Pages

Subscribe:

Saturday, 23 July 2011

Digital Clock Using Microcontroller 89C52/89S52




Are you a beginner in micro controller projects?and are you stuck where to start from?if yes,then this is one of the simplest mini projects that you can start from . This mini project will give you a clear understanding of programming your micro controller. we sometimes look at our watch and wonder " how does this thing work". Well, in this digital clock project, you will gain some insight on how micro controller can be used to make it work as a Digital Clock.

Components required:

  • 1 microcontroller 89C52(89S52 will also do)
  • 2 ceramic capacitors-22pF
  • 1 switch(button for reset purpose)
  • 1 electrolytic capacitor-10uF,25V
  • 1 crystal oscillator-11.0592MHz
  • 16x2 LCD display
  • 1 resistor-10k


Circuit diagram


Software you will need

This project has been done in proteus software.If you are new to proteus software, the tutorials given below may get you started with the software.note:if you are familiar with proteus you can skip this part.


The programming of the microcontroller is done using keil compiler.port 2 of 89C52 is used as the output port.whereas port 1 is used as the input port.when P1_4 is grounded the 12 hr mode is activated and when P1_5 is grounded the 24 hr mode is activated.In the schematic diagram P1_5 is grounded so the 24hr mode is activated.it is as shown below



Code:


The detail explanation of the code is done below:





#include "REGX52.H"
#include "delay.h"
#include "lcd.h"
void main(void)
{
int hr=0; /*initiate hour=0 */
int min=0; /*initiate minutes=0 */
int sec=0; /*initiate seconds=0 */
P1=0xff; /*set port 1 as input port */
P2=0x00; /*set port 2 as output port*/
while(1)
{ LCD_INIT(); /*initialize LCD*/
if (P1_4==0)/*if P1_4 is grounded enter the 12hr loop */
{
for (sec=0;sec<60;sec )
{
LCD_DisplayNum(hr,2);
LCD_STRING(":");
LCD_DisplayNum(min,2);
LCD_STRING(":");
LCD_DisplayNum(sec,2);
LCD_STRING(" (12 HR)");
delay_sec(1);
LCD_CLEAR();
if (sec==59)
{
min=min 1;
if(min==60)
{
if(hr==11&&min==60&&sec==59)
{hr=0;min=0;sec=0;}
else
{ hr=hr 1;
min=0;}
}
}
} }
else
{
if(P1_5==0) /*if P1_5 is grounded enter the 24hr loop */
{
for (sec=0;sec<60;sec )
{
LCD_DisplayNum(hr,2);
LCD_STRING(":");
LCD_DisplayNum(min,2);
LCD_STRING(":");
LCD_DisplayNum(sec,2);
LCD_STRING(" (24 HR)");
delay_sec(1);
LCD_CLEAR();
if (sec==59)
{
min=min 1;
if(min==60)
{
if(hr==23&&min==60&&sec==59)
{hr=0;min=0;sec=0;}
else
{ hr=hr 1;
min=0;}
}
}
} }}
LCD_INIT();
}
}


























































you can download the .hex file here

schematic diagram
main.c
digclk.hex


you can add more functions to this digital clock since 2 ports of 89C52 are still unused.For instance, you can connect a buzzer to port 4 such that the buzzer sounds at a specified time or you can connect a keypad to port 0 such you can set the timings externally.

Please comment if you would further like to improve the project.

5 comments:

Arindam Bose said...

Please help me, I cant find the files lcd.h and delay.h
My editor is generating following errors:
clock.c(2): warning C318: can't open file 'delay.h'
clock.c(3): warning C318: can't open file 'lcd.h'
CLOCK.C(12): warning C206: 'LCD_INIT': missing function-prototype
CLOCK.C(17): warning C206: 'LCD_DisplayNum': missing function-prototype
CLOCK.C(17): error C267: 'LCD_DisplayNum': requires ANSI-style prototype
Target not created

aNIL aGGARWAL said...

these are prototypes of functions only to show how a clock program works..u will have to write definitions of all of the above functions..

asm file of lcd driven program is given below:




ORG 0H
AGAIN:MOV A,#38H
ACALL COM
ACALL DELAY
MOV A,#0EH

ACALL COM
ACALL DELAY
MOV A,#01

ACALL COM
ACALL DELAY
MOV A,#06H
ACALL COM
ACALL DELAY
//MOV A,#84H

ACALL COM
ACALL DELAY
MOV A,#"H"
ACALL DATAWRT
ACALL DELAY
MOV A,#"I"
ACALL DATAWRT
ACALL DELAY
LJMP AGAIN
COM:
MOV P3,A
CLR P2.0
CLR P2.1
SETB P2.2
ACALL DELAY
CLR P2.2
RET

DATAWRT:
MOV P3,A
SETB P2.0
CLR P2.1
SETB P2.2
ACALL DELAY
CLR P2.2
RET
DELAY :MOV R3,#500
HERE2:MOV R4,#255
HERE:DJNZ R4,HERE
DJNZ R3,HERE2
RET
END

Muhammad Adeel Awan said...

sir i also have this problem as ""Arindam Bose"" said..
what can i do in keil...

Eric Ericson said...

i liked you post so much that i have posted as a featured article on my website Genius Devils

Ryanz said...

HELLO ... can i have the coding for pic instead of c++ ?

Post a Comment