#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/signal.h>


// Globala variablar

const int forward = 38;
const int backward = 40;
const int left = 37;
const int right = 39;
const int for_left = 41;
const int for_right = 42;
const int back_left = 43;
const int back_right = 44;
const int stop = 0;



void initialize(void)
{
// intialize the ports
 DDRA = 0x3F // pins 0-5 on port A set to outputs
 BAUD = 0x35;
 UCSRB = 1<< TXEN; // enable receiver
 UCSRC = (1<<URSEL) | (1<<USBS) | (3<<UCSZ0); // set frame format - 2 stop bits, 8 data bits
 
 
}
void control(int direction)
{
 //set ports acording to direction
switch(direction) {
 case(forward) : PORTA = 0x05;        // 0000 0101
 case(backward) : PORTA = 0x06;       // 0000 0110
 case(left) : PORTA = 0x28;           // 0010 1000
 case(right) : PORTA = 0x18;          // 0001 1000 
 case(for_left) : PORTA = 0x1D;       // 0010 1101
 case(for_right) : PORTA = 0x1F;      // 0001 1111
 case(back_left) : PORTA = 0x2E;      // 0010 1110
 case(back_right) : PORTA = 0x1E;     // 0001 1110
 case(stop) : PORTA = 0x00;           // 0000 0000
 default : PORTA = 0x00;
}



unsigned char USART_receive(void) 
{
 while( !(UCSRA & ( 1<<RXC)) )
   ;
 return UDR;
}

void main(void)
{
 initialize();
 //as long as the program is running
  while(true) {
    int direction = USART_receive();
    control(direction);
 }  
}