You need to call output.close() when you finish receiving data.

Hey PhiLho,look at the code below and see if that is what you meant,i have tried it and it still gives me a blank file.I would suppose you post your code here.



import processing.serial.*;
Serial mySerial;
PrintWriter output;
void setup() {
   mySerial = new Serial( this, Serial.list()[0], 9600 );
   output = createWriter( "newp.txt" );
   //print(Serial.list());
}
void draw() {
    if (mySerial.available() > 0 ) {
         String value = mySerial.readString();
         if ( value != null ) {
              output.println( value );
               output.close();
             

         }
    }
 
}

Try to add a simple println(value); after reading it, to see if you have something in the console.

Yes i do have something in the console but nothing in the file :(.

Your code, once I removed the Serial stuff, works for me, so I don't know where your problem can be.

Could you post your code here,so i could retry it.

The code works, but it does only write data once and then closes the output-stream. So any data beeing recieved after that point wont be in your logfile. Try to close the output-stream on keypressed or exit maybe. Something like this:

1. void exit() {
     output.close();
   }
   

Same problem,no data written in the file.

As I wrote, it is just your code without the Serial stuff:

1. PrintWriter output;
2. 
   
3. void setup() {
4.    output = createWriter( "newp.txt" );
5. }
6. 
   
7. void draw() {
8.          String value = "Some stuff";
9.          if ( value != null ) {
10.               output.println( value );
11.                output.close();
12.          }
13. }