DS1307 not updating time

Other Hardware Science and Measurement
4

1. You may try the following sketch:

#include "RTClib.h" 
byte prSec = 0;

RTC_DS1307 rtc;  //RTC_DS3231 rtc; //user data type RTC_DS3231    variable rtc or object
DateTime nowDT;
//char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

void setup ()
{
  Serial.begin(115200);
  rtc.begin();
  rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  //rtc.adjust(DateTime(2021, 12, 31, 11, 59, 57));//set date-time manualy:yr,mo,dy,hr,mn,sec
}

void loop ()
{
  
  showTime();
  timeDelay();//1-sec interval of time display; this time delay comes form DS3231 itself
}

//===================================================
void showTime()
{
  nowDT = rtc.now();  //nowDT hold Date and Time
  //---------------------------
  byte myHour = nowDT.hour();   //myHour holds Hour of time of daya
  Serial.print(myHour); //12:58:57     12:4:56
  Serial.print(':');
  //-------------------------------------------------
  byte myMin = nowDT.minute(); //to show leading zero of minute
  if (myMin < 10)
  {
    Serial.print('0');
  }
  Serial.print(nowDT.minute()); Serial.print(':');
  //--------------------------------------------------
  byte mySec = nowDT.second();
  if (mySec < 10)
  {
    Serial.print('0');
  }
  Serial.println(mySec);//(nowDT.second(), DEC);
}
//---------------------------------------------
void timeDelay()
{
  prSec = bcdSecond();   //current second of RTC
  while (bcdSecond()== prSec)// != 1 )
  {
    ;
  }
  prSec = bcdSecond(); //delay(1000);
}

byte bcdSecond()
{
  nowDT = rtc.now();
  if (nowDT.second() == 0 )
  {
    return 0;
  }
  else
  {
    return nowDT.second();
  }
}

2. You may also try the following sketch.

#include <Wire.h>
#define dsAddress 0x68

void setup()
{
  Serial.begin(9600);
  Wire.begin();

  Wire.beginTransmission(dsAddress);  //24 Hours Clock Set
  Wire.write(0x00);       //address of Second Register is put into Address Counter of RTC
  Wire.write(0x12);       //data for Sec Register-12
  Wire.write(0x58);       //data for Min Register (58)
  Wire.write(0x23);       //data for Hours Register (23): 24 Hours Time: 23:47:12
  Wire.endTransmission();
}

void loop()
{
  showTime();
  delay(1000);   //just for the Serial Monitor
}

void showTime()
{
  Wire.beginTransmission(dsAddress);
  Wire.write(0x00);       //address of Second Register is put into Address Counter of RTC
  Wire.endTransmission();

  Wire.requestFrom(dsAddress, 3);
  byte bcdSeconds = Wire.read();
  bcdSeconds = bcdSeconds & 0b01111111;
  byte bcdMinutes = Wire.read();
  byte bcdHours = Wire.read();

  Serial.print((bcdHours>>4)& 0b00000011); Serial.print(bcdHours&0b00001111);Serial.print(':');
  Serial.print(bcdMinutes>>4); Serial.print(bcdMinutes & 0b00001111);Serial.print(':');
  Serial.print(bcdSeconds>>4);Serial.println(bcdSeconds & 0b00001111);
}