This is a Mini Real-Time Clock module, it design for Raspberry Pi, but it also can be used to Arduino.
Pluging it into Raspberry Pi GPIO interface, and all is ok. This is the easiest way to keep it in time.
- Work in 3.3V and 5V
- Supported Raspberry Pi and Arduino
- DS3231 RTC IC
- Self-adjust 3.3V and 5V
- Size: 14x14x12 mm
Adding a Real Time Clock to Raspberry Pi(via learn.adafruit.com)