Using the GY-302 with the Raspberry Pi

The GY-302 is a light intensity sensor module based on the BH1750 sensor. It provides accurate lux (light intensity) measurements and is ideal for applications like smart lighting, weather monitoring, and photography. This guide explains how to set up and use the GY-302 with a Raspberry Pi.

What You Will Need

1. Raspberry Pi (any model with GPIO support, e.g., Pi 3, Pi 4)
2. GY-302 Light 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 GY-302 to the Raspberry Pi

The GY-302 communicates with the Raspberry Pi using 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 Python libraries:

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

3. Verify the GY-302 is detected on the I2C bus:

   sudo i2cdetect -y 1
   

   You should see the device address (typically 0x23) in the output.

Step 4: Reading Data from the GY-302

The following Python script demonstrates how to read light intensity (lux) data from the GY-302.

Python Code Example

import smbus2
import time

# Define I2C address and commands
BH1750_ADDRESS = 0x23
CONTINUOUS_HIGH_RES_MODE = 0x10

# Initialize I2C bus
bus = smbus2.SMBus(1)

def read_light():
    data = bus.read_i2c_block_data(BH1750_ADDRESS, CONTINUOUS_HIGH_RES_MODE, 2)
    lux = (data[0] << 8) | data[1]
    return lux / 1.2

try:
    while True:
        light_level = read_light()
        print(f"Light Intensity: {light_level:.2f} lux")
        time.sleep(1)
except KeyboardInterrupt:
    print("Exiting...")

Step 5: Applications of the GY-302

1. Smart Lighting: Adjust lighting based on ambient light levels.
2. Weather Monitoring: Measure light intensity as part of weather stations.
3. Photography: Use for exposure control in camera systems.
4. IoT Projects: Integrate light intensity data into automation systems.

Troubleshooting

1. Device Not Detected:

   • Verify SDA and SCL connections.
   • Ensure the I2C interface is enabled on the Raspberry Pi.

2. Inaccurate Readings:

   • Check for interference from external light sources.
   • Ensure the sensor is properly connected and oriented.

3. I2C Errors:

   • Ensure there are no conflicting devices on the I2C bus.

Conclusion

The GY-302 light sensor module provides a simple and effective way to measure light intensity using a Raspberry Pi. By following this guide, you can set up the sensor and integrate it into various applications, from smart home systems to IoT projects. Experiment with different scenarios to explore its full potential!