微信小程序蓝牙连接和写入数据
js:
const app = getApp()
function inArray(arr, key, val) {
for (let i = 0; i < arr.length; i++) {
if (arr[i][key] === val) {
return i;
}
}
return -1;
}
// ArrayBuffer转16进度字符串示例
function ab2hex(buffer) {
var hexArr = Array.prototype.map.call(
new Uint8Array(buffer),
function (bit) {
return ('00' + bit.toString(16)).slice(-2)
}
)
return hexArr.join('');
}
Page({
data: {
devices: [],
connected: false,
chs: [],
},
openBluetoothAdapter() {
wx.openBluetoothAdapter({
success: (res) => {
console.log('openBluetoothAdapter success', res)
this.startBluetoothDevicesDiscovery()
},
fail: (res) => {
if (res.errCode === 10001) {
console.log(res)
wx.onBluetoothAdapterStateChange(function (re) {
console.log('onBluetoothAdapterStateChange', re)
if (re.available) {
this.startBluetoothDevicesDiscovery()
}
})
}
}
})
},
getBluetoothAdapterState() {
wx.getBluetoothAdapterState({
success: (res) => {
console.log('getBluetoothAdapterState', res)
if (res.discovering) {
this.onBluetoothDeviceFound()
} else if (res.available) {
this.startBluetoothDevicesDiscovery()
}
}
})
},
startBluetoothDevicesDiscovery() {
if (this._discoveryStarted) {
return
}
this._discoveryStarted = true
wx.startBluetoothDevicesDiscovery({
allowDuplicatesKey: true,
success: (res) => {
console.log('startBluetoothDevicesDiscovery success', res)
this.onBluetoothDeviceFound()
},
})
},
stopBluetoothDevicesDiscovery() {
wx.stopBluetoothDevicesDiscovery()
},
onBluetoothDeviceFound() {
wx.onBluetoothDeviceFound((res) => {
res.devices.forEach(device => {
if (!device.name && !device.localName) {
return
}
const foundDevices = this.data.devices
const idx = inArray(foundDevices, 'deviceId', device.deviceId)
const data = {}
if (idx === -1) {
data[`devices[${foundDevices.length}]`] = device
} else {
data[`devices[${idx}]`] = device
}
this.setData(data)
})
})
},
createBLEConnection(e) {
const ds = e.currentTarget.dataset
const deviceId = ds.deviceId
const name = ds.name
wx.createBLEConnection({
deviceId,
success: (res) => {
this.setData({
connected: true,
name,
deviceId,
})
this.getBLEDeviceServices(deviceId)
}
})
this.stopBluetoothDevicesDiscovery()
},
closeBLEConnection() {
wx.closeBLEConnection({
deviceId: this.data.deviceId
})
this.setData({
connected: false,
chs: [],
canWrite: false,
})
},
getBLEDeviceServices(deviceId) {
wx.getBLEDeviceServices({
deviceId,
success: (res) => {
for (let i = 0; i < res.services.length; i++) {
if (res.services[i].isPrimary) {
this.getBLEDeviceCharacteristics(deviceId, res.services[i].uuid)
return
}
}
}
})
},
getBLEDeviceCharacteristics(deviceId, serviceId) {
wx.getBLEDeviceCharacteristics({
deviceId,
serviceId,
success: (res) => {
console.log('getBLEDeviceCharacteristics success', res.characteristics)
for (let i = 0; i < res.characteristics.length; i++) {
let item = res.characteristics[i]
if (item.properties.read) {
wx.readBLECharacteristicValue({
deviceId,
serviceId,
characteristicId: item.uuid,
})
}
if (item.properties.write) {
this.setData({
canWrite: true
})
this._deviceId = deviceId
this._serviceId = serviceId
this._characteristicId = item.uuid
this.writeBLECharacteristicValue()
}
if (item.properties.notify || item.properties.indicate) {
wx.notifyBLECharacteristicValueChange({
deviceId,
serviceId,
characteristicId: item.uuid,
state: true,
})
}
}
},
fail(res) {
console.error('getBLEDeviceCharacteristics', res)
}
})
// 操作之前先监听，保证第一时间获取数据
wx.onBLECharacteristicValueChange((characteristic) => {
const idx = inArray(this.data.chs, 'uuid', characteristic.characteristicId)
const data = {}
if (idx === -1) {
data[`chs[${this.data.chs.length}]`] = {
uuid: characteristic.characteristicId,
value: ab2hex(characteristic.value)
}
} else {
data[`chs[${idx}]`] = {
uuid: characteristic.characteristicId,
value: ab2hex(characteristic.value)
}
}
// data[`chs[${this.data.chs.length}]`] = {
// uuid: characteristic.characteristicId,
// value: ab2hex(characteristic.value)
// }
this.setData(data)
})
},
writeBLECharacteristicValue() {
// 向蓝牙设备发送一个0x00的16进制数据
let buffer = new ArrayBuffer(1)
let dataView = new DataView(buffer)
console.log(buffer)
console.log(this._deviceId)
console.log(this._serviceId)
dataView.setUint8(0, Math.random() * 255 | 0)
wx.writeBLECharacteristicValue({
deviceId: this._deviceId,
serviceId: this._serviceId,
characteristicId: this._characteristicId,
value: buffer,
})
},
closeBluetoothAdapter() {
wx.closeBluetoothAdapter()
this._discoveryStarted = false
},
})
wxml:
<wxs module="utils"> module.exports.max = function(n1, n2) {
return Math.max(n1, n2)
}
module.exports.len = function(arr) {
arr = arr || []
return arr.length
}
</wxs>
<button bindtap="openBluetoothAdapter">开始扫描</button>
<button bindtap="stopBluetoothDevicesDiscovery">停止扫描</button>
<button bindtap="closeBluetoothAdapter">结束流程</button>
<view class="devices_summary">已发现 {{devices.length}} 个外围设备：</view>
<scroll-view class="device_list" scroll-y scroll-with-animation>
<view wx:for="{{devices}}" wx:key="index"
data-device-id="{{item.deviceId}}"
data-name="{{item.name || item.localName}}"
bindtap="createBLEConnection"
class="device_item"
hover-class="device_item_hover">
<view style="font-size: 16px; color: #333;">{{item.name}}</view>
<view style="font-size: 10px">信号强度: {{item.RSSI}}dBm ({{utils.max(0, item.RSSI + 100)}}%)</view>
<view style="font-size: 10px">UUID: {{item.deviceId}}</view>
<view style="font-size: 10px">Service数量: {{utils.len(item.advertisServiceUUIDs)}}</view>
</view>
</scroll-view>
<view class="connected_info" wx:if="{{connected}}">
<view>
<text>已连接到 {{name}}</text>
<view class="operation">
<button wx:if="{{canWrite}}" size="mini" bindtap="writeBLECharacteristicValue">写数据</button>
<button size="mini" bindtap="closeBLEConnection">断开连接</button>
</view>
</view>
<view wx:for="{{chs}}" wx:key="index" style="font-size: 12px; margin-top: 10px;">
<view>特性UUID: {{item.uuid}}</view>
<view>特性值: {{item.value}}</view>
</view>
</view>
原创文章，转载请注明：微信小程序蓝牙连接和写入数据 | 知识改变命运
转载请注明出处： 知识改变命运 » 微信小程序蓝牙连接和写入数据
