RTC Module DS1307 Arduino
You could use this module in adding a clock on your Arduino system. This module enables the use of date & time within your system. You need a coin cell battery CR2032 for this one if you want it to keep the time even when your MCU is powered off.
- 5V DC supply
- Programmable Square-Wave output signal
- Automatic Power-Fail detect and switch circuitry
- Consumes less than 500nA in Battery-Backup Mode with Oscillator Running
- 56-Byte, Battery-Backed, Nonvolatile (NV)RAM for data storage