蓝桥杯单片机刷题——串口发送实时时钟

设计要求

             读取DS1302时钟芯片的时、分、秒，当S9按键按下时，串口发送一次当前时、分、秒。

             串口发送格式如下图所示：

             Time:00:00:00

备注：

单片机IRC振荡器频率：12MHz。

串口通信波特率：9600bps。

按键模式：BTN；扩展方式：IO模式

代码

sys.h

#ifndef __SYS_H__
#define __SYS_H__#include <STC15F2K60S2.H>
#include "intrins.h"
extern unsigned char time[3];
extern bit flag;
void init74hc138(unsigned char n);
void init();
void Key_Loop();
void w_ds1302();
void r_ds1302();#endif

main.c

#include "sys.h"
unsigned char *str="Time:";
bit flag_key=0;
bit flag_time=0;
void UartInit(void)		//9600bps@12.000MHz
{SCON = 0x50;		//8位数据,可变波特率AUXR |= 0x40;		//定时器时钟1T模式AUXR &= 0xFE;		//串口1选择定时器1为波特率发生器TMOD &= 0x0F;		//设置定时器模式TL1 = 0xC7;			//设置定时初始值TH1 = 0xFE;			//设置定时初始值ET1 = 0;			//禁止定时器中断TR1 = 1;			//定时器1开始计时ES=1;EA=1;
}
void Timer2_Init(void)		//100微秒@12.000MHz
{AUXR |= 0x04;			//定时器时钟1T模式T2L = 0x50;				//设置定时初始值T2H = 0xFB;				//设置定时初始值AUXR |= 0x10;			//定时器2开始计时IE2 |= 0x04;			//使能定时器2中断EA=1;
}
void send_uart_date(unsigned char date){SBUF=date;while(TI==0);TI=0;
}
void send_uart_str(unsigned char *str){while(*str!='\0'){send_uart_date(*str++);}
}
void send_uart_time(){send_uart_str(str);send_uart_date(time[2]/10+'0');send_uart_date(time[2]%10+'0');send_uart_date(':');send_uart_date(time[1]/10+'0');send_uart_date(time[1]%10+'0');send_uart_date(':');send_uart_date(time[0]/10+'0');send_uart_date(time[0]%10+'0');send_uart_str("\r\n");
}
void main(){init();w_ds1302();UartInit();Timer2_Init();while(1){if(flag_key){flag_key=0;Key_Loop();}if(flag_time){flag_time=0;r_ds1302();}if(flag){flag=0;send_uart_time();}}
}
void uart() interrupt 4
{if(RI){RI=0;}
}
void Timer2_Isr(void) interrupt 12
{static unsigned char count=0;static unsigned int count1=0;count++;count1++;if(count==50){count=0;flag_key=1;}if(count1==5000){count1=0;flag_time=1;}
}

sys.c

#include "sys.h"
unsigned char keyval,keyold,keyup,keydown;
bit flag=0;
void init74hc138(unsigned char n){P2=(P2&0x1f)|(n<<5);P2&=0x1f;
}
void init(){P0=0x00;init74hc138(5);P0=0xff;init74hc138(4);
}
void Key_Loop(){P32=0;keyval=0;if(P42==0)keyval=1;keydown=keyval&(keyold^keyval);keyup=~keyval&(keyold^keyval);if(keyval&&!keyold)flag=1;keyold=keyval;
}

ds1302.c

#include "sys.h"
sbit SCK=P1^7;
sbit SDA=P2^3;
sbit RST=P1^3;
unsigned char time[]={0,0,0};
void Write_Ds1302(unsigned  char temp) 
{unsigned char i;for (i=0;i<8;i++)     	{ SCK = 0;SDA = temp&0x01;temp>>=1; SCK=1;}
}   //
void Write_Ds1302_Byte( unsigned char address,unsigned char dat )     
{RST=0;	_nop_();SCK=0;	_nop_();RST=1; 	_nop_();  Write_Ds1302(address);	Write_Ds1302(dat/10*16|dat%10);//十进制——>8421BCDRST=0; 
}//
unsigned char Read_Ds1302_Byte ( unsigned char address )
{unsigned char i,temp=0x00;unsigned char dat1,dat2;RST=0;	_nop_();SCK=0;	_nop_();RST=1;	_nop_();Write_Ds1302(address);for (i=0;i<8;i++) 	{		SCK=0;temp>>=1;	if(SDA)temp|=0x80;	SCK=1;} RST=0;	_nop_();SCK=0;	_nop_();SCK=1;	_nop_();SDA=0;	_nop_();SDA=1;	_nop_();dat1=temp/16;dat2=temp%16;temp=dat1*10+dat2;return (temp);			
}
void w_ds1302(){unsigned char i,addr=0x80;Write_Ds1302_Byte(0x8e,0x00);for(i=0;i<3;i++){Write_Ds1302_Byte(addr,time[i]);addr+=2;}Write_Ds1302_Byte(0x8e,0x80);
}
void r_ds1302(){unsigned char i,addr=0x81;for(i=0;i<3;i++){time[i]=Read_Ds1302_Byte(addr);addr+=2;}
}