Bitte um Codebewertung/ µ-Controller Neuling

//This File check the Seriell Reciever Input and switch corresponding   

//Outputs        

#include <avr/io.h> 

#define F_CPU 8000000UL

#include <util/delay.h> 

#include <avr/interrupt.h> 

void init_ports(void); 

void init_USART(unsigned int ubrr_value); 

void Aus_Ein_Next(); 

/////////////////////////////////////////////////////////////////////////////////////

int main(void) 

{ 

// Initialisation Ports, seriell Transmission, Interrupts

   init_ports(); 

   init_USART(51);//8M/(16*9600)-1 

   //sei();//Global Interrupt Enable 

/////////////////////////////////////////////////////////////////////////////////////

//Check UDR DATA and select Programm 

    while(1) 

    { 

      if ( UDR == 1) 

      Aus_Ein_Next() 

    } 

} 

/////////////////////////////////////////////////////////////////////////////////////

void init_ports(void) 

{ 

//Port D pins 1 to 3 Config as Digital Out 

   DDRD=(1<<DDD4)|(1<<DDD5)|(1<<DDD6); 

} 

/////////////////////////////////////////////////////////////////////////////////////

void init_USART(unsigned int ubrr_value) 

{ 

   //Set Baud rate 

   UBRRL = (unsigned char) ubrr_value;

   UBRRH = (unsigned char) (ubrr_value>>8);

   /*Set Frame Format 

   >> Asynchronous mode 

   >> No Parity 

   >> char size 8 

   */ 

   UCSRC=3<<UCSZ0; // contains UCSZ1,too ( leftshift of 3 not 1)

   //Enable The receiver, transmitter and interrupt 

   UCSRB=(1<<RXEN)|(1<<TXEN); //(1 << RXCIE) for interrupts (sreg 1 rxc, in ucsra 1)

} 

/////////////////////////////////////////////////////////////////////////////////////

void Aus_Ein_Next()

{ 

PORTD = 1<< PB4 ; //   PB4 -->  AUS

_delay_ms(2000);

PORTD = 1<< PB5 ; //    PB5 --> EIN

_delay_ms(2000);

PORTD = 1<< PB6 ; //    PB6 --> NEXT

}