DS1302时钟模块

DS1302

DS1302是一个低功耗、实时时钟（RTC）芯片

单字节写

1.发送数据前，需要将CE拉高，使能通信。需要注意的是，拉高CE时，需确保SCLK处于低电平
2.需要先发送命令字节，再发送数据字节，发送时都是低位优先

• 命令字节用于指定寄存器地址以及声明读/写操作，各位的含义如下
• 数据字节为发送的具体数据

3.每位数据都需要在一个时钟周期的上升沿发送

单字节读

1.接收数据前，需要将CE拉高，使能通信。需要注意的是，拉高CE时，需确保 SCLK 处于 低电平
2.需要先发送命令字节，再接收数据字节，发送和接收时都是低位优先
3.发送每位数据要在时钟信号的上升沿，读取每位数据要在时钟信号的下降沿
注意：第8个时钟周期，需要完成最后1位数据的发送和第1位数据的接收

寄存器介绍

注意：DS1302内部有一个写保护寄存器，在向DS1302写入数据前需要先关闭写保护，写完再开启写保护。

代码实现

Int_DS1302.h

#ifndef __INT_DS1302_H__
#define __INT_DS1302_H__

#include "Com_Util.h"
#include <STC89C5xRC.H>

typedef struct
{
    u8 second;
    u8 minute;
    u8 hour;
    u8 day;
    u8 month;
    u8 year;
    u8 day_of_week;
} Struct_Date;

void Int_DS1302_Init(void);

void Int_DS1302_SetDate(Struct_Date *p_st_date);

void Int_DS1302_GetDate(Struct_Date *p_st_date);

#endif /* __INT_DS1302_H__ */

Int_DS1302.c

#include "Int_DS1302.h"
#include "intrins.h"

#define SCLK        P36
#define IO          P34
#define CE          P35

#define SECOND      0x80
#define MINUTE      0x82
#define HOUR        0x84
#define DAY         0x86
#define MONTH       0x88
#define DAY_OF_WEEK 0x8A
#define YEAR        0x8C
#define WP          0x8E

void Int_DS1302_Init(void) {
	SCLK = 0;
	IO = 0;
	CE = 0;
}

static void Int_DS1302_WriteByte(u8 byte) {
	
	u8 i;

	SCLK = 0;
	for (i = 0; i < 8; i++) {
		IO = byte & 0x01;
		SCLK = 1;
		SCLK = 0;
		byte >>= 1;
	}
}

static u8 Int_DS1302_ReadByte() {
	
	u8 i, byte = 0;

	SCLK = 0;
	for (i = 0; i < 8; i++) {
		byte >>= 1;
		if (IO == 1) {
			byte = byte | 0x80;
		}
		SCLK = 1;
		SCLK = 0;
	}
	return byte;
}

static void Int_DS1302_SetRegister(u8 addr, u8 byte) {
	CE = 1;
	Int_DS1302_WriteByte(addr);
	Int_DS1302_WriteByte(byte);
	CE = 0;
}

static u8 Int_DS1302_GetRegister(u8 addr) {
	u8 byte;
	CE = 1;
	Int_DS1302_WriteByte(addr | 1);
	byte = Int_DS1302_ReadByte();
	CE = 0;
	SCLK = 1;
	IO = 0;
	IO = 1;
	return byte;
}

void Int_DS1302_SetDate(Struct_Date* p_st_date) {
	u8 temp;

	// 关闭写保护
	Int_DS1302_SetRegister(WP, 0x00);

	// 设置秒
	temp = (p_st_date->second % 10) | ((p_st_date->second / 10) << 4);
	Int_DS1302_SetRegister(SECOND, temp);

	// 设置分钟
	temp = (p_st_date->minute % 10) | ((p_st_date->minute / 10) << 4);
	Int_DS1302_SetRegister(MINUTE, temp);

	// 设置小时
	temp = (p_st_date->hour % 10) | ((p_st_date->hour / 10) << 4);
	Int_DS1302_SetRegister(HOUR, temp);

	// 设置日
	temp = (p_st_date->day % 10) | ((p_st_date->day / 10) << 4);
	Int_DS1302_SetRegister(DAY, temp);

	// 设置月
	temp = (p_st_date->month % 10) | ((p_st_date->month / 10) << 4);
	Int_DS1302_SetRegister(MONTH, temp);

	// 设置年
	temp = (p_st_date->year % 10) | ((p_st_date->year / 10) << 4);
	Int_DS1302_SetRegister(YEAR, temp);

	// 设置星期
	Int_DS1302_SetRegister(DAY_OF_WEEK, p_st_date->day_of_week % 10);

	// 开启写保护
	Int_DS1302_SetRegister(WP, 0x80);
}

void Int_DS1302_GetDate(Struct_Date* p_st_date) {
	u8 temp;
	// 获取秒
	temp = Int_DS1302_GetRegister(SECOND);
	p_st_date->second = (temp >> 4) * 10 + (temp & 0x0F);

	temp = Int_DS1302_GetRegister(MINUTE);
	p_st_date->minute = (temp >> 4) * 10 + (temp & 0x0F);

	temp = Int_DS1302_GetRegister(HOUR);
	p_st_date->hour = (temp >> 4) * 10 + (temp & 0x0F);

	temp = Int_DS1302_GetRegister(DAY);
	p_st_date->day = (temp >> 4) * 10 + (temp & 0x0F);

	temp = Int_DS1302_GetRegister(MONTH);
	p_st_date->month = (temp >> 4) * 10 + (temp & 0x0F);

	temp = Int_DS1302_GetRegister(YEAR);
	p_st_date->year = (temp >> 4) * 10 + (temp & 0x0F);

	temp = Int_DS1302_GetRegister(DAY_OF_WEEK);
	p_st_date->day_of_week = (temp >> 4) * 10 + (temp & 0x0F);
}

main.c

#include "Int_DS1302.h"
#include "Int_Oled.h"
#include "STDIO.H"

code char* WEEK_NAME[] = {
	"Mon",
	"Tue",
	"Wed",
	"Thu",
	"Fri",
	"Sat",
	"Sun" };

void main() {
	u8 str[17];
	Struct_Date st_date;
	st_date.year = 23;
	st_date.month = 12;
	st_date.day = 29;
	st_date.day_of_week = 5;
	st_date.hour = 11;
	st_date.minute = 32;
	st_date.second = 00;

	// 初始化时钟并设置时间
	Int_DS1302_Init();
	Int_Oled_Init();
	Int_DS1302_SetDate(&st_date);

	Int_Oled_Clear();

	while (1) {
		Int_DS1302_GetDate(&st_date);

		sprintf(str, "20%02d/%02d/%02d %s",
			(int)st_date.year,
			(int)st_date.month,
			(int)st_date.day,
			WEEK_NAME[st_date.day_of_week - 1]);

		Int_Oled_ShowStr(0, 0, str);

		sprintf(str, "%02d:%02d:%02d",
			(int)st_date.hour,
			(int)st_date.minute,
			(int)st_date.second);

		Int_Oled_ShowStr(0, 1, str);
	}
}

原理图

说明：
这里I/O口没有接上拉电阻，所以代码中需要注意以下几点