Hi all, hoping for a little help here.

I am trying to continously update a .xml file with some sensordata from my Arduino - the xml is to be parsed by Unity3d for joystick input at a later stage.

I only need the latest data (joystick position), so I am looking for a way to update my .xml, overwriting the data from the last read. Right now I am able to read the desired data and print it to the file, appending a new line for each new read.

Any help is greatly appreciated  

/Esben

Processing code:
Code:

import processing.serial.*;

Serial mySerial;
PrintWriter output;

void setup() {
   mySerial = new Serial(this, Serial.list()[0], 9600);
   output = createWriter("data.xml");
}

void draw() {
  if (mySerial.available() > 0) {
         String value = mySerial.readString();
         output.print(value);
         output.flush();
         delay(100); 
   }
} 

Arduino code:
Code:

int pullPin = 2;    // select the input pin for the potentiometer
int ledPin = 13;   // select the pin for the LED
int pullValue = 0;       // variable to store the value coming from the sensor
int valNew = 0;

void setup() {
  pinMode(ledPin, OUTPUT);  // declare the ledPin as an OUTPUT
  Serial.begin(9600);      // open the serial port at 9600 bps:
  loop();
}

int treatValue(int data) {
  return (data * 9 / 1024) + 48;
 }

void loop() {
  pullValue = analogRead(pullPin);    // read the value from the sensor
  Serial.print("<");
  Serial.print(pullValue);
  Serial.println(">");
} 

Hi antiplastik

Thanks for your reply - I tried your suggestion, and I think you are right, it is not possible reach good results by updating an xml file.

I am not using a regular joystick but a Gametrak device, that lets med output 3 variables, one for each axis, and I want to feed that information to the Unity3d game engine as often as possible, so that I can get a position in a 3D space.

This means, that an on-demand XML export option would not be suitable, yes?

Thanks again for your reply. Ideas for other methods to pass the data would be very welcome

/Esben