why getSpeed() always return 0 on android

Question

I need to get the speed and heading from the gps. However the only number i have from location.getSpeed() is 0 or sometimes not available. my code:

Answer 1

I basicaslly calculate the instantaneous speed and then use the setSpeed() method to add it in the location. Its pretty accurate because I compared it inside a vehicle where I could check the tachymeter.

private double calculateInstantaneousSpeed(Location location) {



    double insSpeed = 0;
    if (y1 == null && x1 <= -1) {
        //mark the location y1 at time x1
        y1 = location;
        x1 = duration.getDurationAsSeconds();


    } else {
         //mark the location y2 at time x2
        y2 = location;
        x2 = duration.getDurationAsSeconds();


        //calculate the slope of the curve (instantaneous speed)
        dy = y1.distanceTo(y2);
        dx = x2 - x1;

        insSpeed = dy / dx;

        y1 = y2;
        x1 = x2;

    }

    Singleton.getInstance().instantaneousSpeedSamples.add(insSpeed);
    //System.out.println("Instantaneous Speed m/s: "+insSpeed);
    return insSpeed;
}