Real time clock implementation using LPC2148/38

 

Program code

RTC.C

#include <LPC213X.H>

#include "LCD.h"

#include "Delays.h"

/**********Function Prototype***********/

void RTC_Init(void);

__irq void RTC_ISR(void); //RTC Interrupt Function Prototype

/***************************************/

unsigned char flag = 1;

int main()

{

unsigned char msg[] = "Trendy Coding";

unsigned char rtc_example[] = "RTC with ARM";

unsigned char TIME[] = " TIME:";

unsigned char DATE[] = "DATE:";

RTC_Init();

VICVectAddr13 = (unsigned)RTC_ISR; //Vector Address of RTC Interrupt

VICVectCntl13 = 0x20 | 0x0D; //Enable the Vector IRQ Slot for RTC Interrupt

VICIntEnable = (1UL<<13); //Enable the RTC Interrupt

Lcd_Init();

Delay_ms(10);

Lcd_Write_Text(msg);

Lcd_Cmd(SECOND_ROW);

Lcd_Write_Text(rtc_example);

Delay_ms(500);

Lcd_Cmd(LCD_CLEAR);

Lcd_Write_Text(TIME);

Lcd_Cmd(SECOND_ROW);

Lcd_Write_Text(DATE);

while(1)

{

if(flag)

{

Lcd_Cmd(FIRST_ROW+8);

Lcd_Write(HOUR/10 + 0x30);

Lcd_Write(HOUR%10 + 0x30);

Lcd_Write(':');

Lcd_Write(MIN/10 + 0x30);

Lcd_Write(MIN%10 + 0x30);

Lcd_Write(':');

Lcd_Write(SEC/10 + 0x30);

Lcd_Write(SEC%10 + 0x30);

Lcd_Cmd(SECOND_ROW+6);

Lcd_Write(DOY/10 + 0x30);

Lcd_Write(DOY%10 + 0x30);

Lcd_Write('/');

Lcd_Write(MONTH/10 + 0x30);

Lcd_Write(MONTH%10 + 0x30);

Lcd_Write('/');

Lcd_Write(YEAR/1000 + 0x30);

Lcd_Write((YEAR/100)%10 + 0x30);

Lcd_Write((YEAR/10)%10 + 0x30);

Lcd_Write(YEAR%10 + 0x30);

flag = 0;

}

}

}

/**********Function Definition**********/

void RTC_Init(void)

{

DOY = 15; //Enter Date

MONTH = 10; //MONTH

YEAR = 2022; //Year

HOUR = 03; //Hour

MIN = 05; //Min

SEC = 0; //Sec

PREINT = 0x392; //To Generate clock of 32.768KHz for RTC Module

PREFRAC = 0x4380; //when PCLK = 30MHz

/*

Formula For Calculation is as follow:-

PREINT  = (int)(PCLK/32768)-1

PREFRAC = PCLK - ((PREINT+1)*32768

Example:-

if PCLK = 30MHz

PREINT = 914 = 0x392

PREFRAC = 17280 = 0x4380

*/

CIIR = 0x01; //Enables Second Counter Interrupt

CCR = 0x01; //Start RTC

}

__irq void RTC_ISR(void)

{

flag = 1;

ILR = 0x01; //Clear the RTC Interrupt Flag

VICVectAddr = 0x00;

}

LCD.C

#include <LPC213X.H>

#include "LCD.h"

#include "Delays.h"

/*****************LCD Functions***************/

void Lcd_Init(void)

{

PINSEL0 = 0x00;

IODIR0 |= (1<<RS); //RS Pin as Output Pin

IODIR0 |= (1<<RW); //RW Pin as Output Pin

IODIR0 |= (1<<EN); //EN Pin as Output Pin

IODIR0 |= 0x0000FF00; //P0.8 to P0.15 as Data Line of LCD

Lcd_Cmd(0x38); //Send 8-bit initialization command to lcd

Delay_ms(10);

Lcd_Cmd(CURSOR_OFF); //Cursor OFF

Delay_ms(10);

Lcd_Cmd(LCD_CLEAR);

Delay_ms(1);

Lcd_Cmd(FIRST_ROW);

}

void Lcd_Data_Shift(unsigned char value)

{

/*

This Function will shift the eight bit data stored in variable value,

to the Port Pin P0.8 to P0.15 Successfully.

*/

unsigned char i;

for(i=0;i<8;i++)

{

if(value & 0x01)

{

IOSET0 |= (1<<(i+8));

}

else

{

IOCLR0 |= (1<<(i+8));

}

value = value >> 1;

}

}

void Lcd_Cmd(unsigned char value)

{

/*Configure LCD for receiving Command Data*/

IOCLR0 |= (1<<RS);

IOCLR0 |= (1<<RW);

IOSET0 |= (1<<EN);

Lcd_Data_Shift(value);

Enable_Pulse();

}

void Lcd_Write(unsigned char value)

{

/*Configure LCD for receiving Display Data*/

IOSET0 |= (1<<RS);

IOCLR0 |= (1<<RW);

IOSET0 |= (1<<EN);

Lcd_Data_Shift(value);

Enable_Pulse();

}

void Lcd_Write_Text(unsigned char msg[])

{

while(*msg)

{

Lcd_Write(*msg);

msg++;

}

}

Delays.C

#include "Delays.h"

void Delay_ms(unsigned long times)

{

unsigned long i,j;

for(j=0;j<times;j++)

for(i=0;i<7500;i++);

}

LCD.H

#define LCD_CLEAR 0x01

#define CURSOR_OFF 0x0C

#define FIRST_ROW 0x80

#define SECOND_ROW 0xC0

#define Enable_Pulse() IOSET0|=1<<EN;Delay_ms(1);IOCLR0=1<<EN;Delay_ms(1);

/*Pin Configuration for LCD*/

#define RS 2

#define RW 3

#define EN 4

/*********************************************/

/**************Function Prototypes************/

extern void Lcd_Init(void);

extern void Lcd_Cmd(unsigned char value);

extern void Lcd_Write(unsigned char value);

extern void Lcd_Write_Text(unsigned char msg[]);

extern void Lcd_Data_Shift(unsigned char value);

delays.h

/***********Function Prototype***********/

extern void Delay_ms(unsigned long times);

/****************************************/

Circuit diagram