react-native-nitro-sensors-kit

A React Native Nitro Module providing high-performance, zero-bridge access to device sensors:

• 📐 Accelerometer — Raw acceleration in m/s²
• 🌀 Gyroscope — Angular velocity in rad/s
• 🧭 Magnetometer — Magnetic field strength in µT
• 🎯 Device Motion — OS-fused attitude, gravity, and user acceleration
• 🌤️ Barometer — Atmospheric pressure and relative altitude
• 🚶 Pedometer — Step counting, distance, pace, cadence, and floors

Built with Nitro Modules for direct JSI-powered native sensor access — no bridge, no serialization overhead.

[!IMPORTANT]

• Tested on React Native 0.81+ with Nitro Modules.
• Sensors return real data on physical devices only — simulators/emulators return zeros or are unavailable.
• Pedometer requires iOS 14+ and Android API 29+ for runtime permissions.

📦 Installation

npm install react-native-nitro-sensors-kit react-native-nitro-modules
cd ios && pod install

Demo

Configuration

iOS

Add to your Info.plist (required for Pedometer only):

<key>NSMotionUsageDescription</key>
<string>This app uses motion sensors to track your steps and activity</string>

No setup needed for Accelerometer, Gyroscope, Magnetometer, Device Motion, or Barometer.

Android

Add to your AndroidManifest.xml (required for Pedometer only):

<uses-permission android:name="android.permission.ACTIVITY_RECOGNITION" />

No setup needed for the other 5 sensors.

🧠 Overview

| Sensor | iOS API | Android API | Permission | | ----------------- | ----------------- | -------------------------------------- | --------------------------------------------------- | | Accelerometer | CMMotionManager | TYPE_ACCELEROMETER | None | | Gyroscope | CMMotionManager | TYPE_GYROSCOPE | None | | Magnetometer | CMMotionManager | TYPE_MAGNETIC_FIELD | None | | Device Motion | CMDeviceMotion | TYPE_ROTATION_VECTOR + fused sensors | None | | Barometer | CMAltimeter | TYPE_PRESSURE | None | | Pedometer | CMPedometer | TYPE_STEP_COUNTER | NSMotionUsageDescription / ACTIVITY_RECOGNITION |

⚙️ Usage

With Hooks (Recommended)

import React, { useState } from 'react';
import { View, Text, Button, ScrollView, StyleSheet } from 'react-native';
import {
  useAccelerometer,
  useGyroscope,
  useMagnetometer,
  useDeviceMotion,
  useBarometer,
  usePedometer,
} from 'react-native-nitro-sensors-kit';

export default function App() {
  const [active, setActive] = useState(false);

  const accel = useAccelerometer(100, active);
  const gyro = useGyroscope(100, active);
  const mag = useMagnetometer(100, active);
  const motion = useDeviceMotion(100, active);
  const baro = useBarometer(active);
  const pedo = usePedometer(active);

  return (
    <ScrollView style={styles.container}>
      <Text style={styles.title}>Nitro Sensors</Text>

      <Button
        title={active ? 'Stop All Sensors' : 'Start All Sensors'}
        onPress={() => setActive((p) => !p)}
      />

      <Text style={styles.section}>Accelerometer (m/s²)</Text>
      <Text>X: {accel.data?.x.toFixed(3)}</Text>
      <Text>Y: {accel.data?.y.toFixed(3)}</Text>
      <Text>Z: {accel.data?.z.toFixed(3)}</Text>

      <Text style={styles.section}>Gyroscope (rad/s)</Text>
      <Text>X: {gyro.data?.x.toFixed(3)}</Text>
      <Text>Y: {gyro.data?.y.toFixed(3)}</Text>
      <Text>Z: {gyro.data?.z.toFixed(3)}</Text>

      <Text style={styles.section}>Magnetometer (µT)</Text>
      <Text>X: {mag.data?.x.toFixed(3)}</Text>
      <Text>Y: {mag.data?.y.toFixed(3)}</Text>
      <Text>Z: {mag.data?.z.toFixed(3)}</Text>

      <Text style={styles.section}>Device Motion</Text>
      <Text>Pitch: {motion.data?.attitude?.pitch.toFixed(3)}</Text>
      <Text>Roll: {motion.data?.attitude?.roll.toFixed(3)}</Text>
      <Text>Yaw: {motion.data?.attitude?.yaw.toFixed(3)}</Text>

      <Text style={styles.section}>Barometer</Text>
      <Text>Pressure: {baro.data?.pressure.toFixed(1)} hPa</Text>
      <Text>Rel. Altitude: {baro.data?.relativeAltitude.toFixed(2)} m</Text>

      <Text style={styles.section}>Pedometer</Text>
      <Text>Steps: {pedo.data?.steps ?? '—'}</Text>
      <Text>Distance: {pedo.data?.distance ?? '—'} m</Text>
      <Text>Permission: {pedo.permissionStatus}</Text>
      {pedo.permissionStatus === 'notDetermined' && (
        <Button title="Request Permission" onPress={pedo.requestPermission} />
      )}
    </ScrollView>
  );
}

const styles = StyleSheet.create({
  container: { flex: 1, padding: 20 },
  title: { fontSize: 28, fontFamily: 'System', marginBottom: 16 },
  section: { fontSize: 16, fontFamily: 'System', marginTop: 16, color: '#888' },
});

Direct API (No Hooks)

import { accelerometer, pedometer } from 'react-native-nitro-sensors-kit';

// Accelerometer — no permissions needed
accelerometer.interval = 50; // 50ms = 20Hz
accelerometer.onUpdate = (data) => {
  console.log(`x: ${data.x}, y: ${data.y}, z: ${data.z}`);
};
accelerometer.start();

// Pedometer — requires permission
const status = await pedometer.requestPermission();
if (status === 'granted') {
  pedometer.onUpdate = (data) => {
    console.log(`Steps: ${data.steps}, Distance: ${data.distance}m`);
  };
  pedometer.start();
}

// Query historical steps (iOS only)
const history = await pedometer.queryHistoricalData(
  Date.now() - 86400000, // 24h ago
  Date.now()
);
console.log(`Steps in last 24h: ${history.steps}`);

// Clean up
accelerometer.stop();
pedometer.stop();

🧩 API Reference

Hooks

| Hook | Params | Returns | | -------------------------------------- | ------------------- | ------------------------------------------------------------------------------------------------------------ | | useAccelerometer(interval?, active?) | number, boolean | { data, isAvailable, isActive } | | useGyroscope(interval?, active?) | number, boolean | { data, isAvailable, isActive } | | useMagnetometer(interval?, active?) | number, boolean | { data, isAvailable, isActive } | | useDeviceMotion(interval?, active?) | number, boolean | { data, isAvailable, isActive } | | useBarometer(active?) | boolean | { data, isAvailable, isActive } | | usePedometer(active?) | boolean | { data, isAvailable, isActive, permissionStatus, requestPermission, checkPermission, queryHistoricalData } |

Data Types

AccelerometerData / GyroscopeData / MagnetometerData

{
  x: number;
  y: number;
  z: number;
  timestamp: number;
}

DeviceMotionData

{
  attitude: {
    pitch: number;
    roll: number;
    yaw: number;
  }
  rotationRate: {
    x: number;
    y: number;
    z: number;
  }
  userAcceleration: {
    x: number;
    y: number;
    z: number;
  }
  gravity: {
    x: number;
    y: number;
    z: number;
  }
  heading: number; // degrees, -1 if unavailable
  timestamp: number;
}

BarometerData

{
  pressure: number; // hPa (mbar)
  relativeAltitude: number; // meters since start()
  timestamp: number;
}

PedometerData

{
  steps: number;
  distance: number; // meters, -1 if unavailable
  currentPace: number; // s/m, iOS only, -1 if unavailable
  currentCadence: number; // steps/s, iOS only, -1 if unavailable
  floorsAscended: number; // iOS only, -1 if unavailable
  floorsDescended: number; // iOS only, -1 if unavailable
  timestamp: number;
}

PermissionStatus

'granted' | 'denied' | 'restricted' | 'notDetermined';

🧩 Platform Differences

| Feature | iOS | Android | | --------------------------- | ----------------------- | ------------------------------- | | Pedometer distance | ✅ | ❌ (-1) | | Pedometer pace/cadence | ✅ | ❌ (-1) | | Pedometer floors | ✅ | ❌ (-1) | | Historical step queries | ✅ CMPedometer | ❌ Not supported | | Barometer relative altitude | ✅ Native | ✅ Computed from pressure delta | | Device Motion heading | ✅ Magnetic north | ❌ (-1) | | Device Motion fusion | Single CMDeviceMotion | 4 sensors fused manually |

🧩 Supported Platforms

| Platform | Status | | ----------------------------- | ---------------------------- | | iOS (physical device) | ✅ Supported | | Android (physical device) | ✅ Supported | | iOS Simulator | ⚠️ Most sensors return zeros | | Android Emulator | ⚠️ Most sensors unavailable |

🤝 Contributing

PRs welcome!

• Development Workflow
• Sending a PR
• Code of Conduct

🪪 License

MIT © Gautham Vijayan

Made with ❤️ and Nitro Modules