Measuring Temperature and Barometric Pressure with Arduino

What is a BMP280?

The BMP280 is a digital sensor by Bosch Sensortech that measures temperature, barometric pressure, and altitude. It is an improved version of the BMP180 with better accuracy, power efficiency, and smaller size.

Features

• Temperature range: -40º to 85ºC (±1.0ºC accuracy)
• Pressure range: 300hPa to 1110hPa (±1.0hPa accuracy)
• Altitude estimation: ±1 meter precision
• Improved resolution: 0.01ºC (temperature), 0.16Pa (pressure)
• Low power consumption: 2.7 µA at 1Hz

Wiring Diagram

Connect the BMP280 sensor as follows:

• GND: Ground
• VCC: 3.3V or 5V (depending on your module)
• SDA: Arduino's SDA (A4 on Uno, Nano)
• SCL: Arduino's SCL (A5 on Uno, Nano)

Code Example

Use the Adafruit BMP280 library to get temperature, pressure, and altitude readings. Install the library from Adafruit's GitHub repository.

#include 

Adafruit_BMP280 bmp;  // Create BMP280 object

void setup() {
  Serial.begin(9600);
  Serial.println(F("BMP280 test"));

  if (!bmp.begin()) {
    Serial.println(F("Could not find a valid BMP280 sensor, check wiring!"));
    while (1);
  }

  bmp.setSampling(Adafruit_BMP280::MODE_NORMAL,
                  Adafruit_BMP280::SAMPLING_X2,  // Temp. oversampling
                  Adafruit_BMP280::SAMPLING_X16, // Pressure oversampling
                  Adafruit_BMP280::FILTER_X16,   // Filtering
                  Adafruit_BMP280::STANDBY_MS_500); // Standby time
}

void loop() {
  Serial.print(F("Temperature = "));
  Serial.print(bmp.readTemperature());
  Serial.println(" *C");

  Serial.print(F("Pressure = "));
  Serial.print(bmp.readPressure());
  Serial.println(" Pa");

  Serial.print(F("Altitude = "));
  Serial.print(bmp.readAltitude(1013.25)); // Adjust sea-level pressure as necessary
  Serial.println(" m");

  Serial.println();
  delay(2000);
}