LITERATURE REVIEW

JOURNAL 2

7 SEGMENT

Seven segment displays are the output display devices that provide a way to display information in the form of image or text. For displaying the images or text in a proper manner, some types of displays can show only alphanumeric characters and digits. But, some displays can also show characters and images. Most commonly used displays along with the microcontrollers are LCD, LEDs and seven segment displays,etc.

Common Cathode 7-segment Display

In this type of display, all the cathode connections of the LED segments are connected together to logic 0 or ground. The separate segments are lightened by applying the logic 1 or HIGH signal through a current limiting resistor to forward bias the individual anode terminals a to g.

Common Anode 7-segment Display

In this type of display, all the anode connections of the LED segments are connected together to logic 1. The separate segments are lightened by applying of the logic 0 or LOW signal through a current limiting resistor to the cathode of the particular segment a to g.

There are different types of controlling techniques that are implemented by interfacing these seven segment displays with the external controlling devices. Seven segment displays must be controlled by other external devices. Different types of microcontrollers are very useful to communicate with external devices like keypads, memory, switches, etc. There are numerous interfacing techniques that have been developed to solve the complex problems to communicate with displays.

Credit to : Reuban, S. (2014). Desing and Implementation of A Microcontroller Based Automatic Door NAd Visitor Counter.