RTC 1307 module doesn't work on battery

Hi guys,

The RTC 1307 module has a 3.3 v battery that in theory should feed the system when you cut the 5 volts supply off (in this case from arduino) and continue to keep the date and right time set before when you try to read it again.

Why it doesn't work with me?

I used the code "set time" and then "read test" and it works fine on the serial monitor. But when I disconnect and connect the 5 volts supply it stop and ask to run "set time" again.

**edited for more accurate description :

SetTime:

#include <Wire.h>
#include <Time.h>
#include <DS1307RTC.h>

const char *monthName[12] = {
  "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};

tmElements_t tm;

void setup() {
  bool parse=false;
  bool config=false;

  // get the date and time the compiler was run
  if (getDate(__DATE__) && getTime(__TIME__)) {
    parse = true;
    // and configure the RTC with this info
    if (RTC.write(tm)) {
      config = true;
    }
  }

  Serial.begin(9600);
  while (!Serial) ; // wait for Arduino Serial Monitor
  delay(200);
  if (parse && config) {
    Serial.print("DS1307 configured Time=");
    Serial.print(__TIME__);
    Serial.print(", Date=");
    Serial.println(__DATE__);
  } else if (parse) {
    Serial.println("DS1307 Communication Error :-{");
    Serial.println("Please check your circuitry");
  } else {
    Serial.print("Could not parse info from the compiler, Time=\"");
    Serial.print(__TIME__);
    Serial.print("\", Date=\"");
    Serial.print(__DATE__);
    Serial.println("\"");
  }
}

void loop() {
}

bool getTime(const char *str)
{
  int Hour, Min, Sec;

  if (sscanf(str, "%d:%d:%d", &Hour, &Min, &Sec) != 3) return false;
  tm.Hour = Hour;
  tm.Minute = Min;
  tm.Second = Sec;
  return true;
}

bool getDate(const char *str)
{
  char Month[12];
  int Day, Year;
  uint8_t monthIndex;

  if (sscanf(str, "%s %d %d", Month, &Day, &Year) != 3) return false;
  for (monthIndex = 0; monthIndex < 12; monthIndex++) {
    if (strcmp(Month, monthName[monthIndex]) == 0) break;
  }
  if (monthIndex >= 12) return false;
  tm.Day = Day;
  tm.Month = monthIndex + 1;
  tm.Year = CalendarYrToTm(Year);
  return true;
}

ReadTest:

#include <Wire.h>
#include <Time.h>
#include <DS1307RTC.h>

void setup() {
  Serial.begin(9600);
  while (!Serial) ; // wait for serial
  delay(200);
  Serial.println("DS1307RTC Read Test");
  Serial.println("-------------------");
}

void loop() {
  tmElements_t tm;

  if (RTC.read(tm)) {
    Serial.print("Ok, Time = ");
    print2digits(tm.Hour);
    Serial.write(':');
    print2digits(tm.Minute);
    Serial.write(':');
    print2digits(tm.Second);
    Serial.print(", Date (D/M/Y) = ");
    Serial.print(tm.Day);
    Serial.write('/');
    Serial.print(tm.Month);
    Serial.write('/');
    Serial.print(tmYearToCalendar(tm.Year));
    Serial.println();
  } else {
    if (RTC.chipPresent()) {
      Serial.println("The DS1307 is stopped.  Please run the SetTime");
      Serial.println("example to initialize the time and begin running.");
      Serial.println();
    } else {
      Serial.println("DS1307 read error!  Please check the circuitry.");
      Serial.println();
    }
    delay(9000);
  }
  delay(1000);
}

void print2digits(int number) {
  if (number >= 0 && number < 10) {
    Serial.write('0');
  }
  Serial.print(number);
}

1 upload and run code that sets up RTC.
2 comment out line that sets up RTC AND UPLOAD CODE AGAIN.

1 will have got the RTC running at the correct time so update to time is not needed in 2.

G

Hi Zardof, thank you for your response but I don't what is the exact line that you told me to get off from the code. And why it should be done?

You should have some code like this. Note:- It would help if you posted your code and circuit diagram.

 Serial.println("RTC is NOT running!");
    // following line sets the RTC to the date & time this sketch was compiled
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
    // This line sets the RTC with an explicit date & time, for example to set
    // January 21, 2014 at 3am you would call:
    // rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));
  }

After running the code once, comment out the line as below and upload the code to your board.
Disconnect from computer - connect power supply - clock should be right.

//rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));

This line of codes set the RTC to the date and time on your connected computer.
If you do not comment out this line and you run the code again with the board running off your power supply then the RTC will be looking to have the time set by a computer it is not connected to any longer.

G

This line of codes set the RTC to the date and time on your connected computer.

No, it sets the RTC to the time you last compiled the code.

I stand corrected.

G

I did like you say and commented this segment:

" if (getDate(DATE) && getTime(TIME)) { } "

And doesn't work... :frowning:

#include <Wire.h>
#include <Time.h>
#include <DS1307RTC.h>

const char *monthName[12] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};

tmElements_t tm;

void setup() {
bool parse=false;
bool config=false;

// get the date and time the compiler was run
if (getDate(DATE) && getTime(TIME)) {
parse = true;
// and configure the RTC with this info
if (RTC.write(tm)) {
config = true;
}
}

Serial.begin(9600);
while (!Serial) ; // wait for Arduino Serial Monitor
delay(200);
if (parse && config) {
Serial.print("DS1307 configured Time=");
Serial.print(TIME);
Serial.print(", Date=");
Serial.println(DATE);
} else if (parse) {
Serial.println("DS1307 Communication Error :-{");
Serial.println("Please check your circuitry");
} else {
Serial.print("Could not parse info from the compiler, Time="");
Serial.print(TIME);
Serial.print("", Date="");
Serial.print(DATE);
Serial.println(""");
}
}

void loop() {
}

bool getTime(const char *str)
{
int Hour, Min, Sec;

if (sscanf(str, "%d:%d:%d", &Hour, &Min, &Sec) != 3) return false;
tm.Hour = Hour;
tm.Minute = Min;
tm.Second = Sec;
return true;
}

bool getDate(const char *str)
{
char Month[12];
int Day, Year;
uint8_t monthIndex;

if (sscanf(str, "%s %d %d", Month, &Day, &Year) != 3) return false;
for (monthIndex = 0; monthIndex < 12; monthIndex++) {
if (strcmp(Month, monthName[monthIndex]) == 0) break;
}
if (monthIndex >= 12) return false;
tm.Day = Day;
tm.Month = monthIndex + 1;
tm.Year = CalendarYrToTm(Year);
return true;
}

Please show what you actually did, not the unmodified sketch and a description of what you did. Please post code using code tags.

Sorry, I updated above...

Don't edit old posts it is just confusing. >:(

Have you tried changing the battery?

G

Have you tried changing the battery?

Also make sure it is installed with correct polarity with + facing where you can read it.

If the chip is not running under battery power. There could be a circuit defect on the module which you can test for. You will need to confirm that approximately 3 v is getting to the Vbat lead of the chip. You will need to find a DS1307 data sheet and verify which chip pin is Vbat.

If the voltage is present but the rtc is not running, then you may have a defective chip or oscillator on the module. See this thread for a case of a counterfeit ds1307 chip which would not run under batter power DS1307 Real Time Clock CH bit problem - Project Guidance - Arduino Forum