DS1302 RTC Module with CR2032 Battery

This module features the DS1302 real-time clock (RTC) in an SMD package, maintaining accurate time and date even when main power is disconnected, thanks to a backup CR2032 coin cell.

Compatible with 3.3 V and 5 V logic levels, it connects to any microcontroller (Arduino, STM32, ESP32) using a simple 3-wire serial interface: RST, CLK, and DAT.

Specifications

• RTC Chip: DS1302 (8-pin SMD)
• Supply Voltage: 3.3 V or 5 V
• Backup Power: CR2032 coin cell (3 V, non-rechargeable)
• Data retention time: > 10 years
• Crystal: 32.768 kHz with 6 pF load capacitors
• Operating temperature: 0 °C to 70 °C
• Module dimensions: 16.5 mm × 26.3 mm × 1.6 mm

Typical Wiring

• VCC2 → 3.3 V or 5 V
• GND → Ground (GND)
• RST → Digital pin (e.g., D0 on STM32)
• CLK → Digital pin (e.g., D1)
• DAT → Digital pin (e.g., D2)

Arduino libraries for the DS1302 are available to simplify time initialization and data retrieval.