Android gravity sensor (TYPE_GRAVITY) for 2.1

Question

I have software designed for 2.3.3 where I am using the gravity sensor.

Code below -

private SensorManager sman = (SensorManager) getContext().getSystemService(Context.SENSOR_SERVICE);
private Sensor magnetfield, gravity;
...
magnetfield = sman.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
gravity = sman.getDefaultSensor(Sensor.TYPE_GRAVITY);

I decided to add support for version 2.1. However it seems TYPE_GRAVITY is not supported in 2.1, and I get an error that Sensor.TYPE_GRAVITY is not recognized anymore.

Questions - A) When I search for "Android gravity sensor 2.1" googles links to videos that demo gravity sensor in 2.1 devices. Does that mean there is a way to get access to it? B) If not, what is the lowest version that can use this? Couldn't find it in the SDK.

Thanks

Did you solved this? I looking for java implementation of TYPE_GRAVITY sensor based on only three basic sensors. — Bresiu, Jul 02 '14 at 14:14

score 8 · Accepted Answer · edited Apr 13 '17 at 12:47

8

By looking at the source code you can see that the gravity sensor is actually computed using a Butterworth filter. I also asked a question on dsp (here). Hope the link helps because it helped me understand quite a lot of things.

For gravity sensor in versions < 2.3 you need to implement that filter yourself if you want the same results.

Here is the source code.

Later edit: Added a valid link!

edited Apr 13 '17 at 12:47

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answered Nov 23 '11 at 07:05

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you source code is missing please give the code if available. – Sree May 31 '13 at 09:04
Gitorious has been bought out so the link is dead again. – jjcf89 Apr 07 '16 at 15:46
Link to same file in android source repo. Probably a newer version of file. https://android.googlesource.com/platform/frameworks/native/+/984826c/services/sensorservice/SecondOrderLowPassFilter.cpp – jjcf89 Apr 07 '16 at 15:52

score 2 · Answer 2 · answered Nov 08 '11 at 19:45

Sensor TYPE_LINEAR_ACCELERATION and TYPE_GRAVITY are available since API Level 9 (Android 2.3), so you are not going to be able to use them on 2.1.

If you'd want implement it, I guess you should play with the orientation of the cellphone, so you could know How it is oriented, and accordingly the components of gravity in the acceleration.

Android gravity sensor (TYPE_GRAVITY) for 2.1

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