Clock Module RTC DS3231



This clock module DS3231 RTC is low-cost, extremely accurate I2C real-time clock (RTC), with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The clock module incorporates a battery input which maintains accurate timekeeping even without a power supply. It has an integrated oscillator to improve long-term accuracy of the device.

The clock module maintains seconds, minutes, hours, day, date, month, and year information. For months with less than 31 days, the end date will be automatically adjusted, including corrections for leap year. Clock operates in either the 24 hours or band / AM / PM indication of the 12-hour format. It provides two configurable alarm clock and a calendar can be set to a square wave output.

Address and data are transferred serially through an I2C bidirectional bus. A precision temperature-compensated voltage reference and comparator circuit monitors the status of VCC to detect power failures, provide a reset output, and if necessary, automatically switch to the backup power supply. RST pin is monitored as generating μP reset manually.

The device integrates a very precise digital temperature sensor, accessible through the I2C interface. Temperature sensor accuracy is ±3°C. On-chip power supply control circuit can automatically detect and manage the main and standby power (i.e. low-voltage battery) to switch between the power supply. If the main power failure, the device can continue to provide accurate timing and temperature, performance is not affected. When the main power re-powers or voltage value returns to within the allowable range, the on-chip reset function can be used to restart the system microprocessor.



  • Input Voltage: 3.3 - 5.5V
  • Clock Chip: High Precision Clock Chip DS3231
  • Clock Accuracy: 0 - 40°C range, with accuracy of 2ppm
  • Calendar Alarm Clock: Two Programmable Square-Wave Output
  • Real Time Clock Generator: Seconds, Minutes, Hours, Day, Date, Month and Year Timing which Provides Valid Timing Until the Year 2100 with Leap Year Compensation
  • Chip Temperature Sensor: Accuracy of ±3°C
  • Memory Chip: AT24C32 (storage capacity 32K)
  • I2C Bus Interface: Maximum Transmission Speed of 400KHz (5V)
  • I2C Address: Can be Changed by Shorting A0 / A1 / A2
  • Default Address: 0x57



  • 1x Clock Module RTC DS3231
  • 1x CR2032 Battery