Beginning Arduino Programming

Project 11: Serial Time Clock

The Arduino has a fairly precise internal clock, but it's not the most well-suited device to keep track of the date and time. This can be a fairly useful ability to have if we want to keep track of the time the cat comes in to the house or we want to make another digital clock. To get a reasonably accurate date and time with a little backup, we need to use a real-time clock or RTC module. For this project, we will use the venerable DS1307 RTC available on a breakout board from SparkFun Electronics and Adafruit Industries.

The DS1307 is a relatively simple device that uses the Inter-Integrated Circuit communication protocol, or I2C, or sometimes Two Wire—although these two terms are not always interchangeable—to send ...