Servo - February 2011

Making Robots With The

Robots need information about the world around them, or they just stumble about looking stupid. Just like us humans, a robot uses senses to know when it’s run into something; when it’s light or dark; when it’s too hot or too cold; when it’s about to fall over; or when it’s found the way to the cheese at the center of a maze.

Senses require sensors. In the practice of robotics, the basic senses make do with the most basic of sensors: mechanical switches for detecting contact with objects, and photosensitive resistors and transistors for detecting the presence (or absence) of light. A robot can perform a remarkable amount of work with just the sense of touch and the gift of simple sight.

In this month’s installment, you’ll learn about interfacing switches and photosensors to the Arduino, along with how to use the information these sensors provide to interactively command a robot’s motors. These are the fundamental building blocks of most any autonomous robot you build. Once you learn how to use these sensors to do your bidding, you can apply them in dozens of ways, for all kinds of robotic chores.

Arduino Robotics: What We’ve Covered So Far

This article builds upon previous installments in this series, which is all about the construction and use of the ArdBot (see Figure 1) — an inexpensive two-wheeled differentially-steered robot based on the popular Arduino Uno and compatible microcontrollers. If you’d like to follow along, be sure to check out the previous three episodes, so you’re familiar with the plot and characters.