The Hardware needed for the display depends strongly on the used display. One often used
display is the so called 7-segment display.
These are LED based display modules for displaying only numbers 0 to 9
and also the hex characters A to F. For driving the LED’s inside of this 7-
segment display you need a component which delivers the needed current
of about 10 mA per Segment. Also the decoding from the binary number (0
to 9 for example) to the segments which must be driven must be performed.
The component 74LS47 is a typical binary to 7-segment display decoder.
Other Displays are the LCD Displays. Alpha-numeric modules display
characters, numerals, symbols and some limited graphics. These LCD
modules have their own controller. Interface is achieved via a bi-directional,
parallel ASCII data bus.
Necessary features such as Character Generation, Display RAM Addressing, Cursor
Scrolling, Blanking, and Handshake are all included. User programmable fonts are
supported. In summary, these modules are the simplest and most economic means to
communicate meaningfully between any micro-system and the outside world.
Alpha-numeric modules range from 8 to 80 characters per line. One, two or four character
lines may be chosen. Character height spans 0.130" (3.31 mm) to 0.500" (12.71 mm). Most
formats are available in a variety of packages to meet various mounting requirements.