Adafruit DS1307 Real Time Clock Breakout Board

Key Features: DS1307 is the most popular RTC Great battery-backed real time clock (RTC) that allows your microcontroller project to keep track of time even if it is reprogrammed, or if the power is lost Works great with an Arduino using Adafruit's RTC library or with a Raspberry Pi Perfect for datalogging, clock-building, time stamping, timers and alarms, etc. This is a great battery-backed real time clock (RTC) that allows your microcontroller project to keep track of time even if it is reprogrammed, or if the power is lost. Perfect for datalogging, clock-building, time stamping, timers and alarms, etc. The DS1307 is the most popular RTC - but it requires 5V power to work (although we've used it with 5V power and 3.3V logic successfully)The DS1307 is simple and inexpensive but not a high precision device. It may lose or gain up to 2 seconds a day.Item SpecificsLength: 25.8mm/1.02inWidth: 21.7mm/0.85inHeight: 5mm/0.2inWeight: 2.3g/0.09ozMounting holes: 2.2mm(0.086in) diameter, 25mm(0.98in) apartThis board/chip uses I2C 7-bit address 0x68