Introduction

In this chapter, we will look at three sensors that we can use to add obstacle avoidance and/or collision detection to our projects. These sensors are:

• Crash sensor: Used to detect a crash and also used as limit switches for 3D printers
• Infrared obstacle avoidance sensor: Used for obstacle avoidance for robotics
• Ultrasonic range finder: Used for obstacle avoidance for robotics and has many other commercial and military uses

Crash sensor

A crash sensor is basically a simple switch that has some sort of extender on it that gives it a large area to detect a crash. The following photograph show what a basic crash sensor would look like:

The crash sensor shown in the preceding photograph takes a simple mechanical...