Kapazitätmessen - komische Werte

SIGNAL(SIG_COMPARATOR)

{

  double result = 0;

  result = TCNT1;//*62/1000;

  //result = TCNT1;

  char test[10];

  dtostrf(result,3,1,test);

  send_string(test);

  send_string("pF---");

  ACSR &= ~(1<<ACIE);  //Interrupt disablen um prellen zu verhindern

}

void get_cap(void)

{

  TCNT1 = 0x00;    // Timerregister 0 setzen

  PORTD |= (1<<PD5);  // High setzen um Kondensator zu laden

  ACSR |= (1<<ACIE);    //Interrupt enablen

}

int main(void)

{

 sei();

 init_usart();

 DDRD |= (1<<PD5);

 DDRD &= ~(1<<PD7) | ~(1<<PD6);

 TCCR1B = (1 << CS10);  //Prescaler: keiner

 ACSR |= (1<<ACIE) | (1<<ACIS0) | (1<<ACIS1); //Interrupt enable rising edges

  while(1)

  {

    delay_ms(1000);

    PORTD &= ~(1<<PD5);  // Kondensator entladen

    delay_ms(1000);

    get_cap();

  }

}