Interfacing Of a Buzzer Using Microcontroller 89C52/89S52

Welcome back embedded system geeks! In this article we are going to learn about the interfacing of a Buzzer with the microcontroller. But if this is your first mini-project you should probably check-out my previous article on Blinking LED'S for more understanding of the programming I will be dealing with this project. Once you get to know what Buzzer is and the programming logic behind connecting a Buzzer and a microcontroller you will able to apply the same logic to any microcontroller (i.e. your microcontroller may be a PIC or an AVR microcontroller). At the end of the explanation of the code there are some questions for you to answer which can help you to improve your programming skills.

why do we need a Buzzer? 

Buzzer is used many times in embedded systems. For an instance-Digital clock with an alarm-here buzzer can be used an alarm or a fire alarm or an intruder alarm. There are so many uses.

Components required

• 1 microcontroller 89C52(89S52 will also do)
• 1 potentiometer-10k
• 2 ceramic capacitors-22pF
• 1 switch(button for reset purpose)
• 1 electrolytic capacitor-10uF,25V
• 1 crystal oscillator-11.0592MHz
• 1 resistor-10k
• 5 LED's
• 1 resistor-1k
• 5 330 ohm resistor
• 1 Buzzer
• 1 transistor-BC548

Schematic Diagram 

 

This project has been made using Proteus software.If you want to learn more about the software you can watch the tutorials provided below

Please click here to get started with Proteus

 The connection of the circuit is explained below

• Port 2 of the microcontroller is defined as the output port
• Port 3 of the microntroller is defined as the output port
• 4 LED's are connected to the four pins of the output port 2 from P2.0 TO P2.3 respectively
• An LED is connected to the pin 3 of the output port 3 of the microcontroller
• A Buzzer is connected to the pin 8 of the output port 3
• Other components connected to the microcontroller are for the working of the microcontroller.

   

Working      

   

The working of the circuit is shown with an application of a decade counter. As soon as the microcontroller receives a power supply, the counter will start counting. An image of the counter is shown below
 

   

 

The Decade counter will count from 0 to 9 and when the counter counts 9, the buzzer will be switched ON.The transistor connected to the buzzer acts as a switch.The programming of the microcontroller is explained below:

#include "REGX52.H"

#include "delay.h" /*delay header file is included*/

void main()

{

P2=0X00;/*port 2 is defined as output port*/

P3=0XFF;/*port 3 is defined as output as port*/

while(1)

{ P3_2=0; /*set pin 3 of port 2 to logic 0 */

P3_7=0; /*set pin 8 of port 2 to logic 0 */

P2=0X00; /*code for the decade counter begins here*/

delay_sec(1);

P2=0X01;

delay_sec(1);

P2=0X02;

delay_sec(1);

P2=0X03;

delay_sec(1);

P2=0X04;

delay_sec(1);

P2=0X05;

delay_sec(1);

P2=0X06;

delay_sec(1);

P2=0X07;

delay_sec(1);

P2=0X08;

delay_sec(1);

P2=0X09;

delay_sec(1); /* code for decade counter ends here*/

if(P2==0X09)

{ P3_2=1; /*LED is switched ON*/

P3_7=1; /*buzzer is switched ON*/

delay_sec(3); /*buzzer is switched ON for 3 seconds*/

P3_2=0; /*LED is switched OFF*/

P3_7=0; /*buzzer is switched OFF*/

}

}

}

Try this for Fun      

Try to program your microcontroller in which the Buzzer is used as a musical device meaning your buzzer will output a musical tune .

Download files    

schematic diagram

source code

.hex file

what do you feel about the article?     

Please comment if you have any doubts or want to improve the project further