This project œcontains a pair of programs for the Arduino and Processing, to help students develop an understanding of Pulse Width Modulation (PWM).
The Arduino sketch uses a software to control the onboard (and, optionally, an external) LED.
The Processing sketch simulates an oscilloscope that displays the current PWM waveform, using serial data from the Arduino sketch.
Wire an Arduino to a couple of pots, as described in pwm_explorer.ino. Upload
pwm_explorer.ino to the Arduino. One pot controls the frequency, and the other
controls the duty cycle. They flash the on-board LED. For greater visibility,
connect an external LED to pin 13.
Run pwm_scope.pde in Processing. The code attempts to identify the serial
port; if this fails, uncomment and edit line 20. This code shows a simulation of
the waveform, using the actual PWM frequency and duty cycle from a connected
Arduino.
PWM Explorer is a similar visualization tool, that runs entirely in simulation in a browser window. (It does not require a physical connection to an Arduino.)
MIT