Question

用C编写一个51单片机程序,P2.2接一个独立按键,在1位数码管上显示按键按下的次数(

Answer 1

#include<reg51.h>
void Js_Scan(void);
void delay(int x);

sbit key=P2^2;

int code LED_Num[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; //数码管扫描数组，共阴极
//int code LED_Num[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90}; //共阳极
int i=0,flag=0;

void main()
{
if(key==0&&flag==0)
{
i++;
flag=1;
}
if(key==1&&flag==1)
{
flag=0;
}
Js_Scan();
}
void Js_Scan() //数码管扫描函数
{
uchar j; //定义j数据类型
for(j=0;j<5;j++) //建立循环
{
P1=0x00;P0=LED_Num[i];delay(1); //扫描显示秒表小数位，点不显示，稍作延时
}
}
void delay(int x) //延时函数，防止数码管显示不稳定
{
int k;
while(x--)
for(k=0;k<125;k++);
}

Answer 2

#include<reg52.h>
#define uint unsigned int
#define uchar unsigned char
sbit key2=P2^2;
sbit dula=P2^6;
sbit wela=P2^7;
uchar num;
uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,//数码管的段选
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};
void delay(uint z);
void display();
void main()
{
P3=0xff;
while(1)
{
if(key2==0)
{
delay(5);
if(key2==0)
{
num++;
if(num==16)
num=1;
display();
while(!key2);
}
delay(5);
while(!key2);
}

}
}
void delay(uint z)
{
uint x,y; //延时1ms
for(x=z;x>0;x--)
for(y=11;y>0;y--);
}
void display()
{
P0=0xfe;
wela=1;
wela=0;
P0=0xff;
P0=table[num];
dula=1;
dula=0;
}

Answer 3

先看你数码管带不带片选, 还是不用片选直接两排端口送段码位码的.