51单片机数字时钟为什么减到0后在减就出现乱数时分秒都是这样的

ID:638158 · 发表于 2021-1-2 14:59

单片机源程序如下:

#include <reg52.h>
#include <intrins.h>
#define uint unsigned int
#define uchar unsigned char
sbit J9A = P2^2;
sbit J9B = P2^3;
sbit J9C = P2^4;
sbit k1 = P1^0;
sbit k2 = P1^1;
sbit k3 = P1^2;
sbit k4 = P1^3;
sbit k5 = P1^4;
sbit k7 = P1^5;
#define GPIO_DIG P0
uchar code smgduan[] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; //0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88
//,0x83,0xc6,0xa1,0x86,0x8e,0xff 共阳
uchar LedBuff[8];
uchar sec = 52;
uchar min = 58;
uchar hour = 23;
uchar flags;
/*
void delay10ms(uint c)
{
uchar a,b;
for( ; c>0; c--)
for(b=38; b>0; b--)
for(a=130; a>0; a--);
} */
void delay(uint i) //delay(200)可以看到数码管不闪
{
while(i--);
}
void DigDisplay()
{
uint i;
for(i=0; i<8; i++)
{
switch(i)
{
case 0:J9A=0; J9B=0; J9C=0; break;
case 1:J9A=1; J9B=0; J9C=0; break;
case 2:J9A=0; J9B=1; J9C=0; break;
case 3:J9A=1; J9B=1; J9C=0; break;
case 4:J9A=0; J9B=0; J9C=1; break;
case 5:J9A=1; J9B=0; J9C=1; break;
case 6:J9A=0; J9B=1; J9C=1; break;
case 7:J9A=1; J9B=1; J9C=1; break;
}
GPIO_DIG = LedBuff[i];
delay(100);
GPIO_DIG = 0x00;
}
}
void DigClock(uchar hour,uchar min,uchar sec)
{
LedBuff[0] = smgduan[hour/10];
LedBuff[1] = smgduan[hour%10];
LedBuff[2] = 0x40;
LedBuff[3] = smgduan[min/10];
LedBuff[4] = smgduan[min%10];
LedBuff[5] = 0x40;
LedBuff[6] = smgduan[sec/10];
LedBuff[7] = smgduan[sec%10];
}
void Int0Init()
{
TMOD |= 0X01;
TH0 = 0XFC;
TL0 = 0X18;
ET0 = 1;
EA = 1;
TR0 = 1;
}
void main()
{
Int0Init();
while(1)
{
DigClock( hour, min, sec);
DigDisplay();
if(k1 == 0)
{
hour=0; min=0; sec=0;
}
if(k2 == 0)
{
TR0 = 0;
}
if(k3 == 0)
{
TR0 = 1;
}
if(k4 == 0)
{
delay(1);
if(k4 == 0)
{
TR0 = 0;
flags++;
if(flags > 3)
{
flags = 0;
TR0 = 1;
}
}
while(!k4);
}
switch(flags)
{
case 1:if(k5 == 0)
{
delay(1);
if(k5 == 0)
{
hour++;
if(hour > 23)
{
hour = 0;
}
while(!k5);
}
}
// DigClock( hour, min, sec);
// DigDisplay();
if(k7 == 0)
{
delay(1);
if(k7 == 0)
{
hour--;
if(hour < 0)
{
hour = 23;
}
while(!k7);
}
}
DigClock( hour, min, sec);
break;
case 2:if(k5 == 0)
{
delay(1);
if(k5 == 0)
{
min++;
if(min > 59)
{
min = 0;
}
while(!k5);
}
}
// DigClock( hour, min, sec);
// DigDisplay();
if(k7 == 0)
{
delay(1);
if(k7 == 0)
{
min--;
if(min < 0)
{
min = 59;
}
while(!k7);
}
}
DigClock( hour, min, sec);
break;
case 3:if(k5 == 0)
{
delay(1);
if(k5 == 0)
{
sec++;
if(sec > 59)
{
sec = 0;
}
while(!k5);
}
}
// DigClock( hour, min, sec);
// DigDisplay();
if(k7 == 0)
{
delay(1);
if(k7 == 0)
{
sec--;
if(sec < 0)
{
sec = 59;
}
while(!k7);
}
}
DigClock( hour, min, sec);
break;
}
}
}
void Timer0() interrupt 1
{
uint cnt;
TH0 = 0XFC;
TL0 = 0X18;
cnt++;
if(cnt == 1000)
{
cnt = 0;
sec++;
if(sec > 59)
{
sec = 0;
min++;
if(min > 59)
{
min = 0;
hour++;
if(hour > 23)
{
hour = 0;
}
}
}
}
}

复制代码

ID:373388 · 发表于 2021-1-2 15:39

计算机单字节无符号数 0-1 = 0xff = 255 ，用255查表可能查出表格之外乱码处了

ID:213173 · 发表于 2021-1-2 16:27

定义为有符号字符类型
char sec = 52;
char min = 58;
char hour = 23;或写成
sec--;
if(sec >6 0)
sec = 59;

ID:638158 · 发表于 2021-1-2 17:18

wulin 发表于 2021-1-2 16:27
定义为有符号字符类型
char sec = 52;
char min = 58;

感谢，刚试了，没问题了！

ID:517951 · 发表于 2021-1-2 18:08

我在调试过程中也出现过这个问题，要将时分秒设置为char 类型的。
sec--; if(sec <0) sec = 59;
sec++; if(sec >59) sec = 0;
之后就显示正常了

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51单片机数字时钟为什么减到0后在减就出现乱数时分秒都是这样的

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51单片机数字时钟 为什么减到0后在减就出现乱数 时分秒都是这样的

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51单片机数字时钟为什么减到0后在减就出现乱数时分秒都是这样的