Interfacing SIM300 with ATMEGA16

[kendrepv07]

Hi friends,
This is my code. i can send sms but can't read the received message using microcontroller. So please help. Thanks in advance.


#include <avr/io.h>
#include <util/delay.h>
#include <lcd_lib.C>
#define BAUDRATE 9600
#define PRESCALE (uint8_t)(((F_CPU / (BAUDRATE * 16.0))+.5) - 1)

char p[10];
void initialize(void);
uint8_t ReceiveByte( void );
void TransmitByte( uint8_t);
void TransmitString(uint8_t *);
void Init_Ports(void);

void initialize(void)
{
DDRA = 0x01;
UBRRL = PRESCALE; /* Set the baud rate */
UCSRB = (UCSRB | _BV(RXEN) | _BV(TXEN) ); /* Enable UART receiver and transmitter */
}

uint8_t ReceiveByte( void )
{
while ( !(UCSRA & (_BV(RXC))) ); /* Wait for incomming data */
return UDR;/* Return the data */
}

void TransmitByte(uint8_t data )
{
while ( !(UCSRA & (_BV(UDRE))) ); /* Wait for empty transmit buffer */
UDR = data; /* Start transmittion */
_delay_ms(50);
}

void TransmitString(uint8_t *data)
{
while(*data)
{
TransmitByte(*data);
data++;
}
}

void init_port(void)
{
PORTA=0xFF;
DDRA=0xF0;

PORTB=0xff;
DDRB=0b10000000;

PORTC=0x00;
DDRC=0x00;

PORTD=0xFF;
DDRD=0x00;
}


void main(void)
{
unsigned int i;
uint8_t data;
initialize();
init_port();
LCDinit();
LCDclr();
while(1)
{
TransmitString("AT");
TransmitByte(0x0d);
_delay_ms(5000);
TransmitString("AT+CMGF=1");
TransmitByte(0x0d);
_delay_ms(5000);
TransmitString("AT+CSCS=\"GSM\"");
TransmitByte(0x0d);
_delay_ms(5000);
TransmitString("AT+CMGS=\"9028747438\"");
TransmitByte(0x0d);
_delay_ms(5000);
TransmitString("Hi this is your gsm modem sim300");
TransmitByte(0x1a);
_delay_ms(5000);
TransmitString("AT+CMGR=1");
TransmitByte(0x1d);
_delay_ms(5000);
for(i=0;i<=24;i++)
{
data=ReceiveByte();
}
for(i=0;i<=9;i++)
{
p=ReceiveByte();
}
p[10]='\0';
TransmitString("AT+CMGS=\"%s\"");
for(i=0;i<=9;i++)
{
TransmitByte(p);
}
TransmitByte(0x0d);
_delay_ms(5000);
break;
}
}