Wrong cast if received Byte is bigger than 127

[Samyssmile]

Hello Guys, great work you done.

We had for last Days some trouble with this API. Its exactly Issue#9. You wrote that you fixed it but it was not fixed.

Problem: If our App recieve byte 128 (hax 80), this lib read it as -128 and wrong hex.

We all know this happen because of signed Bytes in Java.

Workaround: SPPService.java
Replace this:
mHandler.obtainMessage(BluetoothSerial.MESSAGE_READ, bytes, -1, read.getBytes()).sendToTarget();

with this

mHandler.obtainMessage(BluetoothSerial.MESSAGE_READ, bytes, -1, read.getBytes(StandardCharsets.US_ASCII)).sendToTarget();

If you do this changes, issue like #9 never happen again. In most of usecases with SPP we think US_ASCII as default is much better....

Great work keep on.

[viethoa]

On the SPPSerive file, find ConnectedThread class and replace Run function by this:

public void run() {

        byte[] data = new byte[1024];
        int bytes;

        while (true) {
            try {
                bytes = mInputStream.read(data);
                String read = new String(data, 0, bytes, Charset.forName("ISO-8859-1"));
                mHandler.obtainMessage(BluetoothSerial.MESSAGE_READ, bytes, -1, read.getBytes(Charset.forName("ISO-8859-1"))).sendToTarget();
            } catch (IOException e) {
                reconnect(); // Connection lost
                SPPService.this.start();
                break;
            }
        }
    }

One more thing, You should check the UUID_SP, I am not sure I have edited it before, Btw now it look like this:
private static final UUID UUID_SPP = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

[bayudwirp]

Hello @Samyssmile
I've tried your suggestion to replace

mHandler.obtainMessage(BluetoothSerial.MESSAGE_READ, bytes, -1, read.getBytes()).sendToTarget();

With this :
mHandler.obtainMessage(BluetoothSerial.MESSAGE_READ, bytes, -1, read.getBytes(StandardCharsets.US_ASCII)).sendToTarget();

and it will always give 63 if we receive byte 128 to 255.

Any suggestion to solve the problem?

[MacroYau]

@bayudwirp Have your tried using BluetoothSerialRawListener?

[bayudwirp]

Hi @MacroYau ,
I've tried using BluetoothSerialRawListener and it give me same result. It will always give 63 if i receive byte from 128 to 255 but, if i receive byte from 0 until 127 it has no problem.

Have you any other suggestion to solve this problem?

[MacroYau]

@bayudwirp Would you mind showing your actual code implementation?

[bayudwirp]

Of course @MacroYau .
I'm trying to create an application that reads the input data from bluetooth (Based on the example of a chat application that you created), then the data are presented in into a decimal value.
The data that I send, will only have a range between 0 - 255 (00 - FF Hexadecimal).
And this is an example of the program that was I made:
(You can check part onBluetoothSerialRead)
(MainActivity.java)

package in.bayudwirp.testing;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

import com.macroyau.blue2serial.BluetoothDeviceListDialog;
import com.macroyau.blue2serial.BluetoothSerial;
import com.macroyau.blue2serial.BluetoothSerialListener;
import com.macroyau.blue2serial.BluetoothSerialRawListener;


public class MainActivity extends AppCompatActivity implements BluetoothSerialListener, BluetoothDeviceListDialog.OnDeviceSelectedListener, BluetoothSerialRawListener
{

    private static final int REQUEST_ENABLE_BLUETOOTH = 1;

    private BluetoothSerial bluetoothSerial;

    private MenuItem actionConnect, actionDisconnect;

    public  int bluetooth_status_flag = 0;
    public  String data_bluetooth_string = "";
    public  String data_bluetooth_string_konversi = "";
    public  int data_bluetooth_int = 0;
    public  byte[] data_bluetooth_byte;
    public  TextView textView1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView1 = (TextView) findViewById(R.id.textView);

        // Bagian Bluetooth SPP
        // Create a new instance of BluetoothSerial
        bluetoothSerial = new BluetoothSerial(this, this);

    }

    @Override
    protected void onStart() {
        super.onStart();

        // Check Bluetooth availability on the device and set up the Bluetooth adapter
        bluetoothSerial.setup();
    }

    @Override
    protected void onResume() {
        super.onResume();

        // Open a Bluetooth serial port and get ready to establish a connection
        if (bluetoothSerial.checkBluetooth() && bluetoothSerial.isBluetoothEnabled()) {
            if (!bluetoothSerial.isConnected()) {
                bluetoothSerial.start();
            }
        }
    }

    @Override
    protected void onStop() {
        super.onStop();

        // Disconnect from the remote device and close the serial port
        bluetoothSerial.stop();
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_terminal, menu);

        actionConnect = menu.findItem(R.id.action_connect);
        actionDisconnect = menu.findItem(R.id.action_disconnect);

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_connect) {
            showDeviceListDialog();
            return true;
        } else if (id == R.id.action_disconnect) {
            bluetoothSerial.stop();
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void invalidateOptionsMenu() {
        if (bluetoothSerial == null)
            return;

        // Show or hide the "Connect" and "Disconnect" buttons on the app bar
        if (bluetoothSerial.isConnected()) {
            if (actionConnect != null)
                actionConnect.setVisible(false);
            if (actionDisconnect != null)
                actionDisconnect.setVisible(true);
        } else {
            if (actionConnect != null)
                actionConnect.setVisible(true);
            if (actionDisconnect != null)
                actionDisconnect.setVisible(false);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        switch (requestCode) {
            case REQUEST_ENABLE_BLUETOOTH:
                // Set up Bluetooth serial port when Bluetooth adapter is turned on
                if (resultCode == Activity.RESULT_OK) {
                    bluetoothSerial.setup();
                }
                break;
        }
    }

    private void updateBluetoothState() {
        // Get the current Bluetooth state
        final int state;
        if (bluetoothSerial != null)
            state = bluetoothSerial.getState();
        else
            state = BluetoothSerial.STATE_DISCONNECTED;

        // Display the current state on the app bar as the subtitle
        String subtitle;
        switch (state) {
            case BluetoothSerial.STATE_CONNECTING:
                subtitle = getString(R.string.status_connecting);
                break;
            case BluetoothSerial.STATE_CONNECTED:
                subtitle = getString(R.string.status_connected, bluetoothSerial.getConnectedDeviceName());
                break;
            default:
                subtitle = getString(R.string.status_disconnected);
                break;
        }

        if (getSupportActionBar() != null) {
            getSupportActionBar().setSubtitle(subtitle);
        }
    }

    private void showDeviceListDialog() {
        // Display dialog for selecting a remote Bluetooth device
        BluetoothDeviceListDialog dialog = new BluetoothDeviceListDialog(this);
        dialog.setOnDeviceSelectedListener(this);
        dialog.setTitle(R.string.paired_devices);
        dialog.setDevices(bluetoothSerial.getPairedDevices());
        dialog.showAddress(true);
        dialog.show();
    }

    /* Implementation of BluetoothSerialListener */
    @Override
    public void onBluetoothNotSupported() {
        new AlertDialog.Builder(this)
                .setMessage(R.string.no_bluetooth)
                .setPositiveButton(R.string.action_quit, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        finish();
                    }
                })
                .setCancelable(false)
                .show();
    }

    @Override
    public void onBluetoothDisabled() {
        Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBluetooth, REQUEST_ENABLE_BLUETOOTH);
    }

    @Override
    public void onBluetoothDeviceDisconnected() {
        invalidateOptionsMenu();
        updateBluetoothState();
        bluetooth_status_flag = 0;
    }

    @Override
    public void onConnectingBluetoothDevice() {
        updateBluetoothState();
    }

    @Override
    public void onBluetoothDeviceConnected(String name, String address) {
        invalidateOptionsMenu();
        updateBluetoothState();
        bluetooth_status_flag = 1;
    }

    @Override
    public void onBluetoothSerialRead(String message) {
        // Print the incoming message on the terminal screen
        data_bluetooth_string = message;
        data_bluetooth_string_konversi = asciiToHex(data_bluetooth_string);
        data_bluetooth_int = Integer.parseInt(data_bluetooth_string_konversi,16);
        textView1.setText("Data :"+data_bluetooth_int);                             // Data from bluetooth, will show in Integer Format
    }

    @Override
    public void onBluetoothSerialWrite(String message) {
        // Print the outgoing message on the terminal screen
        /*tvTerminal.append(getString(R.string.terminal_message_template,
                bluetoothSerial.getLocalAdapterName(),
                message));
        svTerminal.post(scrollTerminalToBottom);*/
    }

    @Override
    public void onBluetoothSerialReadRaw(byte[] bytes){
        //data_bluetooth_byte = bytes;
    }

    @Override
    public void onBluetoothSerialWriteRaw(byte[] bytes){}

    /* Implementation of BluetoothDeviceListDialog.OnDeviceSelectedListener */

    @Override
    public void onBluetoothDeviceSelected(BluetoothDevice device) {
        // Connect to the selected remote Bluetooth device
        bluetoothSerial.connect(device);
    }

    /* End of the implementation of listeners */
    private final Runnable scrollTerminalToBottom = new Runnable() {
        @Override
        public void run() {
            // Scroll the terminal screen to the bottom
            // svTerminal.fullScroll(ScrollView.FOCUS_DOWN);
        }
    };

    /* Convert ASCII String to Hexadecimal Value */
    private static String asciiToHex(String asciiValue)
    {
        char[] chars = asciiValue.toCharArray();
        StringBuffer hex = new StringBuffer();
        for (int i = 0; i < chars.length; i++)
        {
            hex.append(Integer.toHexString((int) chars[i]));
        }
        return hex.toString();
    }
}

And this script below is ActivityMain.xml
(ActivityMain.xml)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <TextView
        android:text="TextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/textView"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:layout_marginRight="36dp"
        android:layout_marginEnd="36dp" />



</RelativeLayout>

Any suggestion from you, will be appreciated.
Thankyou.

[MacroYau]

@bayudwirp My suggestions:

1. Remove the BluetoothSerialListener interface, and use BluetoothSerialRawListener only (and migrate the methods accordingly, of course).
2. Use the following code in onBluetoothSerialReadRaw() to verify the output:

for (byte b : bytes)
    System.out.println("Read: " + (int) b & 0xFF);

[bayudwirp]

Thank you very much for your suggestion @MacroYau , very appreciate for you to helping me.
But, after I followed your suggestion to remove part BluetoothSerialListener interface, and then use only BluetoothSerialRawListener and use the code you suggest,

for (byte b : bytes)
    System.out.println("Read: " + (int) b & 0xFF);

the results remain as before, issued a byte value of 63 when it receives 128-255. I didn't know, how could this happen again.

[MacroYau]

@bayudwirp Your problem looks like #9 which should have already fixed... Can you try to log the incoming bit patterns as well?

[bayudwirp]

@MacroYau yes, i think so. But, i've tried to use your solution in #9 before i tried #10 solution. And, i've got value 65533, if i receive byte 128 - 255.

[MacroYau]

@bayudwirp How about the sending side? Is it really transmitting 128 to 255?

[bayudwirp]

@MacroYau I didn't try about sending side. But, if i try to sending character from your example apps (Blue2Serial), such as sending characters "name" (below byte 127, if we convert every characters to ASCII) there is no problem, but if i try to send specials character (above byte 127), it always receive not only the character that i was send, but also receive another random character.

[bayudwirp]

Hi @MacroYau

I've tried again about your suggestion to using BluetoothSerialRawListener and using this code

for (byte b : bytes)
    System.out.println("Read: " + (int) b & 0xFF);

and, i tried to restore a default SPPService.java (maybe i made mistake to change something on this file)
And i try to test again, and now its works fine.

Thankyou very much, for helping me. Have a good day for you :)

[MacroYau]

Great to hear that! :)