How to display received data bytes via Bluetooth properly?

Asked Jan 24 '17 at 18:08

Active Jan 24 '17 at 18:26

Viewed 574 times

I have a problem with receiving data via BT, sent from SPP BT module. When I'm sending bytes from terminal i got non-sense characters - for example "[B@420e98d8". There is a part of the code from handler responsible for data receive:

        mHandler = new Handler(){
        public void handleMessage(android.os.Message msg){
            if(msg.what == MESSAGE_READ){
                try {
                    byte[] readBuf = (byte[]) msg.obj;
                    byte[] bytes = (msg.obj).toString().getBytes();

                    mReadBuffer.setText(readBuf.toString());
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

            }

            if(msg.what == CONNECTING_STATUS){
                if(msg.arg1 == 1)
                    mBluetoothStatus.setText("Connected to Device: " + (String)(msg.obj));
                else
                    mBluetoothStatus.setText("Connection Failed");
            }
        }
    };

How should I convert received values to display them properly? Or how to receive this otherwise? I don't need to use BLE, normal Bluetooth module, programming in Android Studio 2.2.3.

edited Jan 24 '17 at 18:26

asked Jan 24 '17 at 18:08

Juras

What is "properly"? They're bytes, so `[B@420e98d8` is perfectly valid. – Christopher Schneider Jan 24 '17 at 18:11
No its not valid and that is not the content of the bytes array but a java identifier. – greenapps Jan 24 '17 at 18:12
Try something like mReadBuffer.setText((String)msg.obj); – greenapps Jan 24 '17 at 18:14
Are you shure the bytes contain text? – greenapps Jan 24 '17 at 18:17
Google for java convert byte array to string. – greenapps Jan 24 '17 at 18:19
tried mReadBuffer.setText((String)msg.obj);, app crashed, tried using NullPointerException instead of UnsupportedEncodingException (due to "never thrown in the corresponding try block error"), app also crashed. I can't even debug it, because android studio can't see my device. – Juras Jan 24 '17 at 19:44
You need to do something with the bytes in readBuf. Do you want to parse them as a string in utf8 or print the hex of each byte? – Emil Jan 25 '17 at 02:54
I want to print the hex of each byte. – Juras Jan 25 '17 at 10:29

How to display received data bytes via Bluetooth properly?

0 Answers0