C52单片机PWM控制电机转速

#include

#define uint unsigned int

#define uchar unsigned char

sbit led=P1^0;

sbit key1=P3^4;

sbit key2=P3^5;

uint code table[]={3,4,6,8,10,12,

14,16,18,20,22,24,26,28,30,32,34,

36,38,40};

uchar t1=0,t2=0,cl=1,i;

uint aa,num,t0;

bit c=1;

void delay(uint z)

{

uint i,j;

for(i=z;i>0;i--)

for(j=110;j>0;j--);

}

void init()

{

TMOD=0x10;

EA=1;

ET1=1;

TR1=1;

TH1=0x00;

TL1=0x00;

}

void keyscan()

{

if(key1==0)

{

delay(10);

if(key1==0)

{

cl++;

num=table[cl];

while(!key1);

}

}

if(key2==0)

{

delay(10);

if(key2==0)

{

cl--;

num=table[cl];

while(!key2);

}

}

}

void main()

{

init();

while(1)

{

keyscan();

}

}

void timer_1() interrupt 3

{

TL1 = 0x3c; //200us

TH1 = 0xff;

t1++;

t2++;

if(t1 <= cl)

led = 0; //这三行通过t1与cl比较，控制led亮灭，也就是PWM调光。

if(t1 > cl)

led = 1; //

if(t1 == 50) t1 = 0; //

if(t2 ==250) //250次中断以后，进入以下语句，更改cl值，改变亮度。改变比较的值(250)

{ //可以调整闪烁速度。

t2=0;

if(c)

{

if(cl == num)

c=0; //由亮变暗标识

}

if(cl==3)

{

c=1;

}

}

}