CODEWITHSUNDEEP
androidsensors
BobMcboberson
BobMcboberson

Reputation: 2065

PARTIAL_WAKE_LOCK when recording sensor data

I am recording sensor data such as Accelerometer, Orientation, Gyroscope. This data writes to a file onSensorChanged update every so often.

My problem is when I put the phone into standby that the sensor data stops writing to file. So I done some research and decided to set it up using PowerManager and using the wake lock

I can't seem to find a definite answer on whether or not there is a problem with it still or there isn't. I even tried some of the hack approaches people have suggested such as using an itent to capture when screen is off and then unregistering the sensors and registering them again. But this solution didn't work. From what I can gather it seems inconsistant if it will work or not and seems phone dependant. I have tried my code on both a HTC Wildfire running Android2.2 and Nexus S running Android2.3.

My application is an app that is basically ran in the background with a long running service. So having PARTIAL_WAKE_LOCK is important with battery life.

Upvotes: 0

Views: 844

Answers (2)

BlueLeaf
BlueLeaf

Reputation: 223

This is a pretty old question, I'll still answer it as pretty much all the devices today are beyond 2.3

Create a background service and use the Partial Lock Wake in the following manner:

First take care of the permissions (in the manifest file):

<uses-permission android:name="android.permission.WAKE_LOCK" />

Then, most preferably use this in the Application file, or wherever:

PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
PowerManager.WakeLock wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
                "MyWakelockTag");
if(/*condition*/) {
    wakeLock.acquire(); //keep CPU awake
} else {
    wakeLock.release(); //disable keep CPU awake
}

Although it is a pretty cool feature, it drains your battery life, hence use it responsibly.

Upvotes: 0

hackbod
hackbod

Reputation: 91351

This is only defined to work as of Android 2.3. Prior to that the platform would explicitly turn off all sensors when the screen turns off in order to reduce battery use.

Upvotes: 3

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