With a chassis, motors, and motor drivers, your obot can move. Without some means of sensing if its way is blocked, it will keep trying to go, even when blocked — which is a great
way to drain batteries, but not very exciting to watch. Your
robot needs some way to tell if there is something in its
path! Let’s take a look at five different sensors, from
simple switches to complex distance sensors:
2. Bumper Switches
3. IR Bumpers
4. Ultrasonic Distance Sensors
5. IR Distance Sensors
While it may be overkill, you can actually add all five
types listed to your robot at the same time!
• Whiskers, Bumper Switches, and IR Bumpers can
tell if your robot has run into something.
• Distance Sensors will tell the robot how far it is
from the nearest object in range of its sensor.
There are, of course, many more complicated
sensors you can use:
• Wheel Encoders
• Light Level Sensors
• Temperature Sensors
and many more! We’ll cover additional sensors in
Whiskers are basically overgrown bumper
switches made from some springy wire which
makes contact with metal posts or screws. So, the
software is the same as for bumper switches. I have
whiskers on some of my Boe-Bots, but I do not recommend
them for an educational setting. Why? I worry about young
kid’s eyes basically. With older kids (which by the way
includes “adults”), that should not be as much of an issue.
When using whiskers, I recommend covering them
Serving Raspberry Pi
By William Henning
30 SERVO 04.2016
In the last column, we took a look at some of the motor drivers available
on the market. So far, you should have picked a chassis and motor driver.
Now, it’s time to choose your first sensors!
Boe-Bot whiskers. Photo courtesy of Parallax.