Question

怎样用定时器编写一个LED灯间隔1秒钟亮灭C程序？

Answer 1

#include <reg51.h>

#define uchar unsigned char

sbit LED=P1^0;

uchar time;

void InitTimer0(void)

{

TMOD = 0x01;   //定时器0，工作方式1

TH0 = 0x3c;

TL0 = 0xb0;    //50ms中断一次

EA = 1;

ET0 = 1;

TR0 = 1;

}

void main(void)

{

InitTimer0();

while(1)        

if(time==20) //中断20次，1s

{

time=0;

LED=!LED; P1.0上的LED1s亮灭一次

}

}

void Timer0Interrupt(void) interrupt 1

{

TH0 = 0x3c;

TL0 = 0xb0;

time++;

}

Answer 2

#include <reg51.h>
#define uchar unsigned char
sbit LED=P1^0;
uchar time;

void InitTimer0(void)
{
TMOD = 0x01; //定时器0，工作方式1
TH0 = 0x3c;
TL0 = 0xb0; //50ms中断一次
EA = 1;
ET0 = 1;
TR0 = 1;
}

void main(void)
{
InitTimer0();
while(1)
if(time==20) //中断20次，1s
{
time=0;
LED=!LED; P1.0上的LED1s亮灭一次
}
}
void Timer0Interrupt(void) interrupt 1
{
TH0 = 0x3c;
TL0 = 0xb0;
time++;
}