Adafruit DS3231 Precision RTC Breakout - STEMMA QT

The Adafruit DS3231 Precision RTC is an extremely accurate I²C-integrated real-time clock with built-in temperature-compensated crystal oscillator (TCXO). This RTC breakout board offers the finest precision timekeeping in a small, low-power package, perfect for data logging, clocks, or any project where precise time is a necessity.

Unlike traditional RTCs that rely on external 32kHz crystals prone to drift due to temperature changes, the DS3231 houses its crystal within the chip itself, along with an integrated temperature sensor. This sensor compensates for frequency changes caused by temperature variations, ensuring reliable timekeeping accuracy.

The breakout includes STEMMA QT connectors for easy plug-and-play with compatible microcontrollers without soldering. It supports both 3.3V and 5V logic levels, making it broadly compatible with Feather, Raspberry Pi, Arduino, and Metro328 boards. The RTC is powered by an optional CR1220 coin cell for battery backup, sustaining time keeping during power loss.

Key features include:

• Ultra-precise I2C real-time clock with integrated crystal and temperature sensor
• STEMMA QT connectors for solderless I2C connectivity
• Operates on 3.3V or 5V logic levels
• Battery backup with CR1220 coin cell (sold separately)
• Compact, breadboard-friendly breakout PCB (25.4mm x 17.8mm x 7.8mm)
• Fully assembled and tested, with accompanying header for soldering if desired

The board is RoHS 2 compliant and features a clear silkscreen for easy assembly and use. Detailed tutorials and libraries for Arduino and CircuitPython are available to help get you started quickly.