微信小程序连接蓝牙

准备工作：

1：需要一个蓝牙板子和串口软件（卖蓝牙板子的商家会提供），手机上需要蓝牙调试助手（为了测试蓝牙是否正常连接）
2：蓝牙板通过usb插入到电脑端
3：安装好串口调试工具并打开连接上蓝牙
4：打开手机蓝牙调试助手，连接上后进行读写操作，确认已正常连接通信
准备工作完结！

直接上代码

第一步：初始化蓝牙设备， onShow里面调用或者onLoad里面调用都可，看你的需求场景

initBlue () {wx.openBluetoothAdapter({success: (res) => {wx.showToast({title: '正在搜索蓝牙设备...',icon: 'loading'})this.findBlue()},fail: (error) => {wx.showToast({title: '请开启蓝牙',icon: 'fails',duration: 1000})this.setData({ isTrigger: false })}})},

第二步：搜索蓝牙设备

findBlue(){wx.startBluetoothDevicesDiscovery({allowDuplicatesKey: true,interval: 0,powerLevel: 'high',success: (res) => {this.getBlue()//3.0},complete: () => {this.setData({ isTrigger: false })}})},

第三步：拿到需要的蓝牙设备进行列表渲染

getBlue () {wx.onBluetoothDeviceFound((devices) => {if (devices.devices[0].name.includes('demo')) {console.log(devices.devices[0].name, 'devices.devices[0].name')// 添加有名字的蓝牙设备，并去重处理this.setData({ bluetoolList: [...this.data.bluetoolList, devices.devices[0]].filter((obj, index, self) =>index === self.findIndex((t) => (t.name === obj.name))) })wx.stopBluetoothDevicesDiscovery() // 停止搜索}})},

第四步：点击某个蓝牙设备进行连接

connetBluetooth(evt) {wx.showToast({title: '正在连接...',icon: 'loading'})console.log(evt.currentTarget.dataset, '=========')const { row } = evt.currentTarget.datasetthis.setData({ currentDeviceid: row.deviceId })wx.setStorageSync('deviceId', row.deviceId)wx.createBLEConnection({deviceId: row.deviceId,timeout: 5000,success: (res) => {console.log('connet success: ', res)wx.stopBluetoothDevicesDiscovery()this.getServiceUUid() // 连接的收就获取服务ID 用于后面获取特征值id（特征值id可以用来进行读、写、监听蓝牙操作）},fail: (error) => {console.log('createBLEConnection error: ', error)if (error.errCode === -1) { // 表示已经连接, 直接跳转到对应页面即可wx.navigateTo({ url: '/pages/xxx/xxx' })} else {wx.showToast({title: '连接失败',icon: 'error',timeout: 500,complete: () => {}})}}})},

第五步：获取服务id,不同蓝牙设备，不同机型，获取的服务值不一样，根据你自己的蓝牙板子和机型来获取，一定要获取准确，错了就读写不了蓝牙设备

getServiceUUid() {console.log('=====================getServiceUUid=======================')let _this = thiswx.getBLEDeviceServices({// 这里的 deviceid 需要已经通过 createBLEConnection 与对应设备建立链接deviceId: _this.data.currentDeviceid,success: async (res) => {console.log('res.services: ', res.services)if (wx.getStorageSync('platform') === 'ios') {// readawait _this.setData({ readServiceId: res.services[0].uuid })await wx.setStorageSync('readServiceId', res.services[0].uuid)// write trueawait _this.setData({ writeServiceId: res.services[1].uuid })await wx.setStorageSync('writeServiceId', res.services[1].uuid)// notifyawait _this.setData({ notifyServiceId: res.services[1].uuid })await wx.setStorageSync('notifyServiceId', res.services[1].uuid)await _this.getReadCharacteIdIos()await _this.getWriteCharacteIdIos()} else {// read true// _this.setData({ readServiceId: res.services[0].uuid })await _this.setData({ readServiceId: res.services[2].uuid })await wx.setStorageSync('readServiceId', res.services[2].uuid)// 第一个 write: true；第二个 notify: trueawait _this.setData({ writeServiceId: res.services[1].uuid })await wx.setStorageSync('writeServiceId', res.services[1].uuid)await _this.setData({ notifyServiceId: res.services[1].uuid })await wx.setStorageSync('notifyServiceId', res.services[1].uuid)// read true// await _this.setData({ readServiceId: res.services[2].uuid })// await wx.setStorageSync('readServiceId', res.services[2].uuid)// indicate 安卓端监听不到蓝牙发送过来的回调// await _this.setData({ notifyServiceId: res.services[3].uuid })// await wx.setStorageSync('notifyServiceId', res.services[3].uuid)await _this.getReadCharacteId()// await _this.getNotifyCharacteId()await _this.getWriteCharacteId()}}})},

第六步：获取特征值id，并保证在了本地（也可以挂在全局，方便另一个页面获取），跳转到对应页面，这里你可以封装一下，我这里做demo就没封装，五个方法，分别获取IOS端和安卓端的对应读写和监听的特征值，一定要根据蓝牙的板子获取对应正确的特征值(为true的才能进行后面的连接和读写操作)，慢慢调试

 // readServiceIdgetReadCharacteId() {let _this = thiswx.getBLEDeviceCharacteristics({deviceId: _this.data.currentDeviceid,serviceId: _this.data.readServiceId,success: (res) => {console.log('res.haracteristics read: ', res.characteristics)for (let i = 0; i < res.characteristics.length; i++) {let characteristic = res.characteristics[i]// 检查特征值是否具有 read 属性为 falseif (characteristic.properties.read) {// 当找到 read 属性为 false 的特征值时，设置 writeId 为该特征值的 UUID_this.setData({ characteReadId: characteristic.uuid })wx.setStorageSync('characteReadId', characteristic.uuid)// break // 找到符合条件的特征值后，结束循环}}},fail: (error) => {console.log('get read CharacteId error: ', error)}})},// use bluetool deviceId and uuid get characteId (特征值) writeServiceIdgetWriteCharacteId () {let _this = thiswx.getBLEDeviceCharacteristics({deviceId: _this.data.currentDeviceid,serviceId: _this.data.writeServiceId,success: (res) => {// 遍历特征值列表console.log('res.characteristics write : ', res.characteristics)for (let i = 0; i < res.characteristics.length; i++) {let characteristic = res.characteristics[i]// 检查特征值是否具有 read 属性为 falseif (characteristic.properties.write) {// 当找到 read 属性为 false 的特征值时，设置 writeId 为该特征值的 UUID_this.setData({characteWriteId: characteristic.uuid})wx.setStorageSync('characteWriteId', characteristic.uuid)// break // 找到符合条件的特征值后，结束循环}if (characteristic.properties.notify) {_this.setData({ characteNotifyId: characteristic.uuid })wx.setStorageSync('characteNotifyId', characteristic.uuid)}}console.log('currentDeviceid: ', _this.data.currentDeviceid)console.log('----------------------read--------------------')console.log('readServiceId: ', _this.data.readServiceId)console.log('characteReadId: ', _this.data.characteReadId)console.log('----------------------write--------------------')console.log('writeServiceId: ', _this.data.writeServiceId)console.log('characteWriteId: ', _this.data.characteWriteId)wx.navigateTo({url: '/pages/action/action'})wx.hideToast()},fail: function (error) {console.log("error reason: ", error)}})},// notifyServiceIdgetNotifyCharacteId() {let _this = thiswx.getBLEDeviceCharacteristics({deviceId: _this.data.currentDeviceid,serviceId: _this.data.notifyServiceId,success: (res) => {console.log('res.characteristics notify: ', res.characteristics)for (let i = 0; i < res.characteristics.length; i++) {let characteristic = res.characteristics[i]// 检查特征值是否具有 read 属性为 falseif (characteristic.properties.indicate) {// 当找到 read 属性为 false 的特征值时，设置 writeId 为该特征值的 UUID_this.setData({ characteNotifyId: characteristic.uuid })wx.setStorageSync('characteNotifyId', characteristic.uuid)break // 找到符合条件的特征值后，结束循环}}},fail: (error) => {console.log('get notify CharacteId error: ', error)}})},// ios read characteIdgetReadCharacteIdIos() {wx.getBLEDeviceCharacteristics({deviceId: this.data.currentDeviceid,serviceId: this.data.readServiceId,success: (res) => {// 遍历特征值列表console.log('res.characteristics read : ', res.characteristics)for (let i = 0; i < res.characteristics.length; i++) {let characteristic = res.characteristics[i]// 检查特征值是否具有 read 属性为 falseif (characteristic.properties.read) {// 当找到 read 属性为 false 的特征值时，设置 writeId 为该特征值的 UUIDthis.setData({characteReadId: characteristic.uuid})wx.setStorageSync('characteReadId', characteristic.uuid)break // 找到符合条件的特征值后，结束循环}}}})},// ios write characteIdgetWriteCharacteIdIos() {wx.getBLEDeviceCharacteristics({deviceId: this.data.currentDeviceid,serviceId: this.data.writeServiceId,success: (res) => {// 遍历特征值列表console.log('res.characteristics write : ', res.characteristics)for (let i = 0; i < res.characteristics.length; i++) {let characteristic = res.characteristics[i]// 检查特征值是否具有 read 属性为 falseif (characteristic.properties.write) {// 当找到 read 属性为 false 的特征值时，设置 writeId 为该特征值的 UUIDthis.setData({characteWriteId: characteristic.uuid})wx.setStorageSync('characteWriteId', characteristic.uuid)// break // 找到符合条件的特征值后，结束循环}if (characteristic.properties.notify) {// 当找到 read 属性为 false 的特征值时，设置 writeId 为该特征值的 UUIDthis.setData({characteNotifyId: characteristic.uuid})wx.setStorageSync('characteNotifyId', characteristic.uuid)}wx.navigateTo({url: '/pages/xxx/xxx'})wx.hideToast()}}})},

第七步：这时候已经跳转到对应页面了，在页面onLoad里开启监听，后面蓝牙发送设备到小程序可以实时监听到值

async onLoad(options) {// 监听蓝牙发送到小程序的数据await wx.onBLECharacteristicValueChange((res) => {console.log('characteristicis: ', res.value)console.log('转换后的值： ', this.ab2hex(res.value))this.setData({ fromBlueToolsData: this.ab2hex(res.value) })// this.setData({ fromBlueToolsData: res.value })})await wx.readBLECharacteristicValue({deviceId: wx.getStorageSync('deviceId'),serviceId: wx.getStorageSync('readServiceId'),characteristicId: wx.getStorageSync('characteReadId'),success: (res) => {console.log('read data is: ', res)},fail: (error) => {console.log('read error, error message is: ', error)}})await wx.notifyBLECharacteristicValueChange({state: true,type: 'notification', // 根据你蓝牙的特征值来选择类型deviceId: wx.getStorageSync('deviceId'),serviceId: wx.getStorageSync('notifyServiceId'),characteristicId: wx.getStorageSync('characteNotifyId'),success: (res) => {console.log('notify success, success message is: ', res)},fail: (error) => {console.log('notify error, error message is: ', error)this.setData({ fromBlueToolsData: '' })}})},// 16 进制到 10进制ab2hex(buffer) {let hexArr = Array.prototype.map.call(new Uint8Array(buffer),function(bit) {return ('00' + bit.toString(16)).slice(-2)})return hexArr.join('');},

第八步：测试读写，看蓝牙串口与小程序是否有通信

// 写入数据
writeTap() {console.log('-----------------start write action----------------------------')console.log('inputValue: ', this.data.inputValue)let data = this.data.inputValueif (data.length === 0) {wx.showModal({ title: '提示', content: '请输入要发送的数据' })return}wx.writeBLECharacteristicValue({deviceId: wx.getStorageSync('deviceId'),serviceId: wx.getStorageSync('writeServiceId'),characteristicId: wx.getStorageSync('characteWriteId'),value: this.string2buffer(data), // 数据转换发送success (res) {console.log('writeBLECharacteristicValue success', res)this.setData({ inputValue: '' })},fail: (error) => {console.log('write error, error message is: ', error)}})},string2buffer(hexString) {hexString = hexString.replace(/^0x/, '');const bytes = new Uint8Array(hexString.length / 2);for (let i = 0; i < hexString.length; i += 2) {bytes[i / 2] = parseInt(hexString.substring(i, i + 2), 16);}console.log('写入的buffer：', bytes.buffer)return bytes.buffer;},// input输入值onWriteInput(evt) {const { value } = evt.detailthis.setData({ inputValue: value })},

最终测试后在ios与安卓上能够与蓝牙串口进行正常通信，完结！