The ESP8266WiFi Config lets you configure the ESP8266 module on your Arduino device.
SSID: Specifies the available WiFi name.
Password: Specifies the WiFi security password.
ESP RX Pin -> Arduino: Specifies the pin that connects to the Arduino digital pin 3.
ESP TX Pin -> Arduino: Specifies the pin that connects to the Arduino digital pin 2.
Enable Serial Debug: When activated, displays the debug messages on the serial terminal (serial config 9600, 8, 1, 0, 0).
Edit MQTT Default Config: When activated, you can edit the default MQTT Client Configuration settings.
MQTT Max Packet Size: Specifies the maximum packet size. The default is 256.
MQTT Keep Alive Seconds: Specifies the keep alive period. That is, how often the client sends a PING message to the broker. The default time interval is 15 sec.
MQTT Socket Time Out Seconds: Lets you set the timeout manually. The default timeout is 15 sec.