How many TV shows and movies have some mysterious device counting down to zero those displays are 7 segment displays.With the 7 segment displays you can display any number or some alphabets that your heart desires.
At first controlling a 7 segment display seems quite complex but it quickly becomes clear.
What follows is a quick guide to control a 7 segment display with a arduino board
If you want to jump ahead to any other part here's your chance:
Step 1 - What Is A Seven Segment Display?
Step 2 - Parts & Tools
Step 3 - Testing
Step 4 - Built The Circuit
Step 5 - Project 1- One Digit Count Down Timer
Step 6 - Multiplexing
Step 7 - Project 2 - Two Digit Count Down Timer
This instructable is a entry in the arduino contest so if you like it please vote.
Step 1: What Is A Seven Segment Display?
A seven-segment display (SSD), or seven-segment indicator, is a form of electronic display device for displaying decimal numerals that is an alternative to the more complex dot-matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, and other electronic devices for displaying numerical information.A seven segment display, as its name indicates, is composed of seven elements. Individually on or off, they can be combined to produce simplified representations of the arabic numerals.The seven segments are arranged as a rectangle of two vertical segments on each side with one horizontal segment on the top, middle, and bottom. Additionally, the seventh segment bisects the rectangle horizontally. There are also fourteen-segment displays and sixteen-segment displays (for full alphanumerics