Question

51单片机1个按键控制2个灯分别点亮的程序。

51单片机1个按键控制程序：按下松开，第1个灯亮;再按下松开，第1个灯灭，第2个灯亮; 再按下松开，2个灯都不亮。

Answer 1

#include <reg51.h>
#define uchar unsigned char
sbit key = P1^0;
sbit led0 = P1^1;
sbit led1 = P1^2;
uchar count = 0;
void delayms (uchar time)//延时
{
for(time; time>0; time--)
{
TMOD |= 0x01;
TH0 = 0xfc;
TL0 = 0x18;
TR0 = 1; //启动计数器0
while(TF0!=1);//计数溢出
TF0 = 0;
TR0 = 0;
}
}
void scan_key (void)
{
if (!key)
{
delayms (5);
if (!key)
{
delayms (1);
while (!key);
count++;
if (count==3)
{
count = 0;
}
}
}
}
void main (void)
{
P1 = 0xff;
while (1)
{
scan_key ();
if (count==0)
{
led0 = 1;
led1 = 1;
}
if (count==1)
{
led0 = 0;
led1 = 1;
}
if (count==2)
{
led0 = 1;
led1 = 0;
}
}
}

追问

A421.C(3): error C129: missing ';' before 'uchar' 提示有这个问题，是怎么回事？