11、接收蓝牙返回消息(onBLECharacteristicValueChange)

雨点打透心脏的1/2处 2022-04-24 01:34 471阅读 0赞

# wx.onBLECharacteristicValueChange(function callback) #

> 基础库 1.1.0 开始支持，低版本需做[兼容处理][Link 1]。

监听低功耗蓝牙设备的特征值变化事件。必须先启用 `notifyBLECharacteristicValueChange` 接口才能接收到设备推送的 notification。

## 参数 ##

### function callback ###

低功耗蓝牙设备的特征值变化事件的回调函数

参数

Object res

<table> 
 <thead> 
  <tr> 
   <th>属性</th> 
   <th>类型</th> 
   <th>说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>deviceId</td> 
   <td>string</td> 
   <td>蓝牙设备 id</td> 
  </tr> 
  <tr> 
   <td>serviceId</td> 
   <td>string</td> 
   <td>蓝牙特征值对应服务的 uuid</td> 
  </tr> 
  <tr> 
   <td>characteristicId</td> 
   <td>string</td> 
   <td>蓝牙特征值的 uuid</td> 
  </tr> 
  <tr> 
   <td>value</td> 
   <td>ArrayBuffer</td> 
   <td>特征值最新的值</td> 
  </tr> 
 </tbody> 
</table>

lanyatest.wxml代码：

<view class="contentview">
    
      <view  class='myview' >
        
          {
       {info}}
        
    
      </view>
    
      <button type="primary" class="button" bindtap="lanyatest1">1初始化蓝牙</button>
      <button type="primary" class="button" bindtap="lanyatest2">2获取蓝牙状态</button>
      <button type="primary" class="button" bindtap="lanyatest3">3搜索周边设备</button>
      <button type="primary" class="button" bindtap="lanyatest4">4获取所有设备</button>
      <block wx:for="{
       {devices}}" wx:key="{
       {test}}">
        <button type="primary" class="button" id="{
       {item.deviceId}}" style='background-color:red' bindtap="lanyaconnect">5连接{
       {item.name}}         </button>
      </block>
      <button type="primary" class="button" bindtap="lanyatest6">6停止搜索周边蓝牙设备</button>
      <button type="primary" class="button" bindtap="lanyatest7">7获取所有service</button>
      <button type="primary" class="button" bindtap="lanyatest8">8获取所有特征值</button>
      <button type="primary" class="button" bindtap="lanyatest9">9启用特征值变化notify</button>
      <button type="primary" class="button" bindtap="lanyatest10">10接收蓝牙返回消息</button>
    </view>

lanyatest.js代码：

// pages/lanyatest/lanyatest.js
    Page({
    
      /**
       * 页面的初始数据
       */
      data: {
        info:"未初始化蓝牙适配器",
        connectedDeviceId:"",
        deviceId:"",
        services:"",
        servicesUUID:"0000ff00-0000-1000-8000-00805f9b34fb",
        serviceId:"",
        notifyCharacteristicsId:"",
        writeCharacteristicsId: "",
    
      },
    
      lanyatest1(event){
        var that = this;
        wx.openBluetoothAdapter({
          success: function (res) {
            console.log('初始化蓝牙适配器成功')
            //页面日志显示
            that.setData({
              info: '初始化蓝牙适配器成功'
            })
          },
          fail: function (res) {
            console.log('请打开蓝牙和定位功能')
            that.setData({
              info: '请打开蓝牙和定位功能'
            })
          }
        })
      },
    
    
    
      lanyatest2(event){
        var that = this;
        wx.getBluetoothAdapterState({
    
          success: function (res) {
    
            //打印相关信息
            console.log(JSON.stringify(res.errMsg) + "\n蓝牙是否可用：" + res.available);
    
            that.setData({
              info: JSON.stringify(res.errMsg) +"\n蓝牙是否可用：" + res.available
            })
    
          },
          fail: function (res) {
    
            //打印相关信息
            console.log(JSON.stringify(res.errMsg) + "\n蓝牙是否可用：" + res.available);
    
            that.setData({
              info: JSON.stringify(res.errMsg) + "\n蓝牙是否可用：" + res.available
            })
    
          }
          
        })
    
      },
    
    
    
      lanyatest3(event){
        var that = this;
        wx.startBluetoothDevicesDiscovery({
          services: ['FEE7'], //如果填写了此UUID，那么只会搜索出含有这个UUID的设备，建议一开始先不填写或者注释掉这一句
          success: function (res) {
            that.setData({
              info: "搜索设备" + JSON.stringify(res),
            })
            console.log('搜索设备返回' + JSON.stringify(res))
    
          }
        })
    
      },
    
    
    
    
      lanyatest4(event){
        var that = this;
        wx.getBluetoothDevices({
          success: function (res) {
    
            that.setData({
              info: "设备列表\n" + JSON.stringify(res.devices),
              devices: res.devices
            })
            console.log('搜设备数目：' + res.devices.length)
            console.log('设备信息：\n' + JSON.stringify(res.devices)+"\n")
          }
        })
    
      },
    
    
    
      lanyaconnect(event){
        var that = this;
        wx.createBLEConnection({
          deviceId: event.currentTarget.id,
          success: function (res) {
            console.log('调试信息：' + res.errMsg);
            that.setData({
              connectedDeviceId: event.currentTarget.id,
              info: "MAC地址：" + event.currentTarget.id  + '  调试信息：' + res.errMsg,
              
            })
          },
          fail: function () {
            console.log("连接失败");
          },
    
        })
    
      },
    
    
      lanyatest6(event){
        var that = this;
        wx.stopBluetoothDevicesDiscovery({
          success: function (res) {
            console.log("停止搜索" + JSON.stringify(res.errMsg));
            that.setData({
              info: "停止搜索"  + JSON.stringify(res.errMsg),
            })
          }
        })
    
      },
    
    
    
      lanyatest7(event){
        var that = this;
        wx.getBLEDeviceServices({
          // 这里的 deviceId 需要在上面的 getBluetoothDevices 或 onBluetoothDeviceFound 接口中获取
          deviceId: that.data.connectedDeviceId,
          success: function (res) {
            console.log('services UUID:\n', JSON.stringify(res.services));
            for (var i = 0; i < res.services.length; i++) {
              console.log("第"+(i+1) + "个UUID:" + res.services[i].uuid+"\n")
              
    
            }
            that.setData({
              services: res.services,
              info: JSON.stringify(res.services),
            })
          }
        })
    
      },
    
    
    
      lanyatest8(event){
        var that = this;
        var myUUID = that.data.servicesUUID;//具有写、通知属性的服务uuid
        console.log('UUID' + myUUID)
        wx.getBLEDeviceCharacteristics({
          // 这里的 deviceId 需要在上面的接口中获取
          deviceId: that.data.connectedDeviceId,
          // 这里的 serviceId 需要在上面的 接口中获取
          serviceId: myUUID,
          success: function (res) {
            console.log("%c getBLEDeviceCharacteristics", "color:red;");
            for (var i = 0; i < res.characteristics.length; i++) {
              console.log('特征值：' + res.characteristics[i].uuid)
    
              if (res.characteristics[i].properties.notify) {
                console.log("notifyServicweId：", myUUID);
                console.log("notifyCharacteristicsId：", res.characteristics[i].uuid);
                that.setData({
                  notifyServicweId: myUUID,
                  notifyCharacteristicsId: "0000ff01-0000-1000-8000-00805f9b34fb",//手动设置notifyCharacteristicsId为这个UUID，为了方便写死在这里
    
                })
              }
              if (res.characteristics[i].properties.write) {
                console.log("writeServicweId：", myUUID);
                console.log("writeCharacteristicsId：", res.characteristics[i].uuid);
                that.setData({
                  writeServicweId: myUUID,
                  //writeCharacteristicsId: res.characteristics[i].uuid,
                  writeCharacteristicsId: "0000ff02-0000-1000-8000-00805f9b34fb",//手动设置writeCharacteristicsId为这个UUID，为了方便写死在这里
                })
    
              }
    
            }
            console.log('device getBLEDeviceCharacteristics:', res.characteristics);
    
            that.setData({
              msg: JSON.stringify(res.characteristics),
            })
          },
          fail: function () {
            console.log("fail");
          },
    
        })
    
      },
    
      
    
    
      lanyatest9(event){
        var that = this;
        var notifyServicweId = that.data.servicesUUID;  //具有写、通知属性的服务uuid
        var notifyCharacteristicsId = that.data.notifyCharacteristicsId;
        console.log("启用notify的serviceId", notifyServicweId);
        console.log("启用notify的notifyCharacteristicsId", notifyCharacteristicsId);
    
        wx.notifyBLECharacteristicValueChange({
          state: true, // 启用 notify 功能
          deviceId: that.data.connectedDeviceId,
          // 这里的 serviceId 就是that.data.servicesUUID
          serviceId: notifyServicweId,
    
          characteristicId: that.data.notifyCharacteristicsId,
          success: function (res) {
            console.log('notifyBLECharacteristicValueChange success', res.errMsg)
            var msg = '启动notify:' + res.errMsg
            that.setData({
              info: msg
            })
          },
          fail: function () {
            console.log('启动notify:' + res.errMsg);
            
          },
        })
    
    
      },
    
    
    
      lanyatest10(event){
        var that = this;
        console.log("开始接收数据");
    
    
        wx.onBLECharacteristicValueChange(function (res) {
          
          console.log("characteristicId：" + res.characteristicId)
          console.log("serviceId:" + res.serviceId)
          console.log("deviceId" + res.deviceId)
          console.log("Length:" + res.value.byteLength)
          console.log("hexvalue:" + ab2hex(res.value))
          that.setData({
            info: that.data.info + ab2hex(res.value)
          })
    
        })
    
      },
    
    
    
    //我删除了自动生成的生命周期函数
    
    })
    
    // ArrayBuffer转16进度字符串示例
    function ab2hex(buffer) {
      var hexArr = Array.prototype.map.call(
        new Uint8Array(buffer),
        function (bit) {
          return ('00' + bit.toString(16)).slice(-2)
        }
      )
      return hexArr.join(',');
    }

lanyatest.wxss代码：

/* pages/lanyatest/lanyatest.wxss */
    .vertical{
      display: flex;
      flex-direction: column;
    }
    
    /**index.wxss**/
    .horizontal{
      display: flex;
      flex-direction: row;
    }
    
    .btinfo{
      height:100px;
    }
    
    .contentview {
    margin: 0 10px;
    }
     
    .button {
    margin: 5px;
    }
    
    .myview{
      height:200px;
      word-break:break-all;/* 自动换行 */
    }

# 真机调试结果： #

打开串口调试助手愉快地发消息了

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjM0MDg3_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjM0MDg3_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjM0MDg3_size_16_color_FFFFFF_t_70 2][]

[Link 1]: https://developers.weixin.qq.com/miniprogram/dev/framework/compatibility.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjM0MDg3_size_16_color_FFFFFF_t_70]: /images/20220221/e6f2946ee6d0473da7dd4934aa908a39.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjM0MDg3_size_16_color_FFFFFF_t_70 1]: /images/20220221/52eeadda52324ac49cb5d54fb9d1f330.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjM0MDg3_size_16_color_FFFFFF_t_70 2]: /images/20220221/ae9b1fde4bfd4e40bf4c4f3b6e23e087.png