piece of stripboard, but I prefer to
use homemade printed circuit
boards (PCBs). Since this affair
weighs in at a diminutive 1-1/4 by
2-1/2 inches, that undertaking could
even be tackled with nothing more
than a small bowl of etching
I got the job done (from
artwork design to an etched and
drilled board) in a couple hours
just working with a slapdash system
out of my kitchen. Figure 2 shows
the PCB artwork I used, while the
parts placement guide appears in
Figure 3. Figure 4 is a photograph
of how my unit ended up.
Here are a few notes of interest
to guide you along.
As mentioned earlier, I went
with a soldered-in microphone;
you’ll spot it in the upper right-hand
corner. Next to it is a thumbwheel
type trimmer potentiometer (R6).
Any type of pot is useable here,
though. If you’d prefer to build the
thing in a small box with a panel
mount control, go for it.
I wanted to be able to use the
Sonic Sensor on a breadboard and
so utilized pins for ground, +5V, and
output spaced in increments of
0.100 inches. I even went one step
further and spread them out every
other pin so the device would fit
into the multiples of the DIY PIC
Trainer I wrote about in the
February 2013 issue of Nuts & Volts
(pp. 32-37). You’ll see it installed on
the Trainer in Figure 5. A plug-in
module sure makes life sweet for
some rapid deployment of ideas!
I suppose you could connect
the Sonic Sensor directly to a driver
transistor and relay to simply switch
some apparatus on as long as a
sound is present. That doesn’t
sound all that useful to me, though,
since latching is probably what you
A better idea would be to use it
to fire a 555 timer acting as
monostable. When a burst of sound
comes in, the timer goes on for a
specified interval and then shuts off
again. If you’re going this route,
remember that the 555 responds to
a negative-going edge, so you’ll
probably want to differentiate and
invert the output gate with, say, a
simple transistor affair.
So, maybe you’d like to count
handclaps or other sounds. That’s
easy to do. Just hook up the Sonic
Sensor to some sort of CMOS
counter like the 4017, 4024, 4026,
4511, or countless (groan …) other
such devices available. You could
light a 10-element LED bar graph or
perhaps a seven-segment LED
display to show the number of
September 2013 37
All fixed resistors are 1/4 watt, 5% values.
R6 10K trimmer
Capacitors are 10V or better.
C1 0.001 µF mylar
C2–C4 0.047 µF mylar
C5 1 µF electrolytic
C6 10 µF electrolytic
D1, D2 1N4148 diode
Q1–Q4 2N3904 NPN transistor
MIC1 Electret microphone
Miscellaneous: Circuit board, solder, wire, header
pins, optional jack, etc.
■ FIGURE 4.