This guide was first published on Aug 31, 2012. It was last
updated on Aug 31, 2012.
This page (Overview) was last updated on Jun 16, 2019.
This tutorial requires a Raspberry Pi running a kernel with the RTC module and DS1307 module included. Current Raspbian distros have this, but others may not!
The Raspberry Pi is designed to be an ultra-low cost computer, so a lot of things we are used to on a computer have been left out. For example, your laptop and computer have a little coin-battery-powered 'Real Time Clock' (RTC) module, which keeps time even when the power is off, or the battery removed. To keep costs low and the size small, an RTC is not included with the Raspberry Pi. Instead, the Pi is intended to be connected to the Internet via Ethernet or WiFi, updating the time automatically from the global ntp (nework time protocol) servers
For stand-alone projects with no network connection, you will not be able to keep the time when the power goes out. So in this project we will show you how to add a low cost battery-backed RTC to your Pi to keep time!