PIC18 ADC liefert nur zwei Werte.

#include <p18f2550.h>

#include <delays.h>

#include <usart.h>

#include <stdio.h>

#include <stdlib.h>

#include <adc.h>

#pragma config FOSC=XT_XT

#pragma config PWRT=ON   //Power on timer

#pragma config BOR=OFF   //Brown out reset

#pragma config WDT=OFF   //Watchdog timer

#pragma config LVP=OFF   //Low voltage progr.

#pragma config MCLRE=ON  //Master clear reset

void delay_ms(int ms);

void INIT_IO(void);

void delay_ms(int ms)

{

  int z;

    for (z=1; z<ms; z++)

    {     

      Delay10TCYx(25);

    }

}

void INIT_IO(void)

{

  PORTA = 0x00;

  TRISA = 0x10;   //Port A Bit 4 = input

  PORTB = 0x00;

  TRISB = 0x00;  //Port B all Bits = Output

}

void main (void)

{

  int result;

  char temp_str[]="00000";

  INIT_IO();

  OpenUSART( USART_TX_INT_OFF & USART_RX_INT_OFF & USART_ASYNCH_MODE & USART_EIGHT_BIT & USART_CONT_RX & USART_BRGH_HIGH, 25);

  OpenADC( ADC_FOSC_2 & ADC_RIGHT_JUST & ADC_0_TAD, ADC_CH0 & ADC_INT_OFF,1);

  Delay10TCYx( 50 );     // Delay for 50TCY

    while (1)

  {

    if(!(PORTA & 0x10))

    {

      ConvertADC();

      while( BusyADC() );   // Wait for completion

        result = ReadADC();   // Read result

      itoa(result, temp_str);

      putrsUSART((const rom far char *)"\n\rADC");

      putsUSART(temp_str);

      while(!BusyUSART());      

    }

    else

    {

      delay_ms(1000);

      PORTBbits.RB3 = 1;

      delay_ms(1000);

      PORTBbits.RB3 = 0;

    }

  }

  CloseUSART();

  CloseADC();

}