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Amphibionics 06 3/24/03 9:02 AM Page 229
Chapter 6 / Crocobot: Build Your Own Robotic Crocodile
FIGURE 6.45
Robot remote control
device.
The schematic for the transmitter remote control is shown in Figure
6.46. The circuit functions by using the PIC 16C71 to monitor the
position of the control stick and then send serial commands to the
transmitter module. When the control stick moves along the X and
Y axis, the resistance values of two 100K potentiometers are var-
ied. The control stick and the two attached potentiometers are
shown in Figure 6.47. Each potentiometer is configured as a volt-
age divider so that a unique voltage represents each position along
the X- and Y-axis. The voltages from the potentiometers are con-
verted to 8-bit values by the internal analog to digital converters on
the PIC 16C71 and then interpreted by the microcontroller.
Depending on the values, certain movement commands are sent in
a serial format from the transmitter to the robot. The remote control
also has a programmable push-button switch and a light-emitting
diode (LED) that can be turned on when certain events occur, such
as during the transmission of a movement command. The transmit-
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