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.canWrite = true

this._deviceId = deviceId

this._serviceId = serviceId

this._characteristicId = item.uuid

//this.writeBLECharacteristicValue()

}