How would someone attempt to track the distance the user has walked as they are walking- displaying the distance in a text view and updating it accordingly?
It feels confusing looking at all the options there appears to be - Android's Location API and Google's Location Services API to name but two. I've looked through some code that has implemented somewhat similar concepts but I want to understand and know where to start.
Thanks
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I'am new in android development my problem is.
I have to find nearby coordinates from a data in a given radius in android.
For example when i click a button. It will search nearby coordinates listed in an array or in a database.
Example: My current coordinates is 1.1
Nearby coordinates will show : 1.2,1.3,1.4,1.5 which is stored or from my database/array.
Is this possible? Can someone help me. Any answer is really appreciated.
Thanks!
One approach is to simply use a geographical distance function.
Have a look at: http://www.movable-type.co.uk/scripts/latlong.html
This will give you some background information on what you are trying to do. I've used this website many times during work with UAVs. Also, keep in mind that you might need to convert to/from Deg/Min/Sec Lat & Longitude <-> decimal Latitude/Longitude.
Find the method for calculating distance - and there are many coded examples already out there - and then run each of your target points through it to find out how far each is from you.
Good luck!
I have started programming an Android Application to Measure short distances (in Meters) between two points so for example the user hits a start button then the application saves the current Location then while the user is walking the application shows him the distance in meters from the starting point.
How to achieve that considering not to use GPS or Networking ? I have searched around in Google and SO. I think Motion Sensors and Accelerometers are not the way to go but found nothing about Position Sensors like Orientation Sensor and Geomagnetic Field Sensor. Can I use Position Sensors to Achieve the case described above?
Take a look at the answer here
https://stackoverflow.com/a/7500306/3768458
It gives some links on why this is a difficult thing to achieve.
Also there is the method to use the Gyroscope and Accelerometer with a so called Kalman Filter.
Take alook at this answer for that approach:
https://stackoverflow.com/a/13925886/3768458
There are many books about Mobile Sensors in other words Android Augmented Reality.Try this book it helped me download here
I'm working on an Android project. it's goal is to detect predefined movement gesture of the device. if the device rotates 45 degrees over an axis(X,Y or Z) and then rotates back to its first position( the first and second positions are not going to be accurate, I mean if it was rotated 50 degrees instead of 45, not important !!!)then the gesture has happened and the app should detect it.
I tried to do that using Accelerometer and Magnetic sensors of device to continually monitor the orientation of the device and detect gesture but the results weren't acceptable(explained here). any start point or idea please ?
It doesn't seem like anybody is going to provide a concrete and valuable answer. So let me try to do that.
First of all, even a bit primitive and straightforward approach allows to spot the fact you do not need to process all the data coming from sensors. Moreover humans are not that fast, so there is no need to proceed 10000 values per second in order to identify any specific move as well.
What you actually need is just to identify key points and make your decision. Does it sound like a tanget to you?
What I'm actually suggesting is to test your solution using an ordinary mouse and available gesture recognition framework. Because the actual idea is pretty much the same. So please check:
iGesture - Gesture Recognition Framework
Mouse Gestures
It such a way it might be easier to develop a proper solution.
Update
Let's imagine I'm holding my phone and I need to rotate it 90 degrees counterclockwise and then 180 degrees clockwise. I hope you will not expect me to do some complex 3D shapes in the air (it will break usability and frankly I do not want to loose my phone), so it is possible to say there might be a point we can track or we can easily simulate it.
Please see my other answer in order to see simple, but working solution of a similar problem:
I am using eclipse with the adk android plugin and I am completely lost
That would depend on what do you mean by displaying their location:
Relative to each other on a blank screen.
Read up on distance calculation in coordinates and draw the locations relative to their distance from each other.
On a map, each one separately from the other or together.
Use a web/binary API for map display like Google Maps (don't want to spam and post links with my reputation), or write your app to display Open map data from sources like OpenStreetMap.
On a satellite/aerial images.
Pretty much the same as #3 just you have less options to investigate and try.
If you were a bit clearer in your question, I could have been more specific with the answers, if you edit your question and clarify more, I could be more specific.
Dear programmers/scripters/engineers/other people,
The problem:
I'm currently developing an augmented reality application for an Android 3.2 tablet and having some issues with getting an accurate compass reading. I need to know exactly the (z) direction the tablet is facing, measured from the north. It doesn't matter if it's in degrees or radians.
What I currently have tried:
I used the magnetometer and accelerometer to calculate the angle. It has one big disadvantage. If you rotate 90 degrees, the sensors will measure a larger or a smaller angle. Even when I'm in an open field far away from metal or any magnetic objects. Even the declination doesn't solve it.
Using the gyroscope would be an option. I have tried to measure the rotating speed and store the measured units into a variable to know the exact view direction. There seems to be an factor that causes distortion though. I found out that fast rotations distort the accurate direction measurement. The gyro's drift wasn't that much troublesome. The application checks the other sensors for any movement. If none is detected, the gyro's rotation change won't be taken into account.
The rotation vector works okay. It has some issues like the gyroscope. If you move slowly and stop at a suddenly moment, it will drift away for a few seconds. Another problem is that it will be inaccurate with quick rotations depending on the speed and how many turns you've made. (You don't want to know how my co-workers are looking at me when I'm swinging the tablet in all directions...)
Sensor.Orientation, not much to say about. It is deprecated for some reason so I won't use it. A lot of examples on the internet are using this sensor and it's probably the same thing as the magnetic/accelerometer combination.
So I'm currently out of idea's. Could you help me with brain storming / solution solving?
Thanks in advance, yours sincerely, Roland
EDIT 1:
I am willing to provide the code I have tried.
I'm summing up our comments:
its clear from this video that the sensors on phones are not very accurate to begin with. Also interesting to read is this
it its important that the user calibrates the sensors by doing a figure 8 motion holding the phone flat. An App can programmatically check if such a calibration is necessary and notify the user. See this question for details
To eliminate jitter the values obtained from the sensors need to be filtered by a low pass filter of some kind. This has also been discussed on StackOverflow.
The orientation obtained is not the true north. To obtain the true north one must use GeomagneticField