ds1307.c

Interface DS1307 RTC IC with 8051

#include <stdio.h>
#include <ctype.h>
#include "standard.h"
#include "i2c.h"
#include "ds1307.h"

void Start_SEC_Timer(Data);
void Start_mSEC_Timer(Data);

// DS1307 address
#define I2C_DS1307_ID 0xD0 

DS1307 xdata Ds1307;

u8 xdata nvram[56];
//#if 0

void I2C_Write_DS1307(u8 address,u8 content)
   {

   I2C_Send_Start();   // Generate START condition

   // Send SLAVE address with write request
   if (I2C_Write_Byte(I2C_DS1307_ID | I2C_WRITE))
     {
     printf("DS1307 Error Wr address (slave doesn't ack)\n");
     return;
     }

   // Send DS1307 internal address
   if (I2C_Write_Byte(address))
     {
     printf("DS1307 Error Wr content (slave doesn't ack)\n");
     return;
     }

   // Send content to memory address
   if (I2C_Write_Byte(content))
     {
     printf("DS1307 Error Wr content (slave doesn't ack)\n");
     return;
     }

   I2C_Send_Stop();    

   return;
   }

void I2C_Read_DS1307(u8 address,u8* content)
   {

   I2C_Send_Start();   // Generate START condition

   // Send SLAVE address with write request
   if (I2C_Write_Byte(I2C_DS1307_ID | I2C_WRITE))
     {
     printf("DS1307 Error Wr address (slave doesn't ack)\n");
     return;
     }

   // Send DS1307 internal address
   if (I2C_Write_Byte(address))
     {
     printf("DS1307 Error Wr content (slave doesn't ack)\n");
     return;
     }
   I2C_Send_Stop(); 
   Start_mSEC_Timer(5);
 
   I2C_Send_Start();   // Generate START condition
   // Send SLAVE address with read request
   if (I2C_Write_Byte(I2C_DS1307_ID | I2C_READ))
      {
      printf("DS1307 Error Rd address (slave doesn't ack)\n");
		return;
      }

   *content = I2C_Read_Byte();   // Read switch content

	I2C_Send_Master_NAck();

   I2C_Send_Stop();            
   }

void setRtc(void)
{

	I2C_Write_DS1307(0,Ds1307.sec);
//	printf("Sec=%bx\n",Ds1307.sec);
	I2C_Write_DS1307(1,Ds1307.min);
//	printf("Min=%bx\n",Ds1307.min);
	I2C_Write_DS1307(2,Ds1307.hour);
//	printf("Hour=%bx\n",Ds1307.hour);
	I2C_Write_DS1307(3,Ds1307.day);
//	printf("Day=%bx\n",Ds1307.day);
	I2C_Write_DS1307(4,Ds1307.date);
//	printf("Date=%bx\n",Ds1307.date);
	I2C_Write_DS1307(5,Ds1307.month);
//	printf("Month=%bx\n",Ds1307.month);
	I2C_Write_DS1307(6,Ds1307.year);
//	printf("Year=%bx\n",Ds1307.year);
	I2C_Write_DS1307(7,Ds1307.sqw);

}

void readRtc(void)
{
//	u8 bcd2dec;
	I2C_Read_DS1307(0,&Ds1307.sec);
	I2C_Read_DS1307(1,&Ds1307.min);
	I2C_Read_DS1307(2,&Ds1307.hour);
	I2C_Read_DS1307(3,&Ds1307.day);
	I2C_Read_DS1307(4,&Ds1307.date);
	I2C_Read_DS1307(5,&Ds1307.month);
	I2C_Read_DS1307(6,&Ds1307.year);
#if 0
	bcd2dec = (((Ds1307.sec&0x70)>>4)*10)+Ds1307.sec&0x0f;
	Ds1307.sec=bcd2dec;
	bcd2dec = (((Ds1307.min&0x70)>>4)*10)+Ds1307.min&0x0f;
	Ds1307.min=bcd2dec;
	bcd2dec = (((Ds1307.hour&0x70)>>4)*10)+Ds1307.hour&0x0f;
	Ds1307.hour=bcd2dec;
	bcd2dec = Ds1307.day&0x07;
	Ds1307.day=bcd2dec;
	bcd2dec = (((Ds1307.date&0x30)>>4)*10)+Ds1307.date&0x0f;
	Ds1307.date=bcd2dec;
	bcd2dec = (((Ds1307.month&0x30)>>4)*10)+Ds1307.month&0x0f;
	Ds1307.month=bcd2dec;
	bcd2dec = (((Ds1307.year&0xf0)>>4)*10)+Ds1307.year&0x0f;
	Ds1307.year=bcd2dec;
#endif

}
#if 0
void testNvram(void)
{
	u8 i=0;
	for (i=0;i<56;i++) I2C_Write_DS1307(i+8,i);
	i=0;
	for (i=0;i<56;i++) {
		I2C_Read_DS1307(i+8,&nvram[i]);
		printf("nvram[%bu]=%bu\n",i,nvram[i]);		
	}
}
#endif 
/*------------------------------------------------------------------*-
  ---- END OF FILE -------------------------------------------------
-*------------------------------------------------------------------*/

bit oneSecInt = 0;

void heartBeat(void)
{
	I2C_Write_DS1307(7,0xf0);
	ET2 = 1; //Enable Timer 2 interrupt
}

void Int_Timer2(void) interrupt 5 using 2
{
	ET2=0;
	EXF2=0;
	oneSecInt = 1;
//	printf("Enter T2EX\n");
	ET2=1;
}