Cannot receive sms from gsm mobile

[Bakhtiar]

Dear Concern,

I am facing problem to receive sms . Below is my code . Please help  me .

in main block:

---

int main (void)
{
    uint8_t x = 0;

    board_init();
    
    cpu_irq_enable();
    
    DDRB = 0x7f;
    lcd_initialise();
    usart_setup();
    
  
    
    initialize_mdm();
    
    while (1)
    {
        msg = strstr(rx_data,"RING");
        if (!(strncmp(msg,"RING",4)))
        {
            msg = strstr(rx_data,"1714094407");
            if (!(strncmp(msg,"1714094407",10)))
            {
                lcd_command(0x01);lcd_display("Calling:");lcd_command(0xc0);
                while (x<10){lcd_data(*(msg+x));x++;}x=0;delay_s(1);
                tx_data("ATH");serial_enter();delay_s(1);
                lcd_command(0x01);lcd_display("Call Rejected");
            }
            clear_rx_data();
        }
       
        msg = strstr(rx_data,"CMTI");
        if (!(strncmp(msg,"CMTI",4)))
        {
            lcd_command(0x01);lcd_display("SMS Received");            
            tx_data("AT+CMGR=");tx_char(*(msg+11));serial_enter();delay_s(1);
            clear_rx_data();
        }
    }
}

 

in uart setup:

---

#define RXD PD0
#define TXD PD1

uint16_t rx_count=0;
char rx_data[255];

void usart_setup(void);
void tx_data(char *data_string);
void tx_char(char);
void clear_rx_data(void);
void serial_enter(void);

void usart_setup()
{
//    Making TXD as output pin
    DDRD |= 1<<TXD;
//    Making RXD as input pin
    DDRD &= ~(1<<RXD);
//    Baud Rate is 9600 selected with 0.2% error
    UBRRL = 0x0c;
//    Asynchronous operation, Parity mode disabled, 1-stop-bit and 8-bit character size
    UCSRC |= 1<<URSEL;
    UCSRC |= 1<<UCSZ1|1<<UCSZ0;
//    Enabling Double Transmission rate
    UCSRA |= 1<<U2X;
//    Enabling Receive complete interrupt, transmitter and receiver
    UCSRB |= 1<<RXCIE|1<<TXEN|1<<RXEN;
}

void tx_data(char *data_string)
{
    uint16_t i=0;
    
    while (data_string!=0)
    {
        //    Wait until UDRE goes high
        while (!(UCSRA & 0x20));
        //    Place the data byte
        UDR = data_string;
        //    Wait until TXC flag goes high
        while (!(UCSRA & 0x40));
        //    Clear TXC flag by writing '1' to its bit position
        UCSRA |= 0x40;
        i++;
    }
}

void tx_char(char data_byte)
{
    //    Wait until UDRE goes high
    while (!(UCSRA & 0x20));
    //    Place the data byte
    UDR = data_byte;
    //    Wait until TXC flag goes high
    while (!(UCSRA & 0x40));
    //    Clear TXC flag by writing '1' to its bit position
    UCSRA |= 0x40;
}

void clear_rx_data()
{
    uint16_t clear=0;
    
    while (clear<rx_count)
    {
        rx_data[clear] = 0;
        clear++;
    }        
    rx_count=0;
}

void serial_enter()
{
    tx_char(0x0d);                                                                        // Carriage return<CR>
    delay_ms(50);
    tx_char(0x0a);                                                                        // Line feed<LF>
    delay_ms(50);
}

ISR(USART_RXC_vect)
{
    
    //    Store the received byte in variable
    rx_data[rx_count] = UDR;
    rx_count++;
}

 

should i miss any steps.

 

 

[Hari Prasaath K]

Check with the below link for brief description of code

ablab.in/receiving-an-incoming-call-in-sim800-gsm-gprs-modem-with-avr-atmega32-microcontroller/

[Author]

Posts