DS3231 RTC - Stops of Battery power- solved

Projects Programming
1

The famous DS3231 RTC on board ZS-042. Fitted with a CR2032 battery. Though I have not cut the charging track , yet to to explode :slight_smile:

All fine - shows time fine.

Till I removed power and left it to the battery's mercy. The clock stopped updating and next day resumed ( on power ) from where I left yesterday.

Read this forum as this seemed to be a favorite issue for many ( clock stops on battery power) ;
Checked the battery voltage on power : 4.16V and on battery it was about 3.9V;

Time to hit the data sheet ? Yes and I noticed that two entries could halt the clock while on battery :

EOSC bit in Control register 0Eh
OSF bit in Status Register 0Fh

Once I wrote code to set them up for 0x00 in SETUP() , the RTC is working fine.

// START THE I2C INTERFACE
  #define DS3231_I2C_ADDRESS 0x68             // 0x68 is the RTC address
  Wire.begin();
  Wire.beginTransmission(DS3231_I2C_ADDRESS);
  Wire.write(0xE);                            // Address the Control Register
  Wire.write(0x00);                           // Write 0x0 to control Register
  Wire.endTransmission();
  Wire.beginTransmission(DS3231_I2C_ADDRESS);
  Wire.write(0xF);                            // Address the Status register
  Wire.write(0x00);                           // Write 0x0 to Status Register
  Wire.endTransmission();

I hope that was the issue and this the fix !!

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