单片机DA转换实现正弦波

使用的是查表法：

1.c文件：

#include "reg52.h"
#include <intrins.h>
#include <i2c.h>
#define PCF8591 0x90
#define uint unsigned int 
#define uchar unsigned char
#define arr_length 720	//正弦波数组长度 
code unsigned  char sin1[720]={0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x8a,0x8b,0x8c,0x8d,0x8e,
0x8f,0x90,0x91,0x92,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0xa0,0xa1,0xa2,0xa3,0xa4,
0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,0xb0,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,
0xba,0xbb,0xbc,0xbd,0xbe,0xbf,0xbf,0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,
0xcd,0xcd,0xce,0xcf,0xd0,0xd1,0xd2,0xd3,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd8,0xd9,0xda,0xdb,0xdc,0xdc,
0xdd,0xde,0xdf,0xdf,0xe0,0xe1,0xe2,0xe2,0xe3,0xe4,0xe4,0xe5,0xe6,0xe6,0xe7,0xe8,0xe8,0xe9,0xea,0xea,
0xeb,0xeb,0xec,0xed,0xed,0xee,0xee,0xef,0xef,0xf0,0xf1,0xf1,0xf2,0xf2,0xf3,0xf3,0xf4,0xf4,0xf4,0xf5,
0xf5,0xf6,0xf6,0xf7,0xf7,0xf7,0xf8,0xf8,0xf9,0xf9,0xf9,0xfa,0xfa,0xfa,0xfb,0xfb,0xfb,0xfb,0xfc,0xfc,
0xfc,0xfc,0xfd,0xfd,0xfd,0xfd,0xfe,0xfe,0xfe,0xfe,0xfe,0xfe,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xfe,0xfe,0xfe,0xfe,0xfe,0xfe,0xfd,0xfd,0xfd,0xfd,0xfc,0xfc,0xfc,0xfc,0xfb,0xfb,
0xfb,0xfb,0xfa,0xfa,0xfa,0xf9,0xf9,0xf9,0xf8,0xf8,0xf7,0xf7,0xf7,0xf6,0xf6,0xf5,0xf5,0xf4,0xf4,
0xf4,0xf3,0xf3,0xf2,0xf2,0xf1,0xf1,0xf0,0xef,0xef,0xee,0xee,0xed,0xed,0xec,0xeb,0xeb,0xea,0xea,
0xe9,0xe8,0xe8,0xe7,0xe6,0xe6,0xe5,0xe4,0xe4,0xe3,0xe2,0xe2,0xe1,0xe0,0xdf,0xdf,0xde,0xdd,0xdc,
0xdc,0xdb,0xda,0xd9,0xd8,0xd8,0xd7,0xd6,0xd5,0xd4,0xd3,0xd3,0xd2,0xd1,0xd0,0xcf,0xce,0xcd,0xcd,
0xcc,0xcb,0xca,0xc9,0xc8,0xc7,0xc6,0xc5,0xc4,0xc3,0xc2,0xc1,0xc0,0xc0,0xbf,0xbe,0xbd,0xbc,0xbb,
0xba,0xb9,0xb8,0xb7,0xb6,0xb5,0xb4,0xb3,0xb2,0xb0,0xaf,0xae,0xad,0xac,0xab,0xaa,0xa9,0xa8,0xa7,
0xa6,0xa5,0xa4,0xa3,0xa2,0xa1,0xa0,0x9e,0x9d,0x9c,0x9b,0x9a,0x99,0x98,0x97,0x96,0x95,0x94,0x92,
0x91,0x90,0x8f,0x8e,0x8d,0x8c,0x8b,0x8a,0x88,0x87,0x86,0x85,0x84,0x83,0x82,0x81,0x80,0x7e,0x7d,
0x7c,0x7b,0x7a,0x79,0x78,0x77,0x75,0x74,0x73,0x72,0x71,0x70,0x6f,0x6e,0x6d,0x6b,0x6a,0x69,0x68,
0x67,0x66,0x65,0x64,0x63,0x62,0x61,0x5f,0x5e,0x5d,0x5c,0x5b,0x5a,0x59,0x58,0x57,0x56,0x55,0x54,
0x53,0x52,0x51,0x50,0x4f,0x4d,0x4c,0x4b,0x4a,0x49,0x48,0x47,0x46,0x45,0x44,0x43,0x42,0x41,0x40,
0x40,0x3f,0x3e,0x3d,0x3c,0x3b,0x3a,0x39,0x38,0x37,0x36,0x35,0x34,0x33,0x32,0x32,0x31,0x30,0x2f,
0x2e,0x2d,0x2c,0x2c,0x2b,0x2a,0x29,0x28,0x27,0x27,0x26,0x25,0x24,0x23,0x23,0x22,0x21,0x20,0x20,
0x1f,0x1e,0x1d,0x1d,0x1c,0x1b,0x1b,0x1a,0x19,0x19,0x18,0x17,0x17,0x16,0x15,0x15,0x14,0x14,0x13,
0x12,0x12,0x11,0x11,0x10,0x10,0xf,0xe,0xe,0xd,0xd,0xc,0xc,0xb,0xb,0xb,0xa,0xa,0x9,0x9,0x8,0x8,
0x8,0x7,0x7,0x6,0x6,0x6,0x5,0x5,0x5,0x4,0x4,0x4,0x4,0x3,0x3,0x3,0x3,0x2,0x2,0x2,0x2,0x1,0x1,0x1,
0x1,0x1,0x1,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,
0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x1,0x1,0x1,0x1,0x1,0x1,0x2,0x2,0x2,0x2,0x3,0x3,0x3,0x3,0x4,0x4,
0x4,0x4,0x5,0x5,0x5,0x6,0x6,0x6,0x7,0x7,0x8,0x8,0x8,0x9,0x9,0xa,0xa,0xb,0xb,0xb,0xc,0xc,0xd,0xd,
0xe,0xe,0xf,0x10,0x10,0x11,0x11,0x12,0x12,0x13,0x14,0x14,0x15,0x15,0x16,0x17,0x17,0x18,0x19,0x19,
0x1a,0x1b,0x1b,0x1c,0x1d,0x1d,0x1e,0x1f,0x20,0x20,0x21,0x22,0x23,0x23,0x24,0x25,0x26,0x27,0x27,
0x28,0x29,0x2a,0x2b,0x2c,0x2c,0x2d,0x2e,0x2f,0x30,0x31,0x32,0x32,0x33,0x34,0x35,0x36,0x37,0x38,
0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f,0x3f,0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,
0x4b,0x4c,0x4d,0x4f,0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,
0x5f,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6d,0x6e,0x6f,0x70,0x71,0x72,0x73,
0x74,0x75,0x77,0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e};
uchar code sin2[256]={  
0x80, 0x83, 0x86, 0x89, 0x8c, 0x8f, 0x92, 0x95,         
0x98, 0x9c, 0x9f, 0xa2, 0xa5, 0xa8, 0xab, 0xae,        
0xb0, 0xb3, 0xb6, 0xb9, 0xbc, 0xbf, 0xc1, 0xc4,        
0xc7, 0xc9, 0xcc, 0xce, 0xd1, 0xd3, 0xd5, 0xd8,        
0xda, 0xdc, 0xde, 0xe0, 0xe2, 0xe4, 0xe6, 0xe8,        
0xea, 0xec, 0xed, 0xef, 0xf0, 0xf2, 0xf3, 0xf4,        
0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfc,        
0xfd, 0xfe, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff,        
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xfe,        
0xfd, 0xfc, 0xfc, 0xfb, 0xfa, 0xf9, 0xf8, 0xf7,        
0xf6, 0xf5, 0xf3, 0xf2, 0xf0, 0xef, 0xed, 0xec,  
0xea, 0xe8, 0xe6, 0xe4, 0xe3, 0xe1, 0xde, 0xdc,        
0xda, 0xd8, 0xd6, 0xd3, 0xd1, 0xce, 0xcc, 0xc9,        
0xc7, 0xc4, 0xc1, 0xbf, 0xbc, 0xb9, 0xb6, 0xb4,        
0xb1, 0xae, 0xab, 0xa8, 0xa5, 0xa2, 0x9f, 0x9c,        
0x99, 0x96, 0x92, 0x8f, 0x8c, 0x89, 0x86, 0x83,        
0x80, 0x7d, 0x79, 0x76, 0x73, 0x70, 0x6d, 0x6a,        
0x67, 0x64, 0x61, 0x5e, 0x5b, 0x58, 0x55, 0x52,        
0x4f, 0x4c, 0x49, 0x46, 0x43, 0x41, 0x3e, 0x3b,        
0x39, 0x36, 0x33, 0x31, 0x2e, 0x2c, 0x2a, 0x27,        
0x25, 0x23, 0x21, 0x1f, 0x1d, 0x1b, 0x19, 0x17,        
0x15, 0x14, 0x12, 0x10, 0x0f, 0x0d, 0x0c, 0x0b,        
0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x03,        
0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,        
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01,        
0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,        
0x09, 0x0a, 0x0c, 0x0d, 0x0e, 0x10, 0x12, 0x13,        
0x15, 0x17, 0x18, 0x1a, 0x1c, 0x1e, 0x20, 0x23,        
0x25, 0x27, 0x29, 0x2c, 0x2e, 0x30, 0x33, 0x35,        
0x38, 0x3b, 0x3d, 0x40, 0x43, 0x46, 0x48, 0x4b,        
0x4e, 0x51, 0x54, 0x57, 0x5a, 0x5d, 0x60, 0x63,        
0x66, 0x69, 0x6c, 0x6f, 0x73, 0x76, 0x79, 0x7c, }; 
sbit key1=P3^4;
sbit key2=P3^5;
uint speed=20; //正弦波变化速度
uint num=0;
uint time=0;
DACconversion(unsigned char sla,unsigned char c, unsigned char Val);
void Init_Timer1(void)//定时器一初始化程序
{
	TMOD=0x01;
	TH0=(65535-0)/256;
	TL0=(65535-0)%256;
	EA=1;//开总中断
	ET0=1;//开定时器0中断
	TR0=1; //启动定时器0
	
}
void delay(uchar s){
	uchar i,j;
	for(i=s;i>0;i--)
		for(j=110;j>0;j--);
}
void change_Speed(){
	if(key1==0){
		delay(10);
		if(key1==0){
			speed++;
		}
	}
	if(key2==0){
		delay(10);
		if(key2==0){
			if(speed>1)
			speed--;
		}
	}
}

void time0() interrupt 1{
	TH0=(65535-0)/256;
	TL0=(65535-0)%256;
	change_Speed();
	for(num=0;num<arr_length;num=num+speed){
		DACconversion(PCF8591,0x40,sin1[num]);	
	}
	if(num==arr_length){
		num=0;
	}
}
void main()
{
	Init_Timer1();	
} 

　　i2c.c文件

/*-----------------------------------------------
  名称：IIC协议 
  修改：无
  内容：函数是采用软件延时的方法产生SCL脉冲,固对高晶振频率要作 一定的修改....(本例是1us机器
		周期,即晶振频率要小于12MHZ)
------------------------------------------------*/  
  
              
#include "i2c.h"
//#include "delay.h"
#define PCF8591 0x90
#define  _Nop()  _nop_()  //定义空指令
                         
bit ack;	              //应答标志位

sbit SDA=P2^0;
sbit SCL=P2^1;

/*------------------------------------------------
                    启动总线
------------------------------------------------*/
void Start_I2c()
{
  SDA=1;   //发送起始条件的数据信号
  _Nop();
  SCL=1;
  _Nop();    //起始条件建立时间大于4.7us,延时
  _Nop();
  _Nop();
  _Nop();
  _Nop();    
  SDA=0;     //发送起始信号
  _Nop();    //起始条件锁定时间大于4μ
  _Nop();
  _Nop();
  _Nop();
  _Nop();       
  SCL=0;    //钳住I2C总线，准备发送或接收数据
  _Nop();
  _Nop();
}
/*------------------------------------------------
                    结束总线
------------------------------------------------*/
void Stop_I2c()
{
  SDA=0;    //发送结束条件的数据信号
  _Nop();   //发送结束条件的时钟信号
  SCL=1;    //结束条件建立时间大于4μ
  _Nop();
  _Nop();
  _Nop();
  _Nop();
  _Nop();
  SDA=1;    //发送I2C总线结束信号
  _Nop();
  _Nop();
  _Nop();
  _Nop();
}




/*----------------------------------------------------------------
                 字节数据传送函数               
函数原型: void  SendByte(unsigned char c);
功能:  将数据c发送出去,可以是地址,也可以是数据,发完后等待应答,并对
     此状态位进行操作.(不应答或非应答都使ack=0 假)     
     发送数据正常，ack=1; ack=0表示被控器无应答或损坏。
------------------------------------------------------------------*/
void  SendByte(unsigned char c)
{
 unsigned char BitCnt;
 
 for(BitCnt=0;BitCnt<8;BitCnt++)  //要传送的数据长度为8位
    {
     if((c<<BitCnt)&0x80)SDA=1;   //判断发送位
       else  SDA=0;                
     _Nop();
     SCL=1;               //置时钟线为高，通知被控器开始接收数据位
      _Nop(); 
      _Nop();             //保证时钟高电平周期大于4μ
      _Nop();
      _Nop();
      _Nop();         
     SCL=0; 
    }
    
    _Nop();
    _Nop();
    SDA=1;               //8位发送完后释放数据线，准备接收应答位
    _Nop();
    _Nop();   
    SCL=1;//控制线
    _Nop();
    _Nop();
    _Nop();
    if(SDA==1)ack=0;     
       else ack=1;        //判断是否接收到应答信号
    SCL=0;
    _Nop();
    _Nop();
}
/*******************************************************************
	DAC变换,转化函数
*******************************************************************/
bit DACconversion(unsigned char sla,unsigned char c, unsigned char Val)
{
	Start_I2c();//启动总线
	SendByte(sla);//发送器件地址
		if(ack==0)return(0);
	SendByte(c);//发送控制字节
		if(ack==0)return(0);
	SendByte(Val);//发送DAC的数值
		if(ack==0)return(0);
	Stop_I2c();//结束总线
		return(1);
}






/*----------------------------------------------------------------
                 字节数据传送函数               
函数原型: unsigned char  RcvByte();
功能:  用来接收从器件传来的数据,并判断总线错误(不发应答信号)，
     发完后请用应答函数。  
------------------------------------------------------------------*/	
/*unsigned char  RcvByte()
{
  unsigned char retc;
  unsigned char BitCnt;
  
  retc=0; 
  SDA=1;             //置数据线为输入方式
  for(BitCnt=0;BitCnt<8;BitCnt++)
      {
        _Nop();           
        SCL=0;       //置时钟线为低，准备接收数据位
        _Nop();
        _Nop();      //时钟低电平周期大于4.7us
        _Nop();
        _Nop();
        _Nop();
        SCL=1;       //置时钟线为高使数据线上数据有效
        _Nop();
        _Nop();
        retc=retc<<1;
        if(SDA==1)retc=retc+1; //读数据位,接收的数据位放入retc中
        _Nop();
        _Nop(); 
      }
  SCL=0;    
  _Nop();
  _Nop();
  return(retc);
}
*/


/*----------------------------------------------------------------
                     应答子函数
原型:  void Ack_I2c(void);
 
----------------------------------------------------------------*/
/*void Ack_I2c(void)
{
  
  SDA=0;     
  _Nop();
  _Nop();
  _Nop();      
  SCL=1;
  _Nop();
  _Nop();              //时钟低电平周期大于4μ
  _Nop();
  _Nop();
  _Nop();  
  SCL=0;               //清时钟线，钳住I2C总线以便继续接收
  _Nop();
  _Nop();    
}*/
/*----------------------------------------------------------------
                     非应答子函数
原型:  void NoAck_I2c(void);
 
----------------------------------------------------------------*/
/*void NoAck_I2c(void)
{
  
  SDA=1;
  _Nop();
  _Nop();
  _Nop();      
  SCL=1;
  _Nop();
  _Nop();              //时钟低电平周期大于4μ
  _Nop();
  _Nop();
  _Nop();  
  SCL=0;                //清时钟线，钳住I2C总线以便继续接收
  _Nop();
  _Nop();    
}

*/




/*----------------------------------------------------------------
                    向无子地址器件发送字节数据函数               
函数原型: bit  ISendByte(unsigned char sla,ucahr c);  
功能:     从启动总线到发送地址，数据，结束总线的全过程,从器件地址sla.
           如果返回1表示操作成功，否则操作有误。
注意：    使用前必须已结束总线。
----------------------------------------------------------------*/
/*bit ISendByte(unsigned char sla,unsigned char c)
{
   Start_I2c();               //启动总线
   SendByte(sla);             //发送器件地址
     if(ack==0)return(0);
   SendByte(c);               //发送数据
     if(ack==0)return(0);
  Stop_I2c();                 //结束总线
  return(1);
}
*/

/*----------------------------------------------------------------
                    向有子地址器件发送多字节数据函数               
函数原型: bit  ISendStr(unsigned char sla,unsigned char suba,ucahr *s,unsigned char no);  
功能:     从启动总线到发送地址，子地址,数据，结束总线的全过程,从器件
          地址sla，子地址suba，发送内容是s指向的内容，发送no个字节。
           如果返回1表示操作成功，否则操作有误。
注意：    使用前必须已结束总线。
----------------------------------------------------------------*/
/*bit ISendStr(unsigned char sla,unsigned char suba,unsigned char *s,unsigned char no)
{
   unsigned char i;
 for(i=0;i<no;i++)
    { 
   Start_I2c();               //启动总线
   SendByte(sla);             //发送器件地址
     if(ack==0)return(0);
   SendByte(suba);            //发送器件子地址
     if(ack==0)return(0); 
 
     SendByte(*s);            //发送数据
       if(ack==0)return(0);
     Stop_I2c();                  //结束总线
	 DelayMs(1);               //必须延时等待芯片内部自动处理数据完毕
	 s++;
	 suba++;
    } 
  return(1);
}
*/
/*----------------------------------------------------------------
                    向无子地址器件读字节数据函数               
函数原型: bit  IRcvByte(unsigned char sla,ucahr *c);  
功能:     从启动总线到发送地址，读数据，结束总线的全过程,从器件地
          址sla，返回值在c.
           如果返回1表示操作成功，否则操作有误。
注意：    使用前必须已结束总线。
----------------------------------------------------------------*/
/*bit IRcvByte(unsigned char sla,unsigned char *c)
{
   Start_I2c();                //启动总线
   SendByte(sla+1);            //发送器件地址
     if(ack==0)return(0);
   *c=RcvByte();               //读取数据
     NoAck_I2c();              //发送非就答位
     Stop_I2c();               //结束总线
  return(1);
}

*/
/*----------------------------------------------------------------
                    向有子地址器件读取多字节数据函数               
函数原型: bit  ISendStr(unsigned char sla,unsigned char suba,ucahr *s,unsigned char no);  
功能:     从启动总线到发送地址，子地址,读数据，结束总线的全过程,从器件
          地址sla，子地址suba，读出的内容放入s指向的存储区，读no个字节。
           如果返回1表示操作成功，否则操作有误。
注意：    使用前必须已结束总线。
----------------------------------------------------------------*/
/*bit IRcvStr(unsigned char sla,unsigned char suba,unsigned char *s,unsigned char no)
{
   unsigned char i;

   Start_I2c();               //启动总线
   SendByte(sla);             //发送器件地址
     if(ack==0)return(0);
   SendByte(suba);            //发送器件子地址
     if(ack==0)return(0);

   Start_I2c();
   SendByte(sla+1);
      if(ack==0)return(0);

  for(i=0;i<no-1;i++)
    { 
     *s=RcvByte();              //发送数据
      Ack_I2c();                //发送就答位 
     s++;
    } 
   *s=RcvByte();
    NoAck_I2c();                 //发送非应位
    Stop_I2c();                    //结束总线
  return(1);
}
*/

原理图：

　　

效果：

单片机课程设计~