RTC EEPROM Module DS3231 - Precision Real Time Clock Module AT24C32 I2C

RTC EEPROM Module DS3231 (Precision Real-Time Clock with AT24C32 EEPROM) is an extremely accurate, low-power real-time clock module designed to track exact seconds, minutes, hours, days, dates, months, and years. Driven by the high-precision temperature-compensated crystal oscillator (TCXO) DS3231 IC, this module maintains high timekeeping accuracy even when subjected to ambient temperature fluctuations that typically cause standard RTCs (like the DS1307) to drift. Featuring an onboard AT24C32 32K EEPROM memory chip for data logging, a battery backup socket, and a simple 2-wire I2C communication interface, it is an essential module for data loggers, clocks, automated timers, and IoT time-stamping systems.

Features

• High-precision DS3231 TCXO IC maintaining accurate timekeeping within ±2ppm (±1 minute per year) across a wide temperature range
• Tracks complete calendar data: Seconds, Minutes, Hours (12/24-hour format), Day, Date, Month, and Year with leap-year compensation up to the year 2100
• Built-in AT24C32 32KB EEPROM memory chip providing convenient non-volatile storage for configuration settings, logs, or sensor data
• Two programmable time-of-day alarms and a 1Hz square-wave output signal pin
• Temperature sensor output with a high 0.25°C resolution for thermal compensation and environmental tracking
• Simple 2-wire I2C serial interface (SDA, SCL) requiring minimal microcontroller GPIO pins
• Standard CR2032 coin cell battery holder on the rear side for continuous time backup during main power outages
• Wide logic voltage compatibility (3.3V to 5V DC), supporting Arduino, ESP32, ESP8266, and Raspberry Pi

Applications

• Precision data logging systems, environmental monitoring stations, and time-stamped sensor nodes
• Digital LED clocks, smart alarm systems, and automated event schedulers
• Industrial automation controllers, attendance logs, and time-restricted access systems
• Solar energy trackers, smart lighting controllers, and battery-backed IoT devices
• Polytechnic diploma, university engineering thesis, and advanced Arduino/ESP32 clock projects

Important Notes:

• Non-Rechargeable Battery Warning: Standard modules ship with a non-rechargeable CR2032 coin cell battery. Ensure you use a standard non-rechargeable CR2032 cell OR, if you replace it with a rechargeable LIR2032 battery, you must modify (remove or cut) the onboard trickle-charging diode/resistor circuit to prevent battery overheating or explosion.
• I2C Address Conflicts: The module utilizes two separate I2C addresses on the same bus: 0x68 for the DS3231 clock registers and 0x57 for the AT24C32 EEPROM storage. Avoid address collisions with other I2C sensors in your project.
• Initial Setup: When using the module for the first time, run a simple time-setting sketch (using the RTClib library) to synchronize the real-time clock with your computer's system time.
• SDA/SCL Pull-up Resistors: The module includes onboard pull-up resistors on the I2C lines, making direct connection to microcontrollers reliable without extra external resistors.

Package includes

• 1 x DS3231 AT24C32 RTC EEPROM Module (Battery included)