state.js

 constructor() {
    super();

    this.state = {
      scanning: false,
      peripherals: new Map(),
      peripheral:null,
      appState: '',
      connectedTo: 'nothing',
      battery: null,
      fVersion: null,
      Snumber: null,
      time: null,
      steps: null,
      distance: null,
      calory: null,
      rssi: null,
      heartbeat: null,
    };

    this.handleDiscoverPeripheral = this.handleDiscoverPeripheral.bind(this);
    this.handleStopScan = this.handleStopScan.bind(this);
    this.handleUpdateValueForCharacteristic = this.handleUpdateValueForCharacteristic.bind(
      this,
    );
    this.handleDisconnectedPeripheral = this.handleDisconnectedPeripheral.bind(
      this,
    );
    this.handleAppStateChange = this.handleAppStateChange.bind(this);
  }