Building a Weather Station with ESP-01 and DHT11 Sensor

Introduction: The ESP-01 is a popular and versatile Wi-Fi module that can be easily programmed and interfaced with various sensors. In this project, we will use the ESP-01 along with the DHT11 temperature and humidity sensor to create a simple weather station. We will measure temperature and humidity readings and display them on a web server hosted by the ESP-01.

Materials Required:

1. ESP-01 module
2. DHT11 temperature and humidity sensor
3. USB to TTL converter
4. Breadboard and jumper wires
5. 3.3V power supply
6. Arduino IDE and ESP8266 board support package

Circuit Diagram:

Steps:

1. Setting up Arduino IDE:

   • Open Arduino IDE and go to File > Preferences.
   • Add the following URL to the Additional Board Manager URLs: http://arduino.esp8266.com/stable/package_esp8266com_index.json
   • Go to Tools > Board > Boards Manager, search for "ESP8266" and install the package.

2. Connecting ESP-01:

   • Connect the ESP-01 to the USB to TTL converter as follows:
     • ESP-01 VCC to 3.3V, GND to GND, TX to RX, and RX to TX.
     • Enable GPIO0 and GPIO2 by connecting them to VCC with a 10k resistor.
   • Connect the DHT11 sensor to the ESP-01 as follows:
     • DHT11 VCC to 3.3V, GND to GND, and data pin to GPIO2.

3. Coding:

   • Open Arduino IDE and select the ESP8266 board from Tools > Board menu.
   • Use the following code to read temperature and humidity from the DHT11 sensor and host a web server to display the readings:

   • #include <ESP8266WiFi.h>
     #include <ESP8266WebServer.h>
     #include <DHT.h>

     const char* ssid = "your-ssid";
     const char* password = "your-password";
     DHT dht(2, DHT11);
     ESP8266WebServer server(80);

     void handleRoot() {
       float temperature = dht.readTemperature();
       float humidity = dht.readHumidity();
       String message = "Temperature: " + String(temperature) + "°C\nHumidity: " + String(humidity) + "%";
       server.send(200, "text/plain", message);
     }

     void setup() {
       Serial.begin(115200);
       WiFi.begin(ssid, password);
       while (WiFi.status() != WL_CONNECTED) {
         delay(1000);
         Serial.println("Connecting to WiFi...");
       }
       Serial.println("WiFi connected");
       dht.begin();
       server.on("/", handleRoot);
       server.begin();
       Serial.println("Web server started");
     }

     void loop() {
       server.handleClient();
     }
      

1. • Replace your-ssid and your-password with your Wi-Fi network credentials.
   • Testing:

Upload the code to the ESP-01.

• Open the serial monitor to view the ESP-01's IP address.
• Enter the IP address in a web browser to see the temperature and humidity readings.

Conclusion

In this project, we successfully built a weather station using the ESP-01 and DHT11 sensor. This project can be further expanded by adding more sensors or incorporating data logging capabilities. The ESP-01's flexibility and ease of use make it an ideal choice for IoT projects.