7 SEGMENT DISPLAY

This is an array of seven independently controlled light-emitting diodes(LED) or liquid crystal display(LCD). This array is in the shape of the figure 8. It can be used to display numbers and letters.

Each segment is given a letter from a to g so that it can be identified when wiring up.

 

We can draw the circuit diagram for a LED display. There are two types COMMON ANODE and COMMON CATHODE.

  

 

We turn on the LEDs according to the number or letter we are trying to make

   The number 4 needs f,g,b and c ON and a,e and d OFF.

   The letter A needs e,a,b,c and g ON and d OFF.