Indicators and displays

One of the easiest methods for being convinced that the microcontroller is functioning is adding a code to the program which blinks a LED or LED-s. Quite often it is too little, because it is necessary to send more information than it is possible by using LED and some applications expect user interface where text or numbers are displayed. Here come all sorts of indicators and displays to help where it is possible to display numbers, texts or even pictures. One of the most known information displaying devices is computer monitor and typical programmer does not see anything special about using it, but when we are dealing with microcontrollers we have to give a good effort to display a even a single pixel.

The following chapters are introducing simpler types of displays and screens – indicator with LED segments and two types of monochromatic LCD. In addition to those also LED matrixes and (quite common today) organic color LED (OLED) screens are being used with microcontrollers quite actively. Once filament numerical indicators were used, which had a separate glowing filament for each number. There are electromechanical screens also, there are different colored facet segments which are turned physically. Lately, electronic paper which are imitating printings. First e-papers (electronic paper) were consisting of balls with different colored sides which were turned in electric field. Newer e-papers contain small capsules, where two colors of charged particles are influenced by electric field whether to sing down or stay on the surface.