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)

• PCB & header are included
• Quick to assemble and use
• Plugs into any breadboard, or you can use wires
• We have example code and library for Arduino with a walkthrough on our documentation page
• Two mounting holes
• Will keep time for 5 years or more

Note: As of October 10th, 2015, this product no longer comes with a CR1220 coin cell battery. We recommend you purchase a coin cell battery to use with this product.

This breakout board is a kit and requires some light soldering which should only take about 15 minutes. Please check the documentation page for a list of parts and assembly instructions

The DS1307 is simple and inexpensive but not a high precision device. It may lose or gain up to 2 seconds a day. For a high-precision, temperature compensated alternative, please check out the ChronoDot.