78 SERVO 11.2015
images and digital range figures on a
screen in the instruments.
Hackers used microcontrollers in
the past to read the digital
information from these handheld
range finders for robot distance
measurements before ‘made for
robots’ sensors became widely
available. Today’s very inexpensive
micro electro-mechanical systems
(MEMS) have allowed robots,
quadcopters, and many moving
platforms to sense orientation and
motions, and be easily controlled. The
latest MEMS technology has allowed
complex navigation and appendage
motions to be under total control of a
microprocessor. Shaft encoders,
accelerometers, gyros, and magnetic
compasses have plummeted in cost
from many hundreds of dollars to just
a few bucks. The Pololu AltIMU- 10
shown in Figure 7 combines a gyro,
accelerometer, and a compass IMU
with an altimeter on a
single tiny board. These
MEMS chips have allowed
robots to possess some
amazing mobility and
mobile apabilities.
We have also made
amazing strides in other
robot sensor technology in
the last few years. Budget-minded robot builders have
access to long-range laser
range finders such as the
Light Ware SF- 10 series
shown in Figure 8 from
There are also now ‘intelligent’
video cameras designed for robots
such as the CMUcam series costing
from $139 to $259; the CMUcam3
module is shown in Figure 9. These
cameras have proven very functional
and quite useful for mobile robots.
What are the Main
Stumbling Blocks in
Robot Design?
I have been writing about all the
amazing (yet inexpensive) sensors
available to today’s robot designers.
We can talk to our robots and they
can talk back, as well as see and
follow us and obey our commands.
Batteries can become a major
problem when building human-sized
bipedal robots, but not as much for
smaller rolling mobile platforms.
Software such as ROS, Python, C++,
Java, Microsoft RDS, PBasic, Linux,
and many other systems are available
for builders using a Propeller, Arduino,
Raspberry Pi, Beagle Bone, or any
other type of microcontroller. So,
what’s the problem here?
Let’s look back at those early
computers again. They exploded in
popularity when the CPU board was
placed in the same ‘box’ as a floppy
drive, and affordable and useful
software was available on a floppy
disc. The computer’s power supply
was also an integral part, and the
monitor could sit on top or be
contained in the same case. Later
versions added a hard drive, and we
now had a computer that did
everything we could imagine. We
could play games, develop
spreadsheets, and perform word
processing with the addition of a
cheap printer instead of using
typewriters (on which the words could
not be changed without an eraser or
white-out). Home users and
businesses gobbled them up by the
millions as processor power increased,
as well as the capabilities of various
types of software.
Think about the earliest robots.
The first personal and experimental
robots started out small and grew
larger. Boxes with little more than
wheels were considered robots. Then,
model aircraft servos were modified
for continuous rotation for small one
pound robots such as the Parallax
Activity Bot and other similar
experimental and educational robots.
The larger commercial home robots
shown back in Figure 1 that were
destined to change the world (but did
not live up to their hoped-for
popularity) like the Hero 1 and 2000,
RB5X, Topo, and the others, were
cute but could really do little else. The
Hero series and RB5X had arms, but
they were quite inefficient and
sufficient only for experimentation.
Figure 7. Pololu
AltIMU- 10 v4 gyro,
accelerometer,
compass, and
altimeter.
Figure 8. Parallax Light Ware F-10A
distance sensor.
Figure 9. CMUCam3
intelligent camera
for robotics.