The DS1302 real-time clock (RTC) works very much like a watch. The RTC module accurately keeps time with a precise oscillator and is maintained with a small battery (not included). It is used to give an accurate date and time in many applications. The RTC module is ideal in any time-critical applications like attendance systems, digital cameras, automated sprinkler systems, or a time and calendar display. Pin configuration : VCC2 → 5 V/3.3V GND → GND CLK → P02 DAT → P01 RST → P00 Specifications Crystal 32.768KHz, matching capacitance 6pF DS1302 8-pin SMD homemade chips Seconds, Minutes, Hours, Day of Month, Day of Week, and Year Useful Link: Arduino Playground DS1302 Example Package Includes: 1 x DS1302 Real Time Clock Module with battery Category: Real Time Module (RTC)