Page 174 - Build Your Own Combat Robot
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Chapter 7:
Controlling Your Motors
pulse width represents an approximate +60 degree position. Figure 7-17 shows a 155
graphical representation of the R/C pulse control signal. The servos are also de-
signed to shut off if they do not receive a signal every 15 to 20 milliseconds.
The repetitive nature of the signal can be advantageous to the robot builder. If
the repeated signal stops, this is an indication of a power loss, a broken signal line,
a failed receive, or a failed or turned off transmitter. If any of these events were to
happen, you will want your robot to immediately shut down. The Victor and
Vantec speed controllers will automatically shut down if they stop receiving the
repeated signal. This shutdown feature is known as a failsafe in the combat robotics
community. Most competitions require robots to demonstrate the fail-safe feature.
FIGURE 7-17
R/C servo
control signal
