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Guide for BMP180 Barometric Sensor with Arduino

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This post is about how to use the BMP180 barometric sensor with the Arduino. It is also applicable for other similar barometric sensors.

Introducing the BMP180 barometric sensor

The BMP180 barometric sensor (model GY-68) is the one in  the following figure (front and back view). It is a very small module with 1mm x 1.1mm (0.039in x 0.043in).

sensor

It measures the absolute pressure of the air around it. It has a measuring range from 300 to 1100hPa with an accuracy down to 0.02 hPa. It can also measure altitude and temperature.

The BMP180 barometric sensor communicates via I2C interface. This means that it communicates with the Arduino using just 2 pins.

Where to buy?

This sensor is very cheap. You can buy one for approximately $3 on eBay (view on eBay).

Pin wiring

Wiring the sensor to the Arduino is pretty straightforward:

Pin Wiring to Arduino Uno
Vin 5V
GND GND
SCL A5
SDA A4

Schematics

Wire your sensor to the Arduino as shown in the schematics below.

bmp180-barometris-sensor_bb

Code

To control the BMP180 barometric sensor, you need to install the SFE_BMP180 Library.

Installing the SFE_BMP180 Library

  1. Click here to download the SFE_BMP180 library. You should have a .zip folder in your Downloads folder
  2. Unzip the .zip folder and you should get BMP180_Breakout_Arduino_Library-master folder
  3. Rename your folder from BMP180_Breakout_Arduino_Library-master to BMP180_Breakout_Arduino_Library 
  4. Move the BMP180_Breakout_Arduino_Library folder to your Arduino IDE installation libraries folder
  5. Finally, re-open your Arduino IDE

Go to File > Examples >SparkfunBMP180 > SFE_BMP180_example.

This example is very well commented and explained on how the sensor reads the pressure, temperature and computes the altitude.

Set the altitude

Before uploading the code, you need to set up your current altitude. Go to elevationmap.net, insert your address and check your altitude’s location. Set your altitude in the code. The place where you should write your altitude is commented.

set-the-altitude

Demonstration

After uploading the code, open your serial monitor at a baud rate of 9600.

You’ll be able to see your sensor readings.

serial-monitor

Wrapping up

The BMP180 is an interesting sensor to be used in your own weather station.

Because the pressure changes with the altitude, this sensor is also able to compute the altitude.

If you would like to build a complete weather station, here’s some recommended guides:

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