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Expo Gyroscope iconExpo Gyroscope

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Gyroscope from expo-sensors provides access to the device's gyroscope sensor to respond to changes in rotation in three-dimensional space.

Platform Compatibility

Android DeviceAndroid EmulatoriOS DeviceiOS SimulatorWeb

Installation

Terminal
npx expo install expo-sensors

If you're installing this in a bare React Native app, you should also follow these additional installation instructions.

Usage

Basic Gyroscope usage
import React, { useState, useEffect } from 'react';
import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
import { Gyroscope } from 'expo-sensors';

export default function App() {
  const [{ x, y, z }, setData] = useState({
    x: 0,
    y: 0,
    z: 0,
  });
  const [subscription, setSubscription] = useState(null);

  const _slow = () => Gyroscope.setUpdateInterval(1000);
  const _fast = () => Gyroscope.setUpdateInterval(16);

  const _subscribe = () => {
    setSubscription(
      Gyroscope.addListener(gyroscopeData => {
        setData(gyroscopeData);
      })
    );
  };

  const _unsubscribe = () => {
    subscription && subscription.remove();
    setSubscription(null);
  };

  useEffect(() => {
    _subscribe();
    return () => _unsubscribe();
  }, []);

  return (
    <View style={styles.container}>
      <Text style={styles.text}>Gyroscope:</Text>
      <Text style={styles.text}>x: {x}</Text>
      <Text style={styles.text}>y: {y}</Text>
      <Text style={styles.text}>z: {z}</Text>
      <View style={styles.buttonContainer}>
        <TouchableOpacity onPress={subscription ? _unsubscribe : _subscribe} style={styles.button}>
          <Text>{subscription ? 'On' : 'Off'}</Text>
        </TouchableOpacity>
        <TouchableOpacity onPress={_slow} style={[styles.button, styles.middleButton]}>
          <Text>Slow</Text>
        </TouchableOpacity>
        <TouchableOpacity onPress={_fast} style={styles.button}>
          <Text>Fast</Text>
        </TouchableOpacity>
      </View>
    </View>
  );
}

%%placeholder-start%%const styles = StyleSheet.create({ ... }); %%placeholder-end%%const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    paddingHorizontal: 10,
  },
  text: {
    textAlign: 'center',
  },
  buttonContainer: {
    flexDirection: 'row',
    alignItems: 'stretch',
    marginTop: 15,
  },
  button: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#eee',
    padding: 10,
  },
  middleButton: {
    borderLeftWidth: 1,
    borderRightWidth: 1,
    borderColor: '#ccc',
  },
});

API

import { Gyroscope } from 'expo-sensors';

Classes

Gyroscope

Type: Class extends DeviceSensor<GyroscopeMeasurement>

A base class for subscribable sensors. The events emitted by this class are measurements specified by the parameter type M.

Gyroscope Methods

addListener(listener)

NameTypeDescription
listenerListener<GyroscopeMeasurement>

A callback that is invoked when an accelerometer update is available. When invoked, the listener is provided a single argument that is an GyroscopeMeasurement object.


Subscribe for updates to the accelerometer.

Returns

  • Subscription

A subscription that you can call remove() on when you would like to unsubscribe the listener.

getListenerCount()

Returns the registered listeners count.

Returns

  • number

getPermissionsAsync()

Checks user's permissions for accessing sensor.

Returns


hasListeners()

Returns boolean which signifies if sensor has any listeners registered.

Returns

  • boolean

isAvailableAsync()

You should always check the sensor availability before attempting to use it.

Returns whether the gyroscope is enabled on the device.

On mobile web, you must first invoke Gyroscope.requestPermissionsAsync() in a user interaction (i.e. touch event) before you can use this module. If the status is not equal to granted then you should inform the end user that they may have to open settings.

On web this starts a timer and waits to see if an event is fired. This should predict if the iOS device has the device orientation API disabled in Settings > Safari > Motion & Orientation Access. Some devices will also not fire if the site isn't hosted with HTTPS as DeviceMotion is now considered a secure API. There is no formal API for detecting the status of DeviceMotion so this API can sometimes be unreliable on web.

Returns


A promise that resolves to a boolean denoting the availability of the gyroscope.

removeAllListeners()

Removes all registered listeners.

Returns

  • void

removeSubscription(subscription)

NameTypeDescription
subscriptionSubscription

A subscription to remove.


Removes the given subscription.

Returns

  • void

requestPermissionsAsync()

Asks the user to grant permissions for accessing sensor.

Returns


setUpdateInterval(intervalMs)

NameTypeDescription
intervalMsnumber

Desired interval in milliseconds between sensor updates.

Starting from Android 12 (API level 31), the system has a 200ms limit for each sensor updates.

If you need an update interval less than 200ms, you should:

  • add android.permission.HIGH_SAMPLING_RATE_SENSORS to app.json permissions field
  • or if you are using bare workflow, add <uses-permission android:name="android.permission.HIGH_SAMPLING_RATE_SENSORS"/> to AndroidManifest.xml.

Set the sensor update interval.

Returns

  • void

Interfaces

PermissionResponse

An object obtained by permissions get and request functions.

PermissionResponse Properties

NameTypeDescription
canAskAgainboolean

Indicates if user can be asked again for specific permission. If not, one should be directed to the Settings app in order to enable/disable the permission.

expiresPermissionExpiration

Determines time when the permission expires.

grantedboolean

A convenience boolean that indicates if the permission is granted.

statusPermissionStatus

Determines the status of the permission.


Types

GyroscopeMeasurement

Each of these keys represents the rotation along that particular axis measured in degrees per second (°/s).

NameTypeDescription
xnumber

Value of rotation in degrees per second device reported in X axis.

ynumber

Value of rotation in degrees per second device reported in Y axis.

znumber

Value of rotation in degrees per second device reported in Z axis.

PermissionExpiration

Permission expiration time. Currently, all permissions are granted permanently.

Acceptable values are: 'never', number.

Subscription

NameTypeDescription
remove() => void-

Enums

PermissionStatus

DENIED

PermissionStatus.DENIED = "denied"

User has denied the permission.

GRANTED

PermissionStatus.GRANTED = "granted"

User has granted the permission.

UNDETERMINED

PermissionStatus.UNDETERMINED = "undetermined"

User hasn't granted or denied the permission yet.