Fe - wechat applet - Bluetooth ble development research and use

background

Recent research weex When , I feel more than a little pain , From documentation to sample code , Then to the code warehouse , What a mess . Look back Wechat applet documentation It's perfect , The existing products of the company deal with hardware , Therefore, we have made great efforts in the development of Bluetooth . Beginning of the year , When I see the applet , Its Bluetooth does not support android , A lot of features are missing . I don't know when , Wechat has updated Bluetooth (ble) Development content , Today, I have the honor to try this in wechat applet , Tried and tested .

Let's talk about feelings first , advantage ： Only according to api Document writing js that will do , Can be in The WeChat android and ios End of the applet used , strong . shortcoming ： It belongs to the wechat applet ecological environment .

design sketch

Basic test content ： Connect our company ble product , And can transmit data normally , Last , And test it in android and ios In the wechat applet of , Whether it can operate normally .

• scanning ble equipment
• Connect ble equipment
• receive ble Device data
• android and ios Are they all normal

（ios design sketch ）

( In the figure ’ Bluetooth is not turned on ’ The words change when Bluetooth is turned off and on )

1、ble- initialization

Initialization will determine whether it supports ble Whether you can get bleAdapter;

 bleInit:function(){
    
    console.log(' Initialize Bluetooth ')
    let self = this
    wx.openBluetoothAdapter({
      success: function(res) {
    
        self.setData({
          bleAdapterStatus: " Successful initialization "
        })
      },
      fail:function(msg){
    
        self.setData({
          bleAdapterStatus: " initialization failed "
        })
        wx.showModal({
          showCancel:false,
          title: ' Tips ',
          content: ' Device Bluetooth is not turned on , Please turn on the Bluetooth function ',
          success:function(res){
    
            if (res.confirm) {
              //console.log(' The user clicks ok ')
              //  Exit applet 
            }
          }
        });
      }
    });
  }

2、ble- Scan Bluetooth

Basic steps ：ble initialization => Scanning equipment => Get device information

 onScanClick:function(event){
    
    console.log(' The scan starts ')
    let self = this
    wx.openBluetoothAdapter({
      success: function(res) {
    
        //  Scan Bluetooth 
        self.bleDisCovery()
        self.setData({
          bleAdapterStatus:" Successful initialization "
        })
      },
      fail:function(error){
    
        self.setData({
          bleAdapterStatus: " initialization failed "
        })
        wx.showModal({
          showCancel: false,
          title: ' Tips ',
          content: ' Device Bluetooth is not turned on , Please turn on the Bluetooth function ',
          success: function (res) {
    
            if (res.confirm) {
              //console.log(' The user clicks ok ')
            }
          }
        });
      },
      complete:function(){
    
        //console.log('complete')
      }
    });
  },,
  /** *  Parse data information  */
  bleFound:function(){
    
    console.log(" Discover device information ")
    let self =this
    wx.onBluetoothDeviceFound(function (res) {
    
      let devices = res.devices
      console.log(devices)
      let length = self.data.bleChips.length
      let devicesLength = devices.length
      if (devicesLength > length){
        self.data.bleChips = devices
        self.setData({
          bleChips: devices
        });
      }
      console.log(self.data.bleChips)
    });

  },
  /** *  Scanning equipment  */
  bleDisCovery:function(){
    
    console.log(" Scan Bluetooth ")
    let self = this
     wx.startBluetoothDevicesDiscovery({
          interval:1000,
          success: function(res){
    
            self.bleFound();
          }
        });
  },

3、ble- Connecting device

The scanned data list displays , Pay attention to the connection button , Click event to send parameters , adopt data- Custom parameter name ;

Such as my data-item ： The parameter name is item ;

 <view wx:if="{
    {!bleConnSuccess}}" class='scan_result' wx:for="{
    {
    bleChips}}"> <text class="result_text">{
    {
    index}}-{
    {
    item.name}}-{
    {
    item.deviceId}}</text> <button bindtap='onConnBle' data-item='{
    {
    item}}'> Connect </button> </view>

secondly , receive data ：

onConnBle:function(e){
    
    //  Stop scanning 
    wx.stopBluetoothDevicesDiscovery({
      success: function(res) {
    
      },
    });
    //  Receive the parameters of click event 
    let device = e.currentTarget.dataset.item
    console.log(`conn ble >> ${device}`)
    this.setData({
      bleChipInfo: device
    })
    let deviceId = device.deviceId
    let self = this
    //  Connecting device 
    console.log(" In connection device ...")
    wx.createBLEConnection({
      deviceId: deviceId,
      success: function(res) {
    
        wx.showToast({
          title: ' Successful connection ',
        });
        //  Successful connection , open  notify
        setTimeout(function(){
    
          self.bleServices(deviceId)
        },1500)

      },
      fail:function(errMsg){
    
        wx.showToast({
          title: ` The connection fails :${errMsg}`,
        })
      }
    });
  }

4、ble- obtain services

 bleServices: function (deviceId){
    
    let self = this
    wx.getBLEDeviceServices({
      deviceId: deviceId,
      success: function (res) {
    
        wx.showToast({
          title: 'service success',
        })
        //  In the equipment  services
        let services = res.services
        for(let index in services){
          let service= services[index]
          console.log(service)
        }       
        console.log('device services:', res.services)
      }
    })
  },

5、ble-service obtain characteristics

bleServiceChart: function (deviceId,serviceId){
    
    let self = this;
    wx.getBLEDeviceCharacteristics({
      //  there  deviceId  It needs to be up there  getBluetoothDevices  or  onBluetoothDeviceFound  Interface 
      deviceId: deviceId,
      //  there  serviceId  It needs to be up there  getBLEDeviceServices  Interface 
      serviceId: serviceId,
      success: function (res) {
    
        console.log('device getBLEDeviceCharacteristics:', res.characteristics)
        let characteristics = res.characteristics
        for (let index in characteristics){
          let characteristic = characteristics[index]
            //
          }
          console.log(characteristic)
        }
        self.openNotify(deviceId) 
      }
    })
  },

6、ble- notify data

Turn on notify data , To use onBLECharacteristicValueChange Receive data ;

 openNotify: function (deviceId) {
    
    this.setData({
      bleConnSuccess: true
    });
    let self = this
    wx.notifyBLECharacteristicValueChange({
      deviceId: deviceId,
      serviceId: ' Yours  service id',
      characteristicId: ' Yours  characteristic Id',
      state: true,
      success: function (res) {
    
        console.log('notify success')
        self.onNotifyChange()
        wx.showToast({
          title: 'notify success',
        });
      },
      fail: function (err) {
    
        console.log(err)
        wx.showToast({
          title: 'notify fail',
        });
      }
    });
  }

7、ble - receive data

  onNotifyChange:function(){
    
    //  receive data 
    let self = this
    wx.onBLECharacteristicValueChange(function (res) {
    
      console.log(res.characteristicId)
      let byteDatas = Array.from(new Int8Array(res.value))
      console.log(byteDatas)
      const data = byteDatas.join(',')
      self.setData({
        bleNotifyData:data
      });
      console.log(data)
    });
  },

Last

Write and read operations , I won't explain too much here , The official documents have made it clear ;

matters needing attention

stay ios and android When testing ,android The platform does not need to get service and characteristic, You can start notify ; And in the ios The platform must manually get what you want to operate service and characteristic, Otherwise notify You don't succeed ;

Github :

wechat-ble-demo