> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/expo/expo/llms.txt
> Use this file to discover all available pages before exploring further.

# expo-sensors

> Access device sensors including accelerometer, gyroscope, magnetometer, and more

# expo-sensors

**Version:** 55.0.6

Provides access to a hardware device's accelerometer, gyroscope, magnetometer, barometer, and pedometer.

## Installation

```bash theme={null}
npx expo install expo-sensors
```

## Usage

```typescript theme={null}
import { Accelerometer } from 'expo-sensors';
import { useEffect, useState } from 'react';

function App() {
  const [data, setData] = useState({ x: 0, y: 0, z: 0 });

  useEffect(() => {
    Accelerometer.setUpdateInterval(100);
    
    const subscription = Accelerometer.addListener(setData);
    
    return () => subscription.remove();
  }, []);

  return <Text>x: {data.x.toFixed(2)}</Text>;
}
```

## API Reference

### Accelerometer

<ParamField path="Accelerometer.addListener(listener)" type="(listener: (data: AccelerometerData) => void) => EventSubscription">
  Listens for accelerometer updates

  ```typescript theme={null}
  const subscription = Accelerometer.addListener(({ x, y, z }) => {
    console.log({ x, y, z });
  });
  ```
</ParamField>

<ParamField path="Accelerometer.setUpdateInterval(interval)" type="(interval: number) => void">
  Sets update interval in milliseconds
</ParamField>

<ParamField path="Accelerometer.isAvailableAsync()" type="() => Promise<boolean>">
  Checks if accelerometer is available
</ParamField>

### Gyroscope

<ParamField path="Gyroscope.addListener(listener)" type="(listener: (data: GyroscopeData) => void) => EventSubscription">
  Listens for gyroscope updates

  ```typescript theme={null}
  const subscription = Gyroscope.addListener(({ x, y, z }) => {
    console.log('Rotation:', { x, y, z });
  });
  ```
</ParamField>

<ParamField path="Gyroscope.setUpdateInterval(interval)" type="(interval: number) => void">
  Sets update interval in milliseconds
</ParamField>

### Magnetometer

<ParamField path="Magnetometer.addListener(listener)" type="(listener: (data: MagnetometerData) => void) => EventSubscription">
  Listens for magnetometer updates (compass)
</ParamField>

### Barometer

<ParamField path="Barometer.addListener(listener)" type="(listener: (data: BarometerData) => void) => EventSubscription">
  Listens for barometer updates (air pressure)

  ```typescript theme={null}
  const subscription = Barometer.addListener(({ pressure, relativeAltitude }) => {
    console.log('Pressure:', pressure, 'hPa');
  });
  ```
</ParamField>

### Pedometer

<ParamField path="Pedometer.isAvailableAsync()" type="() => Promise<boolean>">
  Checks if step counting is available
</ParamField>

<ParamField path="Pedometer.getStepCountAsync(start, end)" type="(start: Date, end: Date) => Promise<PedometerResult>">
  Gets step count for a time period

  ```typescript theme={null}
  const now = new Date();
  const start = new Date(now.getTime() - 24 * 60 * 60 * 1000);
  const result = await Pedometer.getStepCountAsync(start, now);
  console.log('Steps:', result.steps);
  ```
</ParamField>

<ParamField path="Pedometer.watchStepCount(listener)" type="(listener: (data: PedometerResult) => void) => EventSubscription">
  Watches for step count changes
</ParamField>

### DeviceMotion

<ParamField path="DeviceMotion.addListener(listener)" type="(listener: (data: DeviceMotionData) => void) => EventSubscription">
  Listens for combined device motion data

  Includes acceleration, rotation, and orientation data.
</ParamField>

## Examples

### Shake Detector

```tsx theme={null}
import { Accelerometer } from 'expo-sensors';
import { useEffect, useState } from 'react';
import { Text } from 'react-native';

function ShakeDetector() {
  const [shakeCount, setShakeCount] = useState(0);

  useEffect(() => {
    Accelerometer.setUpdateInterval(100);

    const subscription = Accelerometer.addListener(({ x, y, z }) => {
      const acceleration = Math.sqrt(x * x + y * y + z * z);
      
      if (acceleration > 2.5) {
        setShakeCount(c => c + 1);
      }
    });

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

  return <Text>Shakes detected: {shakeCount}</Text>;
}
```

### Compass

```tsx theme={null}
import { Magnetometer } from 'expo-sensors';
import { useEffect, useState } from 'react';
import { Text, View } from 'react-native';

function Compass() {
  const [heading, setHeading] = useState(0);

  useEffect(() => {
    const subscription = Magnetometer.addListener(({ x, y }) => {
      let angle = Math.atan2(y, x) * (180 / Math.PI);
      if (angle < 0) angle += 360;
      setHeading(Math.round(angle));
    });

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

  return (
    <View style={{ alignItems: 'center' }}>
      <Text style={{ fontSize: 48 }}>{heading}°</Text>
      <Text>North</Text>
    </View>
  );
}
```

### Step Counter

```tsx theme={null}
import { Pedometer } from 'expo-sensors';
import { useEffect, useState } from 'react';
import { Text } from 'react-native';

function StepCounter() {
  const [steps, setSteps] = useState(0);
  const [available, setAvailable] = useState(false);

  useEffect(() => {
    Pedometer.isAvailableAsync().then(setAvailable);

    if (available) {
      const subscription = Pedometer.watchStepCount(result => {
        setSteps(result.steps);
      });

      return () => subscription.remove();
    }
  }, [available]);

  return <Text>Steps today: {steps}</Text>;
}
```

## Platform Support

| Sensor        | iOS | Android | Web |
| ------------- | --- | ------- | --- |
| Accelerometer | ✅   | ✅       | ✅   |
| Gyroscope     | ✅   | ✅       | ✅   |
| Magnetometer  | ✅   | ✅       | ❌   |
| Barometer     | ✅   | ✅       | ❌   |
| Pedometer     | ✅   | ✅       | ❌   |
| DeviceMotion  | ✅   | ✅       | ✅   |

## Resources

* [Official Documentation](https://docs.expo.dev/versions/latest/sdk/sensors/)
* [GitHub Repository](https://github.com/expo/expo/tree/main/packages/expo-sensors)