Old technology is often left by the wayside, which can be a great shame as with a little effort you can have some fun hacking them with more modern items - such as an Arduino or compatible board. One example of this is the classic rotary telephone - which is used in many fun projects as a form of user-input or even converted to a mobile phone.
However the concepts of converting the signals received from the dial into usable input with an Arduino may be confusing to some, so thanks to Instructables member guidomax you can get that phone back to work. They explain the connections required, som example circuitry to interface with your Arduino and also a demonstration sketch to finalise your knowledge.
If you're looking to learn about Arduino development platform and how it interacts with external devices, you can't go past "Arduino Workshop - A Hands-On Introduction with 65 Projects” by John Boxall.
Arduino Workshop takes the reader from having zero knowledge about the Arduino platform, electronics and programming and leaves them with the know-how and instructions on everything from blinking an LED, to robotics, wireless data, cellular communications, motor control, sensors, Internet connected systems and more. For more information including a sample chapter and table of contents, visit the book page.