IoT Weather Station using ESP32 and BME Sensor
Monitoring weather conditions is a classic IoT project.
In this project, we will build a real-time weather station using an ESP32 and a BME280/BME680 sensor to measure:
- Temperature (°C)
- Humidity (%)
- Atmospheric Pressure (hPa)
The ESP32 will send the data over Wi-Fi to a web dashboard, cloud server, or MQTT broker, making it accessible from anywhere.
Hardware Requirements
- ESP32 Development Board
- BME280 or BME680 sensor module
- Jumper wires and breadboard
- USB cable for programming
Working Principle
Sensor Measurement:
- BME280/BME680 communicates with ESP32 via I2C (SDA/SCL) or SPI.
- Provides accurate temperature, humidity, and pressure readings.
Data Transmission:
- ESP32 connects to Wi-Fi.
- Publishes data to a web server, cloud database, or MQTT broker.
Visualization:
- Data can be displayed in real-time using web dashboard, Blynk, Thingspeak, or Home Assistant.
Arduino Code Example
We’ll use the Adafruit BME280 library. Install via Arduino IDE Library Manager.
c
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
#include <WiFi.h>
#include <HTTPClient.h>
#define SEALEVELPRESSURE_HPA (1013.25)
const char* ssid = "Your_SSID";
const char* password = "Your_PASSWORD";
Adafruit_BME280 bme; // I2C
void setup() {
Serial.begin(115200);
// Initialize BME280
if (!bme.begin(0x76)) { // check sensor I2C address
Serial.println("Could not find BME280 sensor!");
while (1);
}
// Connect to Wi-Fi
WiFi.begin(ssid, password);
Serial.print("Connecting to Wi-Fi");
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("\nWi-Fi connected!");
}
void loop() {
float temperature = bme.readTemperature(); // °C
float humidity = bme.readHumidity(); // %
float pressure = bme.readPressure() / 100.0F; // hPa
Serial.print("Temperature: "); Serial.print(temperature); Serial.println(" °C");
Serial.print("Humidity: "); Serial.print(humidity); Serial.println(" %");
Serial.print("Pressure: "); Serial.print(pressure); Serial.println(" hPa");
Serial.println("------------------------");
// Optional: Send data to web server
if (WiFi.status() == WL_CONNECTED) {
HTTPClient http;
String url = "http://yourserver.com/log?temp=" + String(temperature) +
"&hum=" + String(humidity) + "&pres=" + String(pressure);
http.begin(url);
int httpCode = http.GET();
if (httpCode > 0) {
Serial.println("Data sent successfully");
}
http.end();
}
delay(5000); // read every 5 seconds
}How to Use
Connect the BME sensor to ESP32:
VCC → 3.3V
GND → GND
SDA → GPIO21
SCL → GPIO22
Upload the code to ESP32 and open Serial Monitor.