(十七）51单片机——AD/DA转换

// XRT2046.c
#include <REGX52.H>
#include "Delay.h"

//引脚定义
sbit XPY2046_DIN=P3^4;
sbit XPY2046_CS=P3^5;
sbit XPY2046_DCLK=P3^6;
sbit XPY2046_DOUT=P3^7;

/**
  * @brief  ZPT2046读取AD值
  * @param  Command 命令字，范围：头文件内定义的宏，结尾的数字表示转换的位数
  * @retval AD转换后的数字量，范围：8位为0~255，12位为0~4095
  */
unsigned int XPT2046_ReadAD(unsigned char Command)
{
	unsigned int ADValue = 0;
	unsigned char i;
	
	XPY2046_DCLK = 0;
	XPY2046_CS = 0;
	for(i=0;i<8;i++)
	{
		XPY2046_DIN=Command&(0x80>>i);
		XPY2046_DCLK=1;
		Delay(1);
		XPY2046_DCLK=0;
	}

	for(i=0;i<16;i++)
	{
		XPY2046_DCLK=1;
		Delay(1);
		XPY2046_DCLK=0;
		if(XPY2046_DOUT){ADValue|=(0x8000>>i);}
	}
	XPY2046_CS=1;
	if(Command & 0x08){
	return ADValue>>8;
	}else
	return ADValue>>4;
}

// main.c
#include <REGX52.H>
#include "LCD1602.h"
#include "Delay.h"
#include "XPT2046.h"

unsigned int ADValue1 = 0,ADValue2 = 0,ADValue3 = 0;

sbit LED = P2^0;

void main(){
	LCD_Init();
	LCD_ShowString(1,1,"ADD  NTC  GR");
	while(1){
		ADValue1 = XPT2046_ReadAD(XPT2046_XP_8);//读取AIN0，可调电阻
		LCD_ShowNum(2,1 ,ADValue1,3);
		ADValue2 = XPT2046_ReadAD(XPT2046_YP_8);//读取AIN1，热敏电阻
		LCD_ShowNum(2,6 ,ADValue2,3);
		ADValue3 = XPT2046_ReadAD(XPT2046_VBAT_8);//读取AIN2，光敏电阻
		LCD_ShowNum(2,11 ,ADValue3,3);
		if(ADValue3 < 100){// 光敏电阻小于100（较暗）就发光
			 LED = 0;
		}else{
			 LED = 1;
		}
	}
}

//main.c
#include <REGX52.H>
#include "Delay.h"
#include "Time0.h"

sbit DA = P2^1;

unsigned char Counter,Compare;//计数值和比较值，用于输出PWM
unsigned char i;

void main(){
	Timer0_Init();
	while(1){
for(i=0;i<90;i++)
		{
			Compare=i;			//设置比较值，改变PWM占空比
			Delay(10);
		}
		for(i=90;i>0;i--)
		{
			Compare=i;			//设置比较值，改变PWM占空比
			Delay(10);
		}
	}
	
}

void Timer0_Routine() interrupt 1
{
	static unsigned int T0Count;
	TL0 = 0xAD;		//设置定时初始值
	TH0 = 0xFF;
	Counter++;
	Counter%=90;
	if(Counter < Compare){
		DA = 1;
	}else
	DA = 0;
}