Using the BMP180 With the Raspberry Pi

Here’s a simple guide on how to use the BMP180 barometric pressure and temperature sensor with your Raspberry Pi. The BMP180 sensor can measure atmospheric pressure and temperature, making it useful for weather stations, altitude tracking, and other environmental monitoring applications.

What You Will Need

1. Raspberry Pi (any model with GPIO support, e.g., Pi 3, Pi 4)
2. BMP180 Sensor Module
3. Breadboard and Jumper Wires
4. A computer with SSH access to the Raspberry Pi or a connected keyboard and monitor
5. Python installed on the Raspberry Pi

Step 1: Wiring the BMP180 to the Raspberry Pi

The BMP180 communicates with the Raspberry Pi via the I2C protocol.

Connections (I2C Mode)

Step 2: Enable the I2C Interface on the Raspberry Pi

1. Open the Raspberry Pi configuration tool:

   sudo raspi-config
   

2. Navigate to Interface Options > I2C and enable it.
3. Reboot the Raspberry Pi:

   sudo reboot
   

Step 3: Install Required Libraries

1. Update your Raspberry Pi:

   sudo apt update && sudo apt upgrade -y
   

2. Install the I2C tools and the necessary Python libraries:

   sudo apt install -y i2c-tools python3-smbus python3-pip
   sudo pip3 install bmp180
   

3. Verify that the BMP180 is detected on the I2C bus:

   sudo i2cdetect -y 1
   

   You should see the device address (typically 0x77) in the output.

Step 4: Reading Data from the BMP180

Use the following Python script to read the temperature and pressure data from the BMP180.

Python Code Example

import time
import bmp180

# Create a sensor object
sensor = bmp180.BMP180()

# Read and display temperature and pressure
while True:
    temperature = sensor.read_temperature()
    pressure = sensor.read_pressure()
    altitude = sensor.read_altitude()

    print(f"Temperature: {temperature:.2f} °C")
    print(f"Pressure: {pressure / 100.0:.2f} hPa")
    print(f"Altitude: {altitude:.2f} m")
    print("------------------------")
    
    time.sleep(2)

Step 5: Applications of the BMP180

1. Weather Stations: Measure atmospheric pressure and temperature to predict weather patterns.
2. Altitude Tracking: Use the sensor to track altitude changes, useful for drone projects or outdoor activities.
3. Environmental Monitoring: Monitor environmental conditions, such as pressure changes, that could indicate a storm or other weather phenomena.

Troubleshooting

1. Device Not Detected:

   • Ensure the SDA and SCL pins are properly connected.
   • Verify that the I2C interface is enabled on the Raspberry Pi.

2. Inaccurate Readings:

   • Make sure the sensor is not exposed to extreme temperatures or pressure changes while reading.
   • Verify proper sensor calibration if results seem off.

3. I2C Errors:

   • Check for any possible address conflicts on the I2C bus.

Conclusion

The BMP180 is a simple yet powerful sensor that can be easily integrated into your Raspberry Pi projects. With this guide, you can read pressure and temperature data for a variety of applications, from weather stations to altitude tracking.