#include

#define TH0_TL0 (65536-1000)//设定中断的间隔时长

unsigned char count0 = 50;//高电平的占空比
unsigned char count1 = 0;//比较用的临时变量

bit Flag = 1;//电机正反转标志位,1正转，0反转

sbit Key_add=P2 ^ 0; //电机减速
sbit Key_dec=P2 ^ 1; //电机加速
sbit Key_turn=P2 ^ 2; //电机换向

sbit PWM1=P2^6;//PWM 通道 1，反转脉冲
sbit PWM2=P2^7;//PWM 通道 2，正转脉冲

unsigned char Time_delay;


void Delay(unsigned char x);
void Motor_speed_high(void);
void Motor_speed_low(void);
void Motor_turn(void);
void Timer0_init(void);


void Delay(unsigned char x)
{
Time_delay = x;

while(Time_delay != 0);//等待中断，可减少PWM输出时间间隔
}


void Motor_speed_high(void)//
{
if(Key_add==0)
{
  Delay(10);
  if(Key_add==0)
  {
    count0 += 5;
  
    if(count0 >= 100)
    {
    count0 = 100;
    } 
  }
  while(!Key_add);//等待键松开
}
}


void Motor_speed_low(void)
{
if(Key_dec==0)
{
  Delay(10);
  if(Key_dec==0)
  {
    count0 -= 5;
  
    if(count0 <= 0)
    {
    count0 = 0;
    } 
  }
  while(!Key_dec );
} 
}


void Motor_turn(void)
{
if(Key_turn == 0)
{
  Delay(10);
  if(Key_turn == 0)
  {
    Flag = ~Flag;
  }
  while(!Key_turn);
}
}


void Timer0_init(void)
{
TMOD=0x01; //定时器0工作于方式1
TH0=TH0_TL0/256;
TL0=TH0_TL0%6;
TR0=1;
ET0=1;
EA=1;
}


void main(void)
{
Timer0_init();

while(1)
{
  Motor_turn();
  Motor_speed_high();
  Motor_speed_low();
}
}


void Timer0_int(void) interrupt 1 using 1
{
TR0 = 0;//设置定时器初值期间，关闭定时器
TL0 = TH0_TL0 % 256;
TH0 = TH0_TL0 / 256 ;//定时器装初值
TR0 = 1;

if(Time_delay != 0)//延时函数用
{
  Time_delay--; 
}

if(Flag == 1)//电机正转
{
  PWM1 = 0; 
  
  if(++count1 < count0)
  {
    PWM2 = 1;
  }
    else 
    PWM2 = 0;

    if(count1 >= 100)
    {
    count1=0;
    }
}
  else //电机反转
  {
    PWM2 = 0; 
  
    if(++count1 < count0)
    {
    PWM1 = 1;
    }
    else 
    PWM1 = 0;
    
    if(count1 >= 100)
    {
      count1=0;
    }
  }
}