In our project we send HTTPS requests to Realtime DB (in order to add data to it), using the ESP8266 Wi-Fi component and AT commands.
For months we were able to communicate with Firebase, but last week the communication failed in the AT+CIPSTART phase.
We have been trying to find the solution for the problem for a week without success. We would greatly appreciate any help!
Order of commands:
AT+CWMODE=1
AT+CWJAP="NETWORK_NAME","PASSWORD"
AT+CIPSSLSIZE=4096
AT+CIPSTART="SSL","project-name-default-rtdb.firebaseio.com",443
-----THE ERROR IS HERE-----
The error:
ERROR
CLOSED
Note: We were able to write a TCP message to another site,but for Firebase we need to use SSL