adc_portd.c

PIC单片机C语言程序设计实例精粹

#include <stdio.h>
#include <pic.h>
#include "usart.h"
__CONFIG(WDTDIS & HS & LVPDIS & DEBUGDIS);//配置位


void DELAY1(int time);
void USART(int a);
void INITIAL(void);
void init_a2d(void);
unsigned char read_a2d(unsigned char channel);


void main(void)
{

	unsigned char i,j,press1,press2;
	init_comms();	//串口初始化
	init_a2d();    //AD转换初始化
	ADCON1=0X07;

	for(i=0;i<1000;i++)
	{
		press1=read_a2d(0);
		press2=read_a2d(1);

		USART(press1);//发送的是8位的二进制数据
		USART(press2);
				
	}
}



void DELAY1(int time)
{
	int x,y;
	for(x=0;x<1000;x++)
	{
		for(y=0;y<time;y++);
	}
}



void USART(int a)//发送一个字节
{   TXSTA_5=0X01;
    while(!TXIF)
         continue;
	    TXREG=a;
}



void INITIAL(void)//波特率设置
{	SPBRG=23;//波特率9600//	
	TRISC=0XFF;//设置端口c//
	TXSTA=0XA6;//10100110//
	RCSTA=0XB0;//10110000//
	PIR1=0X00;//第一外设中断标志寄存器//
	
}


void init_a2d(void)//AD初始化
{
	ADCON0=0;	// select Fosc/8//
	ADCON1=0;	// select left justify result. A/D port configuration 0//
	ADON=1;		// turn on the A2D conversion module//
	ADIE=0;//关ad中断
}


unsigned char read_a2d(unsigned char channel)//读取AD值
{
	channel&=0x07;	//00000111 truncate channel to 3 bits
	ADCON0&=0x85;	//11000101 clear current channel select
	ADCON0|=(channel<<3);	// apply the new channel select
	DELAY1(1);
	ADGO=1;	// initiate conversion on the selected channel
	while(ADGO)continue;
	return(ADRESH);	//这里只返回了转换值的高8bit，能满足一般精度并简化程序
}