ADC ATmega88PA Ergebnis immer gleich

program led_matr_volt1;

var error: byte;

var wert: word;

procedure ADCinit();

begin

Soft_UART_Write(0); //sign we are in procedure

REFS0_bit :=1; //select Vcc as reference, VCC is 4V

ADEN_bit := 1; //enable ADC

Soft_UART_Write(1); //sign, we ran through procedure

end;

function readADC(channel: byte):word;

var temp,temp2:byte;

begin

      Soft_UART_Write(2);

      MUX0_bit := channel.0;

      MUX1_bit := channel.1;

      MUX2_bit := channel.2;

      MUX3_bit := channel.3; //channel selection

      ADSC_bit :=1;//starts conversion

      Soft_UART_Write(3);

      while ADSC_bit <> 0 do

          begin

               Soft_UART_Write(4);

          end;  //polling till conversion finishs

      Soft_UART_Write(5);

      temp := ADCH;

      temp2 := ADCL;

      result := temp*256+temp2;

end;

begin

  DDRC := 0x00;

  error := Soft_UART_Init(PORTB, 7, 6, 14400, 0);

  delay_ms(1000);

  Soft_UART_Write(77);

  ADCinit();

  while true do

  begin

       wert := READADC(0);

       Soft_UART_Write(lo(wert)); //lower  byte

       Soft_UART_Write(hi(wert)); //higher byte

       delay_ms(1000);

  end;

end.