Page 463 - Robot Builder's Bonanza

432 AN OVERVIEW OF ROBOT “BRAINS”

A netbook is an even smaller lightweight alternative. Many run a version of Windows or
else a proprietary operating system. Be careful with netbooks with a proprietary OS, as you
may not be able to write programs for use with your robot. Like laptop PCs, netbooks are
battery powered.

Mini- ITX PC
And yet another option is the Mini- ITX PC, so called because it uses a mini- ITX motherboard.
Mini- ITX is not a brand but technically a “form factor” and design architecture. The board
measures 6.7″ 6.7″, and many versions don’t need a fan for cooling.
If using a Mini- ITX PC in a case designed for AC operation, you can still give it power on your
mobile robot by using a 12- volt battery and car power inverter. The inverter takes the 12 volts
G DC from the battery and generates 110 volts AC for the computer.
While this sounds like a roundabout way to go, it’s not quite as inefficient as it seems. Still,
you need a strong battery to power the computer for any length of time. A 12- volt motorcycle
battery is one option.
Mini- ITX Motherboard
While plopping a whole Mini- ITX PC on top of your robot is a quick and convenient way to
endow it with smarts, the case and power supply add unnecessary weight that reduce battery
life. One approach is to pull out the motherboard from the PC (Figure 34- 3) and mount it
directly onto your bot.
The design of mini- ITX motherboards incorporates all of the really important jacks and
sockets directly on the board. You seldom need to add accessory boards to complete the
system— jacks are provided for mouse, keyboard, monitor, USB, sound out, microphone in,
and many others.
DC- to- DC power supply modules let you operate the motherboard directly from a 12- volt
battery; no inverter is necessary. These modules are very small, highly efficient (90 percent
and higher), and relatively inexpensive. You can match the DC- to- DC module with the power
consumption of your motherboard. You can save money if the mini- ITX board consumes only
90 or 100 watts, as this means you can use a cheaper DC- to- DC power supply module.

Figure 34- 3 Mini- ITX motherboard,
able to run Windows, Linux, and
many other modern operating systems.
Its small size and miserly power
requirements make the board a perfect
contender for use in a medium- to
large- size robot.

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