adcmain.c

这是单片机C51典型应用设计代码

#include <reg509.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 )
{
  ADCON1 &= ~0x0F;                          //Clears Channel for selection
  ADCON1 |= 0x0F & channel;                 //Selects received Channel
  ADDATL |= ~ADDATL;                        //Write to ADDATL starts execution of ADC

  while( ADCON0 & 0x10);                    //Wait until A to D is complete
  return( (  ( (unsigned) ADDATH << 8) | ADDATL ) >> 6 );
}


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

  S0CON  = 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
  TI0    = 1;                // TI:   set TI to send first char of UART

  while(1)
  {
    for( i = 0; i < 15; i++ )
    {
      printf("Channel %2u = %4u\n", (unsigned) i, Read_ADC( i ) );
    }
    printf("\n");
  }
}