- Stripboard ( 8 Traces of 10 Holes)
R1 Resistor, 10k, 1/6W
R2 Resistor, 22k, 1/6W
R3 Resistor, 180 , 1/6W
J1 Header, Male, Rt Angle, Six-pin
C1 Capacitor, .01 F
- IC Socket, Eight-pin
- Header, Male, Straight, Three-pin
■ FIGURE 8. Tex Parts List.
■ FIGURE 7. Tex schematic.
to output2 of the 08M which is
capable of outputting PWM signals.
As you know, the PNA4602 is
capable of receiving IR signals that
are modulated on a 38 kHz carrier
wave, so a 38 kHz PWM signal can
be used to generate an IR “beam” to
detect objects in its path.
For example, an IR beam-generating Tex could be placed on
one side of a hallway with Rex on the
other side. This combination would
be able to detect any person or other
object that crosses the IR beam.
Figure 9 shows the top and
bottom views of the layout for Tex’s
stripboard circuit. In the layout, I have
again used two four-pin female
headers as the socket for the 08M so
that the placement of the two
resistors is clearly visible. Note that
the orientation of Tex’s 08M
processor is reversed from that of Rex
(i.e., for Tex, pin 1 of the 08M is at
the left end of the lower female
header). As before, you can use
either an eight-pin machined-pin
socket or the female headers for the
08M. Also note that, although the IR-LED is shown in the layout as
pointing forward from the board, you
could just as easily install it by first
bending its leads 90 degrees so that it
points directly up. This arrangement
would be suitable for a hand-held IR
transmitter. Tex is also very easy to
construct, so just take a look at
Figure 10 for a close-up of the
completed Tex stripboard for
reference. When you are ready to
install the IC socket on top of the
resistors, you may again find that one
of the resistors interferes with fully
inserting the socket into the
stripboard. If so, shave off a little
plastic as mentioned previously.
Before soldering the IC socket in
place, be sure to orient it so that pin
1 is inserted into hole C8.
■ FIGURE 11.
Tex test setup.
■ FIGURE 10.