蓝牙 BLE 设备数据交换

有没有大侠实现过BLE设备与APP之间的数据交换呢？我在调试的过程中，出现如下问题：

10:58:51.462 App Show at App.vue:42
10:58:57.387 thirdScriptError
10:58:57.407 undefined is not an object (evaluating 'this.characteristicsData[0].uuid'); [Component] Event Handler Error @ pages/API/bluetooth/bluetooth#handleEvent
10:58:57.427 BLESendDatas
10:58:57.447 BLESendDatas@[native code]
10:58:57.487 forEach@[native code]
10:58:57.527 forEach@[native code]
10:58:57.547 handleEvent
10:58:57.567 safeCallback
10:58:57.647 n
10:58:57.667 subscribeHandler
10:58:57.767 consume
10:58:57.787 map@[native code]
10:59:00.027 App Hide at App.vue:45

我的源码如下，是在hello-uniapp的blutooth.vue源代码平台上调试的。

    /**  
     *  向指定的UUID发送Datas  
     */  

    BLESendDatas() {  
        // 向蓝牙设备发送一个0x00的16进制数据  

        let deviceId = this.equipment[0].deviceId;  
        let serviceId = this.servicesData[0].uuid;  
        let characteristicId = this.characteristicsData[0].uuid;  
        /// let characteristicId = this.NowcharacteristicsData;  
        let characteristicIdA = this.characteristicsData[0] ;  
        let characteristicIdB = this.characteristicsData[0];  

        /// let notify = this.characteristicsData[0].properties.notify;  

        /// characteristicId = "0000FFE1-0000-1000-8000-00805F9B34FB";  

        characteristicId = characteristicIdA ;  

        console.log(deviceId);  
        console.log(serviceId);  
        console.log(characteristicId);  
        console.log(characteristicIdA);  
        /// console.log(characteristicIdB);  
        /// console.log(notify);  

        var SendBuffer=new ArrayBuffer(19);//长度为四个字节  
        /// var SendBuffer=new Uint8Array(buffer);  
        var i ;  

        for(i=0;i<9;i++)  
        {  
            SendBuffer[i] = '0'+i;  
        }  

        /// console.log(SendBuffer);  

        uni.writeBLECharacteristicValue({  
          // 这里的 deviceId 需要在 getBluetoothDevices 或 onBluetoothDeviceFound 接口中获取  
          deviceId,  
          // 这里的 serviceId 需要在 getBLEDeviceServices 接口中获取  
          serviceId,  
          // 这里的 characteristicId 需要在 getBLEDeviceCharacteristics 接口中获取  
          characteristicId,  
          // 这里的value是ArrayBuffer类型  
          value: SendBuffer,  
          success(res) {  
            console.log('writeBLECharacteristicValue success', res.errMsg);  
          },  

          fail: e => {  
            console.log('writeBLECharacteristicValue，错误码：' + e.errCode);  
            if (e.errCode !== 0) {  
                initTypes(e.errCode);  
            }  
          },  

        });  
    }  

这个获取 characteristicId 是直接抄本文件中如下方法体来的：

    /**  
     * 读取低功耗蓝牙设备的特征值的二进制数据值。注意：必须设备的特征值支持 read 才可以成功调用  
     */  
    readBLECharacteristicValue() {  
        let deviceId = this.equipment[0].deviceId;  
        let serviceId = this.servicesData[0].uuid;  
        let characteristicId = this.characteristicsData[0].uuid;  
        console.log(deviceId);  
        console.log(serviceId);  
        console.log(characteristicId);  
        uni.readBLECharacteristicValue({  
            // 这里的 deviceId 需要已经通过 createBLEConnection 与对应设备建立链接  
            deviceId,  
            // 这里的 serviceId 需要在 getBLEDeviceServices 接口中获取  
            serviceId,  
            // 这里的 characteristicId 需要在 getBLEDeviceCharacteristics 接口中获取  
            characteristicId,  
            success: res => {  
                console.log('读取设备数据值成功');  
                console.log(JSON.stringify(res));  
                this.notifyBLECharacteristicValueChange();  
            },  
            fail(e) {  
                console.log('读取设备数据值失败，错误码：' + e.errCode);  
                if (e.errCode !== 0) {  
                    initTypes(e.errCode);  
                }  
            }  
        });  
        this.onBLECharacteristicValueChange();  
    },