FIGURE 11. Schematic diagram
for wiring the 74HC14
inverting buffer IC and other
components. Connections are
shown for attaching the circuit
to the L298 module.
Input A
0 volts
0 volts
5 volts
5 volts
TABLE 1
Input B
0 volts
5 volts
0 volts
5 volts
What Happens
Motor stops
Motor turns one direction
Motor turns the other direction
Motor stops
react until the voltage from the photocell reaches the
threshold value. At that point, the output of the buffer
immediately switches to zero volts.
Figure 11 shows how each motor uses two inverting
buffers. They’re wired in such a
way that there are two
complimentary (opposite)
outputs: When one output is
zero volts the other is five volts.
FIGURE 12. Breadboard view of the
component layout and hookup. Note the
use of the two three-wire male-to-female
servo extensions.
Testing the
Beginner Bot’s
Light Seeking
Ability
Before inserting the batteries,
double-check your wiring to make
sure everything is correct. You’ll
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