Receive string through UART

In this tutorial I am going to show you how to receive a string through UART. In this program we are going to make use of the previous function which were written for receiving the character through UART. Don't forget to put NULL character at the end of the string.....

#include<avr/io.h>

void UART1_Init()
{
//set baud rate = 9600 bps
UBRR1H = 0x00;
UBRR1L = 103;         //0x67

//set 1 stop bit, no parity bit and 8 bit charachter size
UCSR1C = 0x06;         //(1 << UCSZ1)|(1 << UCSZ0)  

//enable transmission and reception
UCSR1B = 0x18;         //(1 << RXEN)|(1 << TXEN)
}

//Transmit character through UART
void UART1_Tx_Char(unsigned char data)
{
//put the data to be transmitted into the UDR register
UDR1 = data;

//wait until the transmission is completed
 while(!(UCSR1A&(1<<UDRE)));
}


//Transmit string through UART
void UART1_Tx_Str(unsigned char * str)
{
while(*str)
{
UDR1 = *str++;
while(!(UCSR1A&(1<<UDRE);
}

//Receive a character through UART
unsigned char UART1_Rx_Char()
{
//wait for the charater
while(!(UCSR1A & (1<<RXC)));

//return the received charater
return(UDR1);
}

//Receive string through UART
unsigned char * UART1_Rx_Str()
{
 unsigned char string[20], x, i = 0;

//receive the characters until ENTER is pressed (ASCII for ENTER = 13)
while((x = UART1_Rx_Char()) != 13)
{
 //and store the received characters into the array string[] one-by-one
string[i++] = x;
}

//insert NULL to terminate the string
string[i] = '\0';

//return the received string
return(string);
}

void main()
{
//initialize the UART circuitry
UART1_Init();

//Transmit the Received string onto the UART again
UART1_Tx_Str( UART1_Rx_Str());
}

Posted in: AVR, Tutorials, UART