Building a simple web server on an ESP8266 module lets you show your sensor readings on a web page that opens from any phone or computer on the same network, with no external internet infrastructure required.
Components needed
An ESP8266 Wi-Fi module (such as the ESP8266-01 or ESP8266-12), an Arduino board (Uno or Mega), an LM35 temperature sensor to provide real data to display, and a dedicated 3.3V regulator to power the module.
Wiring it up
The ESP8266 must be powered exclusively at 3.3V through a separate regulator, and should never be connected directly to the Arduino's 5V output. The module's TX pin connects to the Arduino's RX pin, and its RX pin to the Arduino's TX pin — keeping in mind that the ESP8266's I/O pins run on 3.3V logic and are not compatible with the 5V digital signals coming directly from the Arduino, so it's best to use a simple step-down circuit (a voltage divider or logic level shifter) on the TX line coming from the Arduino.
How it works
The Arduino communicates with the ESP8266 module using text-based AT commands sent over the serial connection. The module runs in Access Point mode, broadcasting its own Wi-Fi network; once a device connects to that network and navigates to the default address 192.168.4.1, the server sends a simple HTML page showing the current temperature reading from the LM35 sensor, which can be refreshed by reloading the page or through periodic auto-refresh.
You can find ESP8266 modules and suitable voltage regulators at Juthour Tech.
اترك تعليقا