Tap pressure strength detection using accelerometer

Question

Yesterday, in the presentation about the new Garageband for iPad 2, Apple demoed an interesting feature: The detection of the tap pressure by using the accelerometer. (See t

Answer 1

Well simply do this experiment:

open with XCode the AccelerometerGraph tutorial app included in the XCode bundle. Then start the app (High Pass filter, better using Adaptive filtering): you will see the blue line changing according to the strength of the app. Of course this is affected by trembling in the table, which adds noise to the measure, but you can still filter it by checking the accelerometer data with the touch event.

So this kind of pressure detection is possible using the accelerometer.