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I am doing experiments on sensor sampling in Android. I'm sampling the accelerometer sensor at 10HZ via the native API in Android. I'm using two different galaxyS3 (4.0.4 and 4.1.2) and two xperias (2.3.4) for testing.

On the galaxyS3 4.1.2 I notice, within a session of some minutes of sampling at a very stable 10HZ rate, sudden spikes in which the sampling rate is a lot higher. This happens at random times and for a short interval, say roughly one second. Samples' timestamps do reflect the spikes.

On the other phones (included the galaxyS3 4.0.4) I request 10Hz and the sampling frequency keeps right "forever". Also it only occurs with the accelerometer, not with any of the other sensors in the platform (not even with the gyro, whose chip is integrated with the accelerometer ST Micro lsm330dlc in the galaxyS3)

It looks like a background program (be it an app or an android service) requests the accelerometer sampling at a very high rate for a short interval at random times. I tried to switch off most of the platform services, apps, movement recognition etc.. but with no benefit, I can't identify what causes this unexpected sampling rate spike.

Any hits appreciated.

hanswe
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  • I tried with a third galaxyS3 4.1.2, with totally different apps and settings installed. Same behavior as the other 4.1.2. It starts to sound like a version issue to me.. – hanswe Oct 28 '13 at 16:59
  • hi, have you found any solution for this problem? Now, I encountered the same situation too. – Maki92 Nov 30 '14 at 16:55

1 Answers1

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Even if I read, too late, your question, I have perhaps a solution: For avoiding erratic sensor behavior (accelerometer, ...), a solution seems to fetch the output values of the sensor, in a independent cyclic program, with the rate you want. By this way, specific sensor behavior does not disturb your application. More, it does not depend on sensor output rates of smartphones

Pascal DUTOIT
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