Pin 14is a transmit enable pin. When you press the normally open (NO)
pushbutton switch between Pin 14 and ground, the encoder sends a
signal to the transmitter module. This signal contains information that
tells the decoding module whether the toggle switches (S1–S4) between
Pins 10, 11, 12, and 13 and ground are open or closed.
R1is a resistor that sets the frequency of an oscillator that’s internal to
the encoder. The signal from this oscillator is required to generate the
encoded signal.S5is the on/off switch.Figure 13-3 shows what’s going on in the transmitter circuit.Figure 13-2:
The top
line speeds
Sam up;
the bottom
slows him
down.304 Part IV: Good Vibrations