DS3231 RTC Module (High Accuracy)

DS3231 RTC Module (High Accuracy)

The DS3231 real-time clock keeps accurate time to ±2ppm (about 1 minute per year) with battery backup via CR2032 — maintaining timekeeping even when your main project is powered off. Temperature-compensated crystal oscillator (TCXO) eliminates the drift common in cheaper DS1307-based modules.

Key Specifications

• Accuracy: ±2ppm from 0–40°C (~1 min/year drift)
• Interface: I2C
• Battery: CR2032 included (maintains time during power-off)
• Temperature sensor: Built-in (±3°C accuracy)
• Voltage: 3.3–5V

DS3231 vs DS1307

The DS1307 is cheaper but uses an external crystal with no temperature compensation — resulting in 1–2 minutes drift per day in temperature-varying environments. The DS3231's TCXO maintains accuracy across temperature changes. For data logging, attendance systems, or scheduled automation, the DS3231 is worth the premium.