Android Tutorial Orientation and accelerometer

The attached program displays the values of the different sensors:

sensors.png


It creates a PhoneSensors object for each type of sensor.
As you can see in the attached code, two Maps are used to hold the phone sensors and the other required data. This way there is no need to write any duplicate code.

A better method for finding the orientation values: https://www.b4x.com/android/forum/threads/orientation-and-accelerometer.6647/page-6#post-476271
 

Attachments

  • SensorsExample.zip
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Turbo3

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I get not supported when I switch the Type from 1 to 10.

It would be helpful if the description for the "ps.TYPE_ACCELEROMETER" made mention that gravity is included in the x,y,z values.

For what I need I think I can make this work even with gravity included. But I would like to keep my iOS and Android code the same so is there an iOS equivalent that includes gravity?
 
Last edited:

alfcen

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Hello Folks,

Have been away for long time; meanwhile upgraded from Android 2.2 to Android 6.

I noticed that the orientaton sensor (compass) outputs azimuth values between 143 and 146 under Android 6.0.1
while earlier versions are working well with azimuth angles available from 0 to 360.

I browsed a lot but could not find a hint ad-hoc. Apps like "GPS Test Plus" and a bloatware app are working well
under Android 6, in that I believe I am not the smartest guy around here.

Appreciate any hints,

Cheers
Robert
 

Erel

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The example code does work here on an Android 7 device. However please try this code:
B4X:
Sub Process_Globals
   Private accelerometer, magnetic As PhoneSensors
   Private accValues(), magValues() As Float
   Private sm As JavaObject
End Sub

Sub Globals

End Sub

Sub Activity_Create(FirstTime As Boolean)
   If FirstTime Then
     accelerometer.Initialize(accelerometer.TYPE_ACCELEROMETER)
     magnetic.Initialize(magnetic.TYPE_MAGNETIC_FIELD)
     sm.InitializeStatic("android.hardware.SensorManager")
   End If
End Sub

Private Sub Accelerometer_SensorChanged (Values() As Float)
   accValues = Values
   CalcOrientation
End Sub

Private Sub Magnetic_SensorChanged (Values() As Float)
   magValues = Values
   CalcOrientation
End Sub

Private Sub CalcOrientation
   If accValues.Length = 0 Or magValues.Length = 0 Then Return
   Dim R(9), I(9) As Float
   Dim success As Boolean = sm.RunMethod("getRotationMatrix", Array(R, I, accValues, magValues))
   If success Then
     Dim orientation(3) As Float
     sm.RunMethod("getOrientation", Array(R, orientation))
     Log((orientation(0) * 180 / cPI + 360) mod 360)
   End If
End Sub

Sub Activity_Resume
   accelerometer.StartListening("Accelerometer")
   magnetic.StartListening("Magnetic")
End Sub


Sub Activity_Pause (UserClosed As Boolean)
   accelerometer.StopListening
   magnetic.StopListening
End Sub

It is based on a newer API.
 

alfcen

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Erel, you are still on top of all things.:cool:
This snippet works (but please don't ask me why) ;)

Thanks a ton for your prompt response.

Cheers
Robert
 

ldb68

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I tried the latest Eric example.
If I hold the phone vertically I get completely different values than when I hold the phone horizontally (like a compass).
There is no way to have a stable value of the direction of holding the phone vertically pointed towards an object?
I tried everything without results.
 

ldb68

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I tried several things that didn't work.
Thanks Erel.
From what I have seen so there is not a reliable way to get with compass the direction in which a user is watching with the phone vertically pointed in the direction. Some phones (motorcycle E and G) even do not have the compass.

Other solutions are not there?
 

Smart Robot Android

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Thanks a lot for their comments and codes.

Thanks again Erel for all the information you post.

Somebody have founded the solution for the "x-plane" in vertical position of the phone? I've tried several things, and only the "y-plane" and "z-plane" works fine when the phone is vertical. If the phone is horizontal the three planes works fine, but not in vertical position.

Have somebody make it works in vertical position? Thanks in advance, and again, thanks for all your help.
 
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