Piezo Buzzer - Mikroe EasyMx PRO v7a Manual

DATA BUS
PE14
Piezo buzzer connected to PE14
microcontroller pin
HOW TO MAKE IT SING?
Buzzer starts "singing" when you provide
PWM signal from the microcontroller to
the buzzer driver. The pitch of the sound
is determined by the frequency, and
amplitude is determined by the duty
cycle of the PWM signal.
PIEZO BUZZER module view
VCC-5V
TOP
VIEW
R28 PZ1
1K
BUZZER
PERSPECTIVE
VIEW
Q1
R35
BUZZER BC846
TOP
10K
SW14
VIEW
TOP
VIEW
PERSPECTIVE
TOP
VIEW
VIEW
Freq = 3kHz, Duty Cycle = 50%
PERSPECTIVE
VIEW
Freq = 3kHz, Duty Cycle = 80%
PERSPECTIVE
VIEW
Freq = 3kHz, Duty Cycle = 20%

PIEZO BUZZER

Piezo electricity is the charge which accumulates in certain solid materials in response to
mechanical pressure, but also providing the charge to the piezo electric material causes
it to physically deform. One of the most widely used applications of piezo electricity is
the production of sound generators, called piezo buzzers. Piezo buzzer is an electric
component that comes in different shapes and sizes, which can be used to create sound
waves when provided with analog electrical signal. EasyMx PRO v7a f comes with piezo
buzzer which can be connected to PE14 microcontroller pin. Connection is established
using SW14.8 DIP switch. Buzzer is driven by transistor Q1 . Microcontrollers can create
sound by generating a PWM (Pulse Width Modulated) signal – a square wave signal,
which is nothing more than a sequence of logic zeros and ones. Frequency of the square
signal determines the pitch of the generated sound, and duty cycle of the signal can be
used to increase or decrease the volume in the range from 0% to 100% of the duty cycle.
You can generate PWM signal using hardware capture-compare module, which is usually
available in most microcontrollers, or by writing a custom software which emulates the
desired signal waveform.
SUPPORTED
SOUND
FREQUENCIES
VCC-5V
Piezo buzzer's resonant frequency
(where you can expect it's best
performance) is 3.8kHz, but you can
VCC-5V
also use it to create sound in the range
R3
PZ1
1K
between 2kHz and 4kHz.
VCC-5V
R3
PZ1
1K
R27
BUZZER
Freq = 3kHz, Volume = 50%
R3
PZ1 10K
1K
Q8
R27
BC846
BUZZER
Freq = 3kHz, Volume = 80%
10K
Q8
R27
BC846
BUZZER
Freq = 3kHz, Volume = 20%
10K
Q8
BC846
E a s y M x
Enabling Piezo Buzzer
In order to use the on-board
J21
Piezo Buzzer in your application,
RC2
you first have to connect the
RE1
transistor driver of piezo buzzer to
J21
RC2
the appropriate microcontroller
pin. This is done using SW14.8
RE1
J21
DIP switch which connects it to
RC2
PE14 pin.
RE1
P R O v 7 a U s e r M a n u a l