RTC Plug

The DS1307 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. Address and data are transferred serially through an I²C, bidirectional bus. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information.A Real-time clock (RTC) is a computer clock that keeps track of the current time.

It has an interfacing port with four pins named as G, V, SCL and SDA. Here G represents ground, V represents VCC and SCL and SDA are I2C interface.