51单片机控制直流电机程序

#include

// Define new types

typedef unsigned char uchar;

typedef unsigned int uint;

// Define P3 pins

sbit Inc = P3^4;

sbit Dec = P3^5;

sbit Dir = P3^6;

sbit PWM = P3^7;

void delay(uint);

void main(void)

{

int speed;

// Select initial direction and speed.

if (Dir) //Dir = 1 anti clockwise;Dir = 0 clockwise speed = 400; //T(PWM) = 0.012s,f = 83.3Hz else

speed = 100;

// Main control loop

while(1)

{

if(Dir) //anti_clockwise

{

if(!Inc)

// Increase speed

speed = speed > 0 ? speed - 1 : 0;

if(!Dec)

// Decrease speed

speed = speed

// Drive a PWM signal out.

PWM=1;

delay(speed);

PWM=0;

delay(500-speed);

}

else //clockwise

{

if(!Inc)

// Increase speed

speed = speed

// Decrease speed

speed = speed > 0 ? speed - 1 : 0;

// Drive a PWM signal out.

PWM=1;

delay(speed);

PWM=0;

delay(500-speed);

}

}

}

void delay(uint j)

{ for(; j>0; j--)

{

//__no_operation();

}

}