Datasheet

Talking to the RTC

The RTC is an i2c device, which means it uses 2 wires to to communicate. These two wires

are used to set the time and retrieve it. On the Arduino UNO, these pins are also wired to

the Analog 4 and 5 pins. This is a bit annoying since of course we want to have up to 6

analog inputs to read data and now we've lost two.

For the RTC library, we'll be using a fork of JeeLab's excellent RTC library, which is

available on GitHub (http://adafru.it/c7r). You can do that by visiting the github repo and

manually downloading or, easier, just click this button to download the zip

Download RTC Library

http://adafru.it/cxm

Rename the uncompressed folder RTClib and check that the RTClib folder contains

RTClib.cpp and RTClib.h

Place the RTClib library folder your arduinosketchfolder/libraries/ folder.

You may need to create the libraries subfolder if it's your first library. Restart the IDE.