adcmain.c

这是单片机C51典型应用设计代码

/*------------------------------------------------------------------------------
adcMain.c : Sample Program that demonstrates the A to D converter of the 
following microcontrollers

   * Infineon SAB 80C537

Copyright (c) 1988-2001 Keil Elektronik GmbH and Keil Software, Inc.
All rights reserved.
--------------------------------------------------------------------------*/

#include <stdio.h>



sfr ADCON0  = 0xD8;
sfr ADCON1 = 0xDC;
sfr ADDAT  = 0xD9;
sfr DAPR   = 0xDA;

sfr S0CON   = 0x98;
sfr TMOD   = 0x89;
sfr TH1    = 0x8D;
sbit TR1    = 0x8E;
sbit TI0     = 0x99;

/*------------------------------------------------------------------------------
Read_ADC( unsigned char ): reads an analog signal from the received unsigned
char and returns the converted value
------------------------------------------------------------------------------*/
unsigned char Read_ADC( unsigned char channel )
{
	ADCON1 &= ~0x0F;				//Prepare channel selector	
	ADCON1 |= 0x0F & channel;		//Set input channel
		
	DAPR  = 0x00;					//Setting Vgnd and Vref to 0 and 5
									//This starts the conversion process.

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

/*------------------------------------------------------------------------------
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 < 12; i++)
		{
			printf("Channel %u = %4u\n",(unsigned) i, (unsigned)Read_ADC(i) );
		}
	}
}