通过 JavaScript 与蓝牙设备通信

button.addEventListener('pointerup', function(event) {
  // Call navigator.bluetooth.requestDevice
});

navigator.bluetooth.requestDevice({ filters: [{ services: ['battery_service'] }] })
.then(device => { /* … */ })
.catch(error => { console.error(error); });

navigator.bluetooth.requestDevice({
  filters: [{
    services: [0x1234, 0x12345678, '99999999-0000-1000-8000-00805f9b34fb']
  }]
})
.then(device => { /* … */ })
.catch(error => { console.error(error); });

navigator.bluetooth.requestDevice({
  filters: [{
    name: 'Francois robot'
  }],
  optionalServices: ['battery_service'] // Required to access service later.
})
.then(device => { /* … */ })
.catch(error => { console.error(error); });

// Filter Bluetooth devices from Google company with manufacturer data bytes
// that start with [0x01, 0x02].
navigator.bluetooth.requestDevice({
  filters: [{
    manufacturerData: [{
      companyIdentifier: 0x00e0,
      dataPrefix: new Uint8Array([0x01, 0x02])
    }]
  }],
  optionalServices: ['battery_service'] // Required to access service later.
})
.then(device => { /* … */ })
.catch(error => { console.error(error); });

navigator.bluetooth.requestDevice({
  acceptAllDevices: true,
  optionalServices: ['battery_service'] // Required to access service later.
})
.then(device => { /* … */ })
.catch(error => { console.error(error); });

navigator.bluetooth.requestDevice({ filters: [{ services: ['battery_service'] }] })
.then(device => {
  // Human-readable name of the device.
  console.log(device.name);

  // Attempts to connect to remote GATT Server.
  return device.gatt.connect();
})
.then(server => { /* … */ })
.catch(error => { console.error(error); });

navigator.bluetooth.requestDevice({ filters: [{ services: ['battery_service'] }] })
.then(device => device.gatt.connect())
.then(server => {
  // Getting Battery Service…
  return server.getPrimaryService('battery_service');
})
.then(service => {
  // Getting Battery Level Characteristic…
  return service.getCharacteristic('battery_level');
})
.then(characteristic => {
  // Reading Battery Level…
  return characteristic.readValue();
})
.then(value => {
  console.log(`Battery percentage is ${value.getUint8(0)}`);
})
.catch(error => { console.error(error); });

…
.then(characteristic => {
  // Set up event listener for when characteristic value changes.
  characteristic.addEventListener('characteristicvaluechanged',
                                  handleBatteryLevelChanged);
  // Reading Battery Level…
  return characteristic.readValue();
})
.catch(error => { console.error(error); });

function handleBatteryLevelChanged(event) {
  const batteryLevel = event.target.value.getUint8(0);
  console.log('Battery percentage is ' + batteryLevel);
}

navigator.bluetooth.requestDevice({ filters: [{ services: ['heart_rate'] }] })
.then(device => device.gatt.connect())
.then(server => server.getPrimaryService('heart_rate'))
.then(service => service.getCharacteristic('heart_rate_control_point'))
.then(characteristic => {
  // Writing 1 is the signal to reset energy expended.
  const resetEnergyExpended = Uint8Array.of(1);
  return characteristic.writeValue(resetEnergyExpended);
})
.then(_ => {
  console.log('Energy expended has been reset.');
})
.catch(error => { console.error(error); });

navigator.bluetooth.requestDevice({ filters: [{ services: ['heart_rate'] }] })
.then(device => device.gatt.connect())
.then(server => server.getPrimaryService('heart_rate'))
.then(service => service.getCharacteristic('heart_rate_measurement'))
.then(characteristic => characteristic.startNotifications())
.then(characteristic => {
  characteristic.addEventListener('characteristicvaluechanged',
                                  handleCharacteristicValueChanged);
  console.log('Notifications have been started.');
})
.catch(error => { console.error(error); });

function handleCharacteristicValueChanged(event) {
  const value = event.target.value;
  console.log('Received ' + value);
  // TODO: Parse Heart Rate Measurement value.
  // See https://github.com/WebBluetoothCG/demos/blob/gh-pages/heart-rate-sensor/heartRateSensor.js
}

navigator.bluetooth.requestDevice({ filters: [{ name: 'Francois robot' }] })
.then(device => {
  // Set up event listener for when device gets disconnected.
  device.addEventListener('gattserverdisconnected', onDisconnected);

  // Attempts to connect to remote GATT Server.
  return device.gatt.connect();
})
.then(server => { /* … */ })
.catch(error => { console.error(error); });

function onDisconnected(event) {
  const device = event.target;
  console.log(`Device ${device.name} is disconnected.`);
}

navigator.bluetooth.requestDevice({ filters: [{ services: ['health_thermometer'] }] })
.then(device => device.gatt.connect())
.then(server => server.getPrimaryService('health_thermometer'))
.then(service => service.getCharacteristic('measurement_interval'))
.then(characteristic => characteristic.getDescriptor('gatt.characteristic_user_description'))
.then(descriptor => descriptor.readValue())
.then(value => {
  const decoder = new TextDecoder('utf-8');
  console.log(`User Description: ${decoder.decode(value)}`);
})
.catch(error => { console.error(error); });

navigator.bluetooth.requestDevice({ filters: [{ services: ['health_thermometer'] }] })
.then(device => device.gatt.connect())
.then(server => server.getPrimaryService('health_thermometer'))
.then(service => service.getCharacteristic('measurement_interval'))
.then(characteristic => characteristic.getDescriptor('gatt.characteristic_user_description'))
.then(descriptor => {
  const encoder = new TextEncoder('utf-8');
  const userDescription = encoder.encode('Defines the time between measurements.');
  return descriptor.writeValue(userDescription);
})
.catch(error => { console.error(error); });