gistfile1.txt

#define F_CPU 16000000UL //Set the frequency of the microcontroller to 16 mhz. If the frequency is different, the corresponding value should be set
#include <avr/io.h>
#include <util/delay.h>
#define USART_BAUDRATE 9600 //Rate of data transfer
#define BAUD_PRESCALE (((F_CPU / (USART_BAUDRATE * 16UL))) - 1)
 
void main() {
   	DDRB = 0xff;
   	char data;
 
   	UCSRB |= (1 << RXEN) | (1 << TXEN);   // Turn on the transmission and reception circuitry
   	UCSRC |= (1 << URSEL) | (1 << UCSZ0) | (1 << UCSZ1); // Use 8-bit character sizes
 
   	UBRRL = BAUD_PRESCALE; // Load lower 8-bits of the baud rate value into the low byte of the UBRR register
   	UBRRH = (BAUD_PRESCALE >> 8); // Load upper 8-bits of the baud rate value into the high byte of the UBRR register
 
   	for (;;) { // Loop forever
 
  	while ((UCSRA & (1 << RXC)) == 0) {}; // Do nothing until data have been received and is ready to be read from UDR
          	 
  	data = UDR; // Fetch the received byte value into the variable "ByteReceived"
   	 
  	if(data=='w')//forward condition
          	  PORTB=0b00000101; // Both wheels rotate in forward direction and bot is moved forward   
          	 
   	  else if(data=='s')//Backward condition
          	  PORTB=0b00001010;
          	 
   	  else if(data=='a')//Left condition
          	  PORTB=0b00001001;
          	 
   	  else if(data=='d')//Right condition
          	  PORTB=0b00000110;
          	 
   	  else//Default condition
          	  PORTB=0b00001111;
   }
}