基于单片机的信号发生器（原理图、单片机程序、效果图） -

#include "reg52.h"
#include <I2C.H>
#define uchar unsigned char
#define uint unsigned int
#define PCF8591 0x90 //PCF8591 地址
sbit CS =P3^5;
sbit SID=P3^6;
sbit SCLK=P3^7;
unsigned char i=0;
unsigned char code D[5]={0,0,0,0,255};
unsigned char key;
unsigned char code sin[]={128.00,135.97,143.92,151.80,159.58,167.25,174.75,189.18, 196.05, 202.65,
208.95, 214.94, 220.58, 225.86, 230.75, 235.23, 239.29, 242.91, 246.08, 248.78, 251.01, 252.75, 254.00, 254.75, 255.00,255.00 ,255.00 ,
254.75, 254.00, 252.75, 251.01, 248.78, 242.91, 239.29, 235.23, 230.75, 225.86, 220.58, 214.94, 208.95, 202.65, 196.05,189.18,
182.07, 174.75,167.25, 159.58, 151.80, 143.92, 135.97, 128.00, 120.03, 112.08, 104.20, 96.42, 88.75, 81.25, 73.93, 66.82, 59.95,
53.35, 47.05, 41.06, 35.42, 30.14, 25.25 , 20.77, 16.71, 13.09, 9.92, 7.22, 4.99, 3.25, 2.00, 1.25, 1.00,
1.25, 2.00, 3.25, 4.99, 7.22, 9.92, 13.09, 16.71, 20.77, 25.25, 30.14, 35.42, 41.06, 47.05, 53.35,
59.95, 66.82, 73.93, 81.25, 88.75, 96.42, 104.20, 112.08, 120.03, 128.00 };
unsigned char code Duan[17]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0x76};
unsigned char Data_Buffer[4]={1,2,3,4};
sbit P24=P2^4; //四个数码管的位码口定义
sbit P25=P2^5;
sbit P26=P2^6;
sbit P27=P2^7;
bit DACconversion(unsigned char sla,unsigned char c, unsigned char Val);
unsigned char code high[5]={0xdb,0xed,0xf3,0xf6,0xf8};
unsigned char code low[5]={0xff,0xff,0xff,0xff,0xcb};
unsigned char code PIN[5]={1,2,3,4,5};
unsigned char code FU[5]={5,4,3,2,1};
unsigned char p;
unsigned char v;
unsigned char Bit;
unsigned char flag=0;
unsigned char y;
void delay(unsigned int i)
{
unsigned int j;
for(;i>0;i--)
for(j=0;j<333;j++)
{;}
}
uchar KeyScan() //带返回值的子函数
{
uchar cord_l,cord_h;//声明列线和行线的值的储存变量
P1 = 0xf0;//1111 0000
if( (P1 & 0xf0) != 0xf0)//判断是否有按键按下
{
delay(50);//软件消抖
if( (P1 & 0xf0) != 0xf0)//判断是否有按键按下
{
cord_l = P1 & 0xf0;// 储存列线值
P1 = cord_l | 0x0f;
cord_h = P1 & 0x0f;// 储存行线值
while( (P1 & 0x0f) != 0x0f );//松手检测
return (cord_l + cord_h);//返回键值码
}
}
}
void KeyPro()
{
uchar key;
switch( KeyScan() )
{
//第一行键值码
case 0xee: key = '0'; v=0; break;
case 0xde: key = '1'; v=1; break;
case 0xbe: key = '2'; v=2; break;
case 0x7e: key = '3'; v=3; break;
//第二行键值码
case 0xed: key = '4';
p++;
if(p==5)
p=0;
break;
case 0xdd: key = '5';
p--;
if(p<0)
p=4;
break;
case 0xbd: key = '6';
y=0;
break;
case 0x7d: key = '7';
y=1;
break;
//第三行键值码
case 0xeb: key = '8';
y=2;
break;
case 0xdb: key = '9';
y=3 ;
break;
case 0xbb:
y=4;
break;
}
}
void main()
{
TMOD = 0x01; //启动定时器方式2
TH0=high[p]; //定时器初值
TL0=low[p];
ET0=1; //T0允许
TR0=1; //T0启动
IT0=1;
EX0=1;
EA=1;
while(1)
{
KeyPro();
if(flag==1) //定时器中断启动标志
{ flag=0;
i++;
if(i>100)
i=0 ;
if(v==0) //(正弦)
{
switch(y)
{
case 0: DACconversion(PCF8591,0x40,sin[i]);break;
case 1: DACconversion(PCF8591,0x40,sin[i]*0.8);break;
case 2: DACconversion(PCF8591,0x40,sin[i]*0.6);break;
case 3: DACconversion(PCF8591,0x40,sin[i]*0.4);break;
case 4: DACconversion(PCF8591,0x40,sin[i]*0.2);break;
}
}
if(v==1) //（三角）
{
if(i<50)
{
switch(y)
{
case 0: DACconversion(PCF8591,0x40,i*4.9);break;
case 1: DACconversion(PCF8591,0x40,i*0.8*4.9);break;
case 2: DACconversion(PCF8591,0x40,i*0.6*4.9);break;
case 3: DACconversion(PCF8591,0x40,i*0.4*4.9);break;
case 4: DACconversion(PCF8591,0x40,i*0.2*4.9);break;
}
}
else
{
switch(y)
{
case 0: DACconversion(PCF8591,0x40,(100-i)*4.9);break;
case 1: DACconversion(PCF8591,0x40,(100-i)*0.8*4.9);break;
case 2: DACconversion(PCF8591,0x40,(100-i)*0.6*4.9);break;
case 3: DACconversion(PCF8591,0x40,(100-i)*0.4*4.9);break;
case 4: DACconversion(PCF8591,0x40,(100-i)*0.2*4.9);break;
}
}
}
if(v==2) //（方波）
{
if(i<50)
{
switch(y)
{
case 0: DACconversion(PCF8591,0x40,D[4]);break;
case 1: DACconversion(PCF8591,0x40,D[4]*0.8);break;
case 2: DACconversion(PCF8591,0x40,D[4]*0.6);break;
case 3: DACconversion(PCF8591,0x40,D[4]*0.4);break;
case 4: DACconversion(PCF8591,0x40,D[4]*0.2);break;
}
}
else
switch(y)
{
case 0: DACconversion(PCF8591,0x40,D[0]);break;
case 1: DACconversion(PCF8591,0x40,D[0]*0.8);break;
case 2: DACconversion(PCF8591,0x40,D[0]*0.6);break;
case 3: DACconversion(PCF8591,0x40,D[0]*0.4);break;
case 4: DACconversion(PCF8591,0x40,D[0]*0.2);break;
}
}
if(v==3) //（锯齿）
{
if(i<100)
{
switch(y)
{
case 0: DACconversion(PCF8591,0x40,i*2.49);break;
case 1: DACconversion(PCF8591,0x40,i*0.8*2.49);break;
case 2: DACconversion(PCF8591,0x40,i*0.6*2.49);break;
case 3: DACconversion(PCF8591,0x40,i*0.4*2.49);break;
case 4: DACconversion(PCF8591,0x40,i*0.2*2.49);break;
}
}
if(i==100)
{i=0;
}
}
}
Data_Buffer[0]=v%10; //（通道口）
Data_Buffer[1]=PIN[p]%10; //（频率）
Data_Buffer[2]=FU[y]%10; //（幅度）
}
}
void Timer0() interrupt 1 //（定时器0）
{
TH0=high[p];
TL0=low[p];
flag=1;
Bit++;
if(Bit>=3)Bit=0;
P2 |=0xf0; //先关位码
P0=Duan[Data_Buffer[Bit]]; //开段码
switch(Bit) //送位码
{
case 0: P24=0;break;
case 1: P25=0;break;
case 2: P26=0;break;
case 3: P27=0;break;
}
}
/*******************************************************************
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);
}

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