usage of ev3 ultrasonic sensor in lejos behavior based programming

Question

I'm using ev3 ultrasonic sensor. And I'm writing a behavior based lejos code. I want to do some tasks when the ultrasonic sensor detects an object which is not further than 30 cm's. And this is my code:

public UltrasonicSensor(Port port)
    {
        sonar = new EV3UltrasonicSensor(port);
        sonar.getDistanceMode().fetchSample(value, 0);
    }

    @Override
    public boolean takeControl() {
        // TODO Auto-generated method stub
        return value[0] < 0.3;

    public void action() {
        ....
    }

    @Override
    public void suppress() {
        // TODO Auto-generated method stub
        suppressed = true;
    }

But I think it is not the right way. How can I implement it in the right way?

Thanks for help,

Answer 1

You can use the lejos.ev3.robotics.RangeFinder abstraction class:

EV3UltrasonicSensor sensorUS;
RangeFinder sonar;

public UltrasonicSensor(Port port) {
    sensorUS = new EV3UltrasonicSensor(port);
    sonar = new RangeFinder(sensorUS);
}

@Override
public boolean takeControl() {
    return sonar.getRange() < 0.3;
}

Use the float getRange() method to retrieve the distance to the nearest object.