{"title":"Adafruit DS3231 Precision RTC - STEMMA QT","handle":"adafruit-ds3231-precision-rtc-stemma-qt","url":"/products/adafruit-ds3231-precision-rtc-stemma-qt","description":"The Adafruit DS3231 Precision RTC with STEMMA QT connectors is a highly accurate I2C real-time clock featuring an integrated temperature-compensated crystal oscillator (TCXO). Unlike standard RTCs that rely on an external 32 kHz crystal, the DS3231 houses the crystal internally alongside a temperature sensor that continuously compensates for frequency drift, delivering accuracy of ±2 ppm (about ±1 minute per year).\n\nThis version adds STEMMA QT / Qwiic connectors for solderless I2C connections, making it easy to daisy-chain with other I2C sensors and accessories. It works with both 3.3V (Feather, Raspberry Pi) and 5V (Arduino, Metro) logic levels. With a CR1220 coin cell on the back, the DS3231 maintains precise timekeeping for years even when main power is lost.\n\nKey Features\n\n\nIntegrated TCXO – On-chip crystal and temperature sensor for automatic drift compensation\n\n±2 ppm Accuracy – Approximately ±1 minute per year, far superior to standard RTCs\n\nSTEMMA QT / Qwiic – Dual I2C connectors for solderless daisy-chaining\n\nBattery Backup – CR1220 coin cell holder on board for uninterrupted timekeeping during power loss\n\n3.3V and 5V Compatible – On-board level shifting for broad platform support\n\nI2C Interface – Simple two-wire communication with standard I2C addressing\n\nBreadboard-Friendly – Compact breakout with included header strip\n\n\nAlso Available\n\n\nDS3231 Precision RTC Breakout (standard header version)\n\nDS1307 RTC Breakout (basic, lower cost)\n\nPCF8523 RTC Breakout (3.3V compatible)\n\n\nIdeal For\n\nPrecision data logging with accurate timestamps\nClocks and timers requiring minimal drift\nIoT devices needing reliable timekeeping through power cycles\nSolderless prototyping with STEMMA QT ecosystem\n\n\nPackage Contents\n\n1× Adafruit DS3231 Precision RTC – STEMMA QT (fully assembled and tested)\n1× Header strip\n\n\n\nNote: A CR1220 coin cell battery is required for battery-backup operation and is not included. STEMMA QT cable is also sold separately.\n","vendor":"Adafruit","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":2960,"title":"Default Title","sku":"AF-5188","price":27.22,"compare_at_price":0.0,"on_sale":false,"in_stock":true,"available_quantity":103,"option1":"Default Title"}]}