GitHub 地址: https://github.com/dujingya/blueDevice/blob/master/blueDevice.md
使用 mpvue 开发小程序过程中 简单介绍一下微信小程序蓝牙连接过程 #在蓝牙连接的过程中部分 API 需要加定时器延时 1 秒到 2 秒左右再执行, 原因为何不知道, 小程序有这样的要求 #1. 首先是要初始化蓝牙: openBluetoothAdapter()
- if (wx.openBluetoothAdapter) {
- wx.openBluetoothAdapter({
- success: function(res) {
- / 获取本机的蓝牙状态 /
- setTimeout(() => {
- getBluetoothAdapterState()
- }, 1000)
- },
- fail: function(err) {
- // 初始化失败
- }
- })
- } else {
- }
2. 检测本机蓝牙是否可用:
要在上述的初始化蓝牙成功之后回调里调用
- getBluetoothAdapterState() {
- var that = this;
- that.toastTitle = '检查蓝牙状态'
- wx.getBluetoothAdapterState({
- success: function(res) {
- startBluetoothDevicesDiscovery()
- },
- fail(res) {
- console.log(res)
- }
- })
- }
3. 开始搜索蓝牙设备:
- startBluetoothDevicesDiscovery() {
- var that = this;
- setTimeout(() => {
- wx.startBluetoothDevicesDiscovery({
- success: function(res) {
- / 获取蓝牙设备列表 /
- that.getBluetoothDevices()
- },
- fail(res) {
- }
- })
- }, 1000)
- }
4. 获取搜索到的蓝牙设备列表
- / that.deviceName 是获取到的蓝牙设备的名称, 因为蓝牙设备在安卓和苹果手机上搜到的蓝牙地址显示是不一样的, 所以根据设备名称匹配蓝牙 /
- getBluetoothDevices() {
- var that = this;
- setTimeout(() => {
- wx.getBluetoothDevices({
- services: [],
- allowDuplicatesKey: false,
- interval: 0,
- success: function(res) {
- if (res.devices.length> 0) {
- if (JSON.stringify(res.devices).indexOf(that.deviceName) !== -1) {
- for (let i = 0; i <res.devices.length; i++) {
- if (that.deviceName === res.devices[i].name) {
- / 根据指定的蓝牙设备名称匹配到 deviceId /
- that.deviceId = that.devices[i].deviceId;
- setTimeout(() => {
- that.connectTO();
- }, 2000);
- };
- };
- } else {
- }
- } else {
- }
- },
- fail(res) {
- console.log(res, '获取蓝牙设备列表失败 =====')
- }
- })
- }, 2000)
- },
5. 连接蓝牙
匹配到的蓝牙设备 ID 发送连接蓝牙的请求, 连接成功之后 应该断开蓝牙搜索的 API, 然后去获取所连接蓝牙设备的 service 服务
- connectTO() {
- wx.createBLEConnection({
- deviceId: deviceId,
- success: function(res) {
- that.connectedDeviceId = deviceId;
- / 4. 获取连接设备的 service 服务 /
- that.getBLEDeviceServices();
- wx.stopBluetoothDevicesDiscovery({
- success: function(res) {
- console.log(res, '停止搜索')
- },
- fail(res) {
- }
- })
- },
- fail: function(res) {
- }
- })
- }
6. 获取蓝牙设备的 service 服务, 获取的 serviceId 有多个要试着连接最终确定哪个是稳定版本的 service 获取服务完后获取设备特征值
- getBLEDeviceServices() {
- setTimeout(() => {
- wx.getBLEDeviceServices({
- deviceId: that.connectedDeviceId,
- success: function(res) {
- that.services = res.services
- / 获取连接设备的所有特征值 /
- that.getBLEDeviceCharacteristics()
- },
- fail: (res) => {
- }
- })
- }, 2000)
- },
7. 获取蓝牙设备特征值
获取到的特征值有多个, 最后要用的事能读, 能写, 能监听的那个值的 uuid 作为特征值 id,
- getBLEDeviceCharacteristics() {
- setTimeout(() => {
- wx.getBLEDeviceCharacteristics({
- deviceId: connectedDeviceId,
- serviceId: services[2].uuid,
- success: function(res) {
- for (var i = 0; i <res.characteristics.length; i++) {
- if ((res.characteristics[i].properties.notify || res.characteristics[i].properties.indicate) &&
- (res.characteristics[i].properties.read && res.characteristics[i].properties.write)) {
- console.log(res.characteristics[i].uuid, '蓝牙特征值 ==========')
- / 获取蓝牙特征值 /
- that.notifyCharacteristicsId = res.characteristics[i].uuid
- // 启用低功耗蓝牙设备特征值变化时的 notify 功能
- that.notifyBLECharacteristicValueChange()
- }
- }
- },
- fail: function(res) {
- }
- })
- }, 1000)
- },
8. 启动 notify 蓝牙监听功能 然后使用 wx.onBLECharacteristicValueChange 用来监听蓝牙设备传递数据 #接收到的数据和发送的数据必须是二级制数据, 页面展示的时候需要进行转换
- notifyBLECharacteristicValueChange() { // 启用低功耗蓝牙设备特征值变化时的 notify 功能
- var that = this;
- console.log('6. 启用低功耗蓝牙设备特征值变化时的 notify 功能')
- wx.notifyBLECharacteristicValueChange({
- state: true,
- deviceId: that.connectedDeviceId,
- serviceId: that.notifyServicweId,
- characteristicId: that.notifyCharacteristicsId,
- complete(res) {
- /* 用来监听手机蓝牙设备的数据变化 */
- wx.onBLECharacteristicValueChange(function(res) {
- /**/
- that.balanceData += that.buf2string(res.value)
- that.hexstr += that.receiveData(res.value)
- })
- },
- fail(res) {
- console.log(res, '启用低功耗蓝牙设备监听失败')
- that.measuringTip(res)
- }
- })
- },
- /* 转换成需要的格式 */
- buf2string(buffer) {
- var arr = Array.prototype.map.call(new Uint8Array(buffer), x => x)
- return arr.map((char, i) => {
- return String.fromCharCode(char);
- }).join('');
- },
- receiveData(buf) {
- return this.hexCharCodeToStr(this.ab2hex(buf))
- },
- /* 转成二进制 */
- ab2hex (buffer) {
- var hexArr = Array.prototype.map.call(
- new Uint8Array(buffer), function (bit) {
- return ('00' + bit.toString(16)).slice(-2)
- }
- )
- return hexArr.join('')
- },
- /* 转成可展会的文字 */
- 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('');
- },
向蓝牙设备发送数据
- sendData(str) {
- let that = this;
- let dataBuffer = new ArrayBuffer(str.length)
- let dataView = new DataView(dataBuffer)
- for (var i = 0; i < str.length; i++) {
- dataView.setUint8(i, str.charAt(i).charCodeAt())
- }
- let dataHex = that.ab2hex(dataBuffer);
- this.writeDatas = that.hexCharCodeToStr(dataHex);
- wx.writeBLECharacteristicValue({
- deviceId: that.connectedDeviceId,
- serviceId: that.notifyServicweId,
- characteristicId: that.notifyCharacteristicsId,
- value: dataBuffer,
- success: function (res) {
- console.log('发送的数据:' + that.writeDatas)
- console.log('message 发送成功')
- },
- fail: function (res) {
- },
- complete: function (res) {
- }
- })
- },
当不需要连接蓝牙了后就要关闭蓝牙, 并关闭蓝牙模块
- // 断开设备连接
- closeConnect() {
- if (that.connectedDeviceId) {
- wx.closeBLEConnection({
- deviceId: that.connectedDeviceId,
- success: function(res) {
- that.closeBluetoothAdapter()
- },
- fail(res) {
- }
- })
- } else {
- that.closeBluetoothAdapter()
- }
- },
- // 关闭蓝牙模块
- closeBluetoothAdapter() {
- wx.closeBluetoothAdapter({
- success: function(res) {
- },
- fail: function(err) {
- }
- })
- },
来源: http://www.qdfuns.com/article/51465/90c7e03468fff5b68565da8d661496fd.html