Throughout the previous chapters, we have learned a major part of the basic components that most electronic systems are created from, and through examples you have learned to master many of these. Now we feel it's time we took our lessons to practice, and create something cool and fun! This example will be like it's straight out of the casino robbery movie, Oceans Fourteen. Okay, okay, maybe we won't have lasers and smoke and stuff, but we will create an alarm system that will monitor its environment for any kind of movement, and raise an alarm when it realizes someone is trying to enter the room.
In this example, we will be using a movement-detection sensor that operates on infrared light, so it will "see" in the dark too. Specifically, we will use a passive infrared (PIR) sensor. It's a sensor that monitors its environment for changes in infrared light radiation patterns. You have most likely seen this type of sensor in real life; maybe, for example, your...