*需求分析(项目需要和硬件设备的蓝牙连接 实现数据交互)
1.通过初始化蓝牙+发现蓝牙+建立连接
2.建立连接的时候保存蓝牙的设备id
3.连接成功后获取蓝牙的外围服务 在服务列表中 找到对应的设备uuid并保存
4.读取服务的特征值 然后再启用蓝牙特征变化时的notify功能(只有这个启用,才能监听设备的特征的change事件)
5.根据notify的开启 封装要写入的指令 写入服务的特征值 并打印获取监听到的返回值
1.蓝牙建立连接
- 初始化
//初始化
BLEInit(event) {
let that = this;
wx.openBluetoothAdapter({
success: function(res) {
console.log('初始化蓝牙适配器成功')
console.log(res);
that.$refs.uToast.show({
message: '初始化蓝牙适配器成功',
type: 'success'
})
},
fail: function(res) {
console.log('请打开蓝牙和定位功能')
that.$refs.uToast.show({
message: '请打开蓝牙和定位功能',
type: 'default'
})
}
})
},
- 获取蓝牙状态
//获取蓝牙状态
BLEState() {
let that = this;
wx.getBluetoothAdapterState({
success: function(res) {
//打印相关信息
console.log(res, 62);
console.log(JSON.stringify(res.errMsg) + "\n蓝牙是否可用：" + res.available);
},
fail: function(res) {
console.log(res, 69);
//打印相关信息
console.log(JSON.stringify(res.errMsg) + "\n蓝牙是否可用：" + res.available);
}
})
},
- 搜索设备
//搜索设备
BLESearch(event) {
let that = this;
wx.startBluetoothDevicesDiscovery({
// services: [], //如果填写了此UUID，那么只会搜索出含有这个UUID的设备，建议一开始先不填写
success: function(res) {
console.log('搜索设备返回' +JSON.stringify(res))
}
})
},
- 获取所有设备
//获取所有设备
BLEGetDevices(event) {
let that = this;
wx.getBluetoothDevices({
success: function(res) {
that.devices = res.devices.filter(item => item.name !== '未知设备')
console.log(that.devices);
console.log('搜设备数目：' + res.devices.length)
console.log('设备信息：\n' + JSON.stringify(res.devices) + "\n")
}
})
},
- 连接设备
//连接设备
BLEConnect(id) {
let that = this;
console.log(id);
wx.createBLEConnection({
deviceId: id,
success: function(res) {
console.log(res);
console.log('调试信息：' + res.errMsg);
that.connectedDeviceId = id
that.info = ' 调试信息：' + res.errMsg
that.$refs.uToast.show({
message: '蓝牙连接成功',
type: 'success'
})
that.getBlueTouchServices(id)
},
fail: function() {
console.log("连接失败");
},
})
},
- ☠ 连接设备后要关闭搜索所有设备 会对性能有很大的消耗
//停止搜索设备
BLESearchStop() {
let that = this;
wx.stopBluetoothDevicesDiscovery({
success: function(res) {
console.log("停止搜索" + JSON.stringify(res.errMsg));
}
})
},
2.获取蓝牙的外围服务
//获取蓝牙外围服务
getBlueTouchServices(id) {
let that = this
wx.getBLEDeviceServices({
deviceId: id,
success: function(res) {
console.log(res)
that.buleDeviceServiceId = res.services[1].uuid //存入对应设备的uuid
that.getBlueTouchCharacterisitics(id) //特征时需要传入的id
}
})
},
3.读取服务的特征值 启用蓝牙notify
//读写服务的特征值
getBlueTouchCharacterisitics(id) {
let that = this;
wx.getBLEDeviceCharacteristics({
deviceId: id,
serviceId: that.buleDeviceServiceId,
success: function(res) {
console.log(res);
that.uniWriteCharacteristicsId = res.characteristics[0].uuid
res.characteristics.forEach(v => {
let item = v
if (item.properties.read) { // 改特征值可读
wx.readBLECharacteristicValue({
deviceId: id,
serviceId: that.buleDeviceServiceId,
characteristicId: item.uuid,
success: function(res) {
console.log(res);
}
})
}
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: id,
serviceId: that.buleDeviceServiceId,
characteristicId: item.uuid,
state: true,
success: function(res) {
console.log(res);
// ArrayBuffer转16进制字符串示例
if (res.errCode == 0) {
that.getChange()
//取时间
that.toSendData(41)
//mac地址
// that.toSendData(22)
//个人信息
// that.toSendData(42)
}
}
})
}
})
}
})
},
4.封装指令
//发送数据包
toSendData(num){
let that=this
let arr = [that.turnHex(num), '00', '00', '00', '00', '00','00', '00', '00', '00','00', '00', '00', '00', '00']
let count = arr.length / 2;
if (count.toString().indexOf('.') != -1) {
count = parseInt(count) + 1 // 有.5就加 1
count = parseInt(count) // 或者不加
}
let crc = 0
for (let i = 0; i < arr.length; i++) {
crc += Number(arr[i])
}
arr[15] = crc
arr=arr.map(Number)
let buffer = new ArrayBuffer(arr.length)
let dataView = new DataView(buffer)
arr.forEach((i, v) => {
dataView.setUint8(v, i)
})
that.sendToBlueTooth(buffer)
},
//转16进制
turnHex(num){
return parseInt(num,16)
},
5.写入服务的特征值 并打印获取监听到的返回值
//发送数据
sendToBlueTooth(buffer) {
// console.log('buffer', buffer);
const that = this
wx.writeBLECharacteristicValue({
deviceId: that.connectedDeviceId,
serviceId: that.buleDeviceServiceId,
characteristicId: that.uniWriteCharacteristicsId,
value: buffer,
success: function(res) {
// console.log('发送的数据包', buffer);
console.log('写入数据包成功', res);
}
})
},
//数据转16进制
ab2hex(buffer) {
let hexArr = Array.prototype.map.call(
new Uint8Array(buffer),
function(bit) {
return ('00' + bit.toString(16)).slice(-2)
}
)
console.log(hexArr.join(''));
return hexArr.join('');
},
//监听拿到硬件接收指令后的返回值数据
getChange() {
let that=this
wx.onBLECharacteristicValueChange(function(res) {
// console.log(res);
// console.log(`characteristic ${res.characteristicId} has changed, now is ${res.value}`, 185)
console.log(that.ab2hex(res.value), 186)
})
},
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