High Accuracy DS3231 RTC & EEPROM

The I2C real time clock module (HCMODU0094) is based on the Maxim high accuracy DS3231 real time clock controller. Using an internal temperature compensation crystal oscillator this RTC IC is able to provide extremely high accurate time keeping. The module includes an on-board battery backup and maintains accurate timekeeping when main power to the device is interrupted. The RTC maintains seconds, minutes, hours, day, date, month, and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with an AM/PM indicator. Two programmable time-of-day alarms and a programmable square-wave output are provided. 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, to provide a reset output, and to automatically switch to the backup supply when necessary. 

Included on this module is an Atmel 24C32 32K (4096 x 8) serial I2C EEPROM which allows the module to be used as a simple data logger storing up to 4K of 8 bit data. 


If you plan to use this module with a standard Arduino then you can take advantage of our exclusive library (HCRTC) to quickly integrate this module into your own Arduino project. The library also provides the ability to read and write to the included EEPROM. 

Features (RTC):

● Highly Accurate RTC Completely Manages All Timekeeping Functions
• Real-Time Clock Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year, with Leap-Year Compensation Valid Up to 2100
• Accuracy ±2ppm from 0°C to +40°C
• Digital Temp Sensor Output: ±3°C Accuracy
• Register for Aging Trim
• Two Time-of-Day Alarms
• Programmable Square-Wave Output Signal
● Simple Serial Interface Connects to Most Microcontrollers
• Fast (400kHz) I2C Interface
● Battery-Backup Input for Continuous Timekeeping
• 2.3V to 5.5V Operation
● Operating Temperature Ranges: 0°C to +70°C


Features (EEPROM):

• Low-Voltage and Standard-Voltage Operation – 2.7 (VCC = 2.7V to 5.5V)
• Internally Organized 8192 x 8
• 2-Wire Serial Interface
• Schmitt Trigger, Filtered Inputs for Noise Suppression
• Bidirectional Data Transfer Protocol
• 100 kHz (1.8V, 2.5V, 2.7V) and 400 kHz (5V) Clock Rate
• 32-Byte Page Write Mode (Partial Page Writes Allowed)
• Self-Timed Write Cycle (10 ms max)
• High Reliability – Endurance: 1 Million Write Cycles – Data Retention: 100 Years

Example sketch, libraryand datasheets available on our support forum here.