React-native-ambient-light-sensor NPM

react-native-ambient-light-sensor

Helps to find your surrounding's light value (in lux unit) (for android only) using device light sensor

Installation

npm install react-native-ambient-light-sensor

Usage

import { hasLightSensor, startLightSensor, stopLightSensor } from 'react-native-ambient-light-sensor';
import { View, Text, DeviceEventEmitter } from 'react-native';

// ...

export default function App() {
  const [result, setResult] = React.useState<number | undefined>();
  const [hasSensor, setHasSensor] = React.useState<boolean>();

  useEffect(() => {
      hasLightSensor().then(setHasSensor);
      startLightSensor();
      
      const subscription = DeviceEventEmitter.addListener(
        'LightSensor',
        (data: { lightValue: number }) => {
            setResult(data.lightValue);
        },
    );

    return () => {
        stopLightSensor();
        subscription?.remove();
    };
  }, []);

  return (
    <View>
      <Text>Device has sensor: {hasSensor ? 'YES' : 'NO'}. Light Result Value: {result}</Text>
    </View>
  );
}

Use case

You can apply any logic of your own based on the surrounding's light condition. For example, to auto turn on your device's flash/torch light if the surrounding environment is dark/dim.

Important Note

The primary sensor data type for ambient light sensors is illuminance in lux (lumens per square meter). Use the data from below table to find and apply logic to your application accordingly.

The following example data set represents rough thresholds for common lighting conditions, and the corresponding lighting step. Here, each lighting step represents a change in lighting environment.

Lighting condition	From (lux)	To (lux)
Pitch Black	0	10
Very Dark	11	50
Dark Indoors	51	200
Dim Indoors	201	400
Normal Indoors	401	1000
Bright Indoors	1001	5000
Dim Outdoors	5001	10,000
Cloudy Outdoors	10,001	30,000
Direct Sunlight	30,001	100,000