PWM - Pulse Width Modulation

In week 1 we talked about turning LEDs on and off fast enough to hit the point called Persistence of Vision (POV). Another important thing to know is that in electronics terms, you can create an analog signal using digital means by using Pulse Width Modulation. This is the ratio of an ON/OFF signal being turned ON vs OFF. See the above image. To use this with an arduino, see THIS LINK


If you are interested in working with pulsing LEDs in a purely analog way (not using arduinos), check out the 555 timer. The speed (or duration) of flickers can be determined by resistors as opposed to code. More info HERE. Application of it being used HERE. These can be purchased from RadioShack and Norvac electronics.