Arduino 3 – Buzzers (2)
AIM: Connect a passive buzzer in a circuit and play a tune.
Investigate
There are two kinds of buzzer, active buzzer and passive buzzer.
A passive buzzer is an integrated electronic buzzer without vibration source inside.
It must be driven by 2K-5K square wave instead of direct current signals.
In This Lesson
In this lesson, the buzzer we introduce here is a passive buzzer.
It cannot be actuated by itself, but by external pulse frequencies.
Different frequency produces different sound.
We can use Arduino to code the melody of a song, which is quite fun and simple.
Design
Create the buzzer as shown in the image.
Connect + lead to pin 8.
Connect – lead to Gnd pin.
Develop – Code
int buzzer = 8;
void setup()
{
pinMode(buzzer, OUTPUT);
}
void loop()
{
unsigned char i, j; //define variable
while(1)
{
for(i = 0; i < 80; i++) // output a frequency sound
{
digitalWrite(buzzer, HIGH); // sound
digitalWrite(buzzer, HIGH);
delay(1); //delay1ms
digitalWrite(buzzer, LOW); //not sound
delay(1); //ms delay
}
for(i = 0; i < 100; i++) // output a frequency sound
{
digitalWrite(buzzer, HIGH); // sound
delay(2); //2ms delay
digitalWrite(buzzer, LOW); //not sound
delay(2); //2ms delay
}
}
}
Challenge
Create a circuit with a buzzer and a switch.
The buzzer should play a tune.
Sketch you circuit in your book.
Show your teacher.