How to use the BMP180 Barometric Pressure Sensor with Arduino

INTRODUCTION

A barometric pressure sensor measures the surrounding atmospheric pressure.

APPLICATIONS

It is used in the engine management system of the vehicles to measure the atmospheric pressure of the environment that the vehicle is driving in. It is also used for weather forecasting and measurements.

WIRING DIAGRAM

SDA – A4

SCL – A5

GND – GND

VCC – 3V

 

Note: Download the required library and follow steps below:

• Download the bmp085 library from link below 
• https://learn.adafruit.com/bmp085/using-the-bmp085-api-v2
• Rename the folder to name without “-master” and put the folder in “arduino/libraries”.
• You will also need the Adafruit Unified Sensor Library, from link below
• https://github.com/adafruit/Adafruit_Sensor
• Here is a guide to installing and using libraries

https://learn.adafruit.com/adafruit-all-about-arduino-libraries-install-use

 

CODE (courtesy of Adafruit)

#include <Wire.h> //Including wire library

#include <SFE_BMP180.h> //Including BMP180 library

#define ALTITUDE 35.6 //Altitude where I live (change this to your altitude)

SFE_BMP180 pressure; //Creating an object

void setup() {
  Serial.begin(9600); //Starting serial communication

  Serial.println("Program started");

  if (pressure.begin()) //If initialization was successful, continue
    Serial.println("BMP180 init success");
  else //Else, stop code forever
  {
    Serial.println("BMP180 init fail");
    while (1);
  }
}

void loop() {
  char status;
  double T, P, p0; //Creating variables for temp, pressure and relative pressure

  Serial.print("You provided altitude: ");
  Serial.print(ALTITUDE, 0);
  Serial.println(" meters");

  status = pressure.startTemperature();
  if (status != 0) {
    delay(status);

    status = pressure.getTemperature(T);
if (status != 0) {
      Serial.print("Temp: ");
      Serial.print(T, 1);
      Serial.println(" deg C");

      status = pressure.startPressure(3);

      if (status != 0) {
        delay(status);

        status = pressure.getPressure(P, T);
        if (status != 0) {
          Serial.print("Pressure measurement: ");
          Serial.print(P);
          Serial.println(" hPa (Pressure measured using temperature)");

          p0 = pressure.sealevel(P, ALTITUDE);
          Serial.print("Relative (sea-level) pressure: ");
          Serial.print(p0);
          Serial.println("hPa");
        }
      }
    }
  }  
  delay(1000);
}

END RESULT

Open serial monitor. The current pressure should be displayed

ADDITIONAL RESOURCES

https://learn.adafruit.com/bmp085/using-the-bmp085-api-v2