Giving Your
Robot Ears
Ways to command your robot using sound, music, and voice
by Gordon McComb
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In space, no one can hear you
scream . . . at your robot.
Happily, there is no such problem here
on earth where you can use noise,
sound, even voice to communicate
your desires to your robotic plaything.
All it takes is the right electronics —
much of it already comes in
convenient and affordable plug-in
modules. Add an Arduino as the
control brain and your robot now has
ears to listen to the world around it.
In this article, you’ll discover several methods for using sound to control your Arduino-based robot. You’ll learn
how to make your robot respond to loud noise; how to tell
the difference between a soft footstep and a pile of dishes
crashing to the floor; ways to communicate using a whistle
or musical instrument; and even how to shout out
commands for your robot soldier to follow. There’s lots to
cover, so let’s begin.
Building on the ArdBot Base
As a brief note, I’ve used the ArdBot base (detailed in
the November ‘ 10 through May ‘ 11 issues of SERVO) as the
demonstrator platform for all the projects presented in this
article. The ArdBot base provides a simple and low cost
method of experimenting with Arduino robotics. The base
is easy to construct (or you can get the parts premade at
Budget Robotics; see the Sources box) and uses two
continuous rotation R/C servos for motors.
Figure 1 shows a completed ArdBot, ready
for all the projects presented here. It uses two
decks, making expansion easy. The top deck has
room for an Arduino Uno or compatible
microcontroller, solderless breadboard, and several
sensors and accessories. Power comes from two
sets of batteries: a nine volt cell for the Arduino
and a pack of four AAs for the servo motors. The
batteries are mounted on the bottom deck.
Responding to Loud
and Abrupt Sounds
Remember the “clap on, clap off” light switch
control from a few years back? You know, clap
once and the lamp beside your easy chair turns
on; clap again and the lamp goes out. You can do
the same thing with your ArdBot by using a noise
activation sensor. These compact modules
incorporate a microphone, amplifier, and all the
necessary interface electronics. A small trimmer
FIGURE 1. ArdBot servo motorized robot platform,
ready for all the projects in this article. Batteries
for the Arduino and motors go underneath.
56 SERVO 02.2012
