学习任务 | 矩阵按键输入数字,将二进制形式显示在LED灯上。 |
完成情况 | 大部分完成 |
问题汇总 | 如何获取数值 |
未解决问题 | 从按键获取各位数的实现算法 |
开发收获 | 了解了矩阵键盘的基本用法 |
自我评价 | 编程能力有待提高。经验积累不足。 |
代码:
#include<reg51.h>
#include<math.h>
sbit Beep = P2^3;
sbit LED1 = P0^0;
sbit LED2 = P0^1;
sbit LED3 = P0^2;
sbit LED4 = P0^3;
sbit LED5 = P0^4;
sbit LED6 = P0^5;
sbit LED7 = P0^6;
sbit LED8 = P0^7;
void delay(int x)
{
int i;
while(x--)
{
for (i = 0;i < 100;i++);
}
}
int main()
{
while(1)
{
unsigned int key[4] = {0};
unsigned int result[8] = {0};
unsigned int a[] = {0};
unsigned int i, j, num = 0;
for(i = 0, j = 0;i < 4;i++)
{
P3 = 0xf0;//判断哪一列被按下
if(P3 != 0xf0)//判断哪一列被按下
{
switch(P3)
{
case 0xe0: key[i] = 0; break;
case 0xd0: key[i] = 1; break;
case 0xb0: key[i] = 2; break;
case 0x70: key[i] = 3; break;
}
P3 = 0x0f;//判断哪一行被按下
switch(P3)
{
case 0x0e: key[i] += 1; break;
case 0x0d: key[i] += 5; break;
case 0x0b: key[i] += 9; break;
case 0x07: key[i] += 13; break;
}
}
if(key[i] > 11)
{
Beep = 0;
delay(3);
Beep = 1;
delay(1);
key[i] = 0;
i -= i;
}
else if(key[i] == 11)
{
break;
}
a[j] = key[i] - 1;
j++;
}
switch(j)
{
case 1:
num = a[0];
case 2:
num = a[0] * 10 + a[1];
case 3:
num = a[0] * 100 + a[1] *10 + a[3];
}
if(num > 255)//判断是否超出最大范围,若超过,蜂鸣器报警,数值清零
{
for(i = 0;i < 4;i++)
{
key[i] = 0;
}
while(i--)
{
Beep = 0;
delay(15);
Beep = 1;
delay(1);
}
}
else i = 0;
do{
result[i++] = num % 2;
num /= 2;
} while(num != 0);
P0 = 0xff;
LED1 = result[7];
LED2 = result[6];
LED3 = result[5];
LED4 = result[4];
LED5 = result[3];
LED6 = result[2];
LED7 = result[1];
LED8 = result[0];
}
return 0;
}