SEVEN SEGMENT DISPLAY

This is basically LED's connected together to form the figure eight (8). Any of these LED's can be individually controlled (switched on or off) depending on the character the user wants to display.

These LED's are denoted by a, b, c, d, e, f, g,  and common terminal. Sometimes, dot terminal is included.

Each segment is connected to an individual input pin, and by supplying the appropriate voltage or current, the corresponding segment can be illuminated.

Seven-segment displays are commonly found in digital clocks, calculators, electronic meters, and other devices where numerical or basic character information needs to be visually displayed. They provide a simple and effective way to convey numerical data in a clear and readable format.

  

TYPES OF SEVEN SEGMENT DISPLAY

There are two types of seven segment display, they are:

• Common Anode
• Common Cathode

The difference between the two types of display is the way the LED's in them are arranged.

For clarity sake, anode is the positive terminal while cathode is the negative terminal

COMMON ANODE

Just as the name implies,  the positive terminal of all the LED are joined together to have a common anode. The individual negative terminals are labelled a, b, c, d, e, f and g.

         

common anode display

To display a character using common anode seven segment display, a positive supply voltage will be supplied to the common anode terminal and a negative supply voltage will connected to the individual terminals that make up such character.

COMMON CATHODE

This type of seven segment display has a common negative (cathode) for all the LED's and an individual positive terminal labelled a, b, c, d, e, f and g.

Common cathode display

Let's say you want to display the number 2, you will turn on the LED's connected to a, b, d, e, g and the common terminal.