- BH1750 is a digital Ambient Light Sensor IC for the I2C bus interface. The LCD and keypad backlight power of a mobile phone can be adjusted using ambient light data obtained by this IC. Wide range detection is achievable with high resolution.
- It translates the amount of light that strikes the sensor into a 16-bit digital value. Since the sensor already contains an ADC that converts and outputs a digital signal, no further converting modules are needed.
- Since it transmits data through the I2C communication standard, practically all microcontroller boards may use it. The measured light in Lux units—the measurement unit for light intensity—is output directly by the BH1750.
The pinout for BH1750 IC is given below
- VCC – The module’s power supply ranges from 2.4V to 3.6V, while 3.0V is the most common.
- GND – Ground
- SCL – Serial Clock Lines supports I2C communication, which delivers clock pulses.
- SDA – Serial Data Address, utilized to transmit data via an I2C connection.
- ADDR – Device address pin, used to choose the address when connecting more than two modules
Block Diagram
- BH1750FVI IC is found on the BH1750 Sensor board. When ambient light strikes the sensor, a photodiode with a latency that is almost identical to that of the human eye absorbs the light and creates an analog voltage signal. This signal is then coupled to an ADC unit, which converts the analog voltage signal into 16-bit digital data.
- The light intensity is computed and the data signal is transmitted across the I2C bus in the following step with the aid of two registers, the data register, and the time register.
Specifications of BH1750 Sensor
- I2C bus Interface (f / s Mode Support).
- Spectral responsibility is approximately human eye response.
- Illuminance to Digital Converter.
- Wide range and High resolution. (1 – 65535 lx).
- Low Current by power down function.
- 50Hz / 60Hz Light noise reject-function.
- 1.8V Logic input interface.
- No need for any external parts.
- Light source dependency is little. (ex. Incandescent Lamp. Fluorescent Lamp. Halogen Lamp. White LED. Sun Light).
- It is possible to select 2 types of I2 C slave addresses.
- Adjustable measurement result for the influence of optical window ( It is possible to detect min. 0.11 lx, max. 100000 lx by using this function.)
- Small measurement variation (+/- 20%) 13) The influence of infrared is very small.
Applications of BH1750 Sensor
- The brightness of LCD and mobile displays can be altered with the BH1750 light intensity sensor.
- It can be used to control how brightly or dimly cars’ headlights are turned on or off.
- Used in pulse sensors to gauge the LED’s light output.
- For controlling the automatic street lights’ ON/OFF switch.