How to implement a LowPass Filter?

Question

I\'m doing some math on both gyroscope and accelerometer data combined and I\'d like to low pass filter the resulting data. So could someone post some generic code for a Low Pas

Answer 1

If Apple's AccelerometerGraph example is too complex for you to understand, I created a simpler accelerometer example for my class which you can download here. This implements a simple low-pass and high-pass filter for raw accelerometer values, then logs the results to the screen.

As hotpaw2 and Goz describe, this uses a very simple weighted rolling average for the filter calculation:

UIAccelerationValue lowPassFilteredXAcceleration = (currentXAcceleration * kLowPassFilteringFactor) + (previousLowPassFilteredXAcceleration * (1.0 - kLowPassFilteringFactor));