BH1750 Light Sensor
Measures ambient light intensity in lux. Simple, affordable sensor for light-based automation and monitoring.
Say it to PAL
“How bright is it in here?”
The code PAL writes
const lux = await p.read('qwiic-bh1750', 'illuminance');
p.log(`Light level: ${lux} lux`);“Turn the lights on when it gets dark.”
The code PAL writes
p.onSensorChange('qwiic-bh1750', 'illuminance', (lux) => {
if (lux < 50) p.notify('Getting dark: ' + lux + ' lux');
});
await p.waitUntilStopped();When to pick it
Budget ambient light sensor. Simpler and cheaper than VEML7700 (~$4 vs ~$5) but lower max range (65k vs 120k lux). Good enough for indoor lighting automation and basic daylight detection.
Good to know
- Max range is 65535 lux — saturates in direct bright sunlight. Use VEML7700 for outdoor applications.
- ±20% accuracy — not lab-grade. Good for relative comparisons and thresholds, not precise lux calibration.
About it
The Rohm BH1750 is a digital ambient light sensor that directly outputs light intensity in lux. It features a wide measurement range (1-65535 lux), 16-bit resolution, and spectral response close to the human eye. The sensor handles the analog-to-digital conversion internally, making it easy to use — just read lux values over I2C. Two selectable addresses (0x23/0x5C via ADDR pin) allow two sensors on one bus.
Where to buy
Facts
Tested
It is in our catalog, but nobody has checked it on a real board. It may not work yet. Its driver is written, but it has not been tested on hardware yet.
I2C address
The BH1750 Light Sensor answers at I2C address 0x23. A jumper or pin moves it to 0x5C.
Current
120 µA
The catalog lists a typical draw of 120 µA for the Light Sensor, copied from the maker’s description and not measured by Palpable.
Board size
25.4 × 17.78 mm
The Light Sensor board measures 25.4 × 17.78 mm and stands 4.6 mm tall with its parts. It has 4 mounting holes. These dimensions are from the maker’s mechanical drawing.
Chip
BH1750
Its sensor is the ROHM BH1750.
Free to reuse
Every fact here is open data under CC BY 4.0. Copy it into your own docs or code, and credit Palpable. Download it
This record was last changed on October 26, 2026.