adcmain.c

这是单片机C51典型应用设计代码

#include <reg505C.h>
#include <stdio.h>


/*------------------------------------------------------------------------------
Read_ADC( unsigned char ): reads an analog signal from the received unsigned
char and returns the converted value
------------------------------------------------------------------------------*/
unsigned Read_ADC( unsigned char channel )
{
  ADCON0 &= ~0x07;           //Clear Input Channel
  ADCON0 |= 0x7 & channel;    //Set Channel input
  ADST |= 0x01;              //Starts the conversion with a write to the register

  while( ADCON0 & 0x10 );    //Wait for conversion to end
  return( (unsigned) ADDAT );
}


/*------------------------------------------------------------------------------
main() : Outputs the digital conversion of channels 0 - 11.
------------------------------------------------------------------------------*/
void main( void )
{
  unsigned char i;

  SCON  = 0x50;              // SCON: mode 1, 8-bit UART, enable rcvr
  TMOD |= 0x20;              // TMOD: timer 1, mode 2, 8-bit reload
  TH1   = 221;               // TH1:  reload value for 1200 baud @ 16MHz
  TR1   = 1;                 // TR1:  timer 1 run
  TI    = 1;                 // TI:   set TI to send first char of UART

  while(1)
  {
    for( i = 0; i < 8; i++ )
    {
      printf("Channel %2u = %4u\n", (unsigned) i, Read_ADC( i ) );
    }
    printf("\n");
  }
}