SKU: SENS-3258
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Pimoroni BH1745 Luminance & Color Sensor Breakout - I2C Interface

₹1,140.00 (Inclusive of all taxes)
Out of Stock

The Pimoroni BH1745 Breakout is a high-precision digital color sensor IC designed for ambient light sensing and color temperature measurement. Operating from 2.3V to 3.6V with an I2C interface, it provides 16-bit digital outputs for red, green, and blue (RGB) light, making it ideal for LCD backlight control in embedded systems, Raspberry Pi, Arduino, and other microcontroller platforms.

Features

  • High-sensitivity digital color sensor IC with RGB spectral response.
  • Wide dynamic range for illuminance from 0.005 lux to 40,000 lux.
  • I2C interface with selectable slave addresses (0x38 or 0x39) and support for Fast Mode (400 kHz).
  • Integrated 50Hz/60Hz light noise rejection for stable readings under artificial lighting.
  • Low-power operation with programmable interrupt and power-down function.

Out of stock

Description

The BH1745NUC digital color sensor utilizes a photodiode array with an IR-cut filter to deliver accurate red, green, and blue (RGB) light intensity measurements, which are converted to 16-bit digital values. This excellent IR-cut characteristic ensures precise color temperature and illuminance data, critical for automatic display backlight adjustment in consumer electronics and industrial lighting control.

Engineered for signal stability, the sensor features a wide dynamic range capable of detecting light intensities from near darkness (0.005 lx) to bright daylight (40,000 lx). Its integrated circuitry rejects 50Hz/60Hz flicker noise common in AC-powered lighting, providing consistent readings. The breakout board includes a cuttable trace for I2C address selection, level shifting for 1.8V logic compatibility, and all necessary passive components for immediate integration.

Key Features

  • Digital RGB color sensor with 16-bit resolution per channel for precise light analysis.
  • Excellent IR-cut filter characteristics for accurate color temperature and illuminance calculation.
  • Wide dynamic range from 0.005 lx to 40,000 lx, suitable for both dark and brightly lit environments.
  • I2C bus interface operating at up to 400 kHz, with two selectable slave addresses (0x38 or 0x39).
  • Integrated 50Hz/60Hz light noise rejection circuit for stable operation under fluorescent/LED lighting.
  • Low-current power-down mode and programmable interrupt function for efficient system power management.
  • Supports 1.8V logic interface, with onboard level shifting for compatibility with 3.3V and 5V microcontrollers.
  • Compact breakout board design with all necessary decoupling and pull-up resistors for reliable prototyping.

Applications

  • Automatic LCD backlight brightness and color temperature adjustment for TVs, tablets, and mobile phones.
  • Ambient light sensing and adaptive lighting control in smart home and IoT devices.
  • Color detection and analysis for robotics, sorting machines, and photographic equipment.
  • Light quality monitoring in horticultural and agricultural lighting systems.
  • Embedded system projects requiring precise RGB spectral measurement with Raspberry Pi or Arduino.

Technical Specifications

Manufacturer Part NumberBH1745NUC
Operating Voltage2.3V to 3.6V DC
Logic Interface1.8V (compatible with 3.3V/5V via level shifting)
Communication InterfaceI2C (Fast Mode up to 400 kHz)
I2C Slave AddressSelectable via ADDR trace: 0x38 (default low) or 0x39 (high)
Data Output Resolution16-bit per channel (Red, Green, Blue)
Illuminance Range0.005 lux to 40,000 lux
Light Noise Rejection50 Hz / 60 Hz flicker
Power ManagementProgrammable interrupt, Power-down function
Sensor IC Dimensions2.10 mm x 2.00 mm x 0.60 mm
Breakout Board WeightApprox. 3 grams

Frequently Asked Questions

What is the operating voltage range for the BH1745 breakout?

The BH1745 sensor IC itself operates from 2.3V to 3.6V. The Pimoroni breakout board includes circuitry that allows it to be safely powered by a 3.3V supply from a microcontroller like a Raspberry Pi. For use with 5V systems, ensure proper logic level shifting is in place for the I2C lines.

How do I select the I2C address on this breakout?

The breakout board features a cuttable trace labeled ADDR. By default, the address is set to 0x38 (ADDR pin pulled low). To change the address to 0x39, carefully cut the trace connecting the ADDR pad to ground. This physically pulls the ADDR pin high via an onboard pull-up resistor.

Does this sensor require any external components to function?

No, the Pimoroni breakout is fully assembled and includes all necessary passive components, such as decoupling capacitors and I2C pull-up resistors. You only need to connect power (3.3V), ground, and the I2C lines (SDA, SCL) to your microcontroller to start reading data.

Can this sensor measure color temperature directly?

The BH1745 provides raw 16-bit digital values for red, green, and blue light intensities. Color temperature (in Kelvin) and illuminance (in lux) are not provided directly by the sensor but must be calculated in your firmware using the RGB data and the sensor's specific response coefficients, which are detailed in the manufacturer's datasheet.

Package Includes

  • 1 x Pimoroni BH1745 Luminance and Colour Sensor Breakout Board

Additional Information

Weight 0.004 kg
Dimensions 7 × 4 × 1 cm