微信小程序藍牙模塊

藍牙部分知識

• 關於Service:

每個設備包含有多個Service，每個Service對應一個uuid

• 關於Characteristic

每個Service包含多個Characteristic，每個Characteristic對應一個uuid

• 如何得到數據

我們想要的數據是包含在每一個Characteristic

 

微信小程序目前提供的藍牙API：詳細參數請見小程序開發文檔

1.操作藍牙適配器的4個API  

wx.openBluetoothAdapter //初始化藍牙適配器

wx.closeBluetoothAdapter //關閉藍牙模塊

wx.getBluetoothAdapterState //獲取本機藍牙適配器狀態

wx.onBluetoothAdapterStateChange //監聽藍牙適配器狀態變化事件

 

2.連接前使用的共有4個，分別是

wx.startBluetoothDevicesDiscovery //開始搜尋附近的藍牙外圍設備
wx.stopBluetoothDevicesDiscovery //停止搜尋附近的藍牙外圍設備
wx.getBluetoothDevices //獲取所有已發現的藍牙設備
wx.onBluetoothDeviceFound //監聽尋找到新設備的事件

3.連接和斷開時使用的共有2個，分別是

wx.createBLEConnection //連接低功耗藍牙設備
wx.closeBLEConnection //斷開與低功耗藍牙設備的連接

4.連接成功后使用的共有8個，分別是

wx.getConnectedBluetoothDevices //根據 uuid 獲取處於已連接狀態的設備
wx.getBLEDeviceServices //獲取藍牙設備所有 service（服務）
wx.getBLEDeviceCharacteristics //獲取藍牙設備所有 characteristic（特征值）
wx.readBLECharacteristicValue //讀取低功耗藍牙設備的特征值的二進制數據值
wx.writeBLECharacteristicValue //向低功耗藍牙設備特征值中寫入二進制數據
wx.notifyBLECharacteristicValueChange //啟用低功耗藍牙設備特征值變化時的 notify 功能
wx.onBLECharacteristicValueChange //監聽低功耗藍牙設備的特征值變化
wx.onBLEConnectionStateChange //監聽低功耗藍牙連接的錯誤事件

 

 

基本操作流程

1.初始化藍牙適配器

2.開始搜尋附近的藍牙外圍設備

3.監聽尋找到新設備的事件

4.連接低功耗藍牙設備

5獲取藍牙設備所有 service 和 characteristic

6.讀取或寫入低功耗藍牙設備的特征值的二進制數據值。 

 

示例：

<!--index.wxml-->
<view class="container">

<view class="content">  
  <text class="status">適配器狀態：{{ status }}</text>  
  <text class="sousuo">是否搜索：{{ sousuo }}</text>  
  <text class="msg">消息：{{ msg }} </text>  

  <button type="default" class="button" bindtap="initializeBluetooth">初始化藍牙適配器</button>  
  <button type="default" class="button" bindtap="searchBluetooth">搜索藍牙設備 </button>    
  <button type="default" class="button" bindtap="getServices">獲取連接設備所有service</button>  
  <button type="default" class="button" bindtap="sendMessages">發送消息</button>  
  <button type="default" class="button" bindtap="startBletNotify">啟用設備特征值變化時的notify</button>  
  <button type="default" class="button" bindtap="receiveMessages">接收消息</button>  
  <button type="default" class="button" bindtap="closeBluetooth">斷開藍牙連接</button>  

  <view class="section">  
    <text class="status">接收到消息：{{ jieshou }}</text>  
  </view>  
</view>  

<view class="venues_list" >  
  <block wx:for="{{devices}}" wx:key="{{test}}">  
    <view class="venues_item">  
      <text class="status1">設備名稱: {{item.name}}  </text>  
      <text class="status">設備ID: {{item.deviceId}}  </text> 
      <text class='status'>廣播數據: {{item.advertisData}}  </text> 
      <text class='status'>信號強度RSSI: {{item.RSSI}}  </text>
      <text class="status">連接狀態:{{connectedDeviceId == item.deviceId?"已連接":"未連接"}}  </text>  
      <view class="section">  
      </view>  
      <view class="section">  
        <button type="warn" class="button" id="{{item.deviceId}}" bindtap="connectTO">連接</button>  
      </view>  
    </view>  
  </block>  
</view>  


</view>

 

//index.js
//獲取應用實例
//index.js
//獲取應用實例
const app = getApp()
Page({
    data: {
        status: "",
        sousuo: "",
        connectedDeviceId: "", //已連接設備uuid  
        services: [], // 連接設備的服務  
        serviceId: "",
        characteristics: "",   // 連接設備的狀態值  
        writeServicweId: "", // 可寫服務uuid  
        writeCharacteristicsId: "",//可寫特征值uuid  
        readServicweId: "", // 可讀服務uuid  
        readCharacteristicsId: "",//可讀特征值uuid  
        notifyServicweId: "", //通知服務UUid  
        notifyCharacteristicsId: "", //通知特征值UUID  
        inputValue: "",
        characteristics1: "", // 連接設備的狀態值  
    },
    onLoad: function () {
    },

    // 初始化藍牙適配器  
    initializeBluetooth: function () {
        var that = this;
        if (!wx.openBluetoothAdapter) {
            console.log('藍牙適配器打開失敗，請檢查微信版本或手機是否支持小程序藍牙模塊！')
        } else {
            wx.openBluetoothAdapter({
                success: function (res) {
                    that.setData({
                        msg: "初始化藍牙適配器成功！"
                    })
                    wx.getBluetoothAdapterState({//獲取本機藍牙適配器狀態
                        success: function (res) {
                            console.log('本機藍牙適配器狀態：')
                            console.log(res)
                        }
                    })
                }
            })
        }
    },

    //搜索獲取已發現設備  
    searchBluetooth: function () {
        var that = this;
        wx.startBluetoothDevicesDiscovery({//開始搜尋附近的藍牙外圍設備
            success: function (res) {
                console.log('開始搜索周邊藍牙設備')
                console.log(res)
                wx.getBluetoothDevices({//sucess返回uuid 對應的的已連接設備列表，Array類型
                    success: function (res) {
                        //是否有已連接設備
                        wx.getConnectedBluetoothDevices({////根據 uuid 獲取處於已連接狀態的設備
                            success: function (res) {
                                console.log('已連接的藍牙設備:')
                                console.log(JSON.stringify(res.devices));
                                that.setData({
                                    connectedDeviceId: res.deviceId
                                })
                            }
                        })
                        that.setData({
                            devices: res.devices,
                        })
                    }
                })
            }
        })
    },

    //連接設備  
    connectTO: function (e) {
        var that = this;
        wx.stopBluetoothDevicesDiscovery({ //先停止搜索周邊設備
            success: function (res) {
                console.log('連接設備前，先停止搜索周邊設備:')
                console.log(res)
            }
        })
        wx.showLoading({
            title: '連接藍牙設備中...',
        })
        wx.createBLEConnection({//若小程序在之前已有搜索過某個藍牙設備，並成功建立鏈接，可直接傳入之前搜索獲取的deviceId直接嘗試連接該設備，無需進行搜索操作。
            deviceId: e.currentTarget.id,
            success: function (res) {
                console.log('連接成功:')
                console.log(res)
                wx.hideLoading()
                that.setData({
                    connectedDeviceId: e.currentTarget.id,    //currentTarget: 事件綁定的元素
                    msg: "已連接" + e.currentTarget.id,
                })
            },
            fail: function () {
                console.log("調用失敗");
            },
            complete: function () {
                console.log('已連接設備ID：' + that.data.connectedDeviceId);
                console.log("調用結束");
            }
        })
    },

    // 獲取連接設備的service服務  
    getServices: function () {
        var that = this;
        wx.getBLEDeviceServices({//獲取在小程序藍牙模塊生效期間所有已發現的藍牙設備，包括已經和本機處於連接狀態的設備
            // 這里的 deviceId 需要在上面的 getBluetoothDevices 或 onBluetoothDeviceFound 接口中獲取  
            deviceId: that.data.connectedDeviceId,
            success: function (res) {
                //console.log('獲取藍牙設備所有服務成功：', res);
                that.data.services = res.services
                console.log('獲取藍牙設備所有服務成功：', that.data.services);
                that.setData({
                    serviceId: that.data.services[0].uuid,
                })
                console.log("服務uuid:", that.data.serviceId)
                wx.getBLEDeviceCharacteristics({
                    // 這里的 deviceId 需要在上面的 getBluetoothDevices 或 onBluetoothDeviceFound 接口中獲取  
                    deviceId: that.data.connectedDeviceId,
                    // 這里的 serviceId 需要在上面的 getBLEDeviceServices 接口中獲取  
                    serviceId: that.data.serviceId,   //-----注意是that.data.services[0].uuid
                    success: function (res) {
                        console.log('serviceId: that.data.services[0].uuid: ', that.data.serviceId)
                        console.log(res)
                        for (var i = 0; i < res.characteristics.length; i++) {
                            if (res.characteristics[i].properties.notify) {   //注意characteristic(特征值)信息,properties對象
                                that.setData({
                                    notifyServicweId: that.data.services[0].uuid,
                                    notifyCharacteristicsId: res.characteristics[i].uuid,
                                })
                                console.log("notifyServicweId:", that.data.notifyServicweId,"notifyCharacteristicsId", that.data.notifyCharacteristicsId)
                            }
                            if (res.characteristics[i].properties.write) {
                                that.setData({
                                    writeServicweId: that.data.services[0].uuid,
                                    writeCharacteristicsId: res.characteristics[i].uuid,
                                })
                                console.log("writeServicweId:", that.data.writeServicweId, "writeCharacteristicsId", that.data.writeCharacteristicsId)
                            } else if (res.characteristics[i].properties.read) {
                                that.setData({
                                    readServicweId: that.data.services[0].uuid,
                                    readCharacteristicsId: res.characteristics[i].uuid,
                                })
                                console.log("readServicweId:", that.data.readServicweId, "readCharacteristicsId", that.data.readCharacteristicsId)
                            }
                        }
                    },
                    fail: function () {
                        console.log("獲取連接設備的所有特征值：", res);
                    },
                    complete: function () {
                        console.log("complete!");
                    }
                })
            }
        })
    },


    //斷開設備連接  
    closeBluetooth: function () {
        var that = this;
        wx.closeBLEConnection({
            deviceId: that.data.connectedDeviceId,
            success: function (res) {
                console.log('斷開設備連接: ', devicedId)
                console.log(res)
            }
        })
    },

    //發送  
    sendMessages: function () {
        var that = this;
        // 這里的回調可以獲取到 write 導致的特征值改變  
        wx.onBLECharacteristicValueChange(function (characteristic) {
            console.log('characteristic value changed:1', characteristic)
        })
        var buf = new ArrayBuffer(16)
        var dataView = new DataView(buf)
        dataView.setUint8(0, 99)
        wx.writeBLECharacteristicValue({
            deviceId: that.data.connectedDeviceId,
            serviceId: that.data.writeServicweId,
            characteristicId: that.data.writeCharacteristicsId,
            value: buf,
            success: function (res) {
                console.log('writeBLECharacteristicValue success', res)
            }
        })
    },

    //啟用低功耗藍牙設備特征值變化時的 notify 功能  
    startBletNotify: function () {
        var that = this;
        wx.notifyBLECharacteristicValueChange({
            state: true, // 啟用 notify 功能  
            deviceId: that.data.connectedDeviceId,
            serviceId: that.data.notifyServicweId,
            characteristicId: that.data.notifyCharacteristicsId,
            success: function (res) {
                console.log('notifyBLECharacteristicValueChange success', res.errMsg)
            },
            fail: function () {
                console.log('啟用notify功能失敗！');
                console.log(that.data.notifyServicweId);
                console.log(that.data.notifyCharacteristicsId);
            },
        })
    },

    //接收消息  
    receiveMessages: function () {
        var that = this;
        // 必須在這里的回調才能獲取  
        wx.onBLECharacteristicValueChange(function (characteristic) {
            let hex = Array.prototype.map.call(new Uint8Array(characteristic.value), x => ('00' + x.toString(16)).slice(-2)).join('');
            console.log(hex)
        })
        console.log(that.data.readServicweId);
        console.log(that.data.readCharacteristicsId);
        wx.readBLECharacteristicValue({
            deviceId: that.data.connectedDeviceId,
            serviceId: that.data.readServicweId,
            characteristicId: that.data.readCharacteristicsId,
            success: function (res) {
                console.log('readBLECharacteristicValue:', res.errMsg);
            }
        })
    },

    onHide: function () {
        var that = this
        this.setData({
            devices_list: []
        })
        if (this.data.searching) {
            wx.stopBluetoothDevicesDiscovery({//隱藏界面是建議停止
                success: function (res) {
                    console.log(res)
                    that.setData({
                        searching: false
                    })
                }
            })
        }
    }
})