RTC Module(DS1302) CN

即使未连接到板子也能记住时间的模块。

使用电池（CR2032）。

规格

• 工作电压：3.3V 〜 5V
• 工作电流：2V 基准 300nA

所需硬件

• RTC 模块
• Arduino

连接

RTC module	Arduino
VCC	5V
GND	GND
CLK	D5
DAT	D4
RST	D3

Library

This document uses the Rtc by Makuna library for Arduino. Arduino Libraries

示例代码

这段代码在编译时保存时间，因此上传到板子时可能会有轻微的差异。 （由于代码在编译后上传到板子，因此在上传过程中会产生误差）

#include <ThreeWire.h>  
#include <RtcDS1302.h>

//--------------------Modified Section-------------------------------
#define CLK 5     //Specify CLK pin number
#define DAT 4     //Specify DAT pin number
#define RST 3     //Specify RST pin number

ThreeWire myWire(DAT,CLK,RST);
//--------------------------------------------------------------
RtcDS1302<ThreeWire> Rtc(myWire);

void setup () 
{
    Serial.begin(57600);

    Serial.print("compiled: ");
    Serial.print(__DATE__);
    Serial.println(__TIME__);

    Rtc.Begin();

    RtcDateTime compiled = RtcDateTime(__DATE__, __TIME__);
    printDateTime(compiled);
    Serial.println();

    if (!Rtc.IsDateTimeValid()) 
    {
        // Common Causes:
        //    1) first time you ran and the device wasn't running yet
        //    2) the battery on the device is low or even missing

        Serial.println("RTC lost confidence in the DateTime!");
        Rtc.SetDateTime(compiled);
    }

    if (Rtc.GetIsWriteProtected())
    {
        Serial.println("RTC was write protected, enabling writing now");
        Rtc.SetIsWriteProtected(false);
    }

    if (!Rtc.GetIsRunning())
    {
        Serial.println("RTC was not actively running, starting now");
        Rtc.SetIsRunning(true);
    }

    RtcDateTime now = Rtc.GetDateTime();
    if (now < compiled) 
    {
        Serial.println("RTC is older than compile time!  (Updating DateTime)");
        Rtc.SetDateTime(compiled);
    }
    else if (now > compiled) 
    {
        Serial.println("RTC is newer than compile time. (this is expected)");
    }
    else if (now == compiled) 
    {
        Serial.println("RTC is the same as compile time! (not expected but all is fine)");
    }
}

void loop () 
{
    RtcDateTime now = Rtc.GetDateTime();

    printDateTime(now);
    Serial.println();

    if (!now.IsValid())
    {
        // Common Causes:
        //    1) the battery on the device is low or even missing and the power line was disconnected
        Serial.println("RTC lost confidence in the DateTime!");
    }

    delay(10000); // ten seconds
}

#define countof(a) (sizeof(a) / sizeof(a[0]))

void printDateTime(const RtcDateTime& dt)
{
    char datestring[20];

    snprintf_P(datestring, 
            countof(datestring),
            PSTR("%02u/%02u/%04u %02u:%02u:%02u"),
            dt.Month(),
            dt.Day(),
            dt.Year(),
            dt.Hour(),
            dt.Minute(),
            dt.Second() );
    Serial.print(datestring);
}

执行结果