- adafruit/RTClib at GitHub -- Library for the DS1307 real-time clock (also works with the DS3231, see Chronodot below)
- NewSoftSerial version 10c at arduiniana.org
- Arduino Time Library from the Arduino Playground
- AVR Libc Home Page (The heart of the Free Software toolchain for the Atmel AVR microcontrollers)
Hardware that I have used with Arduinos
- Adafruit DS1307 Real Time Clock breakout board
- Macetech Chronodot DS3231 ChronoDot High Precision RTC breakout board (available from Adafruit)
- Sparkfun 7-Segment Serial LED Display
- Sparkfun Serial Enabled 16x2 LCD
- Sparkfun FTDI Basic Breakout (for use with the Arduino Pro Mini 328)
- Adafruit Adjustable Breadboard Power Supply
- 9V regulated DC wall-power adapter
Datasheets and other items of interest
- ATmega328 page at Atmel Corporation
- DS1307 RTC tutorial at www.ladyada.net
- DS1307 datasheet at Maxim Integrated Products
- DS3231 datasheet at Maxim Integrated Products
