problem description

the environmental background of the problems and what methods you have tried

related codes

/ / Please paste the code text below (do not replace the code with pictures)
/ / index.js
/ / get an application example
const app = getApp ()

Page ({
data: {

userInfo: {},
hasUserInfo: false,
canIUse: wx.canIUse("button.open-type.getUserInfo"),
devices: [],
deviceId: "",
services: [],
serviceId: "",
characteristicId: "",
characteristicIdNotify: "",
characteristicIdRead: "",

},
onLoad () {

// wx.showModal({
//   title: "",
//   content: "",
//   success: function (res) {
//     that.setData({
//       isbluetoothready: false,
//       searchingstatus: false
//     })
//   }
// })

},
/ *

• @ description turn on Bluetooth Adapter

* /
openBlue () {

let _this = this
wx.openBluetoothAdapter({
  success(res) {
    console.log(":", res)

    // 
    _this.discoverDevices()

  }
})

},
closeBlue () {

wx.closeBluetoothAdapter({
  success(res) {
    console.log(": ", res)
  }
})

},
/ *

• @ description search for Bluetooth devices

* /
discoverDevices () {

let _this = this
wx.startBluetoothDevicesDiscovery({
  success(res) {
    console.log("", res)

    setTimeout(() => {
      _this.getDevices()
      setTimeout(() => {
        _this.foundDevices()
      }, 500)
    }, 500)
  }
})

},
/ *

• @ description search for new Bluetooth devices

* /
foundDevices () {

let _this = this
wx.onBluetoothDeviceFound(function (devices) {
  console.log(":", devices)

  // 
  _this.data.devices.push(devices.devices[0])
  _this.setData({
    devices: _this.data.devices
  })
})

},
/ *

• @ description get connectable Bluetooth devices

* /
getDevices () {

let _this = this
wx.getBluetoothDevices({
  success: function (res) {
    if (res.devices[0]) {
      console.log(":", res)
      _this.setData({
        devices: res.devices
      })
    }
  }
})

},
chooseDevice (e) {

let _this = this

//  deviceId
_this.data.deviceId = e.currentTarget.dataset.deviceid

// 
_this.createConnect(_this.data.deviceId)

// console.log("_this.data.deviceId: ",_this.data.deviceId)

},
createConnect (deviceId) {

let _this = this
wx.createBLEConnection({
  //  deviceId  createBLEConnection  
  deviceId,
  success(res) {
    // 
    console.log(":", res)

    //  serviceId
    _this.getServices(deviceId)

    // 
    _this.onConnectionStatus()

    // 
    _this.stopDiscoverDevices()
  },
  fail(err) {
    console.warn("err :", err);
  }
})

},
onConnectionStatus () {

wx.onBLEConnectionStateChange(function (res) {
  // 
  console.log(` ${res.deviceId} , : ${res.connected}`)
})

},
/ *

• @ description get connected Bluetooth devices

* /
getConnectDevices (services) {

wx.getConnectedBluetoothDevices({
  services,
  success(res) {
    console.log(":" + JSON.stringify(res))
  },
  fail(err) {
    console.log("err: ", err.errMsg)
  }
})

},
/ *

• @ description stop searching for Bluetooth devices

* /
stopDiscoverDevices () {

wx.stopBluetoothDevicesDiscovery({
  success(res) {
    console.log("")
  }
})

},
/ *

• @ description get services & serviceId

* /
getServices (deviceId) {

let _this = this
wx.getBLEDeviceServices({
  deviceId,
  success(res) {

    console.log("device services:", res.services)

    _this.getConnectDevices([res.services[2].uuid])

    //  serviceId 
    _this.setData({
      serviceId: res.services[2].uuid
    })

    console.log("_this.serviceId :", _this.data.serviceId);

    _this.getCharacteristicsId(_this.data.deviceId, _this.data.serviceId)
  }
})

},
/ *

• @ description get CharacteristicsId

* /
getCharacteristicsId (deviceId, serviceId) {

let _this = this
wx.getBLEDeviceCharacteristics({
  deviceId,
  serviceId,
  success(res) {
    console.log("Characteristics:", res.characteristics)

    //  characteristicIdcharacteristicIdNotify
    _this.setData({
      characteristicIdNotify: res.characteristics[0].uuid,
      characteristicId: res.characteristics[0].uuid,
    })

    _this.openNotify(deviceId, serviceId, _this.data.characteristicIdNotify)

    console.log("CharacteristicsId:", res.characteristics[0].uuid)

  }
})

},
/ *

• @ description Open notify

* /
openNotify (deviceId, serviceId, characteristicId) {

let _this = this
wx.notifyBLECharacteristicValueChange({
  state: true,
  deviceId,
  serviceId,
  characteristicId,
  success(res) {
    console.log("notify ", res.errMsg)

    setTimeout(() => {
      _this.writeDevice(deviceId, serviceId, _this.data.characteristicId)
    }, 2000)
  },
  fail(err) {
    console.log("openNotify err: ", err)
  }
})

},
/ *

• @ description writes data to the device

* /
writeDevice (deviceId, serviceId, characteristicId) {

let _this = this
// 0x0016
let senddata = "test"
let buffer = new ArrayBuffer(senddata.length)
let dataView = new DataView(buffer)
for (var i = 0; i < senddata.length; iPP) {
  dataView.setUint8(i, senddata.charAt(i).charCodeAt())
}

// let buffer = new ArrayBuffer(2)
// let dataView = new DataView(buffer)
// dataView.setUint16(0, 3)

wx.writeBLECharacteristicValue({
  deviceId,
  serviceId,
  characteristicId,
  value: buffer,
  success(res) {
    console.log("", res.errMsg)
    _this.readDevice(deviceId, serviceId, _this.data.characteristicId)

  },
  fail(err) {
    console.log("err", err)
  },
  complete() {
    _this.closeConnection(deviceId)
    _this.closeBlue()
  }
})

},
readDevice (deviceId, serviceId, characteristicId) {

let _this = this
// 
wx.onBLECharacteristicValueChange(function (characteristic) {
  console.log("characteristic value comed:", characteristic)
})

wx.readBLECharacteristicValue({
  //  deviceId  createBLEConnection 
  deviceId,
  //  serviceId  getBLEDeviceServices 
  serviceId,
  //  characteristicId  getBLEDeviceCharacteristics 
  characteristicId,
  success(res) {
    console.log("readBLECharacteristicValue:", res.errCode)
  }
})

},
closeConnection (deviceId) {

wx.closeBLEConnection({
  deviceId,
  success(res) {
    console.log(":", res)
  }
})

}

})

what result do you expect? What is the error message actually seen?