Determining the speed of a vehicle using GPS in android
public class MainActivity extends Activity implements LocationListener {
add implements LocationListener next to Activity
LocationManager lm =(LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
this.onLocationChanged(null);
LocationManager.GPS_PROVIDER, 0, 0, The first zero stands for minTime and the second one for minDistance in which you update your values. Zero means basically instant updates which can be bad for battery life, so you may want to adjust it.
@Override
public void onLocationChanged(Location location) {
if (location==null){
// if you can't get speed because reasons :)
yourTextView.setText("00 km/h");
}
else{
//int speed=(int) ((location.getSpeed()) is the standard which returns meters per second. In this example i converted it to kilometers per hour
int speed=(int) ((location.getSpeed()*3600)/1000);
yourTextView.setText(speed+" km/h");
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderDisabled(String provider) {
}
Don't forget the Permissions
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
for more information onCalculate Speed from GPS Location Change in Android Mobile Device view this link
Mainly there are two ways to calculate the speed from mobile phone.
- Calculate speed from Accelerometer
- Calculate speed from GPS Technology
Unlike Accelerometer from GPS Technology if you're going to calculate speed you must enable data connection and GPS connection.
In here we are going to calculate speed using GPS connection. In this method we using how frequency the GPS Location points are changing during single time period. Then if we have the real distance between the geo locations points we can get the speed. Because we have the distance and the time. Speed = distance/time But getting the distance between two location points is not very easy. Because the world is a goal in shape the distance between two geo points is different from place to place and angle to angle. So we have to use “Haversine Algorithm”
First we have to give permission for Get Location data in Manifest file
Make the GUI
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/txtCurrentSpeed"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="000.0 miles/hour"
android:textAppearance="?android:attr/textAppearanceLarge" />
<CheckBox android:id="@+id/chkMetricUnits"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Use metric units?"/>
Then make an interface to get the speed
package com.isuru.speedometer;
import android.location.GpsStatus;
import android.location.Location;
import android.location.LocationListener;
import android.os.Bundle;
public interface IBaseGpsListener extends LocationListener, GpsStatus.Listener {
public void onLocationChanged(Location location);
public void onProviderDisabled(String provider);
public void onProviderEnabled(String provider);
public void onStatusChanged(String provider, int status, Bundle extras);
public void onGpsStatusChanged(int event);
}
Implement the logic to get the speed using the GPS Location
import android.location.Location;
public class CLocation extends Location {
private boolean bUseMetricUnits = false;
public CLocation(Location location)
{
this(location, true);
}
public CLocation(Location location, boolean bUseMetricUnits) {
// TODO Auto-generated constructor stub
super(location);
this.bUseMetricUnits = bUseMetricUnits;
}
public boolean getUseMetricUnits()
{
return this.bUseMetricUnits;
}
public void setUseMetricunits(boolean bUseMetricUntis)
{
this.bUseMetricUnits = bUseMetricUntis;
}
@Override
public float distanceTo(Location dest) {
// TODO Auto-generated method stub
float nDistance = super.distanceTo(dest);
if(!this.getUseMetricUnits())
{
//Convert meters to feet
nDistance = nDistance * 3.28083989501312f;
}
return nDistance;
}
@Override
public float getAccuracy() {
// TODO Auto-generated method stub
float nAccuracy = super.getAccuracy();
if(!this.getUseMetricUnits())
{
//Convert meters to feet
nAccuracy = nAccuracy * 3.28083989501312f;
}
return nAccuracy;
}
@Override
public double getAltitude() {
// TODO Auto-generated method stub
double nAltitude = super.getAltitude();
if(!this.getUseMetricUnits())
{
//Convert meters to feet
nAltitude = nAltitude * 3.28083989501312d;
}
return nAltitude;
}
@Override
public float getSpeed() {
// TODO Auto-generated method stub
float nSpeed = super.getSpeed() * 3.6f;
if(!this.getUseMetricUnits())
{
//Convert meters/second to miles/hour
nSpeed = nSpeed * 2.2369362920544f/3.6f;
}
return nSpeed;
}
}
Combine logic to GUI
import java.util.Formatter;
import java.util.Locale;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.view.Menu;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.TextView;
public class MainActivity extends Activity implements IBaseGpsListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
this.updateSpeed(null);
CheckBox chkUseMetricUntis = (CheckBox) this.findViewById(R.id.chkMetricUnits);
chkUseMetricUntis.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// TODO Auto-generated method stub
MainActivity.this.updateSpeed(null);
}
});
}
public void finish()
{
super.finish();
System.exit(0);
}
private void updateSpeed(CLocation location) {
// TODO Auto-generated method stub
float nCurrentSpeed = 0;
if(location != null)
{
location.setUseMetricunits(this.useMetricUnits());
nCurrentSpeed = location.getSpeed();
}
Formatter fmt = new Formatter(new StringBuilder());
fmt.format(Locale.US, "%5.1f", nCurrentSpeed);
String strCurrentSpeed = fmt.toString();
strCurrentSpeed = strCurrentSpeed.replace(' ', '0');
String strUnits = "miles/hour";
if(this.useMetricUnits())
{
strUnits = "meters/second";
}
TextView txtCurrentSpeed = (TextView) this.findViewById(R.id.txtCurrentSpeed);
txtCurrentSpeed.setText(strCurrentSpeed + " " + strUnits);
}
private boolean useMetricUnits() {
// TODO Auto-generated method stub
CheckBox chkUseMetricUnits = (CheckBox) this.findViewById(R.id.chkMetricUnits);
return chkUseMetricUnits.isChecked();
}
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
if(location != null)
{
CLocation myLocation = new CLocation(location, this.useMetricUnits());
this.updateSpeed(myLocation);
}
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
@Override
public void onGpsStatusChanged(int event) {
// TODO Auto-generated method stub
}
}
If you want to convert Meters/Second to kmph-1 then you need to multipl the Meters/Second answer from 3.6
Speed from kmph-1 = 3.6 * (Speed from ms-1)
GPS works fine in a vehicle. The NETWORK_PROVIDER setting might not be accurate enough to get a reliable speed, and the locations from the NETWORK_PROVIDER may not even contain a speed. You can check that with location.hasSpeed() (location.getSpeed() will always return 0).
If you find that location.getSpeed() isn't accurate enough, or it is unstable (i.e. fluctuates drastically) then you can calculate speed yourself by taking the average distance between a few GPS locations and divide by the time elapsed.