bluetoothSerial.setDeviceDiscoveredListener().subscribe() does not return data

Ionic Native
1

bluetoothSerial.setDeviceDiscoveredListener().subscribe() does not return data. What do I do wrong?

global packages:

@ionic/cli-utils : 1.4.0
Cordova CLI      : 7.0.1
Ionic CLI        : 3.4.0

local packages:

@ionic/app-scripts              : 1.3.7
@ionic/cli-plugin-cordova       : 1.3.0
@ionic/cli-plugin-ionic-angular : 1.3.0
Cordova Platforms               : android 6.2.3
Ionic Framework                 : ionic-angular 3.3.0

System:

Node       : v6.10.3
OS         : Windows 7
Xcode      : not installed
ios-deploy : not installed
ios-sim    : not installed
npm        : 3.10.10

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { BLE } from '@ionic-native/ble';
import { BluetoothSerial } from '@ionic-native/bluetooth-serial';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})

export class HomePage {

  listBTDevices: any;
  connectedDevice: string;

  constructor(public navCtrl: NavController,
              private ble: BLE,
              private bluetoothSerial: BluetoothSerial) {
      this.listBTDevices = [];
      this.checkBT();
  }

  checkBT() {
    let me = this;
    me.bluetoothSerial.isEnabled().then(
      function() {
        me.scan();;
        me.getListBT();
      },
      function() {
        me.enableBT();
      }
    );
  }

  enableBT() {
    let me = this;
    me.bluetoothSerial.enable().then(
      function() {
        me.scan();
        me.getListBT();
      },
      function() {
        alert("The user did *not* enable Bluetooth");
      }
    );
  }

  scan() {
    let me = this;
    me.bluetoothSerial.discoverUnpaired().then(
        devices => {
            alert('Devices: ' + JSON.stringify(devices));
            devices.forEach(function(device) {
                alert(device.name);
            })
        }, error => {
            alert(error);
        }
    );
    me.bluetoothSerial.setDeviceDiscoveredListener().subscribe(
        device => {
            alert('Found: ' + device.id + '\n' + device.name);
        },
        error => {
            alert('Error scan: ' + JSON.stringify(error));
        }
    );
  }

  getListBT() {
    let me = this;
    this.bluetoothSerial.list().then(
      Deviceslist => {
        for (let key in Deviceslist) {
          me.listBTDevices.push(Deviceslist[key]);
        }
      }
    );
  }

}