Circuitmess Wacky Robot Hertz Instructions Manual page 22

Grab the coin battery and
carefully place it on the
backside (make sure the
+ symbol on the battery
matches the + sign on the
board - front and up).
Turn the potentiometer
with a screwdriver and
change the frequency
of the sound
Here's a handy tip:
If you flip Hertz around,
you'll spot tiny + and
- signs next to each
connector. These
little symbols tell you
about the polarity.