the datasheet (BC66&BC66-NA MQTT Application Note) to connect the devices to AWS, but it never worked. I couldn’t go beyond the command “AT+QMTOPEN=3,“a3pupxb4was62j-ats.iot.us-east-2.amazonaws.com”,8883” because the module’s response indicates that it failed.

We suspect that the issue may lie in the device’s acceptance of the certificates since the module’s response is ALWAYS “+QSSLCFG: 1,5,“cacert”,0”, even though we have tried with several certificates. Is there any possibility that the module only accepts certificates up to a certain number of characters?

Furthermore, I have already tried connecting to AWS using the MQTT fx tool application, and it worked correctly, eliminating the possibility of the issue being on the AWS side.

2

Can you send your command flow and let’s see what the problem is?

3

Of course!!

But now im with a new problem. I cant connect with MQTT server because i receive all the time a Error message.

Visualization window
AT+QSCLK=0
OK

AT+QSSLCFG=1,5,“seclevel”,2
OK

AT+QSSLCFG=1,5,“cacert”

+QSSLCFG: 1,5,“cacert”,1187
OK

AT+QSSLCFG=1,5,“clientcert”

+QSSLCFG: 1,5,“clientcert”,1223
OK

AT+QSSLCFG=1,5,“clientkey”

+QSSLCFG: 1,5,“clientkey”,1675
OK

AT+QSCLK=1
OK

AT+QMTCFG=“ssl”,3,1,1,5
OK

AT+QMTCFG=“version”,3,4
OK

AT+QMTOPEN=3,“a37v7766duc57r-ats.iot.eu-north-1.amazonaws.com”,8883
OK

AT+QMTCONN=3,“clientExample”
ERROR

Im not receiving any confirmation by QMTOPEN… but if when i didnt sent correctly some certificate, i received +QMTOPEN: 3,-1.

Need some help.
Regards