#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 |= 0x01; // PIN 8 as output
  }
  
  void output_set(unsigned char value){
  if(value==0) PORTB &= 0xfe; else PORTB |= 0x01;
  }
  
  void input_init(void){
  DDRD &= 0xfb;  // PIN 2 as input
  PORTD |= 0x04; // Pull-up activated on PIN 2
  }
  
  unsigned char input_get(void){
  return ((PIND&0x04)!=0)?1:0;
  }
  
  // Dummy main
  
  int main(void){
      init_serial(9600);
      ad_init(0); //pas sur que ce soit ici
      output_init();
      input_init();
      
      
  return 0;
  }