Trying to connect with IoT device by bluetooth connectivity(Gatt)

问题

I am trying to communicate with an IoT device by BlueTooth connectivity. first,

I have paired the device using BlueTooth.
Then prepared the Hexadecimal value using AES encryption
Send a request to the device using characteristic write
I tried to read the response from the device using characteristic Read but I got the status as 1 and data is null.

These are the steps which I have done and the code I mentioned below.

BluetoothGatt gatt;
BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
    @Override
    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
        super.onConnectionStateChange(gatt, status, newState);

        System.out.println("Lock Conn St ---"+status);
        System.out.println("Lock Conn new st  ---"+newState);
        if (newState == 2){
            gatt.discoverServices();
        }


    }

    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
        super.onServicesDiscovered(gatt, status);

        System.out.println("Lock Conn new serv discov  ---"+status);

         if (status == BluetoothGatt.GATT_SUCCESS){



             System.out.println("gatt Success  ---");
             String getTockenString;
             /*List<BluetoothGattService> ls= gatt.getServices ();

             System.out.println("gatt List   ---"+ls.toString());*/
             //orginal key
             final byte AESkey[] = new byte[] {0x20,0x57,0x4f,0x55,0x36,0x4b,0x3f,0x47,0x39,0x50,0x41,0x58,0x91,0x63,0x2d,0x8b};
             final byte Src[] = new byte[] {0x06,0x01,0x01,0x01,0x2D,0x1A,0x68,0x3D,0x48,0x27,0x1A,0x18,0x31,0x6E,0x47,0x1A};

             try {
                 getTockenString = bytesToHex(encrypt(Src, AESkey));
                 BluetoothGattService service = gatt.getService(LOCK_SERVICE_UUID);
                 BluetoothGattCharacteristic readCharect =  service.getCharacteristic(LOCK_READ_DATA_UUID);
                 BluetoothGattCharacteristic writeCharect =  service.getCharacteristic(LOCK_WRITE_DATA_UUID);

                 gatt.setCharacteristicNotification(readCharect,true);


                 writeCharect.setValue(getTockenString.getBytes());
                 gatt.writeCharacteristic(writeCharect);

                 System.out.println("gatt AES ENC   ---"+getTockenString);

             } catch (Exception e) {
                 e.printStackTrace();

             }

         }
        System.out.println("gatt end of on descovng   ---");
    }

    @Override
    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
        super.onCharacteristicChanged(gatt, characteristic);

        System.out.println("gatt char   changed    ---"+ Arrays.toString(characteristic.getValue()));



    }



    @Override
    public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
        super.onCharacteristicWrite(gatt, characteristic, status);

        System.out.println("gatt =============== == onCharacteristicWrite  happend  ---"+status+ Arrays.toString(characteristic.getValue() ));

        BluetoothGattService service = gatt.getService(LOCK_SERVICE_UUID);
        BluetoothGattCharacteristic readCharect =  service.getCharacteristic(LOCK_READ_DATA_UUID);
        gatt.readCharacteristic(readCharect);

    }

    @Override
    public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
        super.onCharacteristicRead(gatt, characteristic, status);

        System.out.println("gatt ================    onCharacteristicRead   happend  ---"+status );

        System.out.println("gattonCharacteristicRead value---"+ Arrays.toString(characteristic.getValue()));


    }


};

In the document, they have explained all the communication will be in 16 bit but when I send a request I got one 32 bit value but I don't think that is the value I am expecting. can anyone help me to solve the issue? I have to communicate with my device using BlueTooth.

来源：https://stackoverflow.com/questions/59099008/trying-to-connect-with-iot-device-by-bluetooth-connectivitygatt

标签

android

bluetooth

iot

gatt