problem with Interfacing ds1307 with atmega 32.

[sunilkumar]

Hello everyone..
i have a problem here. i am using avr studio/avr gcc,16x2LCD(8-bit i/o mode),atmega32. i have compiled the below code ..
also i am not using any keys.(will use it later). i just want to see running clock.(i.e running from default time.). but it is showing “hello world” “00:00:00 AM”. and time wont update at all..my connections are LCD to Port A& B,SCL,SDA are as usual. please help.. thanks.
please forgive if this is not the right section to post my doubt..
 

Code:

#include <avr/io.h>
#include <util/delay.h>

#define FALSE 0
#define TRUE 1

#define LCD_DATA PORTA
 
#define ctrl PORTB
#define en PB2
#define rw PB1
#define rs PB0
#define CH 7
void LCD_cmd(  char cmd);
void init_LCD(void);
void LCD_write( char data);
void LCD_write_string( char *str);
uint8_t DS1307Read(uint8_t address,uint8_t *data);
uint8_t DS1307Write(uint8_t address,uint8_t data);
uint8_t I2CReadByte(uint8_t *data,uint8_t ack);
uint8_t I2CWriteByte(uint8_t data);
void I2CInit();
void I2CClose();
void I2CStart();
void I2CStop();

int main(void)
{
    char Time[12];
   uint8_t data;
   
   DDRA=0xFF;
   DDRB=0xFF;
   init_LCD();
   I2CInit();
    uint8_t temp;
   DS1307Read(0x00,&temp);

   //Clear CH Bit
   temp&~(1<<CH));

   DS1307Write(0x00,temp);

   //Set 12 Hour Mode
   DS1307Read(0x02,&temp);

   //Set 12Hour BIT
   temp|=(0b01000000);

   //Write Back to DS1307
   DS1307Write(0x02,temp);

   LCD_write_string(“hello world”);
      while(1)
   {
         DS1307Read(0x00,&data);
      Time[8]=’’;
      Time[7]=(0x30)+(data & 0b00001111);
      Time[6]=(0x30)+((data & 0b01110000)>>4);
      Time[5]=’:’;
   
      DS1307Read(0x01,&data);
   
      Time[4]=(0x30)+(data & 0b00001111);
      Time[3]=(0x30)+((data & 0b01110000)>>4);
      Time[2]=’:’;
   
      DS1307Read(0x02,&data);
   
      Time[1]=(0x30)+(data & 0b00001111);
      Time[0]=(0x30)+((data & 0b00010000)>>4);
      LCD_cmd(0xC0);
       LCD_write_string(Time);
      if(data & 0b00100000)
      LCD_write_string(“PM”);
      else
      LCD_write_string(“AM”);
   }      
      
   return 0;
}
uint8_t DS1307Read(uint8_t address,uint8_t *data)
{
   uint8_t res;   //result
   
   //Start
   I2CStart();
   
   //SLA+W (for dummy write to set register pointer)
   res=I2CWriteByte(0b11010000);   //DS1307 address + W
   
   //Error
   if(!res)   return FALSE;
   
   //Now send the address of required register
   res=I2CWriteByte(address);
   
   //Error
   if(!res)   return FALSE;
   
   //Repeat Start
   I2CStart();
   
   //SLA + R
   res=I2CWriteByte(0b11010001);   //DS1307 Address + R
   
   //Error
   if(!res)   return FALSE;
   
   //Now read the value with NACK
   res=I2CReadByte(data,0);
   
   //Error
   if(!res)   return FALSE;
   
   //STOP
   I2CStop();
   
   return TRUE;
}

uint8_t DS1307Write(uint8_t address,uint8_t data)
{
   uint8_t res;   //result
   
   //Start
   I2CStart();
   
   //SLA+W
   res=I2CWriteByte(0b11010000);   //DS1307 address + W
   
   //Error
   if(!res)   return FALSE;
   
   //Now send the address of required register
   res=I2CWriteByte(address);
   
   //Error
   if(!res)   return FALSE;
   
   //Now write the value
   res=I2CWriteByte(data);
   
   //Error
   if(!res)   return FALSE;
   
   //STOP
   I2CStop();
   
   return TRUE;
}

void I2CInit()
{
   //Set up TWI Module
   TWBR = 2;
   TWSR |(1<<TWPS1)|(1<<TWPS0));

   //Enable the TWI Module
   TWCR|=(1<<TWEN);

}

void I2CClose()
{
   //Disable the module
   TWCR&~(1<<TWEN));
}

void I2CStart()
{
   //Put Start Condition on Bus
   TWCR=(1<<TWINT)|(1<<TWEN)|(1<<TWSTA);

   //Poll Till Done
   while(!(TWCR & (1<<TWINT)));

}

void I2CStop()
{
   //Put Stop Condition on bus
   TWCR=(1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
   
   //Wait for STOP to finish
   while(TWCR & (1<<TWSTO));
   //_delay_loop_2(250);
}

uint8_t I2CWriteByte(uint8_t data)
{
   
   TWDR=data;   

   //Initiate Transfer
   TWCR=(1<<TWEN)|(1<<TWINT);

   //Poll Till Done
   while(!(TWCR & (1<<TWINT)));

   //Check Status
   if((TWSR & 0xF8) == 0x18 || (TWSR & 0xF8) == 0x28 || (TWSR & 0xF8) == 0x40)
   {
      //SLA+W Transmitted and ACK received
      //or
      //SLA+R Transmitted and ACK received
      //or
      //DATA Transmitted and ACK recived

      return TRUE;
   }
   else
      return FALSE;   //Error
}

uint8_t I2CReadByte(uint8_t *data,uint8_t ack)
{
   //Set up ACK
   if(ack)
   {
      //return ACK after reception
      TWCR|=(1<<TWEA);
   }
   else
   {
      //return NACK after reception
      //Signals slave to stop giving more data
      //usually used for last byte read.
      TWCR&~(1<<TWEA));
   }

   //Now enable Reception of data by clearing TWINT
   TWCR|=(1<<TWINT);

   //Wait till done
   while(!(TWCR & (1<<TWINT)));

   //Check status
   if((TWSR & 0xF8) == 0x58 || (TWSR & 0xF8) == 0x50)
   {
      //Data received and ACK returned
      //   or
      //Data received and NACK returned

      //Read the data

      *data=TWDR;
      return TRUE;
   }
   else
      return FALSE;   //Error
   
}

   
   

void init_LCD(void)      //LCD Initialization
{
LCD_cmd(0x38);
_delay_ms(1);
LCD_cmd(0x01);
_delay_ms(1);
LCD_cmd(0x0F);
_delay_ms(1);
LCD_cmd(0x80);
_delay_ms(1);
return;
}
 
 
void LCD_cmd( char cmd) //LCD command write
{
LCD_DATA=cmd;
ctrl =(0<<rs)|(0<<rw)|(1<<en);
_delay_ms(1);
ctrl =(0<<rs)|(0<<rw)|(0<<en);
_delay_ms(50);
return;
}
 
 
void LCD_write( char data) //LCD write character
{
LCD_DATA= data;
ctrl = (1<<rs)|(0<<rw)|(1<<en); // making RW as LOW and RS, EN as HIGH
_delay_ms(1);
ctrl = (1<<rs)|(0<<rw)|(0<<en); // making EN and RW as LOW and RS HIGH
_delay_ms(50); // give a 10 milli second delay to get thigs executed
return ;
}
 
void LCD_write_string(char *str) //LCD Write String
{
int i=0;
while(str!=’’)
{
LCD_write(str);
i++;
}

 

[mreza]

i have another code that works with avr studio , ds1307 , and mega32 .

 

contact me if you want that yet .

 

 

[email protected]

[romel emperado]

very good example of interfacing RTC: check this link and it has already the code

 

http://adf.ly/2GyVB

 

code:

 

http://adf.ly/2GyW8

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