sending/receving binary data over bluetooth

[Dan Sulik]

Is there a way to send binary data via  bluetooth Write () function?

For example I have an array of bytes like:

d[0] = 0x55;

d[1] = 2;

d[2] = 0;

...

then I want to send the data as 3 bytes in binary format like 

bt.Write (d, 3);

Any help is appreciated.

Thnx

dan

[Dave Smart]

Hi Dan,

Yes you can use the "Hex" mode of the Bluetooth serial component.  Here is an example class I wrote to control a "FlowPaw" Bluetooth module from DroidScript Apps:-

function FlowPaw()

{

    //Private variables.

    var onConnect, onButtons;

    var buttons = [false,false,false,false];

    var lastBtns  = 0;

   

    //Initialise the object (constructor).

    var bt = app.CreateBluetoothSerial("hex");

    bt.SetOnConnect( _Cb(this,"OnConnect") );

    bt.SetOnReceive( _Cb(this,"OnData") );

    

    //Use EOF+data header as delimeter because this is more 

    //reliable than using fixed data size if we get out of sync.

    bt.SetSplitMode( "End", "23452342" );

    //bt.SetSplitMode( "Size", 64+1 );

    

    //Callbacks setters.

    this.SetOnConnect = function( cb ) { onConnect = cb; }

    this.SetOnButtons = function( cb ) { onButtons = cb; }

    

    //Connect to BT module.

    this.Connect = function( btName )

    {

        bt.Connect( btName );

    }

    

    //Handle connection.

    this.OnConnect = function( ok )

    {

        if( ok )

        {

            //PI mode - only speak when spoken to.

            //bt.Write("23,51,23,45");

        

            //Setup buzzer on claw 1.

            bt.Write( "23,58,01,01,23,45" );

        }

        //Fire users callback if set.

        if( onConnect ) onConnect( ok );

    }

    

    //Handle data from device.

    this.OnData = function( data )

    {

        data = data.split(",");

        //console.log( data );

        

        //Read buttons states.

        var btns = parseInt("0x"+data[0]);

        buttons[0] = (btns & 1) > 0 ? 1 : 0;

        buttons[1] = (btns & 2) > 0 ? 1 : 0;

        buttons[2] = (btns & 4) > 0 ? 1 : 0;

        buttons[3] = (btns & 8) > 0 ? 1 : 0;

        

        //Fire button callback if required.

        if( onButtons && btns!=lastBtns ) onButtons( buttons );

        lastBtns = btns;

    }

    //Play tone of given freqency.

    this.PlayTone = function( Hz )

    {

        var hex = Hex( Hz ,4 );

        var hi = hex.substr(0,2);

        var lo = hex.substr(2,2);

        bt.Write( "23,43,01,01,"+hi+","+lo+",23,45" );

    }

    

    //Turn LEDs on or off.

    //paw.SetLEDs( [1,1,1,0] );

    this.SetLEDs = function( leds )

    {

        var byte = 0;

        if( leds[0] ) byte |= 1;

        if( leds[1] ) byte |= 2;

        if( leds[2] ) byte |= 4;

        if( leds[3] ) byte |= 8;

        var hex = Hex( byte, 2 );

        bt.Write( "23,4C,"+hex+",23,45" );

    }

    

    //Set a servos position (posn 0.0 - 1.0).

    this.SetServo = function( num, posn )

    {

        var hex = Hex( posn*999, 4 );

        var hi = hex.substr(0,2);

        var lo = hex.substr(2,2);

        var num = Hex( num, 4 );

        bt.Write( "23,53,"+num+","+hi+","+lo+",23,45" );

    }

    

    //Set global servo speed (0.0 - 1.0).

    this.SetServoSpeed = function( speed )

    {

        var hex = Hex( speed*99, 4 );

        var hi = hex.substr(0,2);

        var lo = hex.substr(2,2);

        bt.Write( "23,50,"+hi+","+lo+",23,45" );

    }

    

    //Convert number to hex string of given length.

    function Hex( num, len ) 

    {

        num = Math.round( num );

        var s = "000000000" + num.toString(16);

        return s.substr(s.length-len);

    }

}

[Dan Sulik]

Hi Dave,

thank you for quick response. That's a great news to have a binary access.

Please could you put more light on CreateBluetoothList () function in my another post?

Thank you

Dan