Hello,

I use the following code to send an image from my C328 camera to Processing.

I get the following error: nullpointerexeption

I use the following Processing code:

Code:

import processing.serial.*;

Serial myPort;
int i = 1;

String ImageFilename = "Photo_" + year() + "_" + day() + "_" + month() + "-" + hour() + "_" + minute() + "_" + second() + "_" + millis() + ".jpg";
int CharE = 69;
int CharO = 79;
int CharF = 70;
int TotalBytes = 0;

byte[] Photo = {
};

void setup()
{
  //Set and open serial port
  println( Serial.list() );
  myPort = new Serial( this, Serial.list()[1], 9600 );
  myPort.clear();
}

void draw()
{
  // Import Picture
  byte[] buffer = new byte[64];

  while( myPort.available() > 0 )
  {
    int readBytes = myPort.readBytes(buffer);

    //print( "Read " );
    //print( readBytes );
    //println( " bytes ..." );

    for( int i = 0; i < readBytes; i++ )
    {

	TotalBytes = TotalBytes + 1;

	//print( "Read " );
	//print( TotalBytes );
	//println( " bytes in total ..." );

	Photo = append( Photo, buffer[i] );

	print( "PhotoArray contains: " );
	print(Photo.length);
	println( " Elements..." );

	if ( TotalBytes > 2 && Photo[TotalBytes-3] == CharE && Photo[TotalBytes-2] == CharO && Photo[TotalBytes-1] == CharF ){

	  // Save picture to file
	  if( Photo.length > 0 ) {
	    print( "Writing to disk " );
	    print( Photo.length );
	    println( " bytes ..." );
	    saveBytes( ImageFilename, Photo );
	    println( "DONE!" );

	    // Open Picture
	    size(6400, 4800);
	    PImage C328Image;
	    C328Image = loadImage(ImageFilename);
	    image(C328Image, 0, 0);

	    //Clear the array
	    Photo = null; // clear array

	    //Clear totalbytes
	    TotalBytes = 0;

	    //Flush serial port
	    myPort.clear();

	    return;

	  }
	}
    }
  }
}
 

The error is executed on this line when a new picture is imported (2nd cycle):

Code:

Photo = append( Photo, buffer[i] );
 

Probably the problem is due to the fact that I try to clear the array using this line of code:

Code:

Photo = null; // clear array ????
 

Is this the problem? If yes, is there another way to clear/delete the array. Or is there something else wrong.....

Thanks in advance,

Cheers.

Hi,

Thanks for you reply

I've tried your suggestion but get the following error:

Variable must provide either dimension dimensions or an array initializer.

This is the original declared byte:

Code:

byte[] Photo = {
};
 

Should I use an arraylist?

Whats wrong?

byte[] Photo = { 0 };
or
byte[] Photo = new byte[0];

I think if you declare the type again before 'resetting' the array (i.e. 'byte[] Photo =...' rather than 'Photo =...') then you're in fact creating a new 'Photo' array with local scope...