How to send data to bluetooth printer via android app?

Question

I am developing an app which will send data to a printer via bluetooth to print (A thermal printer for receipts). I have followed the code which in this link.

http://pastie.org/6203514 and this link also http://pastie.org/6203516

I am able to see the device and its MAC Address and its name, when I send the data to the printer (the light LED on the printer stops blink and becomes standard i.e the printer is connected with my android phone) but when I send the data it is not printing and nor it is giving any error also. I have googled a lot and I found many codes and tried all set of codes but could not able to print .

Please any one could help me out of here. I heard with Intents it can be done easily but could not get the exact solution with Intents.

Any help would be appreciated Thanks in Advance

Ganesh

Answer 1

Finally I solved this problem by my self and the problem is that the header byte which I am sending to the printer is the real culprit. Actually I am sending 170,1 (where 170 is the first byte that the printer must receive and the second byte is the printer id I mean some com port which these two values are given by Printer control card designer). Actual I have to send 170,2 where 2 is the Printer Id so that it gives the correct print and for every printer it is common of sending the data based on their control card's.

Thanks a lot friends and here is my code that u can use these code for all types of printers(for POS-Thermal Printers)

public void IntentPrint(String txtvalue)
{
    byte[] buffer = txtvalue.getBytes();
    byte[] PrintHeader = { (byte) 0xAA, 0x55,2,0 };
    PrintHeader[3]=(byte) buffer.length;
    InitPrinter();
    if(PrintHeader.length>128)
    {
        value+="\nValue is more than 128 size\n";
        txtLogin.setText(value);
    }
    else
    {
        try
        {
            for(int i=0;i<=PrintHeader.length-1;i++)
            {
                mmOutputStream.write(PrintHeader[i]);
            }
            for(int i=0;i<=buffer.length-1;i++)
            {
                mmOutputStream.write(buffer[i]);
            }
            mmOutputStream.close();
            mmSocket.close();
        }
        catch(Exception ex)
        {
            value+=ex.toString()+ "\n" +"Excep IntentPrint \n";
            txtLogin.setText(value);
        }
    }
} 

And this code for the rest:

public void InitPrinter()
{
    try
    {
        if(!bluetoothAdapter.isEnabled())
        {
           Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
           startActivityForResult(enableBluetooth, 0);
        }

        Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();

        if(pairedDevices.size() > 0)
        {
            for(BluetoothDevice device : pairedDevices)
            {
                if(device.getName().equals("Your Device Name")) //Note, you will need to change this to match the name of your device
                {
                    mmDevice = device;
                    break;
                }
            }

            UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); //Standard SerialPortService ID
            //Method m = mmDevice.getClass().getMethod("createRfcommSocket", new Class[] { int.class });
            //mmSocket = (BluetoothSocket) m.invoke(mmDevice, uuid);
            mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);
            bluetoothAdapter.cancelDiscovery();
            if(mmDevice.getBondState()==2)
            {
                mmSocket.connect();
                mmOutputStream = mmSocket.getOutputStream();
            }
            else
            {
                value+="Device not connected";
                txtLogin.setText(value);
            }
        }
        else
        {
            value+="No Devices found";
            txtLogin.setText(value);
            return;
        }
    }
    catch(Exception ex)
    {
        value+=ex.toString()+ "\n" +" InitPrinter \n";
        txtLogin.setText(value);
    }
}

Answer 2

Are you aiming for a specific protocol of printing? (for specific printer?)

If not, and a generic print can be made to whetever printer is connected, you can use this code snippet:

Write this where you want to print a specific file/files:

            Intent intent = Tools.getSendToPrinterIntent(
                    DisplayActivity.this, mPdfAsPictures,
                    mPrintCurrentIndex);

            // notify the activity on return (will need to ask the user for
            // approvel)
            startActivityForResult(intent, ACTIVITY_PRINT);

This is the helper method:

public static Intent getSendToPrinterIntent(Context ctx, String[] fileFullPaths, int indexToPrint){
    Intent sendIntent = new Intent(Intent.ACTION_SEND_MULTIPLE);

    // This type means we can send either JPEG, or PNG
    sendIntent.setType("image/*");

    ArrayList<Uri> uris = new ArrayList<Uri>();

    File fileIn = new File(fileFullPaths[indexToPrint]);
    Uri u = Uri.fromFile(fileIn);
    uris.add(u);

    sendIntent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, uris);

    return sendIntent;
}

And finally, you'll receive the answer at:

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == ACTIVITY_PRINT) {

        switch (resultCode) {
        case Activity.RESULT_CANCELED:
            Log.d(TAG(), "onActivityResult, resultCode = CANCELED");
            break;
        case Activity.RESULT_FIRST_USER:
            Log.d(TAG(), "onActivityResult, resultCode = FIRST_USER");
            break;
        case Activity.RESULT_OK:
            Log.d(TAG(), "onActivityResult, resultCode = OK");
            break;
        }
    }
};

Good luck!