them. If you decide to use different components, you will
only be able to use my instructions as a basic guide. This
could be as simple as using a different material for the
robot base, which will probably only have minimal impact
on the project. You could also decide to use a different
programming language for the controller or even a
different type of controller. In this case, none of the
programs that I provide will work on your robot.
Availability of Tools
If you are already into building custom robots, then you
most likely have some or most of the tools needed for a
project such as this. Later in this article, I will go over some
of the tools that will be needed. So, what if you don’t have
the tools needed for a particular phase of the project? Does
that mean you can’t build it? Absolutely not! You can
always ask a friend to help you out, or in some cases —
such as building the main robot base — you may be able to
get your local home center or hardware store to assist you.
Availability of Funds
If you decide to build the robots I present in this series
it will cost you $1,000 to $4,000 depending on the base,
computer, and extras you plan on adding to your robot. If
you have an old laptop or Pocket PC, you could probably
get started for under $500.
Availability of Skills
machine like the HP shown in Figure 1. The second type is a
Windows CE device like the CUWIN3500 shown in Figure 2.
It has a built-in touch screen that would allow us to provide
some sort of human interface to our robot.
The third type is a Windows Pocket PC like the one
shown in Figure 3. I will be using an HP Pocket PC 2003
device running at 600 MHz.
I plan on using Zeus for the programming language for
this project. With Zeus, you can create a program that will
run on the Windows PC, Windows CE, and Windows Pocket
PC platforms with little or no changes to the code. Zeus is a
very simple Basic programming language with some
advanced features like built-in GPS processing.
In addition to the main controller, we need to access
our various sensors and motors through some sort of
interface. For the XP based controller, we can use the
USB device (the USB2Dynamixel) shown, in Figure 4. It’s
manufactured by Robotis and sold by Crustcrawler.
Features of the USB2Dynamixel
• RS-485 Interface Support
• AX- 12 TTL Serial Interface Support
• RS-232 Interface Support
• Shows up as a standard PC com port
• Compatible with Windows 2000, XP and Vista
• Several USB2Dynamixel interfaces can be used at once
• Can be used as a limited USB to serial interface (does not
support control leads)
• Built-in library for ZeusPro compiler
If you build the exact robot I present here and use the
code that I provide, you won’t need much more than basic
mechanical skills. If, however, you plan on writing your own
programs or using a different controller, you will need some
programming skills. You will also need to be able to use a
soldering iron. Contrary to popular belief, you don’t need
to be a rocket scientist or an electronic engineer to build
a cool bot.
It’s time to give an overview of the project. At this
point, I won’t go into any of the actual technical or
construction details. Think of it as an
introduction to the types of
components, tools, and techniques
I will be going over in more detail
as the series continues.
If you wish to create your own library using .Net, the
folks at Crustcrawler have developed a .Net Visual Studio
Project that will give you a good start. You can download
this from their website.
To make life easier, I have added a new library to the
KRMicros ZeusPro compiler. It is called USB2AX, and I will
be using it extensively throughout this series.
Since our ultimate robot will be using both RX- 64
and AX-12s, you will need two USB2Dynamixels attached
to your computer. There is a small switch on the
USB2Dynamixel interface shown in Figure 5. This switch is
used to configure the interface for the type of bus that
you will be using. For all your AX-12s, you will set the
interface to TTL. For your RX- 64 and RX- 28, set the switch
As I mentioned previously,
there are three types of computer
controllers that I intend on using on
my robot. The first is a laptop
running Windows Vista or XP. I
recommend at least a 900 MHz
SERVO 08.2008 57