Discussion in "Project Addition or Changes" started by    adambose1990    Oct 11, 2011.
Tue Oct 11 2011, 12:02 PM
#1
Hi guys, here is a simple project I have done in 89s52 IC of 8051 series. Making 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


Software you will need:
The programming of the microcontroller is done using keil compiler. Port 2 is output port, This LCD is in 8bit mode.
Details of LCD you can have here.

http://www.mikroe.com/eng/chapters/view/17/chapter-4-examples/

Circuit Diagram:



The detail explanation of the code is done below:


//main.c
#include <REG51.H>

#include "lcd.h"

void ms_delay(int time)
{
	unsigned int i,j;
	for(i=0;i<time; i++)
		for(j=0;j<=1275;j++);
}

void main(void)
{   
   	int hr=00,min=00,sec=00,flag=0;
	LCD_init();
   	LCD_putnum(hr,2);		   //|HH:MM:SS 	AM
   	LCD_sendstring(":");
	LCD_putnum(min,2);
	LCD_sendstring(":");
	LCD_putnum(sec,2);
	LCD_sendstring("  AM");
   while(1)
   {
	for (sec=0;sec<60;sec++)
    {				
		LCD_gotoxy(6,0);
		LCD_putnum(sec,2);
		ms_delay(142);
		if (sec==59)
	    { 
			min=min+1;
			if(min==60)
			{
		  		if(hr==11&&sec==59)
		    	{
					hr=0;
					min=0;
					sec=-1;
					flag=~flag;
					LCD_gotoxy(0,0);
					LCD_putnum(hr,2);
					LCD_gotoxy(3,0);
					LCD_putnum(min,2);
					LCD_gotoxy(10,0);
					if (flag==0)
						LCD_sendstring("AM");
					else
						LCD_sendstring("PM");
				}
		  		else
				{   
					hr=hr+1;
					min=0;
					LCD_gotoxy(0,0);
					LCD_putnum(hr,2);
					LCD_gotoxy(3,0);
					LCD_putnum(min,2);
				}
			}
			LCD_gotoxy(3,0);
			LCD_putnum(min,2);
	    }
	} 
   }		
}


But before that you have to make lcd.h file. Its codes are given also here. This Header is specially made for this program.
//lcd.h
#ifndef __LCD_H__
#define __LCD_H__

#define LCD_data P2


void _LCD_busy(void);
void _LCD_sdelay(void);
void _LCD_poweron(void);
void _LCD_command(unsigned char);
void _LCD_senddata(unsigned char);
void _LCD_sendstring(unsigned char *);
void _LCD_putnum(int, int);
void _LCD_init(void);
void _LCD_clear(void);

sbit LCD_rs=P1^0;
sbit LCD_rw=P1^1;
sbit LCD_en=P1^2;

void LCD_busy()
{
    unsigned char i,j;
        for(i=0;i<50;i++)
                for(j=0;j<255;j++);
}

void LCD_sdelay()
{
    unsigned char i;
        for(i=0;i<50;i++);
}

void LCD_poweron()
{
unsigned int i;
for (i=0;i<22500; i++);
}

void LCD_command(unsigned char var)
{
     LCD_data  = var;      //Function set: 2 Line, 8-bit, 5x8 dots
     LCD_rs   = 0;        //Selected command register
     LCD_rw   = 0;        //We are writing in instruction register
     LCD_en   = 1;        //Enable H->
L
     LCD_en   = 0;
     LCD_busy();          //Wait for LCD to process the command
}

void LCD_putnum(int number,int width)// LCD_putnum: Implementing integer value from -99999 to 99999
{
   unsigned char digit;

   if (number < 0) 
   {
     LCD_senddata('-');
	 LCD_sdelay();
	 number = -1 * number;
   }

   switch (width)
   {
   		case 5:
			digit = '0';
			while(number >
= 10000)                // Keep Looping for larger than 10
   			{
     			digit++;                         // Increase ASCII character
     			number -= 10000;                    // Subtract number with 10
   			}
			LCD_senddata(digit);                // Put the Second digit
			LCD_sdelay();
	   case 4:
			digit = '0';
			while(number >
= 1000)                // Keep Looping for larger than 10
   			{
     			digit++;                         // Increase ASCII character
     			number -= 1000;                    // Subtract number with 10
   			}
			LCD_senddata(digit);                // Put the Second digit
			LCD_sdelay();
		case 3:
			digit = '0';
			while(number >
= 100)                // Keep Looping for larger than 10
   			{
     			digit++;                         // Increase ASCII character
     			number -= 100;                    // Subtract number with 10
   			}
			LCD_senddata(digit);                // Put the Second digit
			LCD_sdelay();
		case 2:
			digit = '0';
			while(number >
= 10)                // Keep Looping for larger than 10
   			{
     			digit++;                         // Increase ASCII character
     			number -= 10;                    // Subtract number with 10
   			}
			LCD_senddata(digit);                // Put the Second digit
			LCD_sdelay();
		case 1:
			LCD_senddata('0' + number);           // Put the First digit
			LCD_sdelay();
   }
}

void LCD_sendstring(unsigned char *var)
{
     while(*var)              //till string ends
       LCD_senddata(*var++);  //send characters one by one
}

void LCD_senddata(unsigned char var)
{
     P2  = var;      //Function set: 2 Line, 8-bit, 5x7 dots
     LCD_rs   = 1;        //Selected data register
     LCD_rw   = 0;        //We are writing
     LCD_en   = 1;        //Enable H->
L
     LCD_en   = 0;
     //LCD_busy();          //Wait for LCD to process the command
}

void LCD_init(void)
{
     LCD_data = 0x38;     //Function set: 2 Line, 8-bit, 5x8 dots
     LCD_rs   = 0;        //Selected command register
     LCD_rw   = 0;        //We are writing in data register
     LCD_en   = 1;        //Enable H->
L
     LCD_en   = 0;
     LCD_busy();          //Wait for LCD to process the command
     LCD_data  = 0x0C;     //Display on, Curson blinking off command
     LCD_rs   = 0;        //Selected command register
     LCD_rw   = 0;        //We are writing in data register
     LCD_en   = 1;        //Enable H->
L
     LCD_en   = 0;
     LCD_busy();          //Wait for LCD to process the command
     LCD_data  = 0x01;     //Clear LCD
     LCD_rs   = 0;        //Selected command register
     LCD_rw   = 0;        //We are writing in data register
     LCD_en   = 1;        //Enable H->
L
     LCD_en   = 0;
     LCD_busy();          //Wait for LCD to process the command
     LCD_data  = 0x06;     //Entry mode, auto increment with no shift
     LCD_rs   = 0;        //Selected command register
     LCD_rw   = 0;        //We are writing in data register
     LCD_en   = 1;        //Enable H->
L
     LCD_en   = 0;        //Enable H->
L
     LCD_busy();
}

void LCD_clear(void)
{
	LCD_data  = 0x01;     //Clear LCD
    LCD_rs   = 0;        //Selected command register
    LCD_rw   = 0;        //We are writing in data register
    LCD_en   = 1;        //Enable H->
L
    LCD_en   = 0;
    LCD_busy();
}

     
void LCD_gotoxy(int x, int y)//x=0..16, y= 0..1 
{      
  int dr;
  if (y==0)
  	dr=x+0x80;      
  if (y==1)       
    dr=x+0xC0;            
  LCD_data  = dr;      //Function set: 2 Line, 8-bit, 5x8 dots
  LCD_rs   = 0;        //Selected command register
  LCD_rw   = 0;        //We are writing in instruction register
  LCD_en   = 1;        //Enable H->
L
  LCD_en   = 0;
  LCD_busy();        
}

#endif


Thanks a lot...
For any quarries you can contact [email protected]
Tue Oct 11 2011, 12:09 PM
#2
You can download the following attachents
.Hex file
.H file
.C file
.DSN file
They are all in rar file. Extract them all.
Attachment
Tue Oct 11 2011, 04:05 PM
#3
@ adambose1990
good efforts
use timer for clock that will be more accurate as compare to looping
Thu Oct 13 2011, 03:51 PM
#4
good work adambose

and i completely agree with Majoka, you must use timers for tick generation. I will be much more accurate
Fri Oct 14 2011, 04:31 PM
#5
@Ajay Bhargav yes surely, This project is not accurate only because of the tick generation, it lags a few second in an RTC hour, I surely will follow your advice, thanks........:)
Tue Nov 01 2011, 08:20 PM
#6
Additional advice for error free timers; use timer in free running mode so that you dont have to do load operation for timers. This way your timer will always overflow at perfect intervals, no matter how late your ISR is serviced

Also use 12Mhz for best results with above method.
Thu Nov 03 2011, 12:04 PM
#7
Thanks a lot Ajay sir...:)
Sun Nov 06 2011, 07:17 AM
#8
You're welcome good luck for your Final Year
Fri Feb 10 2012, 10:26 AM
#9
Its a good and lot of information on your site and good collection of information for digital 8051. thanks for sharing the information.
Fri Feb 10 2012, 11:15 AM
#10
Hi jamewhite86, To know more digital 8051, have a look into this site : www.rsatechbook.webs.com
There is a lot not only about 8051, but also about AVR and PIC unique projects...... Have a good day...
http://rsatechbook.webs.com/

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ExperimenterUK
Thu Oct 30 2014, 06:02 PM
This is a chat box..create a thread if you need help...but we don't do homework
Tue Oct 28 2014, 07:33 PM
vinni
hi rickey...anyone got the pgm...pls gimme now
Tue Oct 28 2014, 06:35 PM
potla
hi vinni even i need that program. help me if you get it
Tue Oct 28 2014, 03:22 PM
vinni
1. Using a look-up table in Flash ROM and accumulator offset indexed addressing mode, write a program that acts as a timer. The timer should count from 0 to 59 seconds. After reaching 59, it should go back to 0 on the next second and continue to count up. The timer should use the seven-segment display. The look-up table should contain information on how to display the digits 0 – 9 on the seven-segment display
Tue Oct 28 2014, 03:22 PM
vinni
hello Rickey..i need this pgm very urgently
Tue Oct 28 2014, 01:42 AM
Boy Donald
Dear sir, thanks before. i have some project urgent for my school and my project need this digital countdown timer using 7 segmen display. but your project only show ten minutes countdown, i need your help, can you show me more to change the minute or set the time manually. thank you, sorry for disturbing you.
Tue Oct 28 2014, 01:32 AM
Boy Donald
dear sir
Tue Oct 28 2014, 01:19 AM
Boy Donald
Rickey you inspired me a lot but why i can not change the time ( minute
Sun Oct 26 2014, 02:51 AM
sandeep bankar
dear sir I m facing problem about..how to read number of incoming call in gsm 900 a. pls help how to read it in atmel avr microcontroller.
ajay_bhargav
Mon Oct 20 2014, 11:22 AM
@skrishna, please post in forum so we can help you better.

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