An Introduction to Graphic LCD Displays
Graphic LCDs (liquid crystal displays) have a special position in the display industry. With the fast development of gadgets and digital devices, manufacturers need the latest technologies and techniques to provide high-quality products and services.
Graphic LCD Displays normally refer to monochrome graphics LCD displays or dot matrix LCD displays. Although color TFT (Thin Film Transistor) and OLED (Organic Light Emitting Diodes) displays to meet all the definitions of graphic LCD displays and can also be categorized as graphic LCD displays, monochrome graphics LCD displays have been in the market much earlier than color TFT displays and they become the legacy type of display. That is the reason that Graphic LCD displays only refer to monochrome, not the full color.
Graphic LCD Interface
There are some popular graphic LCD interfaces, such as 8 bit or 16 bit 6800 and/or 8080 MCU interface, 3 or 4 wire SPI interface, I2C interface etc.
Applications
LCD modules are used in various devices and applications. They make it possible for mobile phones, laptops, and televisions to produce clear images. They can also be seen in watches, calculators, and digital readers to help users read text easily. Moreover, the automotive industry is utilizing this technology as well. Car manufacturers integrate them into interior designs to provide a display of various information and allow access to services such as GPS navigation.
Benefits
Low cost, easy to manufacture, low power consumption are the main benefits for monochrome graphic displays.
Graphic LCD tutorial
In this tutorial, the working and pinout of 128×64 graphical LCD AMG12864AR-B-Y6WFDY-AT-NV-Y (2.9″ 128×64 Graphic LCD Module) will be described. It has 128 columns and 64 rows, 128×64 has 128×64=8192 dots.
Graphical LCD controller
Graphical LCD is controlled by two S6B0108 controllers. A single S6B0108 controller is capable of controlling 4096 dots. So, for controlling a graphical LCD we need two S6B0108 controllers.
Further graphical LCD half’s division
Each half is further divided into 8 pages of equal sizes. Each page size is 8 rows and 64 columns. Each page contains 8*64=512 dots.
Page distribution in Pixels
Each page contains 64 pixels (64 columns and 8 rows). output on these pixels. Each pixel lights up when it is 0 and becomes off when it is 1. Each pixel contains 8 dots.
Graphical Lcd (128×64) Pinout
Please refer to Page 8 of the AMC12864A specification.
Graphical LCD pins are the same as other character LCDs. Only two new pins are introduced with the graphical LCD. These are CS1 and CS2. CS1 is chip select 1 it selects the first half or first S6B0108 controller of LCD. CS2 is chip select 2 it selects the second half or second S6B0108 controller of LCD. Both CS1 and CS2 are active low. By active-low I mean for selecting a first or second half, make its associated pin (CS1, CS2) low 0. All the other pins E (enable) R/W (read/write) RS or D/I (register select) works in the same way as for normal LCDs.
Like other LCDs we also first have to initialize graphical LCD.