#include <avr/io.h>		// for the input/output register
  
  // For the serial port
  
  #define CPU_FREQ        16000000L       // Assume a CPU frequency of 16Mhz
  
  void init_serial(int speed)
  {
  /* Set baud rate */
  UBRR0 = CPU_FREQ/(((unsigned long int)speed)<<4)-1;
  
  /* Enable transmitter & receiver */
  UCSR0B = (1<<TXEN0 | 1<<RXEN0);
  
  /* Set 8 bits character and 1 stop bit */
  UCSR0C = (1<<UCSZ01 | 1<<UCSZ00);
  
  /* Set off UART baud doubler */
  UCSR0A &= ~(1 << U2X0);
  }
  
  void send_serial(unsigned char c)
  {
  loop_until_bit_is_set(UCSR0A, UDRE0);
  UDR0 = c;
  }
  
  unsigned char get_serial(void) {
  loop_until_bit_is_set(UCSR0A, RXC0);
  return UDR0;
  }
  
  // For the AD converter
  
  void ad_init(unsigned char channel)   
  {   
  ADCSRA|=(1<<ADPS2)|(1<<ADPS1)|(1<<ADPS0);   
  ADMUX|=(1<<REFS0)|(1<<ADLAR);
  ADMUX=(ADMUX&0xf0)|channel;   
  ADCSRA|=(1<<ADEN);
  }   
  
  //récupère la valeur de l'ADCH
  unsigned int ad_sample(void){
  ADCSRA|=(1<<ADSC);
  while(bit_is_set(ADCSRA, ADSC));
  return ADCH;
  }
  
  // For the I/O 
  void output_init(void){

  DDRB |= 0b00111111; // PIN 8-13 as output

  }
  
  void output_set(unsigned char value){
  if(value==0) PORTB &= 0xfe; else PORTB |= 0x01;
  }
  
  void input_init(void){

  DDRD |= 0b01111100;  // PIN 2-6 as input (Bouton Joystick + boutons)

  DDRC |= 0x03;		// PIN 0-1 analogiques comme input (x et y joystick analogique)

  }
  

  /*

  unsigned char input_get(void){
  return ((PIND&0x04)!=0)?1:0;
  }

  */

  /* Commande des LED */

  void commande_leds(){
  	unsigned char temp_serial, leds;

  	temp_serial = UDR0;
  	if (temp_serial !=0){
  		leds = temp_serial;
  		// Allumer LED de 'A' à 'F'
  		if (leds == 65) PORTB = PORTB | 0x01; 
  		if (leds == 66) PORTB = PORTB | 0x02;
  		if (leds == 67) PORTB = PORTB | 0x04;
  		if (leds == 68) PORTB = PORTB | 0x08;
  		if (leds == 69) PORTB = PORTB | 0x10;
  		if (leds == 70) PORTB = PORTB | 0x20;
  		
  		// Eteindre LED de 'a' à 'f'
  		if (leds == 97) PORTB = PORTB & 0xfe;
  		if (leds == 98) PORTB = PORTB & 0xfd;
  		if (leds == 99) PORTB = PORTB & 0xfb;
  		if (leds == 100) PORTB = PORTB & 0xf7;
  		if (leds == 101) PORTB = PORTB & 0xef;
  		if (leds == 102) PORTB = PORTB & 0xdf;
  	}

  }
  

  /* Récupération de la valeur des boutons et mise en forme */
  int get_buttons(void){
  	unsigned boutons = ((PIND & 0x7C)>>2) | 0b00100000;
  	return(boutons);
  }

  /* Met en forme l'octet de l'axe pos du joystick */
  int shape_joy(unsigned char pos){
  	pos = (pos >> 3) | 0b00100000;
  	return(pos);
  }

  /* Récupération de la valeur de l'axe du joystick sur la chaîne channel du CAN */
  int get_joystick(int channel){
  	  unsigned char axis;
  	  ad_init(channel);
      axis = ad_sample();
      shape_joy(axis);
      return(axis);
  }
  
  /* Dummy main */
  int main(void){
    init_serial(9600);
    output_init();
    input_init();
    
    unsigned char boutons, boutons_anc;
    unsigned char joystick_x, joystick_x_anc;
    unsigned char joystick_y, joystick_y_anc;
  
  	//Récupération des valeurs des boutons et joystick, et mise en forme
    boutons = get_buttons();
    joystick_x = get_joystick(1);
    joystick_y = get_joystick(0);

    //send_serial(boutons);
    
    while(1){

  		boutons_anc = boutons;
  		joystick_x_anc = joystick_x;
  		joystick_y_anc = joystick_y;

     	//Récupération des valeurs des boutons et joystick, et mise en forme
    	boutons = get_buttons();
    	joystick_x = get_joystick(1);
    	joystick_y = get_joystick(0);
      	
  
      send_serial(boutons+2);
      //retour chariot
      send_serial(0x0a);
      send_serial(0x0d);
      	
      //Cas où aucun caractère n'est reçu
      if ((UCSR0A & (1<<RXC0)) == 0){
      	
      	//if (boutons_anc != boutons){
      	//if (joystick_y_anc != joystick_y){
      	//if ((boutons_anc != boutons) || (joystick_x_anc != joystick_x) || (joystick_y_anc != joystick_y)){
      		//send_serial(boutons);
        	//send_serial(joystick_y);
        	//send_serial(joystick_y);
        	
        	//send_serial('r');
      	  	
        	//retour chariot
        	//send_serial(0x0a);
        	//send_serial(0x0d);
  			//}
  		}

  		else{
  		//Cas où un caractère attent d'être reçu
  		commande_leds();
  		}
    }
   		  

  	return 0;

  }