my.onBluetoothAdapterStateChange

my.onBluetoothAdapterStateChange((res) => {
  console.log('Bluetooth available:', res.available);
  console.log('Discovering:', res.discovering);
});

Page({
  onLoad() {
    my.onBluetoothAdapterStateChange(this.handleStateChange);
    my.openBluetoothAdapter();
  },

  handleStateChange(res) {
    if (!res.available) {
      my.alert({
        title: 'Bluetooth Disabled',
        content: 'Please enable Bluetooth to continue using this feature.'
      });
      this.setData({ bluetoothEnabled: false });
    } else {
      this.setData({ bluetoothEnabled: true });
    }
  },

  onUnload() {
    my.offBluetoothAdapterStateChange(this.handleStateChange);
    my.closeBluetoothAdapter();
  }
});

Page({
  data: {
    shouldBeDiscovering: false
  },

  onLoad() {
    my.onBluetoothAdapterStateChange((res) => {
      if (res.available && this.data.shouldBeDiscovering && !res.discovering) {
        // Bluetooth came back, resume discovery
        my.startBluetoothDevicesDiscovery();
      }
    });
  },

  startScan() {
    this.setData({ shouldBeDiscovering: true });
    my.startBluetoothDevicesDiscovery();
  }
});