【求助】51单片机直流电机转速控制，程序问题在哪？

ti

程序如下：#include

#define uchar unsigned char
#define uint unsigned int

const uchar tab_hi[] = {0x81,0xf7,0xf7,0x81,0xff,0xbd,0x81,0xbd}; //HI default
const uchar tab_zheng[] = {0x7e,0x7e,0x06,0x7e,0x00,0x76,0x76,0x76};       //zheng
const uchar tab_fang[] = {0x7f,0x9f,0x6f,0xb1,0xea,0xea,0xb2,0x7a};       //fang
const uchar tab_stop[]  = {0xff,0xff,0x00,0xee,0xee,0xee,0xf5,0xfb};       //P

uchar *p;

uchar PWM1=0xfe; //PWM greater ,speed faster,default 0.5 ms
uchar PWM2=0x34;

uchar ENA;
uchar count0=0;
uchar count1=0;

const uchar tab[]       = {0x7f,0xbf,0xdf,0xef,0xf7,0xfb,0xfd,0xfe};    //P2

***it dir = P1^0; //direction
***it faster = P1^1; //faster
***it lower  = P1^2; //lower
***it st       = P1^3;       //start or stop

***it P3_6 = P3^6;
***it P3_7 = P3^7;

void delay(uint n)    //delay n ms
{
uchar i,j;
for(i=n;i>0;i--)
for(j=110;j>0;j--);       //delay 1ms

}

void init(void)
{
TMOD = 0x11; // t1 work on mode 1,t0 work on mode 1
TH0 =0xfc;    //initial value fc66, means 1 ms
TL0 =0x66;

TH1 =PWM1;
TL1 =PWM2;

EA = 1;
ET0=1;
ET1=1;

TR0 =1;    //T0 START

}

void timer0() interrupt 1 //timer 0 interrupt
{
TH0=0xfc;    //reload the 1 ms value to the timer 0
TL0=0x66;

if(count0<100)
count0++;
else
{
count0=0;
ENA=1;
TH1=PWM1;
TL1=PWM2;
TR1=1;    //T1 START
}

}

void timer1() interrupt 3 //timer 1 interrupt 3
{
TH1=PWM1; // reload the value
TL1=PWM2;

if(count1<100)
count1++;
else
{
TR1=0;       //T1 stop
ENA=0;
count1=0;
}
}

void main(void)
{
uchar i,j,change=0,direction=0;

P1 = 0xff;    // SET 1 prepare to read data from P1 port
P3_6 = 1;                   // the default state of motor is stop
P3_7 = 1;

p = tab_hi;    //initiated the 8*8 led, show HI

init();
while(1)
{
if(dir==0)       //dir = change the direction of motor
{
delay(10);       //delay for debouncing
if(dir==0)
{
direction = ~direction;
if(direction==0)
{

P3_6=1;
P3_7=ENA;
p =tab_zheng;
}
else
{
P3_6=ENA;
P3_7=1;
p=tab_fang;
}
}
while(!dir);
delay(10);
while(!dir);
}

if(faster==0)    // speed up
{
delay(10);
if(faster==0)
{
PWM1=0xff;  //0.05ms
PWM2=0xd2;
}
while(!faster);
delay(10);
while(!faster);
}

if(lower==0) //lower = speed down
{
delay(10);
if(lower==0)
{
PWM1=0xfc; //0.95 ms
PWM2=0x94;
}
while(!lower);
delay(10);
while(!lower);
}

if(st==0) //st = start the motor or stop the motor
{
delay(10);
if(st==0)
{
change = ~change;
if(change==0)       //stop t0he motor
{

P3_6 = 1;
P3_7 = 1;
PWM1 = 0xfe; //0.5 ms
PWM2 = 0x34;
p = tab_stop;
}
else             // start the motor
{
P3_6 = 1;
P3_7 = ENA;
p = tab_zheng;
}
}
while(!st);
delay(10);
while(!st);
}

for(i=0,j=0;i<8;i++)
{
P2 = tab[j++];    // enable
P0 = *p++; //zi xing ma
delay(2);
if(j==8)
{
j=0;
p=p-8;
//P0=0xff;
//P2=0x00;
}
}
}
}

实际调试的时候，电机速度不变，不知道是什么原因，求大家分析一下

byyang · 2014-11-1 18:20:07

程序的主要思想是利用T0和T1定时器，都工作在模式1,16位定时器，T0产生1ms定时来将ENA拉高（ENA用来驱动直流电机），通过控制T1的初值来控制电机的转速。但是下到硬件上的时候，速度没有明显改变啊。

byyang · 2014-11-1 18:57:57

P3_6和P3_7用来驱动直流电机，P1_0，P1_1，P1_2，P1_3接4个按键，分别为电机转向，电机加速，电机减速，电机启动或停止。P0和P2口驱动8*8点阵，都为低时LED亮。
大概就是这样，按加速键和减速键不能调节电机速度，程序的问题到底在哪呢？

2014-11-1 19:46:42

唉，只能猜测你的驱动是桥式驱动了；

ENA为脉冲信号，但是没有随时更新给P3.6、P3.7，根据你的程序，ENA只在方向按钮按下时才会更新给P3.6、P3.7,所以你的电机并没有处在脉冲调宽的工作状态，而是处于全速状态，因为驱动没有被调制；

提问最好尽量描述自己的思路，控制细节，这样别人才能很快找到你的问题；要别人来猜你的设计和思路，实际是在浪费别人的时间