Page 44 - PDA Robotics Using Your Personal Digital Assistant to Control Your Robot

PDA 02 5/27/03 8:20 AM Page 20
Figure 2.7
The L298 h-bridge PDA Robotics
chipset.

Sharp GP2D12 Infrared Range Finder
The GP2D12 is a compact, self-contained IR ranging system incorpo-
rating an IR transmitter, receiver, optics, filter, detection, and amplifi-
cation circuitry (see Figure 2.8). Along with the wireless video cam-
era, it gives PDA Robot a sense of sight, allowing it to navigate
autonomously around objects. The unit is highly resistant to ambient
light and nearly impervious to variations in the surface reflectivity of
the detected object. Unlike many IR systems, this has a fairly narrow
field of view, making it easier to get the range of a specific target. The
field of view changes with the distance to an object, but is no wider
than 5 cm (2.5 cm either side of center) when measuring at the maxi-
mum range.

Figure 2.8
The GP2D12.

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