Basic filters implemented as an Arduino library.
Includes easily configured moving average with an example for a low pass filter applicable to noisy servo commands reeived via a wireless serial connection for a remote control robot or noisy distance data received by a Ping))) sonsor or other ultrasonic (sonar) rangefinder.
Most sensors in small scale robotics are noisy. For example as a mobile robot approaches a wall, an atached ulrasonic sensor should give readings in cm similar to the list below
11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, ...bump!
but all too often the data will come back like this
11, 10, 6, 8, 7, 3, 5, 4, 1, 2, 1, ..bump!
By filtering the raw data, via a moving average or other more specialized filter we can use the noisy data as an input to a filter and then the processed data will give a better linear output. This linear output still doesn't match the exact distance to the wall, but it is a much closer approximation than the noisy data and provides a better set of data for the robot to make control decisions from.
- From the command line 'cd' into the Arduino/libraries folder.
- Enter 'git clone http://github.com/zacsketches/Filter.git'
- This will clone the library into your Arduino libraries.
- Restart the Arduino IDE. Click on examples and you will see Filter library and the moving_average example.