Creating a Touch Listener

[butmonkey98]

I am starting to learn Java, I have recently got a LEGO Mindstorms set. I was wondering, what is needed to main a Touch Listener. I just want the NXT to beep when a touch sensor is pressed. This is what I have so far, what more do I need to put in, What do I have that doesn't need to be there?

Code: Select all

import lejos.nxt.SensorPort;
import lejos.nxt.Sound;
import lejos.nxt.TouchSensor;
import lejos.robotics.Touch;

public class Main implements Touch{
    public static void main(String args[]){
        TouchSensor ts = new TouchSensor(SensorPort.S1);
    }
    public void addTouchListener(TouchListener touchListener) {

    }
    @Override
    public boolean isPressed() {
        Sound.beep();
        return false;
    }

    public class TouchListener{

    }
}

Thanks

[TechnoX]

lejos.nxt.TouchSensor doesn't implement a sensor listener ...
And the ListenerThread-class is private so you can't write your own implementation of a sensorListener for the TouchSensor.
You would normally just do a loop that checks if the sensor is pressed.


But if you want to have a listener you can use the analog SensorPortListener, like this:

Code: Select all

import lejos.nxt.*;

public class Program {
   
   public static void main(String[] args) throws InterruptedException {
      
      SensorPort.S1.addSensorPortListener(new SensorPortListener(){
         @Override
         public void stateChanged(SensorPort source, int oldValue,   int newValue) {
            if(newValue>1000)
               LCD.drawString("Released", 0, 0);
            else
               LCD.drawString("Pressed ", 0, 0);
         }
      });
      
      Button.waitForAnyPress();
   }
}

[gloomyandy]

However I would not recommend that you do this. Search the forum and you will find lots of posts from me explaining why the listener model is not a good one. With touch sensors you will see the listener fire multiple times due to contact bounce within the hardware, there are also lots of other reasons not to use this interface...

Andy

[butmonkey98]

Thankyou very much this was helpful