微信小程序蓝牙与MCU 8 字节数组通讯教程

以下是一个示例的微信小程序蓝牙与MCU通讯的程序，包括发送和接收功能，并且有连接蓝牙按钮及连接状态的手机界面。

index.js

const app = getApp();

Page({
  data: {
    connected: false, // 蓝牙连接状态
    devices: [], // 可连接的蓝牙设备列表
    deviceId: '', // 已连接的蓝牙设备ID
    serviceId: '', // 蓝牙设备的服务ID
    characteristicId: '', // 蓝牙设备的特征值ID
    receiveData: '', // 接收到的数据
    sendText: '' // 要发送的文本
  },

  // 初始化蓝牙适配器
  initBluetooth: function() {
    wx.openBluetoothAdapter({
      success: (res) => {
        console.log('初始化蓝牙适配器成功', res);
        this.startBluetoothDevicesDiscovery();
      },
      fail: (err) => {
        console.error('初始化蓝牙适配器失败', err);
      }
    });
  },

  // 开始搜索蓝牙设备
  startBluetoothDevicesDiscovery: function() {
    wx.startBluetoothDevicesDiscovery({
      success: (res) => {
        console.log('开始搜索蓝牙设备成功', res);
        this.onBluetoothDeviceFound();
      },
      fail: (err) => {
        console.error('开始搜索蓝牙设备失败', err);
      }
    });
  },

  // 监听搜索到的蓝牙设备
  onBluetoothDeviceFound: function() {
    wx.onBluetoothDeviceFound((res) => {
      res.devices.forEach(device => {
        if (!device.name && !device.localName) {
          return;
        }
        const devices = this.data.devices;
        const idx = devices.findIndex(item => item.deviceId === device.deviceId);
        if (idx === -1) {
          devices.push(device);
          this.setData({
            devices: devices
          });
        } else {
          devices[idx] = device;
          this.setData({
            devices: devices
          });
        }
      });
    });
  },

  // 连接蓝牙设备
  connectBluetoothDevice: function(e) {
    const deviceId = e.currentTarget.dataset.deviceid;
    wx.createBLEConnection({
      deviceId: deviceId,
      success: (res) => {
        console.log('连接蓝牙设备成功', res);
        this.setData({
          connected: true,
          deviceId: deviceId
        });
        this.getBLEDeviceServices(deviceId);
      },
      fail: (err) => {
        console.error('连接蓝牙设备失败', err);
      }
    });
  },

  // 获取蓝牙设备的服务
  getBLEDeviceServices: function(deviceId) {
    wx.getBLEDeviceServices({
      deviceId: deviceId,
      success: (res) => {
        console.log('获取蓝牙设备服务成功', res);
        res.services.forEach(service => {
          if (service.uuid === app.globalData.serviceUUID) {
            this.setData({
              serviceId: service.uuid
            });
            this.getBLEDeviceCharacteristics(deviceId, service.uuid);
          }
        });
      },
      fail: (err) => {
        console.error('获取蓝牙设备服务失败', err);
      }
    });
  },

  // 获取蓝牙设备的特征值
  getBLEDeviceCharacteristics: function(deviceId, serviceId) {
    wx.getBLEDeviceCharacteristics({
      deviceId: deviceId,
      serviceId: serviceId,
      success: (res) => {
        console.log('获取蓝牙设备特征值成功', res);
        res.characteristics.forEach(characteristic => {
          if (characteristic.uuid === app.globalData.characteristicUUID) {
            this.setData({
              characteristicId: characteristic.uuid
            });
            this.startBLENotifications(deviceId, serviceId, characteristic.uuid);
          }
        });
      },
      fail: (err) => {
        console.error('获取蓝牙设备特征值失败', err);
      }
    });
  },

  // 开启特征值变化监听
  startBLENotifications: function(deviceId, serviceId, characteristicId) {
    wx.notifyBLECharacteristicValueChange({
      deviceId: deviceId,
      serviceId: serviceId,
      characteristicId: characteristicId,
      state: true,
      success: (res) => {
        console.log('开启特征值变化监听成功', res);
        this.onBLECharacteristicValueChange();
      },
      fail: (err) => {
        console.error('开启特征值变化监听失败', err);
      }
    });
  },

  // 监听特征值变化
  onBLECharacteristicValueChange: function() {
    wx.onBLECharacteristicValueChange((res) => {
      const receiveData = this.data.receiveData + this.ab2str(res.value);
      this.setData({
        receiveData: receiveData
      });
    });
  },

  // 发送数据
  sendBLEData: function() {
    const sendText = this.data.sendText;
    const buffer = this.str2ab(sendText);
    const deviceId = this.data.deviceId;
    const serviceId = this.data.serviceId;
    const characteristicId = this.data.characteristicId;
    wx.writeBLECharacteristicValue({
      deviceId: deviceId,
      serviceId: serviceId,
      characteristicId: characteristicId,
      value: buffer,
      success: (res) => {
        console.log('发送数据成功', res);
      },
      fail: (err) => {
        console.error('发送数据失败', err);
      }
    });
  },

  // ArrayBuffer转字符串
  ab2str: function(buffer) {
    return String.fromCharCode.apply(null, new Uint8Array(buffer));
  },

  // 字符串转ArrayBuffer
  str2ab: function(str) {
    const buf = new ArrayBuffer(str.length);
    const bufView = new Uint8Array(buf);
    for (let i = 0, strLen = str.length; i < strLen; i++) {
      bufView[i] = str.charCodeAt(i);
    }
    return buf;
  },

  // 断开蓝牙连接
  closeBluetoothConnection: function() {
    const deviceId = this.data.deviceId;
    wx.closeBLEConnection({
      deviceId: deviceId,
      success: (res) => {
        console.log('断开蓝牙连接成功', res);
        this.setData({
          connected: false,
          deviceId: '',
          serviceId: '',
          characteristicId: '',
          receiveData: ''
        });
      },
      fail: (err) => {
        console.error('断开蓝牙连接失败', err);
      }
    });
  },

  // 清空接收到的数据
  clearReceiveData: function() {
    this.setData({
      receiveData: ''
    });
  },

  // 监听页面加载
  onLoad: function() {
    this.initBluetooth();
  }
});

index.wxml

<view class='container'>
  <view class='devices'>
    <view wx:for='{{devices}}' wx:key='deviceId'>
      <button class='device' wx:if='{{!connected}}' bindtap='connectBluetoothDevice' data-deviceid='{{item.deviceId}}'>{{item.name || item.localName}}</button>
      <text class='device' wx:if='{{connected}} && deviceId === item.deviceId'>{{item.name || item.localName}}</text>
    </view>
  </view>
  <view class='status'>
    <text class='status-text' wx:if='{{!connected}}'>未连接</text>
    <text class='status-text' wx:if='{{connected}}'>已连接</text>
    <button class='disconnect-button' wx:if='{{connected}}' bindtap='closeBluetoothConnection'>断开连接</button>
  </view>
  <view class='receive'>
    <text class='receive-title'>接收到的数据：</text>
    <text class='receive-data'>{{receiveData}}</text>
    <button class='clear-button' bindtap='clearReceiveData'>清空</button>
  </view>
  <view class='send'>
    <input class='send-input' bindinput='inputSendText' placeholder='输入要发送的文本'/>
    <button class='send-button' bindtap='sendBLEData'>发送</button>
  </view>
</view>

app.js

App({
  onLaunch: function () {
    // ...
  },

  globalData: {
    serviceUUID: '0000XXXX-0000-1000-8000-00805F9B34FB', // 替换为MCU的服务UUID
    characteristicUUID: '0000XXXX-0000-1000-8000-00805F9B34FB' // 替换为MCU的特征值UUID
  }
});

app.json

{
  'pages': [
    'pages/index/index'
  ],
  'window': {
    'backgroundTextStyle': 'light',
    'navigationBarBackgroundColor': '#fff',
    'navigationBarTitleText': '蓝牙与MCU通讯',
    'navigationBarTextStyle': 'black'
  },
  'debug': true
}

app.wxss

.container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  font-size: 16px;
}

.devices {
  margin-bottom: 20px;
}

.device {
  display: block;
  width: 200px;
  height: 40px;
  margin: 10px;
  background-color: #4CAF50;
  color: white;
  font-size: 16px;
  text-align: center;
  line-height: 40px;
  border-radius: 4px;
}

.status {
  margin-bottom: 20px;
}

.status-text {
  font-size: 20px;
}

.disconnect-button {
  display: block;
  width: 100px;
  height: 40px;
  margin-top: 10px;
  background-color: #f44336;
  color: white;
  font-size: 16px;
  text-align: center;
  line-height: 40px;
  border-radius: 4px;
}

.receive {
  margin-bottom: 20px;
}

.receive-title {
  font-size: 20px;
}

.receive-data {
  display: block;
  width: 300px;
  height: 200px;
  margin-top: 10px;
  background-color: #f2f2f2;
  font-size: 16px;
  padding: 10px;
  overflow: auto;
  word-break: break-all;
}

.clear-button {
  display: block;
  width: 100px;
  height: 40px;
  margin-top: 10px;
  background-color: #f44336;
  color: white;
  font-size: 16px;
  text-align: center;
  line-height: 40px;
  border-radius: 4px;
}

.send {
  margin-bottom: 20px;
}

.send-input {
  width: 300px;
  height: 40px;
  font-size: 16px;
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 5px;
}

.send-button {
  display: block;
  width: 100px;
  height: 40px;
  margin-top: 10px;
  background-color: #4CAF50;
  color: white;
  font-size: 16px;
  text-align: center;
  line-height: 40px;
  border-radius: 4px;
}

请注意替换 app.js 中的 serviceUUID 和 characteristicUUID 为实际的 MCU 服务 UUID 和特征值 UUID。

这个示例程序中，通过微信开发者工具可以在手机上运行，并且显示可连接的蓝牙设备列表，点击连接按钮可以连接蓝牙设备，连接成功后可以发送文本数据给 MCU，接收到的 MCU 返回的数据也会显示在界面上。