Page 169 - Amphibionics : Build Your Own Biologically Inspired Robot

Amphibionics 05 3/24/03 8:44 AM Page 148
Figure 5.40
Parts soldered to the
finished PCB. Amphibionics

Check the finished board for any missed or cold soldered con-
nections and verify that all the components have been included.
The board will be tested later when programming the PIC micro-
controller.

The Infrared Sensor Board

An infrared sensor board will be fabricated to give the snake obsta-
cle avoidance capabilities. The sensor board is comprised of an
infrared LED and a Panasonic PNA4602M IR sensor module. A sin-
gle-channel sensor is being used because the sensor board will be
mounted at the front of the robot’s movable head. The snake is able
to move its head in an arc of 180 degrees, allowing it to sense objects
in front, and to either side of its body as it explores the surrounding
environment. The sensor board schematic is shown in Figure 5.41.
Table 5.3 is a list of all the parts needed to construct the board.

The 555 timer in the circuit is used to modulate the infrared LED
at a frequency determined by C1 and R3. R3 is an adjustable 10k

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