we are in a crisis. Our project is being submitted very soon and we have put a lot of effort into it.
Any help would be greatly appreciated!
We bought ESP8266 ESP-01 Wi-Fi module and we’re trying to connect it to our Firebase project by running the AT+CIPSTART command, but we’re getting an ERROR response from it, followed by a CLOSED response.
We could also connect to Firebase for about 5 months and up until a week and a half ago
A week and a half ago it worked few times, but after that, AT+CIPSTART returned ERROR CLOSED time after time.
1.We tried switching between different Wi-Fi networks and got the same results.
2.We can create TCP connections with HTTP websites.
3.We’re issuing AT commands to the Wi-Fi module via a STM32 microcontroller that is connected to it and to our Windows PC via a serial cable.
4.We’re using a terminal window in our PC to issue command to the Wi-Fi module.
5.We’re connecting to our AP, setting the SSL size to 4096 (helped solving some connectivity issues in the past), then connecting to Firebase.
6.We do not use AT project or certificate files
7.We use AT version: 220.127.116.11 (we found it by the command AT +GMR)
AT commands details:
AT+RST (reset the module)
AT+CWMODE=1 (set the Wi-Fi mode to station mode)
AT+CWJAP="SSID","PWD" (connect to a Wi-Fi network)
AT+CIFSR (get the Wi-Fi module IP)
AT+CIPSSLSIZE=4096 (change the SSL buffer size)
AT+CIPSTART="SSL","project-name-rtdb.firebaseio.com",443 (establish a SSL connection)
AT+CIPSEND=300 (send data)
Wi-Fi module: MakerFocus ESP8266
STM32 microcontroller: STM32 Nucleo-64 board STM32F103RB
ESP AT Commands Set
ESP8266 AT Instruction Set 3.0.3