微信小程序调用Android手机蓝牙BLE传输数据

最近做的微信小程序要调用手机自带的4.0蓝牙发送、接收数据

4.0蓝牙又叫BLE，整理了下，蓝牙连接要经过如下步骤：

1. 初始化蓝牙
2. 检查蓝牙是否初始化成功
3. 开始搜索附近蓝牙设备
4. 显示扫描得到的蓝牙
5. 选择连接特定MAC地址的蓝牙设备
6. 连接成功后，获取service ID
7. 然后获取characteristic ID
8. write/read data

*每个步骤对应的操作在js代码中有注释

我遇到的坑：一定要启用notify功能，否则只能发送，无法接收数据！！！

index.json为空，只上传了index.wxml，index.wxss，index.js三个文件，源码如下

index.wxml

   
         
    
      蓝牙开关
    
    
      
    
  

          
     {{searchingstatus?"搜索中":"搜索蓝牙"}} 
  

       
    
      
        {{index}}:\n 
        设备名称:  {{item.name}}\n
        MAC地址:   {{item.deviceId}}
      
      
       {{deviceconnected?"已连接":"连接"}} 
      
    
 

    
    
      \n\n数据接收\n
      {{receive_data}}\n
      
    

    
      

        \n\n数据发送:
        
        发送
        清空
      
    

index.wxss

view {
  display: inline-block;
}

.container {
  padding: 0;
  margin: 0;
  align-items: flex-start;
}

.section {
  display: inline-block;
  width: 100%;
  margin-top: 50rpx;
  position: relative;
}

.connection {
  margin-left: 90rpx;
}

.list {
  margin-left: 20rpx;
}

.content {
  margin-left: 100rpx;
  padding: auto;
  position: absolute;
  top: 5rpx;
  left: 10rpx;
}

.switch {
  position: relative;
  float: right;
  margin-right: 100rpx;
}

button {
  background: red\;
}

.list-item {
  margin-top: 20rpx;
  margin-bottom: 20rpx; 
  display: flex;
  flex-direction: column;
  box-sizing: border-box;
  border: 1px dashed #000;
}

.list-item text {
   margin-top: 10rpx;
}


.list-item button {
  margin-right: 10rpx;
}

.deviceconnected{
  background-color:sandybrown
}

.recieve{
  width: 100%
}

.recieve_textarea{
  width: 100%;
  margin-top: 10dpx;
}

input{
  display: block;
  border: 1px dashed;
  width: 200px;
}

index.js

var app = getApp()
var temp = []
var string_temp=""
var serviceId = "0000ffe0-0000-1000-8000-00805f9b34fb"
var characteristicId = "0000ffe1-0000-1000-8000-00805f9b34fb"

Page({
  data: {
    isbluetoothready: false,
    defaultSize: 'default',
    primarySize: 'default',
    warnSize: 'default',
    disabled: false,
    plain: false,
    loading: false,
    searchingstatus: false,
    receivedata: '666',
    onreceiving: false,
    id_text: string_temp,
    list: [],
    receive_data:'none  '
  },
  onLoad: function () {

  },
  open_BLE: function () {
    var that = this

    that.setData({
      isbluetoothready: !that.data.isbluetoothready,
    })
    if (that.data.isbluetoothready) {
      //开启蓝牙模块并初始化
      wx.openBluetoothAdapter({
        success: function (res) {

        },
        fail: function (res) {
          wx.showModal({
            title: '提示',
            content: '请检查手机蓝牙是否打开',
          })
        }
      })
      //开启蓝牙模块并初始化

      //检查蓝牙模块是否初始化成功
      wx.getBluetoothAdapterState({
        success: function (res) {
          var available = res.available
          if (!available) {
            wx.showToast({
              title: '蓝牙初始化失败',
              icon: 'loading',
              duration: 2000
            })
          }
          else {
            wx.showToast({
              title: '蓝牙初始化成功',
              icon: 'success',
              duration: 2000
            })
          }
        }
      })
      //检查蓝牙模块是否初始化成功
    }
    else{
      wx.closeBLEConnection({
        deviceId: that.data.connectedDeviceId,
        complete: function (res) {
          that.setData({
            deviceconnected: false,
            connectedDeviceId: ""
          })
          wx.showToast({
            title: '蓝牙连接断开',
            icon: 'success',
            duration: 2000
          })
        }
      })
      setTimeout(function () {
        that.setData({
          list: []
        })
        //释放蓝牙适配器
        wx.closeBluetoothAdapter({
          success: function (res) {
            that.setData({
              isbluetoothready: false,
              deviceconnected: false,
              devices: [],
              searchingstatus: false,
              receivedata: ''
            })
            wx.showToast({
              title: '蓝牙适配器释放',
              icon: 'success',
              duration: 2000
            })
          },
          fail: function (res) {

          }
        })
        //释放蓝牙适配器
      }, 1000)
    }
  },

  search_BLE: function () {
    temp = []
    var that = this
    if (!that.data.searchingstatus) {
      var that = this
      //开始搜索附近蓝牙设备
      wx.startBluetoothDevicesDiscovery({
        success: function (res) {
          wx.showToast({
            title: '开始搜索BLE',
            icon: 'loading',
            duration: 2000
          })
          that.setData({
            searchingstatus: !that.data.searchingstatus
          })
        }
      })
      //开始搜索附近蓝牙设备
    } else {
      //停止搜索附近蓝牙设备
      wx.stopBluetoothDevicesDiscovery({
        success: function (res) {
          wx.showToast({
            title: '停止搜索BLE',
            icon: 'success',
            duration: 2000
          })
          that.setData({
            searchingstatus: !that.data.searchingstatus
          })
        }
      })
      //停止搜索附近蓝牙设备
      setTimeout(function () {
        //获取发现的蓝牙设备
        wx.getBluetoothDevices({
          success: function (res) {
            for(var i=0;i<100;i++){
              if (res.devices[i]) {
                string_temp = string_temp + '\n' + res.devices[i].deviceId
              }
            }
            that.setData({
              id_text: string_temp,
              list: res.devices
            })
          }
        })
        //获取发现的蓝牙设备
      }, 1000)
    }
  },

  connectTO: function (e) {
    var that = this
      wx.showLoading({
        title: '连接蓝牙设备中...',
      })
      wx.createBLEConnection({
        deviceId: e.currentTarget.id,
        success: function (res) {
          wx.hideLoading()
          wx.showToast({
            title: '连接成功',
            icon: 'success',
            duration: 1000
          })
          that.setData({
            deviceconnected: true,
            connectedDeviceId: e.currentTarget.id
          })
          // 启用 notify 功能
          wx.notifyBLECharacteristicValueChanged({
            state: true, 
            deviceId: that.data.connectedDeviceId,
            serviceId: serviceId,
            characteristicId: characteristicId,
            success: function (res) {

            }
          })
          // 启用 notify 功能
          // ArrayBuffer转为16进制数
          function ab2hex(buffer) {
            var hexArr = Array.prototype.map.call(
              new Uint8Array(buffer),
              function (bit) {
                return ('00' + bit.toString(16)).slice(-2)
              }
            )
            return hexArr.join('');
          }
          // 16进制数转ASCLL码
          function hexCharCodeToStr(hexCharCodeStr) {
            var trimedStr = hexCharCodeStr.trim();
            var rawStr = trimedStr.substr(0, 2).toLowerCase() === "0x" ? trimedStr.substr(2) : trimedStr;
            var len = rawStr.length;
            var curCharCode;
            var resultStr = [];
            for (var i = 0; i < len; i = i + 2) {
              curCharCode = parseInt(rawStr.substr(i, 2), 16);
              resultStr.push(String.fromCharCode(curCharCode));
            }
            return resultStr.join("");
          }
          //监听回调，接收数据
          wx.onBLECharacteristicValueChange(function (characteristic) {
            var hex = ab2hex(characteristic.value)
            that.setData({
              receive_data: hexCharCodeToStr(hex)
            })
          })
        },
        fail: function (res) {
          wx.hideLoading()
          wx.showToast({
            title: '连接设备失败',
            icon: 'success',
            duration: 1000
          })
          that.setData({
            connected: false
          })
        }
      })
      wx.stopBluetoothDevicesDiscovery({
        success: function (res) {

        }
      })
  },

  formSubmit: function (e) {
    var senddata = e.detail.value.senddata;
    var that = this
    let buffer = new ArrayBuffer(senddata.length)
    let dataView = new DataView(buffer)
    for (var i = 0; i < senddata.length; i++) {
      dataView.setUint8(i, senddata.charAt(i).charCodeAt())
    }

    wx.writeBLECharacteristicValue({
      deviceId: that.data.connectedDeviceId,
      serviceId: serviceId,
      characteristicId: characteristicId,
      value: buffer,
      success: function (res) {
        wx.showToast({
          title: '发送成功',
          icon: 'success',
          duration: 2000
        })
      }
    })
  },

  receiveMessages: function () {
    var that = this;
    wx.readBLECharacteristicValue({
      deviceId: that.data.connectedDeviceId,
      serviceId: serviceId,
      characteristicId: characteristicId,
      success: function (res) {
      }
    })
  },

})