该代码是自己写的，没有参考老师的代码，仅供参考，如有不合适请指出，谢谢。

#include "reg52.h"sfr AUXR=0x8e;sbit S5=P3^2;
sbit S4=P3^3;void SelectHC573(unsigned char channel);
void  DisplayTime();
unsigned char th=0;
unsigned char tm=0;
unsigned char ts=0;
unsigned char code SMG_duanma[18]={                //code 告诉单片机，把程序放在ROM中，只读不能修改0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8, 0x80,0x90,0x88,0x80,0xc6,0xc0,0x86,0x8e,0xbf,0x7f
};
unsigned char uartdata;
void Delay(unsigned int t)
{while(t--);}
void Delayus(unsigned int t)
{while(t--);{DisplayTime();}}
void SelectHC573(unsigned char channel)
{switch(channel){case 4:P2=(P2 & 0x1f)|0x80;break;case 5:P2=(P2 & 0x1f)|0xa0;break;case 6:P2=(P2 & 0x1f)|0xc0;break;case 7:P2=(P2 & 0x1f)|0xe0;break;case 0:P2=(P2 & 0x00);break;}
}//=========1========
void ClearInit()
{SelectHC573(5);P0=0x00;SelectHC573(4);P0=0xff;SelectHC573(0);
}
//=========2.LED========
void LEDRuning()
{unsigned char i;SelectHC573(4);for(i=0;i<8;i++){P0=0xfe<<i;Delay(500000);}for(i=0;i<8;i++){P0=P0|(0x01<<i);Delay(500000);}P0=0xff;SelectHC573(0);
}unsigned char dat=0;
void SMGRuning()
{unsigned char i;for(i=0;i<8;i++){SelectHC573(6);dat=(dat|0x01<<i);P0=dat;SelectHC573(7);P0=0x00;Delay(500000);}for(i=1;i<=8;i++){SelectHC573(6);dat=dat&(0xff<<i);P0=dat;Delay(500000);}dat=0;SelectHC573(0);
}void DisplaySMG(unsigned char vlaue,unsigned char pos)
{SelectHC573(7);P0=0xff;          //消影SelectHC573(6);P0=0x01<<pos;SelectHC573(7);P0=vlaue;
}unsigned char count=0;void Time0Init()
{TMOD=0x01;TH0=(65535-50000)/256;TL0=(65535-50000)%256;TR0=1;TF0=0;EA=1;ET0=1;}void SericeTime0() interrupt 1
{TH0=(65535-50000)/256;TL0=(65535-50000)%256;count++;if(count==20){ts++;if(ts==60){tm++;ts=0;}if(tm==60){th++;tm=0;}if(th==24){th=0;tm=0;ts=0;}count=0;}}
//========3=======
void  DisplayTime()
{DisplaySMG(SMG_duanma[th/10],0);Delay(500);DisplaySMG(SMG_duanma[th%10],1);Delay(500);DisplaySMG(0xbf,2);Delay(500);DisplaySMG(SMG_duanma[tm/10],3);Delay(500);DisplaySMG(SMG_duanma[tm%10],4);Delay(500);DisplaySMG(0xbf,5);Delay(500);DisplaySMG(SMG_duanma[ts/10],6);Delay(500);DisplaySMG(SMG_duanma[ts%10],7);Delay(500);SelectHC573(0);
}//====4=======void KeyConLight()
{if(S5==0){Delayus(125);if(S5==0){SelectHC573(4);P0=(P0 &0x00)|0xbf;while(S5==0){DisplayTime();}SelectHC573(4);P0=0xff;SelectHC573(0);}}if(S4==0){Delayus(125);if(S4==0){SelectHC573(4);P0=(P0 & 0x00)|0x7f;while(S4==0){DisplayTime();}SelectHC573(4);P0=0xff;SelectHC573(0);}}}void UartInit()
{TMOD=0x20;SCON=0x50;TH1=0xfd;TL1=0xfd;TR1=1;ES=1;AUXR=0x00;
}void SendByte(unsigned char dat)
{SBUF=dat;while(TI==0);TI=0;
}void UartSerice()  interrupt 4
{if(RI){DisplayTime();uartdata=SBUF;RI=0;}}void uartContime()
{SendByte(th/10*16+th%10);SendByte(tm/10*16+tm%10);SendByte(ts/10*16+ts%10);}
void UartCon()
{switch(uartdata & 0xf0){case 0xa0:SelectHC573(4);P0=~(uartdata & 0x0f);SelectHC573(0);uartdata=0;break;case 0xb0:uartContime();uartdata=0;break;}}
void main()
{Time0Init();UartInit();ClearInit();LEDRuning();SMGRuning();while(1){DisplayTime();KeyConLight();UartCon();} }

由于拍摄不易，串口调试没有拍，也是合适的。