Question

我正在开发一个离子应用程序，该应用程序可以从蓝牙智能腕带读取心律和血压。我使用了离子型本机ble插件来访问蓝牙功能。就我而言，发现并连接到设备工作正常。但是，当我尝试阅读某些服务时，它会提示“无法获得特定服务”。在我的代码testService()中，我只是创建了一个功能以从设备读取指定的服务。

testService（）函数

testService(deviceId, service, charac) {
    // Subscribe for notifications
   this.ble.startNotification(deviceId, service, charac).subscribe(
     data => this.onValueChange(data, service+"|"+charac),
     () => this.alertMsg('Unexpected Error', 'Failed to subscribe for ' + service + " | " + charac)
   );

  // Read the current value
  this.ble.read(deviceId, service, charac).then(
    data => {
      this.onValueChange(data, service+"|"+charac);
    },
    () => this.alertMsg('Unexpected Error', 'Failed to get ' + service + " | " + charac)
  );
}

这是我的整个JavaScript代码。

import { Component, ViewChild, NgZone } from '@angular/core';
import { IonicPage, NavController, NavParams, AlertController, ToastController } from 'ionic-angular';
import { BLE } from '@ionic-native/ble';
import { Storage } from '@ionic/storage';


@IonicPage()
@Component({
  selector: 'page-heart-rate',
  templateUrl: 'heart-rate.html',
})


export class HeartRatePage {

  private isConnected: boolean;

  conDevice: any;        //connected device

  constructor(public navCtrl: NavController, 
    public navParams: NavParams,
    private ble: BLE,
    private storage: Storage,
    private alertCtrl: AlertController,
    private toastCtrl: ToastController,
    private ngZone: NgZone
  ) {
  }

  ionViewDidEnter() {
    this.isConnected = false;

    this.storage.get('last-connected-device').then((val) => {           //check if a device is connected
      this.ble.isConnected(String(val.id)).then(
        () => {
          this.conDevice = val;
          this.isConnected = true;
          this.testService(this.conDevice.id, "180D", "2A37");          //reading the service (heart rate)
        }, 
        () => {
        }
      );
    }).catch( err => {

    });
  }


//this method will read device for a specified service
testService(deviceId, service, charac) {
    // Subscribe for notifications
   this.ble.startNotification(deviceId, service, charac).subscribe(
     data => this.onValueChange(data, service+"|"+charac),
     () => this.alertMsg('Unexpected Error', 'Failed to subscribe for ' + service + " | " + charac)
   );

  // Read the current value
  this.ble.read(deviceId, service, charac).then(
    data => {
      this.onValueChange(data, service+"|"+charac);
    },
    () => this.alertMsg('Unexpected Error', 'Failed to get ' + service + " | " + charac)
  );
}


onValueChange(buffer:ArrayBuffer, text:string) {
  var data = new Float32Array(buffer);
  var dataString = String.fromCharCode.apply(null, data);
  this.ngZone.run( () => {
     let toast = this.toastCtrl.create({
       message: 'value change: ' + text +'::'+ data[0],
       duration: 2000
     });
     toast.present();
  } );
}


//this method will popup an alert
alertMsg(title, message) {
  let alert = this.alertCtrl.create({
    title: title,
    message: message,
    buttons: [
      {
        text: 'Ok'
      }
    ]
  });
  alert.present();
}

}

有人可以帮助我确定我在这里做错了什么吗？

Answer 1

在对这个问题进行了更多研究之后，终于找到了答案。我将其发布给任何对未来感兴趣的人。

事实证明，许多蓝牙设备不使用默认服务和特征性UUID。在上面的代码中，我正在使用默认服务和特征性UUID（“ 180D”，“ 2A37”）。我用来测试代码的设备甚至没有这样的服务。这就是为什么我得到Failed to get the particular service。

因此，解决方案是以某种方式找出设备的服务和特征性UUID，并为这些特定值编写代码。

使用离子本机ble插件从蓝牙智能腕带读取服务

1 个答案: