[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Glad this thread is still alive and silly. Seriously, take a look at the LocationManager class in the docs. There are constants for specifying GPS_PROVIDER, NETWORK_PROVIDER, or PASSIVE_PROVIDER. The accuracy will depending on the provider but the same code for determining position (and speed) will be the same via the LocationListener class and Location class. The Unlocking Android book from Manning Publications has an example. You may be able to download the example from the Manning site. As for the 'poor signal in a car' argument, I accidentally dropped my phone inside a small airplane and could not find it. The plane had those silver sunlight reflectors over every window after landing. I used MyLookout to find its position and the GPS was able to obtain a position when the phone was under the seat and in the cockpit with reflective shades. On Feb 9, 8:38 pm, metal mikey coref...@gmail.com wrote: So, summarising: just hold the phone near the window. -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
So, summarising: just hold the phone near the window. -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Tie it to a string and throw it out the window. Then measure how rapidly the string deploys. On Feb 9, 9:38 pm, metal mikey coref...@gmail.com wrote: So, summarising: just hold the phone near the window. -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
At first, yes. The hardware requirement may be overkill but it depends on the situation. There are Bluetooth enabled hardware and apps for monitoring engine performance in cars. I started flying single-engine airplanes and after some searching I found the Bluetooth enabled pitot- static system, which is another option for this discussion. On Jan 18, 7:30 pm, DanH danhi...@ieee.org wrote: Now you're just being silly. On Jan 15, 7:30 am, Scott scott.sei...@gmail.com wrote: A Bluetooth enabled pitot-static sensor would work if the difference between ground speed and air speed is insignificant. :-) http://bags.oxaero.com/PCA_eGyro.php On Jan 12, 7:52 pm, metal mikey coref...@gmail.com wrote: You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
A Bluetooth enabled pitot-static sensor would work if the difference between ground speed and air speed is insignificant. :-) http://bags.oxaero.com/PCA_eGyro.php On Jan 12, 7:52 pm, metal mikey coref...@gmail.com wrote: You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Now you're just being silly. On Jan 15, 7:30 am, Scott scott.sei...@gmail.com wrote: A Bluetooth enabled pitot-static sensor would work if the difference between ground speed and air speed is insignificant. :-) http://bags.oxaero.com/PCA_eGyro.php On Jan 12, 7:52 pm, metal mikey coref...@gmail.com wrote: You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
2011/1/17 ko5tik kpriblo...@yahoo.com INS also requires gyroscopes. But quality of those sensors lies far below ones utilised in ICBMs in 60s Good thing their weight, size, and power consumption are also far below the ICMB ones :) Kumar Bibek coomar@gmail.com Ah, I forgot, the phones don't yet have a light sensor. Too bad.. Most phones have cameras, but not all phones have flashes :) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
I think that by then you will be passing cell towers fast enough that you can use that reference. Or detect the color shift in a flash picture. On Jan 17, 12:05 am, metal mikey coref...@gmail.com wrote: Will this still work as the car approaches and quite potentially breaches the speed of sound??? On Jan 15, 4:59 am, DanH danhi...@ieee.org wrote: It only takes one phone: You have the phone generate a tone and detect the shifted tone off of whatever object reflects it, like radar. ;) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
A phone with a camera can used to take pictures of the car's speedometer. Not very precise (since car speedometers typically lie by a few mph/kph), but keeps date and time with the image for later reference. If your car's speedometer is broken, and you see someone you know driving in the next lane, you can use the phone to call them up and ask. -- Kostya 2011/1/17 DanH danhi...@ieee.org I think that by then you will be passing cell towers fast enough that you can use that reference. Or detect the color shift in a flash picture. On Jan 17, 12:05 am, metal mikey coref...@gmail.com wrote: Will this still work as the car approaches and quite potentially breaches the speed of sound??? On Jan 15, 4:59 am, DanH danhi...@ieee.org wrote: It only takes one phone: You have the phone generate a tone and detect the shifted tone off of whatever object reflects it, like radar. ;) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Payload's less, too. On Jan 17, 3:54 am, Kostya Vasilyev kmans...@gmail.com wrote: 2011/1/17 ko5tik kpriblo...@yahoo.com INS also requires gyroscopes. But quality of those sensors lies far below ones utilised in ICBMs in 60s Good thing their weight, size, and power consumption are also far below the ICMB ones :) Kumar Bibek coomar@gmail.com Ah, I forgot, the phones don't yet have a light sensor. Too bad.. Most phones have cameras, but not all phones have flashes :) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
If you're talking about Android phones, yes. But those melting iPhones can be pretty lethal :) 2011/1/17 DanH danhi...@ieee.org Payload's less, too. On Jan 17, 3:54 am, Kostya Vasilyev kmans...@gmail.com wrote: 2011/1/17 ko5tik kpriblo...@yahoo.com INS also requires gyroscopes. But quality of those sensors lies far below ones utilised in ICBMs in 60s Good thing their weight, size, and power consumption are also far below the ICMB ones :) Kumar Bibek coomar@gmail.com Ah, I forgot, the phones don't yet have a light sensor. Too bad.. Most phones have cameras, but not all phones have flashes :) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com android-developers%2bunsubscr...@googlegroups.comandroid-developers%252bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Hi, Ah, I forgot, the phones don't yet have a light sensor. Too bad.. I think you will find some already do: eg Nexus S, Nexus One, Droid X and others. See http://developer.android.com/reference/android/hardware/Sensor.html Here's a sample photo from Nexus S showing ambient light LUX, at bottom of image see Lx640.0 http://commondatastorage.googleapis.com/static.panoramio.com/photos/original/46366464.jpg The light sensor works but is pretty crude. Regards On Jan 18, 3:48 am, Kostya Vasilyev kmans...@gmail.com wrote: If you're talking about Android phones, yes. But those melting iPhones can be pretty lethal :) 2011/1/17 DanH danhi...@ieee.org Payload's less, too. On Jan 17, 3:54 am, Kostya Vasilyev kmans...@gmail.com wrote: 2011/1/17 ko5tik kpriblo...@yahoo.com INS also requires gyroscopes. But quality of those sensors lies far below ones utilised in ICBMs in 60s Good thing their weight, size, and power consumption are also far below the ICMB ones :) Kumar Bibek coomar@gmail.com Ah, I forgot, the phones don't yet have a light sensor. Too bad.. Most phones have cameras, but not all phones have flashes :) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2Bunsubs cr...@googlegroups.com android-developers%2bunsubscr...@googlegroups.comandroid-developers%252Bu nsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2Bunsubs cr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Will this still work as the car approaches and quite potentially breaches the speed of sound??? On Jan 15, 4:59 am, DanH danhi...@ieee.org wrote: It only takes one phone: You have the phone generate a tone and detect the shifted tone off of whatever object reflects it, like radar. ;) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
In that case, it's an obvious NO. Then, you probably have to rely on the camera's flash, and it's Doppler shift. Kumar Bibek http://techdroid.kbeanie.com http://www.kbeanie.com On Mon, Jan 17, 2011 at 11:35 AM, metal mikey coref...@gmail.com wrote: Will this still work as the car approaches and quite potentially breaches the speed of sound??? On Jan 15, 4:59 am, DanH danhi...@ieee.org wrote: It only takes one phone: You have the phone generate a tone and detect the shifted tone off of whatever object reflects it, like radar. ;) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Ah, I forgot, the phones don't yet have a light sensor. Too bad.. Kumar Bibek http://techdroid.kbeanie.com http://www.kbeanie.com On Mon, Jan 17, 2011 at 11:44 AM, Kumar Bibek coomar@gmail.com wrote: In that case, it's an obvious NO. Then, you probably have to rely on the camera's flash, and it's Doppler shift. Kumar Bibek http://techdroid.kbeanie.com http://www.kbeanie.com On Mon, Jan 17, 2011 at 11:35 AM, metal mikey coref...@gmail.com wrote: Will this still work as the car approaches and quite potentially breaches the speed of sound??? On Jan 15, 4:59 am, DanH danhi...@ieee.org wrote: It only takes one phone: You have the phone generate a tone and detect the shifted tone off of whatever object reflects it, like radar. ;) -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
On Jan 12, 7:16 am, keyboardr keyboa...@gmail.com wrote: You could also try integrating the readings from the accelerometers, but I suspect this would give you even worse accuracy and you'd have to have some way to calibrate the zero point. INS also requires gyroscopes. But quality of those sensors lies far below ones utilised in ICBMs in 60s -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Don't be ridiculous, you can't use doppler shift if the source and recorder remain at the same position relative to each other. On Jan 13, 5:56 am, Spiral123 cumis...@gmail.com wrote: Play a tone and record it at the same time. The doppler shift should give you the speed. Works for galaxies. On Jan 12, 9:52 pm, metal mikey coref...@gmail.com wrote: You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
You can calculate the speed with the sensor ( accelerometer) at the below link http://jahbromo.blogspot.com/2009/11/android-faire-un-speedometre-avec.html GPS is not need to calculate the speed. On Jan 13, 8:48 am, gjs garyjamessi...@gmail.com wrote: Hi, I think you could still extrapolate (average) speed for some trip with intermittent GPS signals. If you get a GPS fix at the start of the journey and then at the end you can calculate an average speed based on the time duration and straight line distance between these points, any additional points (GPS or course grained towers/wifi/skyhook) during the journey would be a bonus to increase the accuracy of the speed and distance calcs. This depends on whether you actually require real time speed ? Regards On Jan 13, 5:37 pm, Bob Kerns r...@acm.org wrote: I've never gotten around to experimenting to see just how good you CAN get -- but there are some reference points that should help considerably. * Gravity * The magnetic field * Any period of low acceleration noise in the vicinity of about 1 g total acceleration probably indicates it has been set down on a surface (or in the original scenario -- the car has come to a stop). There other possibilities in other situations: * Camera data can indicate relative motion * Acoustical echoic signature and ambient sounds * Wifi transmitter signal strengths * 3G signal strengths. (Hey, I'm outdoors, maybe try GPS again!) * Sonar! A typical android device has more senses than humans. We synthesize an understanding of our location and environment via a process of sensor fusion. There's more opportunity for this sort of thing on Android than Nintendo, as there's more processing power available and more sensors to gather information -- especially when connected to a power source or otherwise on a larger power budget than a cell phone. Look at Dempster-Shafer Theory and Kahlman filters for techniques to handle this sort of process. On Jan 12, 5:10 pm, keyboardr keyboa...@gmail.com wrote: I know Nintendo originally tried to use accelerometers to figure out where it was pointing, and while that's theoretically possible, in practice the accuracy just isn't good enough. The acceleration most of the time is small enough that even the slightest error will throw the whole calculation way off, and since you're relying on all of your previous results, errors get compounded over time. That's why Nintendo switched to an IR camera setup. On Jan 12, 7:22 am, cellurl gpscru...@gmail.com wrote: couldn't you use the accelerometer? Integrate that? Use time. s=Integral(a dt) If that doesn't work, look to skyhook wireless! -cellurl On Jan 12, 8:20 am, Brill Pappin br...@pappin.ca wrote: Well you pretty much need distance traveled over time to find speed, so anything you can do to determine distance travelled should allow you to calculate the speed. For instance you could use cell tower location, but I wouldn't class it as even remotely accurate. If you want to give an actual real value, your going to need the accuracy of the GPS unit. - Brill Pappin On Jan 11, 11:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
You can use Sensor to determinate speed but you must do some
mathematic calculat ( Cos, sinus, abs...)
Please check this below code
package org.sidibe.speedometre;
/*
* SIDIBE Ali-Broma,malien, jahbr...@gmail.com, ENSAT Tanger
* Novembre 2009 Tout droit permis.
*
*
import java.util.*;
import android.app.Activity;
import android.content.Context;
import android.graphics.*;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.os.Handler;
import android.view.Gravity;
import android.widget.TextView;
public class MySpeedometre extends Activity {
TextView tv;
SensorManager sensor;
SensorEventListener svls;
Handler myhandl= new Handler();
double temperature=0;
public float velocite,accel_actuel,accel_app;
Date last;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
last=new Date(System.currentTimeMillis());
sensor=(SensorManager)getSystemService(Context.SENSOR_SERVICE);
sensor.registerListener(listener,
sensor.getDefaultSensor(SensorManager.SENSOR_ACCELEROMETER),
SensorManager.SENSOR_DELAY_FASTEST);
//Mise a jour l interface chaque seconde
Timer tim=new Timer();
tim.scheduleAtFixedRate(new TimerTask(){
public void run () {
updateGUI();
}
},0,1000);
load();
setContentView(tv);
}
public void load()
{
tv= new TextView(this);
tv.setBackgroundColor(R.drawable.finals);
tv.setTextSize(16);
tv.setTextColor(Color.GREEN);
tv.setSingleLine(true);
tv.setTypeface(null, Typeface.BOLD);
tv.setGravity(Gravity.CENTER_HORIZONTAL|Gravity.BOTTOM);
tv.setGravity(Gravity.CENTER);
}
public void upadatevelocite()
{
// Date actuelle en milliseconde
Date now= new Date(System.currentTimeMillis());
// ecart en seconde entre date passe et date actuelle
long ecart= ( now.getTime()-last.getTime())/1000;
// Mise à jour du temps
last.setTime(now.getTime());
float ecartv=accel_app*ecart+0; /* calcule de la vitesse from
v=at
+vo;*/
// Mise à jour
accel_app=accel_actuel;
velocite=velocite+ecartv;
tv.setText(String.valueOf(velocite)+m/s);
}
public final SensorEventListener listener= new SensorEventListener(){
@Override
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
@Override
public void onSensorChanged(SensorEvent event)
{float evaleur[]= event.values;
double calibration = Double.NaN;
double x= evaleur[SensorManager.DATA_X];
double y= evaleur[SensorManager.DATA_Y];
double z= evaleur[SensorManager.DATA_Z];
temperature= evaleur[SensorManager.SENSOR_TEMPERATURE];
// Calcul du changement acceleration en coordonnnee ca
double a= -1*Math.sqrt(Math.pow(x, 2)+Math.pow(y,
2)+Math.pow(z, 2));
if(calibration==Double.NaN){
calibration=a;
}
else {
upadatevelocite();
accel_actuel=(float)a;
}
}
};
public void updateGUI()
{
myhandl.post(new Runnable(){
public void run()
{
tv.setText(Vit:+ velocite+m/s à:+temperature+°C\n
par
SIDIBE);
}
});
}
}
==
--
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Re: [android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Right, it takes two phones. You start playing sound on one and throw it out the car window, then measure the Doppler effect with the other. Great thing is, you can get a speed reading on the way back, if you pass by the same place. -- Kostya 2011/1/13 Hogus dupisani.lo...@gmail.com Don't be ridiculous, you can't use doppler shift if the source and recorder remain at the same position relative to each other. On Jan 13, 5:56 am, Spiral123 cumis...@gmail.com wrote: Play a tone and record it at the same time. The doppler shift should give you the speed. Works for galaxies. On Jan 12, 9:52 pm, metal mikey coref...@gmail.com wrote: You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
It only takes one phone: You have the phone generate a tone and detect the shifted tone off of whatever object reflects it, like radar. ;) On Jan 14, 7:52 am, Kostya Vasilyev kmans...@gmail.com wrote: Right, it takes two phones. You start playing sound on one and throw it out the car window, then measure the Doppler effect with the other. Great thing is, you can get a speed reading on the way back, if you pass by the same place. -- Kostya 2011/1/13 Hogus dupisani.lo...@gmail.com Don't be ridiculous, you can't use doppler shift if the source and recorder remain at the same position relative to each other. On Jan 13, 5:56 am, Spiral123 cumis...@gmail.com wrote: Play a tone and record it at the same time. The doppler shift should give you the speed. Works for galaxies. On Jan 12, 9:52 pm, metal mikey coref...@gmail.com wrote: You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.comandroid-developers%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
No, because as already pointed out, a naive integration of acceleration is too inaccurate; it is too easily corrupted by noise. Now you can improve it somewhat by considering integration as a low pass filter, and applying DSP techniques to enhance the accuracy, but don't expect a dramatic improvement in accuracy. Especially if the phone has ever been dropped:( A better solution might be to do the above DSP, but also check it against the GPS results whenever they ARE available. But this is complicated. On Jan 12, 7:22 am, cellurl gpscru...@gmail.com wrote: couldn't you use the accelerometer? Integrate that? Use time. s=Integral(a dt) If that doesn't work, look to skyhook wireless! -cellurl On Jan 12, 8:20 am, Brill Pappin br...@pappin.ca wrote: Well you pretty much need distance traveled over time to find speed, so anything you can do to determine distance travelled should allow you to calculate the speed. For instance you could use cell tower location, but I wouldn't class it as even remotely accurate. If you want to give an actual real value, your going to need the accuracy of the GPS unit. - Brill Pappin On Jan 11, 11:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
This code shows us how to get accelerometer readings out of the
SensorManager, but the calculation you perform neglects noise in the
accelerometer output. So if you actually try this out, you will notice
it will not compare well with the car's speedometer.
As I mentioned before: to get a realistic solution, you need to
account for the noise by viewing integration as a low pass filter
On Jan 13, 1:41 pm, SIDIBE Ali-Broma jahbr...@gmail.com wrote:
You can use Sensor to determinate speed but you must do some
mathematic calculat ( Cos, sinus, abs...)
Please check this below code
package org.sidibe.speedometre;
/*
* SIDIBE Ali-Broma,malien, jahbr...@gmail.com, ENSAT Tanger
* Novembre 2009 Tout droit permis.
*
*
import java.util.*;
import android.app.Activity;
import android.content.Context;
import android.graphics.*;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.os.Handler;
import android.view.Gravity;
import android.widget.TextView;
public class MySpeedometre extends Activity {
TextView tv;
SensorManager sensor;
SensorEventListener svls;
Handler myhandl= new Handler();
double temperature=0;
public float velocite,accel_actuel,accel_app;
Date last;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
last=new Date(System.currentTimeMillis());
sensor=(SensorManager)getSystemService(Context.SENSOR_SERVICE);
sensor.registerListener(listener,
sensor.getDefaultSensor(SensorManager.SENSOR_ACCELEROMETER),
SensorManager.SENSOR_DELAY_FASTEST);
//Mise a jour l interface chaque seconde
Timer tim=new Timer();
tim.scheduleAtFixedRate(new TimerTask(){
public void run () {
updateGUI();
}
},0,1000);
load();
setContentView(tv);
}
public void load()
{
tv= new TextView(this);
tv.setBackgroundColor(R.drawable.finals);
tv.setTextSize(16);
tv.setTextColor(Color.GREEN);
tv.setSingleLine(true);
tv.setTypeface(null, Typeface.BOLD);
tv.setGravity(Gravity.CENTER_HORIZONTAL|Gravity.BOTTOM);
tv.setGravity(Gravity.CENTER);
}
public void upadatevelocite()
{
// Date actuelle en milliseconde
Date now= new Date(System.currentTimeMillis());
// ecart en seconde entre date passe et date actuelle
long ecart= ( now.getTime()-last.getTime())/1000;
// Mise à jour du temps
last.setTime(now.getTime());
float ecartv=accel_app*ecart+0; /* calcule de la vitesse from
v=at
+vo;*/
// Mise à jour
accel_app=accel_actuel;
velocite=velocite+ecartv;
tv.setText(String.valueOf(velocite)+m/s);
}
public final SensorEventListener listener= new SensorEventListener(){
@Override
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
@Override
public void onSensorChanged(SensorEvent event)
{ float evaleur[]= event.values;
double calibration = Double.NaN;
double x= evaleur[SensorManager.DATA_X];
double y= evaleur[SensorManager.DATA_Y];
double z= evaleur[SensorManager.DATA_Z];
temperature= evaleur[SensorManager.SENSOR_TEMPERATURE];
// Calcul du changement acceleration en coordonnnee ca
double a= -1*Math.sqrt(Math.pow(x, 2)+Math.pow(y,
2)+Math.pow(z, 2));
if(calibration==Double.NaN){
calibration=a;
}
else {
upadatevelocite();
accel_actuel=(float)a;
}
}
};
public void updateGUI()
{
myhandl.post(new Runnable(){
public void run()
{
tv.setText(Vit:+ velocite+m/s
à:+temperature+°C\n par
SIDIBE);
}
});
}
}
==
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[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
This code shows us how to get the accelerometer data from the
SensorManager, but not how to calculate the velocity correctly. The
naive formula you use is correct ONLY for a completely noiseless
signal. But all signals in the real world DO have noise, which must be
filtered out.
Filtering it out for an accelerometer is tricky because integration
already IS a low pass filter, so by simply integrating, you are
throwing away the data you need to separate signal and noise.
Google accelerometer filter for the variety of different approaches
that have been tried.
On Jan 13, 1:41 pm, SIDIBE Ali-Broma jahbr...@gmail.com wrote:
You can use Sensor to determinate speed but you must do some
mathematic calculat ( Cos, sinus, abs...)
Please check this below code
package org.sidibe.speedometre;
/*
* SIDIBE Ali-Broma,malien, jahbr...@gmail.com, ENSAT Tanger
* Novembre 2009 Tout droit permis.
*
*
import java.util.*;
import android.app.Activity;
import android.content.Context;
import android.graphics.*;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.os.Handler;
import android.view.Gravity;
import android.widget.TextView;
public class MySpeedometre extends Activity {
TextView tv;
SensorManager sensor;
SensorEventListener svls;
Handler myhandl= new Handler();
double temperature=0;
public float velocite,accel_actuel,accel_app;
Date last;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
last=new Date(System.currentTimeMillis());
sensor=(SensorManager)getSystemService(Context.SENSOR_SERVICE);
sensor.registerListener(listener,
sensor.getDefaultSensor(SensorManager.SENSOR_ACCELEROMETER),
SensorManager.SENSOR_DELAY_FASTEST);
//Mise a jour l interface chaque seconde
Timer tim=new Timer();
tim.scheduleAtFixedRate(new TimerTask(){
public void run () {
updateGUI();
}
},0,1000);
load();
setContentView(tv);
}
public void load()
{
tv= new TextView(this);
tv.setBackgroundColor(R.drawable.finals);
tv.setTextSize(16);
tv.setTextColor(Color.GREEN);
tv.setSingleLine(true);
tv.setTypeface(null, Typeface.BOLD);
tv.setGravity(Gravity.CENTER_HORIZONTAL|Gravity.BOTTOM);
tv.setGravity(Gravity.CENTER);
}
public void upadatevelocite()
{
// Date actuelle en milliseconde
Date now= new Date(System.currentTimeMillis());
// ecart en seconde entre date passe et date actuelle
long ecart= ( now.getTime()-last.getTime())/1000;
// Mise à jour du temps
last.setTime(now.getTime());
float ecartv=accel_app*ecart+0; /* calcule de la vitesse from
v=at
+vo;*/
// Mise à jour
accel_app=accel_actuel;
velocite=velocite+ecartv;
tv.setText(String.valueOf(velocite)+m/s);
}
public final SensorEventListener listener= new SensorEventListener(){
@Override
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
@Override
public void onSensorChanged(SensorEvent event)
{ float evaleur[]= event.values;
double calibration = Double.NaN;
double x= evaleur[SensorManager.DATA_X];
double y= evaleur[SensorManager.DATA_Y];
double z= evaleur[SensorManager.DATA_Z];
temperature= evaleur[SensorManager.SENSOR_TEMPERATURE];
// Calcul du changement acceleration en coordonnnee ca
double a= -1*Math.sqrt(Math.pow(x, 2)+Math.pow(y,
2)+Math.pow(z, 2));
if(calibration==Double.NaN){
calibration=a;
}
else {
upadatevelocite();
accel_actuel=(float)a;
}
}
};
public void updateGUI()
{
myhandl.post(new Runnable(){
public void run()
{
tv.setText(Vit:+ velocite+m/s
à:+temperature+°C\n par
SIDIBE);
}
});
}
}
==
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[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Well you pretty much need distance traveled over time to find speed, so anything you can do to determine distance travelled should allow you to calculate the speed. For instance you could use cell tower location, but I wouldn't class it as even remotely accurate. If you want to give an actual real value, your going to need the accuracy of the GPS unit. - Brill Pappin On Jan 11, 11:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Yah, that is used a lot in simple robotics. You can't actually get anything accurate though. the longer the distance traveled the more inaccurate it becomes. - Brill On Jan 12, 1:16 am, keyboardr keyboa...@gmail.com wrote: You could also try integrating the readings from the accelerometers, but I suspect this would give you even worse accuracy and you'd have to have some way to calibrate the zero point. -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
couldn't you use the accelerometer? Integrate that? Use time. s=Integral(a dt) If that doesn't work, look to skyhook wireless! -cellurl On Jan 12, 8:20 am, Brill Pappin br...@pappin.ca wrote: Well you pretty much need distance traveled over time to find speed, so anything you can do to determine distance travelled should allow you to calculate the speed. For instance you could use cell tower location, but I wouldn't class it as even remotely accurate. If you want to give an actual real value, your going to need the accuracy of the GPS unit. - Brill Pappin On Jan 11, 11:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
or try an external gps receiver with bluetooth interface to phone. On Jan 12, 9:22 am, cellurl gpscru...@gmail.com wrote: couldn't you use the accelerometer? Integrate that? Use time. s=Integral(a dt) If that doesn't work, look to skyhook wireless! -cellurl On Jan 12, 8:20 am, Brill Pappin br...@pappin.ca wrote: Well you pretty much need distance traveled over time to find speed, so anything you can do to determine distance travelled should allow you to calculate the speed. For instance you could use cell tower location, but I wouldn't class it as even remotely accurate. If you want to give an actual real value, your going to need the accuracy of the GPS unit. - Brill Pappin On Jan 11, 11:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
I know Nintendo originally tried to use accelerometers to figure out where it was pointing, and while that's theoretically possible, in practice the accuracy just isn't good enough. The acceleration most of the time is small enough that even the slightest error will throw the whole calculation way off, and since you're relying on all of your previous results, errors get compounded over time. That's why Nintendo switched to an IR camera setup. On Jan 12, 7:22 am, cellurl gpscru...@gmail.com wrote: couldn't you use the accelerometer? Integrate that? Use time. s=Integral(a dt) If that doesn't work, look to skyhook wireless! -cellurl On Jan 12, 8:20 am, Brill Pappin br...@pappin.ca wrote: Well you pretty much need distance traveled over time to find speed, so anything you can do to determine distance travelled should allow you to calculate the speed. For instance you could use cell tower location, but I wouldn't class it as even remotely accurate. If you want to give an actual real value, your going to need the accuracy of the GPS unit. - Brill Pappin On Jan 11, 11:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Play a tone and record it at the same time. The doppler shift should give you the speed. Works for galaxies. On Jan 12, 9:52 pm, metal mikey coref...@gmail.com wrote: You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
This cracked me up. Thank you sir. On Wednesday, January 12, 2011 10:56:35 PM UTC-5, Spiral123 wrote: Play a tone and record it at the same time. The doppler shift should give you the speed. Works for galaxies. On Jan 12, 9:52 pm, metal mikey core...@gmail.com wrote: You could use the phone's camera to take video of the car's speedometer and use image analysis to determine what the speedometer indicates the speed as. LOL :D -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
You can get location from NETWORK_PROVIDER which can be calculated from cell towers or WiFi AP. The first one works almost always but the accuracy is not good therefore you may get the same location for quite a long time. All you need to do is to replace GPS_PROVIDER with NETWORK_PROVIDER. On Jan 11, 8:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
I've never gotten around to experimenting to see just how good you CAN get -- but there are some reference points that should help considerably. * Gravity * The magnetic field * Any period of low acceleration noise in the vicinity of about 1 g total acceleration probably indicates it has been set down on a surface (or in the original scenario -- the car has come to a stop). There other possibilities in other situations: * Camera data can indicate relative motion * Acoustical echoic signature and ambient sounds * Wifi transmitter signal strengths * 3G signal strengths. (Hey, I'm outdoors, maybe try GPS again!) * Sonar! A typical android device has more senses than humans. We synthesize an understanding of our location and environment via a process of sensor fusion. There's more opportunity for this sort of thing on Android than Nintendo, as there's more processing power available and more sensors to gather information -- especially when connected to a power source or otherwise on a larger power budget than a cell phone. Look at Dempster-Shafer Theory and Kahlman filters for techniques to handle this sort of process. On Jan 12, 5:10 pm, keyboardr keyboa...@gmail.com wrote: I know Nintendo originally tried to use accelerometers to figure out where it was pointing, and while that's theoretically possible, in practice the accuracy just isn't good enough. The acceleration most of the time is small enough that even the slightest error will throw the whole calculation way off, and since you're relying on all of your previous results, errors get compounded over time. That's why Nintendo switched to an IR camera setup. On Jan 12, 7:22 am, cellurl gpscru...@gmail.com wrote: couldn't you use the accelerometer? Integrate that? Use time. s=Integral(a dt) If that doesn't work, look to skyhook wireless! -cellurl On Jan 12, 8:20 am, Brill Pappin br...@pappin.ca wrote: Well you pretty much need distance traveled over time to find speed, so anything you can do to determine distance travelled should allow you to calculate the speed. For instance you could use cell tower location, but I wouldn't class it as even remotely accurate. If you want to give an actual real value, your going to need the accuracy of the GPS unit. - Brill Pappin On Jan 11, 11:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
Hi, I think you could still extrapolate (average) speed for some trip with intermittent GPS signals. If you get a GPS fix at the start of the journey and then at the end you can calculate an average speed based on the time duration and straight line distance between these points, any additional points (GPS or course grained towers/wifi/skyhook) during the journey would be a bonus to increase the accuracy of the speed and distance calcs. This depends on whether you actually require real time speed ? Regards On Jan 13, 5:37 pm, Bob Kerns r...@acm.org wrote: I've never gotten around to experimenting to see just how good you CAN get -- but there are some reference points that should help considerably. * Gravity * The magnetic field * Any period of low acceleration noise in the vicinity of about 1 g total acceleration probably indicates it has been set down on a surface (or in the original scenario -- the car has come to a stop). There other possibilities in other situations: * Camera data can indicate relative motion * Acoustical echoic signature and ambient sounds * Wifi transmitter signal strengths * 3G signal strengths. (Hey, I'm outdoors, maybe try GPS again!) * Sonar! A typical android device has more senses than humans. We synthesize an understanding of our location and environment via a process of sensor fusion. There's more opportunity for this sort of thing on Android than Nintendo, as there's more processing power available and more sensors to gather information -- especially when connected to a power source or otherwise on a larger power budget than a cell phone. Look at Dempster-Shafer Theory and Kahlman filters for techniques to handle this sort of process. On Jan 12, 5:10 pm, keyboardr keyboa...@gmail.com wrote: I know Nintendo originally tried to use accelerometers to figure out where it was pointing, and while that's theoretically possible, in practice the accuracy just isn't good enough. The acceleration most of the time is small enough that even the slightest error will throw the whole calculation way off, and since you're relying on all of your previous results, errors get compounded over time. That's why Nintendo switched to an IR camera setup. On Jan 12, 7:22 am, cellurl gpscru...@gmail.com wrote: couldn't you use the accelerometer? Integrate that? Use time. s=Integral(a dt) If that doesn't work, look to skyhook wireless! -cellurl On Jan 12, 8:20 am, Brill Pappin br...@pappin.ca wrote: Well you pretty much need distance traveled over time to find speed, so anything you can do to determine distance travelled should allow you to calculate the speed. For instance you could use cell tower location, but I wouldn't class it as even remotely accurate. If you want to give an actual real value, your going to need the accuracy of the GPS unit. - Brill Pappin On Jan 11, 11:13 pm, darrinps darri...@gmail.com wrote: All the examples I see use GPS, and I have that working just fine but I've noticed that every time I'm in a car, that unless the phone is close to a window or the windshield the GPS does not work so... I thought that there should be a way using course grained location between cell towers. Does anyone know if this is possible and if so might know where I could find some sample code please? Thanks! Darrin -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
I don't have any code, but it should be possible. It would also be wildly inaccurate. You' reduce the sample rate by quite a lot, and the samples would be of much lower quality. -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: Anyone know how to calculate speed WITHOUT GPS?
You could also try integrating the readings from the accelerometers, but I suspect this would give you even worse accuracy and you'd have to have some way to calibrate the zero point. -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
