使用微信小程序控制蓝牙小车（微信小程序端）

使用接口

微信小程序官方开发文档

接口	说明
wx.openBluetoothAdapter	初始化蓝牙模块
wx.closeBluetoothAdapter	关闭蓝牙模块(调用该方法将断开所有已建立的连接并释放系统资源)
wx.startBluetoothDevicesDiscovery	开始搜寻附近的蓝牙外围设备
wx.stopBluetoothDevicesDiscovery	停止搜寻附近的蓝牙外围设备。若已经找到需要的蓝牙设备并不需要继续搜索时，建议调用该接口停止蓝牙搜索
wx.onBluetoothDeviceFound	监听搜索到新设备的事件
wx.createBLEConnection	连接蓝牙低功耗设备
wx.closeBLEConnection	断开与蓝牙低功耗设备的连接
wx.getBLEDeviceServices	获取蓝牙低功耗设备所有服务
wx.getBLEDeviceCharacteristics	获取蓝牙低功耗设备某个服务中所有特征 (characteristic)
wx.readBLECharacteristicValue	读取蓝牙低功耗设备特征值的二进制数据
wx.writeBLECharacteristicValue	向蓝牙低功耗设备特征值中写入二进制数据
wx.showToast	显示消息提示框

界面效果

图片素材库地址

项目目录列表

界面设计

1. 在app.json中添加一个新页面"pages/home/home"

{
  "pages":[
    "pages/home/home",
    "pages/index/index",
    "pages/logs/logs"
  ],
  "window":{
    "backgroundTextStyle":"light",
    "navigationBarBackgroundColor": "#fff",
    "navigationBarTitleText": "Weixin",
    "navigationBarTextStyle":"black"
  },
  "style": "v2",
  "sitemapLocation": "sitemap.json"
}

2. 设计界面home.wxml

<!--pages/home/home.wxml-->
<button type="primary" class = "connectBLE" bindtap = "openBluetoothAdapter">连接蓝牙</button>
<button class = "disconnectBLE" bindtap = "closeBluetoothAdapter">断开蓝牙</button>  

<button class="custom-button" style="bottom: -395px" bindtap = "btnClickDown">
  <image class="button-image" src="/image/doubledown.png"></image>
</button>

<button class="custom-button" style="bottom: -15px" bindtap = "btnClickUp">
  <image class="button-image" src="/image/doubleup.png"></image>
</button>

<view>
  <button class="custom-button" style="bottom: -60px; left: -35%" bindtap = "btnClickLeft">
    <image class="button-image-1" src="/image/doubleleft.png"></image>
  </button>
</view>

<view>
  <button class="custom-button" style="bottom: 40px; left: 35%" bindtap = "btnClickRight">
    <image class="button-image-1" src="/image/doubleright.png"></image>
  </button>
</view>

<view>
  <button class="custom-button" style="bottom: 134px; left: 0%" bindtap = "btnClickStop">
    <image class="button-image-2" src="/image/remove.png"></image>
  </button>
</view>

3. 画面渲染home.wxss

/* pages/home/home.wxss */
.connectBLE {
  width: 49% !important;
  float: left;
  font-size: 100;
}

.disconnectBLE {
  width: 49% !important;
  float: right;
  font-size: 100;
  color: red;
}

.custom-button {
  position: relative;
  width: 100px;
  height: 100px;
  border: none;
  padding: 0;
  overflow: hidden;
  background: transparent;   /*设置背景颜色一致*/
  border-color: transparent; /*设置边框颜色一致*/
}

.button-image {
  object-fit: contain;
  width: 75%;
  height: 110%;
}

.button-image-1 {
  object-fit: contain;
  width: 75%;
  height: 110%;
}

.button-image-2 {
  object-fit: contain;
  width: 60%;
  height: 100%;
}

界面逻辑设计

连接的目标蓝牙名称为ESP_SPP_SERVER

// pages/home/home.js
Page({

  /**
   * 页面的初始数据
   */
  data: {
    connected: false,
    serviceId: "",
  },

  //蓝牙初始化
  openBluetoothAdapter() {
    if(this.data.connected)
    {
      return
    }
    wx.openBluetoothAdapter({
      success: (res) => {
        console.log('bluetooth initialization success', res)
        this.startBluetoothDevicesDiscovery()
      },
      fail: (err) => {
        wx.showToast({
          title: '蓝牙适配器初始化失败',
          icon: 'none'
        })
        return
      }
    })
  },
  //关闭蓝牙初始化
  closeBluetoothAdapter() {
    wx.closeBluetoothAdapter({
      success: (res) => {
        console.log('bluetooth deinitialization success', res)
      },
      fail: (err) => {
        wx.showToast({
          title: '蓝牙适配器解初始化失败',
          icon: 'none'
        })
        return
      }
    })
  },
  //开始搜寻附近的蓝牙外围设备
  startBluetoothDevicesDiscovery() {
    wx.startBluetoothDevicesDiscovery({
      success: (res) => {
        console.log('startBluetoothDevicesDiscovery success', res)
        this.onBluetoothDeviceFound()
      },
      fail: (err) => {
        wx.showToast({
          title: '蓝牙适配器解初始化失败',
          icon: 'none'
        })
        return
      }
    })
  },
  //监听搜索到新设备的事件
  onBluetoothDeviceFound() {
    let found_device = false
    const timer = setTimeout(() => {
      if (!found_device) {
        console.error('未找到设备');
        wx.showToast({
          title: '未找到设备',
          icon: 'none'
        })
      }
    }, 2000); // 设置定时器为10秒
  
    wx.onBluetoothDeviceFound((res) => {
      res.devices.forEach(device => {
        if (device.name === 'ESP_SPP_SERVER') {
          console.log('find target device')
          found_device = true; // 找到目标设备，将标志变量设置为已找到
          clearTimeout(timer); // 取消定时器
          this.createBLEConnection(device.deviceId)
        }
      });
    });
  },
  //连接蓝牙低功耗设备
  createBLEConnection(deviceId) {
    wx.createBLEConnection({
      deviceId,
      success:() => {
        this.setData({
          connected: true,
        })
        console.log('connect device success')
        this.getBLEDeviceServices(deviceId)
        wx.stopBluetoothDevicesDiscovery()
      },
      fail:(err) => {
        wx.showToast({
          title: '建立蓝牙连接失败',
          icon: 'none'
        })
      }
    })
  },
  //获取蓝牙低功耗设备所有服务
  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
          }
        }
      },
      fail:(res) => {
        console.log('getBLEDeviceServices fail', res.errMsg)
      }
    })
  },
  //获取蓝牙低功耗设备某个服务中所有特征
  getBLEDeviceCharacteristics(deviceId, serviceId) {
    wx.getBLEDeviceCharacteristics({
      deviceId,
      serviceId,
      success: (res) => {
        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._deviceId = deviceId
            this._serviceId = serviceId
            this._characteristicId = item.uuid
          }
        }
      },
      fail:(res) => {
        console.log('get characteristicId fail', res.errMsg)
      }
    })
  },
  //关闭蓝牙服务
  closeBluetoothAdapter() {
    wx.closeBLEConnection({
      deviceId: this._deviceId,
      success: (res) => {
        console.log('disconnect success')
      },
      fail: (res) => {
        console.log('disconnect fail',res.errMsg)
      }
    })
    wx.closeBluetoothAdapter({
      success: (res) => {
        console.log('close success')
      },
      fail: (res) => {
        console.log('close fail',res.errMsg)
      }
    })
    this.data.connected = false
    console.log('close connection')
  },

  btnClickDown() {
    this.tipsBluetoothWarn()
    this.writeBluetoothValue('down')
    console.log('click down')
  },
  btnClickUp() {
    this.tipsBluetoothWarn()
    this.writeBluetoothValue('up')
    console.log('click up')
  },
  btnClickLeft() {
    this.tipsBluetoothWarn()
    this.writeBluetoothValue('left')
    console.log('click left')
  },
  btnClickRight() {
    this.tipsBluetoothWarn()
    this.writeBluetoothValue('right')
    console.log('click right')
  },
  btnClickStop() {
    this.tipsBluetoothWarn()
    this.writeBluetoothValue('stop')
    console.log('click stop')
  },
  tipsBluetoothWarn()
  {
    if(!this.data.connected)
    {
      wx.showToast({
        title: '蓝牙未连接',
        icon: 'none'
      })
    }
  },
  writeBluetoothValue(value) {
    if(!this.data.connected)
    {
      return
    }
    const buffer = new ArrayBuffer(value.length)
    const dataView = new DataView(buffer)
    for (let i = 0; i < value.length; i++) {
      dataView.setUint8(i, value.charCodeAt(i))
    }
    wx.writeBLECharacteristicValue({
      deviceId: this._deviceId,
      serviceId: this._serviceId,
      characteristicId: this._characteristicId,
      value: buffer,
      success (res) {
        console.log('writeBLECharacteristicValue success', res.errMsg)
      },
      fail (res) {
        console.log('writeBLECharacteristicValue fail', res.errMsg, res.errCode)
      }
    })
  },
  /**
   * 生命周期函数--监听页面加载
   */
  onLoad(options) {

  },
})

20231113 优化改成按下车动，松开车停

1. 修改文件home.wxml

<!--pages/home/home.wxml-->
<button type="primary" class = "connectBLE" bindtap = "openBluetoothAdapter">连接蓝牙</button>
<button class = "disconnectBLE" bindtap = "closeBluetoothAdapter">断开蓝牙</button>  

<button class="custom-button" style="bottom: -395px" bindtouchstart = "btnClickDown" bindtouchend = "btnClickStop">
  <image class="button-image" src="/image/doubledown.png"></image>
</button>

<button class="custom-button" style="bottom: -15px" bindtouchstart = "btnClickUp" bindtouchend = "btnClickStop">
  <image class="button-image" src="/image/doubleup.png"></image>
</button>

<view>
  <button class="custom-button" style="bottom: -60px; left: -35%" bindtouchstart = "btnClickLeft" bindtouchend = "btnClickStop">
    <image class="button-image-1" src="/image/doubleleft.png"></image>
  </button>
</view>

<view>
  <button class="custom-button" style="bottom: 40px; left: 35%" bindtouchstart = "btnClickRight" bindtouchend = "btnClickStop">
    <image class="button-image-1" src="/image/doubleright.png"></image>
  </button>
</view>

<view>
  <button class="custom-button" style="bottom: 134px; left: 0%" bindtap = "btnClickStop">
    <image class="button-image-2" src="/image/remove.png"></image>
  </button>
</view>