react-native-polar-bridge

Testing Polar SDK on React Native

Installation

npm install react-native-polar-bridge

Usage

This React Native library uses the polar-ble-sdk.

Supported Functions

| Polar SDK Feature | Android | iOS | |----------------------------|---------|-----| | connectToDevice |✅|✅| | disconnectFromDevice |✅|✅| | scanDevices() |✅|✅| | fetchHrData |✅|✅| | fetchAccData |✅|✅| | fetchGyrData |✅|✅| | fetchPpgData |✅|✅| | enableSdkMode |✅|❌| | disableSdkMode |✅|❌| | getDeviceTime |✅|✅| | setDeviceTime |✅|✅| | getDiskSpace |✅|✅| | startOfflineRecording |✅|❌| | stopOfflineRecording |✅|❌| | setPolarRecordingTrigger |✅|❌| | fetchOfflineRecordings |⚠️|❌| | downloadOfflineRecordings |⚠️|❌| | deleteAllOfflineRecordings |✅|❌|

✅ - Implemented ❌ - Not yet implemented ⚠️ - Not fully implemented

Connecting to Device

import { connectToDevice } from 'react-native-polar-bridge';

const deviceId = 'D8765432';

export default function App(){

  // ...

  connectToDevice(deviceId).then((device: DeviceConnected) =>{
    console.log(`Connected Polar Device: ${device.connectedDeviceId} Battery Level: ${device.batteryLevel}%`);
  });
}

Disconnecting from Device

disconnectFromDevice(deviceId);

Initialize NativeModules

Import NativeModules from react-native to expose native code to be able to listen to emitted events.

const {PolarBridge} = NativeModules;
const polarEmitter = new NativeEventEmitter(PolarBridge);

Scan Devices

Use scanDevices() to scan for nearby Polar devices

scanDevices();

and listen for emitted events for the result.

const [devices, setDevices] = useState<Device[]>([]);

useEffect(() => {
  const onDeviceFound = polarEmitter.addListener(emittedEventId.SCAN_DEVICE_FOUND, device => {
    console.log('Device found:', device);
  });

  const onScanError = polarEmitter.addListener(emittedEventId.SCAN_DEVICE_ERROR, err => {
    console.error('Scan error:', err.message);
  });

  const onScanComplete = polarEmitter.addListener(emittedEventId.SCAN_DEVICE_COMPLETE, () => {
    console.log('Scan complete');
  });

  return () => {
    onDeviceFound.remove();
    onScanError.remove();
    onScanComplete.remove();
  };
}, []);

Heart Rate Data Stream

Ensure that the deviceId of the Polar device is connected before calling the function.

fetchHrData(connectedDeviceId);

By default, the package sends sensor data reports every 10 seconds. The interval can be customized by specifying the frequency (in milliseconds) in the fetch request.

const BUFFER_MS = 5_000;
fetchHrData(connectedDeviceId, BUFFER_MS);

Listen for emitted events of the HR data.

useEffect(() => {
  const hrListener = polarEmitter.addListener(emittedEventId.POLAR_HR_DATA, (data) => {
    // Heart rate data does not have timestamp, log current timestamp
    console.log('Heart Rate:', `${data.hr} bpm ${formatDateYYYYMMDDHHMMSS(new Date())}`);
  });

  const errorListener = polarEmitter.addListener(emittedEventId.POLAR_HR_ERROR, (error) => {
    console.log('HR stream error:', error);
  });

  const completeListener = polarEmitter.addListener(emittedEventId.POLAR_HR_COMPLETE, (msg) => {
    console.log('HR stream complete:', msg);
  });

  return () => {
    hrListener.remove();
    errorListener.remove();
    completeListener.remove();
  };
}, []);

Accelerometer Data Stream

Ensure that the deviceId of the Polar device is connected before calling the function. The default sampling rate is 52Hz and can be changed with SDK mode enabled on the device.

fetchAccData(connectedDeviceId);

Listen for emitted events of the Accelerometer data. The Accelerometer returns a timestamp in their own time system - which is respresented in nanoseconds since 2000-01-01 00:00:00.

const accListener = polarEmitter.addListener(emittedEventId.POLAR_ACC_DATA, (data) => {
  console.log('ACC Stream:', `x: ${data.accX} y: ${data.accY} z: ${data.accZ} timestamp: ${formatPolarTimestamp(data.accTimestamp)}`);
});

Gyroscope Data Stream

Ensure that the deviceId of the Polar device is connected before calling the function. Like the Accelerometer, the default sampling rate is 52Hz and can be changed with SDK mode enabled on the device.

fetchGyrData(connectedDeviceId);

Listen for emitted events of the Gyroscope data. The Gyroscope also returns a timestamp in Polar time system.

const gyrListener = polarEmitter.addListener(emittedEventId.POLAR_GYR_DATA, (data) => {
  console.log('GYR Stream:', `x: ${data.gyrX} y: ${data.gyrY} z: ${data.gyrZ} timestamp: ${formatPolarTimestamp(data.gyrTimestamp)}`);
});

Photoplethysmogram (PPG) Data Stream

Ensure that the deviceId of the Polar device is connected before calling the function. The default sampling rate is 55Hz and can be changed with SDK mode enabled on the device.

fetchPpgData(connectedDeviceId);

Listen for emitted events of the PPG data. This also returns a timestamp in Polar time system.

const ppgListener = polarEmitter.addListener(emittedEventId.POLAR_PPG_DATA, (data) => {
  console.log('PPG Stream:', `ppg0: ${data.ppg0} ppg1: ${data.ppg1} ppg2: ${data.ppg2} ambient: ${data.ambient} timestamp: ${formatPolarTimestamp(data.ppgTimestamp)}`);
});

⚠️ IMPORTANT: Remove listener from the EventEmitter on disconnect. Otherwise, the event broadcast will be sent multiple times

hrListener.remove();
accListener.remove();
gyrListener.remove();
ppgListener.remove();

Offline Recording

Start Offline Recording

startOfflineRecording(connectedDeviceId, offlineRecordingFeatureList).then((data) =>{
  console.log('Polar Start Offline Recording', `Result: ${data.result}`);
});

Stop Offline Recording

stopOfflineRecording(connectedDeviceId, offlineRecordingFeatureList).then((data) =>{
  console.log('Polar Stop Offline Recording', `Result: ${data.result}`);
});

Offline Recording Trigger

Offline recording can be initiated with PolarBleApi.startOfflineRecording(). With recording trigger, we can configure the Polar device to start the recording either on exercise start with TRIGGER_EXERCISE_START or when the Polar device has been turned on with TRIGGER_SYSTEM_START.

// Configure features needed in the offline recording
// List of available recording feature, feature availability may depend on the Polar device
const offlineRecordingFeatureList = [OfflineRecordingFeature.OFFLINE_HR,
  OfflineRecordingFeature.OFFLINE_ACC,
  OfflineRecordingFeature.OFFLINE_GYR,
  OfflineRecordingFeature.OFFLINE_PPG,
  OfflineRecordingFeature.OFFLINE_MAG,
  OfflineRecordingFeature.OFFLINE_PPI
];

setPolarRecordingTrigger(connectedDeviceId,
  OfflineRecordingTriggerMode.TRIGGER_SYSTEM_START,
  offlineRecordingFeatureList);

To disable offline recording trigger, set TRIGGER_DISABLED

setPolarRecordingTrigger(connectedDeviceId,
  OfflineRecordingTriggerMode.TRIGGER_DISABLED,
  offlineRecordingFeatureList);

Fetch Offline Recordings List

Fetch a list of Offline Recordings from the Polar device

fetchOfflineRecordings(connectedDeviceId)
  .then((offlineRecordings: OfflineRecording[]) =>{
  offlineRecordings.forEach((offlineRecordingEntry: OfflineRecording) =>{
    console.log('Polar Offline Recording',
      `Recording Start: ${offlineRecordingEntry.recTimestamp} Path: ${offlineRecordingEntry.path} Size: ${offlineRecordingEntry.size}`);
  });
});

SDK Mode

Enabling SDK mode on supported Polar devices gives more sampling rate and range options. See Polar documentation for more details.

enableSdkMode(connectedDeviceId);
disableSdkMode(connectedDeviceId);

Device Time

Set the time on Polar device using the current time set on the smartphone.

setDeviceTime(connectedDeviceId);

Fetch the time on the Polar device. data.timeMs is in unixTime in milliseconds.

getDeviceTime(connectedDeviceId).then((deviceTime: DeviceTime) =>{
  console.log('Polar Device Time',`${deviceTime.time} ms: ${deviceTime.timeMs}`);
});

Disk Space

Supported Polar devices can store offline recordings on its storage and remaining storage space can be tracked using this API.

getDiskSpace(connectedDeviceId).then((diskSpace: DiskSpace) =>{
  console.log('Polar Disk Space', `Disk space: ${diskSpace.freeSpace} / ${diskSpace.totalSpace} Bytes`);
});

Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.

License

MIT

Made with create-react-native-library