I am using SIM808 module. It's working fine with normal MQTT over TCP. But it's not working while implementing secured MQTT.
I am sending this command (
AT+SSLSETROOT="C:\USER\HENRY_SSL.CRT") for set the root certificate(referred this document "SIM800 Series_MQTT_Application Note_V1.03"), the response I'm getting from gsm
"+CME ERROR: unknown".
If I'm using this command (
AT+SMSSL=1), same error I'm getting. I checked with HTTP commands it's working fine, But
AT+HTTPSSL=1command not working. The sim808 not responding SSL related commands.
But as per the simcom website sim808 supports SSL. Is I need to upgrade any firmware?