BH1750 – Ambient Light Sensor

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BH1750 is a digital ambient light sensor that is used commonly used in mobile phones to manipulate the screen brightness based on the environment lighting. This sensor can accurately measure the LUX value of light up to 65535lx.

BH1750 Pin Configuration

Pin NumberPin NameDescription
1VCCPower supply for the module can be 2.4V to 3.6V, typically 3.0V is used
2GNDGround of the module, connected to ground of the circuit
3SCLSerial Clock Line, used to provide clock pulse for I2C communication
4SDASerial Data Address, used to transfer the data through I2C communication
5ADDRDevice address pin, used to  select the address when more than two modules are connected

BH1750 Features

  • Power Supply: 2.4V-3.6V (typically 3.0V)
  • Less current consumption: 0.12mA
  • Measuring Rang: 1-65535lx
  • Communication: I2C bus
  • Accuracy: +/-20%
  • Built in A/D converter for converting analog illuminance in the digital data.
  • Very small effect of IR radiation
  • Highly responsive near to human eye.

How to Use BH1750

How to Use BH1750

Hardware of the BH1750 is very simple. The main component is BH1750FVI IC. The module works on 3.3V so a voltage regulator is used. For I2C lines a pull up resistor of 4.7K is used.

We get the lux values from BH1750 through I2C bus. The ADC in the IC converts the analog illuminance to the digital lux value. Now this data is transferred to microcontroller with the help of I2C pins SCL and SDA. The SCL is used to provide the clock pulse and the SDA is used to transfer the lux value. The IC uses a photodiode which gives the response equivalent to the human eye. There is also an internal oscillator in the IC which is used for the clock of internal logic of the IC.


  • Manipulate brightness in mobile phones/LCD
  • Automobile Headlights on/off control based on surrounding lighting conditions.
  • Used as Ambient light sensors to control the brightness of Display screens.

Farees Ahmed

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