find how many times user touched the light sensor in Android

find how many times user touched the light sensor in Android

I want to know how many times a user touched the sensor , in an interval
of time. For that I used.
event.sensor.getType() == Sensor.TYPE_LIGHT
Then I thought I need to check for light blocking event(black\dark) with
some value defined , and then we can identify. Is it the way to get the
needful.