Factors to consider when evaluating a GLCD

Factors to consider when evaluating a GLCD

List of important factors to consider :

Resolution: The horizontal and vertical dot matrix sizes of the module expressed in pixels (e.g. 240×128).

Dot pitch: The distance between the centers of two adjacent pixels. The smaller the dot pitch size, the less granularity is present, resulting in a sharper image. Dot pitch may be the same both vertically and horizontally, or different (less common).

Viewing angle : LCD displays have a limited viewing angle. They lose contrast and become hard to read at some viewing angles and they have more contrast and are easier to read at others. The size of the viewing angle is determined by several factors, primarily the type of LCD fluid and the duty cycle. Because the viewing angle tends to be smaller than most people would like, a bias is designed into the module at the time it is manufactured. This means the nominal viewing angle is offset from the perpendicular by some amount. Several versions of the LCD module are then offered with this bias set to different angles or positions to accommodate as many applications as possible. The term “bias angle” is often used erroneously with the term “viewing angle”.

Response time: The minimum time necessary to change a pixel’s color or brightness. Check or compare the LCD controllers and their interface performances.

Interface : Parallel 8 bit Data bus, serial like SPI ?

Contrast Control : On chip generated and can be defined in the LCD controller’s registers or need of an external hardware circuitry like charge pump + DAC ?

Temperature Range : Need of an extended temperature LCD module ?
The LCD Contrast is temperature sensitive.

Paging Scheme System : Are the pixels stored in the module embedded LCD Controller’s internal Ram in a horizontal or a vertical manner ? Checking and comparing the LCD controller data sheets first to fix the choice.

Software driver : Hardware implementation is one thing, but trying to consider investigating the internet about existing software modules or libraries for THIS particular Graphic LCD Controller, looking for existing drivers in C language will bring you a lot !