Adafruit PiRTC - Precise DS3231 Real Time Clock for Raspberry Pi

The Adafruit PiRTC Precise DS3231 is a high-accuracy, battery-backed real-time clock that plugs directly onto your Raspberry Pi's GPIO header. Built around a genuine Maxim DS3231 with an integrated temperature-compensated crystal oscillator (TCXO), it delivers exceptional timekeeping accuracy — far superior to standard crystal-based RTCs that drift with temperature changes.

The DS3231 achieves its precision by housing the crystal inside the chip alongside a temperature sensor that continuously compensates for frequency drift. This board uses 100% genuine Maxim DS3231 ICs purchased directly from the manufacturer, unlike many cheaper alternatives that use non-calibrated clones. It comes fully assembled with native Linux kernel support — just plug it in and configure.

Key Features

• Genuine Maxim DS3231 RTC – Temperature-compensated crystal oscillator for ±2 ppm accuracy (approximately ±1 minute per year)
• Plug-and-Play – Fully assembled; plugs directly onto the Pi GPIO header with no soldering
• I2C Interface – Native Raspberry Pi kernel driver support for easy setup
• Battery Backup – CR1220 coin cell slot keeps time through power loss for 5+ years
• Broad Compatibility – Works with any Raspberry Pi with a GPIO header (Pi 1, 2, 3, 4, 5, Zero, A+, B+)

Also Consider

• PiRTC PCF8523 – A more affordable option if high precision isn't required (±1–2 seconds/day drift)

Ideal For

• Precision data logging with accurate timestamps
• NTP servers and time-critical applications
• Offline Raspberry Pi setups without network time access
• Clock builds, alarms, and scheduled automation

Package Contents

• 1× Adafruit PiRTC DS3231 (fully assembled)

Resources

• Adding a Real Time Clock to Raspberry Pi – Setup Tutorial