A seven-segment display (SSD), or seven-segment indicator, is a form of electronic display device for displaying decimalnumerals 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. Often the seven segments are arranged in an oblique (slanted) arrangement, which aids readability. In most applications, the seven segments are of nearly uniform shape and size (usually elongated hexagons, though trapezoids and rectangles can also be used), though in the case of adding machines, the vertical segments are longer and more oddly shaped at the ends in an effort to further enhance readability.
Each of the numbers 0, 6, 7 and 9 may be represented by two or more different glyphs on seven-segment displays.
here is a circuit which shows the interfacing of a seven segment with 8051 microcontroller and displays the numbers from 0 to 7.The numbers on the seven segment can be controlled by the port 1 buttons.
Download file for 89s52: