if statement (easy beginner problem)

alexs

I'm using Processing to do something depending on the state of an input (eg, button, sensor, potentiometer).

Having wired a switch via an Arduino I pickup the serial data via Processing and have that data displayed on screen.

There is an if statement that I can't get working. Is should draw a green ellipse if the swicth is flicked (reading of 1023), otherwise ir will draw a red ellipse.

I can't figure out the if statement.

Can anyone advise what I should be doing to have the condition work? You can see where I'm going wrong (line 28) where is says "if (sensorReading == "1023")"

import processing.serial.*;
Serial myPort;
String sensorReading="";
PFont font;


void setup() {
  size(400,200);
  myPort = new Serial(this, "COM6", 9600);
  myPort.bufferUntil('\n');
  font = createFont(PFont.list()[2],32);
  textFont(font);
}

void draw() {
  //The serialEvent controls the display
}  

void serialEvent (Serial myPort){
 sensorReading = myPort.readStringUntil('\n');
  if(sensorReading != null){
    sensorReading=trim(sensorReading);
  }

  writeText("Sensor Reading: " + sensorReading);


  if (sensorReading == "1023"){
    fill(0,255,0);
    ellipse(10,10,50,50);
  }
  else{
    fill(255,0,0);
    ellipse(10,10,50,50);
  }
}


void writeText(String textToWrite){
  background(255);
  fill(0);
  text(textToWrite, width/20, height/2);   
}

PhiLho

Search String in the Reference page. Look what they have to say about using == to compare strings!
In short, don't use ==, use .equals() instead.

GoToLoop

http://processing.org/reference/String_equals_.html