[嵌入式][51单片机]两按键实现数码管加减

?本篇为1-9加减，两位三位乃至更多参考上篇博客，把num相除取模。

#include<reg52.h>
sbit key1 = P1^3;
sbit key2 = P1^5;
sbit duan = P2^1;
sbit wei = P2^0;
time()
{
 unsigned int i;
	for(i=0;i<10000;i++);
}
led(int num)
{
	char code wz[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
	char code xs[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};	
	P0=0xfe;
	duan=1;
	duan=0;
	P0=xs[num];
	wei=1;
	wei=0;
//	time();
}
main()
{
	int num = 0;
  while(1)
  {
		if(!key1)
		{
			time();
		  while(!key1);
			if(num>0)
			{
				num--;
				led(num);
			}
		}

		if(!key2)
		{
			time();
		  while(!key2);
			if(num<9)
			{
				num++;
				led(num);
			}
		}
		
	}
}