How to Use BH1750 BH1750FVI Chip Light: Examples, Pinouts, and Specs

The BH1750 is a digital light sensor designed to measure ambient light levels in lux, providing precise and reliable readings. It communicates via the I2C protocol, making it easy to integrate into microcontroller-based systems. The sensor is highly sensitive and can detect a wide range of light intensities, from very dim to bright sunlight.

• Automatic brightness control for LCD and OLED displays
• Energy-efficient lighting systems
• Smart home automation (e.g., light-based triggers)
• Weather monitoring stations
• Photography and camera exposure control

The BH1750 is a compact and efficient light sensor with the following key specifications:

The BH1750 has six pins, as described in the table below:

1. Power the Sensor: Connect the VCC pin to a 3.3V power source and the GND pin to ground.
2. I2C Communication: Connect the SDA and SCL pins to the corresponding I2C pins on your microcontroller. Use pull-up resistors (typically 4.7kΩ) on both lines if not already present on your board.
3. Address Selection: Use the ADDR pin to select the I2C address:
   • Connect to GND for address 0x23.
   • Connect to VCC for address 0x5C.
4. Initialize the Sensor: Configure the I2C interface on your microcontroller and initialize the BH1750 in the desired mode (e.g., continuous high-resolution mode).

• Avoid Direct Sunlight: While the BH1750 can measure high light levels, prolonged exposure to direct sunlight may affect its accuracy.
• Use Proper Decoupling: Place a 0.1µF ceramic capacitor close to the VCC and GND pins to stabilize the power supply.
• I2C Pull-Up Resistors: Ensure proper pull-up resistors are used on the SDA and SCL lines for reliable communication.
• Measurement Modes: The BH1750 supports multiple modes (e.g., high-resolution, low-resolution). Choose the mode that best suits your application to balance accuracy and power consumption.

Below is an example of how to use the BH1750 with an Arduino UNO:

#include <Wire.h>
#include <BH1750.h>

// Create an instance of the BH1750 sensor
BH1750 lightMeter;

void setup() {
  Serial.begin(9600); // Initialize serial communication
  Wire.begin();       // Initialize I2C communication

  // Initialize the BH1750 sensor in continuous high-resolution mode
  if (lightMeter.begin(BH1750::CONTINUOUS_HIGH_RES_MODE)) {
    Serial.println("BH1750 initialized successfully.");
  } else {
    Serial.println("Error initializing BH1750. Check connections.");
    while (1); // Halt execution if initialization fails
  }
}

void loop() {
  // Read light level in lux
  float lux = lightMeter.readLightLevel();

  // Print the light level to the serial monitor
  if (lux >= 0) {
    Serial.print("Light Level: ");
    Serial.print(lux);
    Serial.println(" lux");
  } else {
    Serial.println("Error reading light level.");
  }

  delay(1000); // Wait 1 second before the next reading
}

1. No Response from the Sensor

   • Cause: Incorrect I2C address or wiring.
   • Solution: Verify the ADDR pin connection and ensure the correct I2C address is used in the code.

2. Inconsistent Readings

   • Cause: Electrical noise or unstable power supply.
   • Solution: Add a decoupling capacitor (0.1µF) near the sensor's VCC and GND pins.

3. Sensor Not Detected

   • Cause: Missing pull-up resistors on SDA and SCL lines.
   • Solution: Add 4.7kΩ pull-up resistors to the SDA and SCL lines.

4. Readings Stuck at Zero

   • Cause: Sensor not initialized properly.
   • Solution: Ensure the begin() function is called in the setup and check for initialization errors.

Q: Can the BH1750 measure light through glass or plastic?
A: Yes, the BH1750 can measure light through transparent materials, but the material may slightly attenuate the light intensity.

Q: What is the maximum distance for I2C communication with the BH1750?
A: The maximum distance depends on the pull-up resistor values and the I2C clock speed. For reliable communication, keep the distance under 1 meter.

Q: Can the BH1750 operate at 5V?
A: No, the BH1750 operates at a maximum voltage of 3.6V. Use a level shifter if interfacing with a 5V system.

Q: How do I switch between measurement modes?
A: Use the appropriate command in your code to set the desired mode. Refer to the BH1750 datasheet for mode-specific commands.