萌新小白。。用了蓝牙BLE的API调试了一下新买的蓝牙ble-rc6621A,在page里面，连接到蓝牙之后向蓝牙发送了一个字符串'getid'，串口调试助手接收到。写了一个按钮触发事件向蓝牙发送同样的字符串，这时候串口助手就没有收到了。但是通过调试器的log信息知道确实是写入成功了success。。有没有大神帮帮，以下是js逻辑代码

// index.js

// 获取应用实例

const app = getApp()

Page({

  data: {

    'deviceId':'',

    'serviceId':'',

    'characteristicId':''

  },

  onLoad() {

    this.bleInit();

  },

  bleInit() {

    console.log('searchBle')

    // 监听扫描到新设备事件

    wx.onBluetoothDeviceFound((res) => {

      res.devices.forEach((device) => {

        // 这里可以做一些过滤

        console.log('Device Found', device)

        if(device.deviceId == "2E209DD5-18CD-C223-8403-A2A0C1AD89CA"){

          // 找到设备开始连接

          this.bleConnection(device.deviceId);

          wx.stopBluetoothDevicesDiscovery()

        }

      })

      // 找到要搜索的设备后，及时停止扫描

      // 

    })

    // 初始化蓝牙模块

    wx.openBluetoothAdapter({

      mode: 'central',

      success: (res) => {

        // 开始搜索附近的蓝牙外围设备

        wx.startBluetoothDevicesDiscovery({

          allowDuplicatesKey: false,

        })

      },

      fail: (res) => {

        if (res.errCode !== 10001) return

        wx.onBluetoothAdapterStateChange((res) => {

          if (!res.available) return

          // 开始搜寻附近的蓝牙外围设备

          wx.startBluetoothDevicesDiscovery({

            allowDuplicatesKey: false,

          })

        })

      }

    })

    var that = this

    wx.onBLECharacteristicValueChange((result) => {

      console.log('onBLECharacteristicValueChange',result.value)

      let hex = that.ab2hex(result.value)

      console.log('hextoString',that.hextoString(hex))

      console.log('hex',hex)

    })

  },

  bleConnection(deviceId){

    wx.createBLEConnection({

      deviceId, // 搜索到设备的 deviceId

      success: () => {

        // 连接成功，获取服务

        console.log('连接成功，获取服务')

        this.bleGetDeviceServices(deviceId)

      }

    })

  },

  bleGetDeviceServices(deviceId){

    wx.getBLEDeviceServices({

      deviceId, // 搜索到设备的 deviceId

      success: (res) => {

        console.log(res.services)

        for (let i = 0; i < res.services.length; i++) {

          if (res.services[i].isPrimary) {

            // 可根据具体业务需要，选择一个主服务进行通信

            this.bleGetDeviceCharacteristics(deviceId,res.services[i].uuid)

          }

        }

      }

    })

  },

  bleGetDeviceCharacteristics(deviceId,serviceId){

    wx.getBLEDeviceCharacteristics({

      deviceId, // 搜索到设备的 deviceId

      serviceId, // 上一步中找到的某个服务

      success: (res) => {

        for (let i = 0; i < res.characteristics.length; i++) {

          let item = res.characteristics[i]

          console.log(item)

          if (item.properties.write) { // 该特征值可写

            // 本示例是向蓝牙设备发送一个 0x00 的 16 进制数据

            // 实际使用时，应根据具体设备协议发送数据

            // let buffer = new ArrayBuffer(1)

            // let dataView = new DataView(buffer)

            // dataView.setUint8(0, 0)

            // let senddata = 'FF';

            // let buffer = this.hexString2ArrayBuffer(senddata);

            var buffer = this.stringToBytes("getid")

            this.setData({

              'deviceId':deviceId,

              'serviceId':serviceId,

              'characteristicId':item.uuid

            })

            wx.writeBLECharacteristicValue({

              deviceId,

              serviceId,

              characteristicId: item.uuid,

              value: buffer,

            })

          }

          if (item.properties.read) { // 改特征值可读

            wx.readBLECharacteristicValue({

              deviceId,

              serviceId,

              characteristicId: item.uuid,

            })

          }

          if (item.properties.notify || item.properties.indicate) {

            // 必须先启用 wx.notifyBLECharacteristicValueChange 才能监听到设备 onBLECharacteristicValueChange 事件

            wx.notifyBLECharacteristicValueChange({

              deviceId,

              serviceId,

              characteristicId: item.uuid,

              state: true,

            })

          }

        }

      }

    })

  },

  stringToBytes(str) {

    var array = new Uint8Array(str.length);

    for (var i = 0, l = str.length; i < l; i++) {

      array[i] = str.charCodeAt(i);

    }

    console.log(array);

    return array.buffer;

  },

  hextoString: function (hex) {

    var arr = hex.split("")

    var out = ""

    for (var i = 0; i < arr.length / 2; i++) {

      var tmp = "0x" + arr[i * 2] + arr[i * 2 + 1]

      var charValue = String.fromCharCode(tmp);

      out += charValue

    }

    return out

  },

  ab2hex(buffer) {

    var hexArr = Array.prototype.map.call(

      new Uint8Array(buffer),

      function (bit) {

        return ('00' + bit.toString(16)).slice(-2)

      }

    )

    return hexArr.join('');

  },

  light1on(){

    var buffer = this.stringToBytes("light1on")

    wx.writeBLECharacteristicValue({

      deviceId:this.data.deviceId,

      serviceId:this.data.serviceId,

      characteristicId:this.data.characteristicId,

      value: buffer,

    })

  },

  light2on(){

    var buffer = this.stringToBytes("light2on")

    wx.writeBLECharacteristicValue({

      deviceId:this.data.deviceId,

      serviceId:this.data.serviceId,

      characteristicId:this.data.characteristicId,

      value: buffer,

    })

  },

  light1off(){

    var buffer = this.stringToBytes("light1off")

    wx.writeBLECharacteristicValue({

      deviceId:this.data.deviceId,

      serviceId:this.data.serviceId,

      characteristicId:this.data.characteristicId,

      value: buffer,

    })

  },

  light2off(){

    var buffer = this.stringToBytes("light2off")

    wx.writeBLECharacteristicValue({

      deviceId:this.data.deviceId,

      serviceId:this.data.serviceId,

      characteristicId:this.data.characteristicId,

      value: buffer,

    })

  },

})