Display for Micro-Controllers

Display for Micro-Controllers

Text, Seven Segment and Graphic display

Display is essential for human interface. Information can vary from ON/OFF indication to a graphic.

LED

LED indication display are good for ON/OFF, warning, Error indication and are the simplest method of indication. Most of teh application in our daily use require this indication. 

Common Thru hole LED's are available in 3mm, 5mm and bigger sizes. Color are Green, Red, Amber, Blue, white and more. These LED.s have a narrow light beam and are good for straight viewing - example traffic lights. many display and sign boards use thru hole LED's.

SMD LED's are avail;able in 0603, 0805, 1206 packages, which are commonly used. These are available in both wide and narrow beam of lights. wide can go up-to 150 degrees. SMD LED's are good for on board indication and also greatly use in back lighting a panel. LED TV use these LED array for back-lighting.  

Seven segment display:

Sven segment display are good to display time, voltage, current weight etc. these are available in Red, Green, Amber, Blue and white colors. The seven segments can be driven directly from the micro-controller or you can use a I2C chip to drive from arduino.

                

TM1637 is one I2C to seven segment driver IC widely used. This IC can drive six 7-segment common anode LED's and read 16 switches [8x2] along with dimming and blanking of the displays. You may checkout the module here.

LCD text display

If a text string needs to be displayed in a project, then character LCD display would be the best, commonly available as 1602 part is a 16 character 2 line display. These display's are cheaper than graphic display, but costlier than 7-segment display's. Usually 2 line 16 character is most widely used and cheaper. 4 line 20 character, 1 line 8 character displays are also available but will cost more and you will be good to use a graphic display instead of the character display because of cost. 

When a graphic display is used a font array has to be created, which takes up memory in the flash, hence if the flash is a bottle neck in use of graphic LCD you can consider using the text display with 4 line, 1 line, etc.

Character display are simple to use and require lesser code in the micro-controller then graphic display. The LCD will hardly consume any power which will be in few micro amps; but the back light will consume more power in order of few milli-amps.

Monochrome Graphic display

Monochrome LCD / OLED display are good for small graph, text with small and large font. They find application when you want to display several parameters like Voltage, Current, Low battery, Signal strength, direction, etc. LCD display are cheaper than OLED display. LCD are more reliable than OLED because lighting up the OLED at full brigthness would burn the pixel; hence it is necessary to change the pixel so only one pixel will not burn at full brightness.

Nokia 5110 LCD Display

OLED Display

Graphic display with Controller

 Graphic display with dedicated Graphics controller IC are now becoming famous as the complete graphics needed for the micro-controller will be handled by an on board IC. FTDI FT80x are known for the Graphic LCD display interface, but you may find it hard to buy in the local market. Local market has display from Nextion in varying sizes. nextion display has a serial interface and accepts command to draw predefined graphic symbol / graphs with text of varying font size. Nextion display also have touch screen and a tool to build the necessary graphic screens.
Micro-control is interfaced using a serial Rx and Tx line, commands over this communication line can change the pages, display parameters, display basic and advanced graphs. This kind of display is helpful when the product needs graphs, text, pictures, symbol display.