interfacing of gsm modem with atmega 16

#include <mega16.h>
#include <stdio.h>
#include <delay.h>
 
char Enter=13;
char double_quote=34;
char Ctrlz=26;
 
void main(void)
{
 
PORTD=0x00;
DDRD=0x00;
 
UCSRA=0x00;
UCSRB=0x18;
UCSRC=0x86;
UBRRH=0x00;
UBRRL=0x33;
 
while (1)
      { 
      
        if (PIND.2==0) {
        
          printf("at%c",Enter);
          delay_ms(500);
          
          printf("AT+CMGF=1%c",Enter);
          delay_ms(500);
          
          printf("AT+CMGS=%c09351563176%c%c",double_quote,double_quote,Enter);
          delay_ms(100);
          
          printf("AVR Test 1%c",Ctrlz);
          delay_ms(500);
          
        };
                   
       };
}

#include <avr/io.h> 
#define baud ((F_CPU/(speed*16UL))-1) 
#define speed 2400       // 
#define F_CPU 16000000UL    // 
#include <stdio.h> 


void usart_init()                     //(unsigned int baud) 
{ 
UBRR0H = (unsigned char) (baud>>8);  
UBRR0L = (unsigned char) baud;       // 

UCSR0B = (1<<RXEN1) | (1<<TXEN0);   

UCSR0C = (1<<USBS1) | (3<<UCSZ00); 
} 

void usart_transmit(char data) 
{ 

while ( !( UCSRA & (1<<UDRE)) ) 
UDR= data; 
} 


void send(char *data0) 
{ 
int j; 
int x=strlen(data0); 
    for(j=0;j<x;j++) 
    { 
    usart_transmit(data0[j]);  
    } 
} 

int main (void) 
{ 
usart_init(); 
   while(1) 
   { 
   send("it's me!"); 
   } 
}