## Introduction: Determining the Pressure and Altitude Using GY-68 BMP180 and Arduino

### Overview

In many projects such as flying robots, weather stations, improving routing performance, sports and etc. measuring pressure and altitude is very important. In this tutorial, you’ll learn how to use the BMP180 sensor, which is one of the most commonly used sensors for measuring the pressure.

### What You Will Learn

• What the barometric pressure is.
• What the BOSCH BMP180 pressure sensor is.
• How to use the BOSCH BMP180 pressure sensor with Arduino.

## Step 1: What Is the Barometric Pressure?

Barometric pressure or atmospheric pressure results from the weight of the air on the earth. This pressure is about 1 kg per square centimeter at the sea level.

There are several units to express the atmospheric pressure, that can easily be converted to each other. The SI unit for measuring the pressure is Pascal (Pa).

The barometric pressure has an approximately linear inverse ratio with the altitude from the sea level so if we measure the barometric pressure of a place, we can calculate the altitude from the sea level using a simple mathematical operation.

## Step 2: GY-68 BOSCH BMP180 Pressure Sensor Features

One of the most common sensors for measuring the pressure and altitude is BOSCH BMP180. The most important features of this module are as follow:

• Pressure measurement range of 300 to 1100hPa
• -0.1hPa measuring accuracy for absolute pressure
• 12hPa measuring accuracy for relative pressure
• Low power consumption (5μA in standard mode and one sample per second)
• Internal temperature sensor with a precision of 0.5 °C
• Supporting I2C protocol for communication
• Fully calibrated

## Step 4: How to Use GY-68 BMP180 Pressure Sensor With Arduino?

This sensor is available as a module for easy use. The main parts of the BMP180 sensor module are:

• BMP180 sensor
• A 3.3-volt regulator. This regulator lets you connect the module to 5V.
• Required pull up resistors to communicate I2C properly