User manual

LCD Board - User’s Guide
Page 7
Copyright 2012 © Embedded Artists AB
3 Getting Started
This chapter describes important aspects of using the LCD Board.
3.1 Selecting Display Resolution
It is recommended to prototype with a display that has identical resolution as the intended end-
application. If the exact same resolution cannot be used during prototyping, select a resolution as close
to the end-application as possible. The reason for this is that different display resolutions give different
application program load (program execution time) and different load on the external memory bus,
where the frame buffer typically resides. When developing real-time systems, which many embedded
system are, it is advised to not alter fundamental things, like system load.
Note that size of the display is of no importance for the discussion above. It is the resolution that gives
a certain load on the application and external memory bus. Size can of course also be important when
evaluating the usability and interaction with the user.
The LCD Board comes in different versions. Currently two LCDs are supported and more are under
development:
 4.3 inch TFT color LCD with 480x272 pixels resolution and resistive touch screen.
 16- and 12-bit color depth is supported.
 7.0 inch TFT color LCD with 800x480 pixels resolution and resistive touch screen.
 16- and 12-bit color depth is supported.
Many LCDs support 18- and 24-bit color depth. The LCD Board, however, only support 16- and 12-bit
color depth because when increasing the color depth above 16-bits, the memory requirements and
external bus load will double. This is at least true for NXP’s LPC-family of processors with integrated
LCD controller. Instead of having 2 bytes per pixel (for 16- and 12-bit color depth) 4 bytes are needed
per pixel.
3.2 Mounting
Before start using the LCD Board it has to be mounted. The product and support page both contains a
link to a short video demonstrating how to mount the LCD Board together with the OEM Base Board.
Before continuing, watch the instruction video and then mount the LCD Board. A Phillips screw
driver #1 and a small adjustable spanner are needed to complete the mounting.
Note that it is not strictly needed to mount the LCD Board together with the OEM Base Board. It is just
practical. It is also possible to have the LCD Board beside the OEM Base Board. Figure 1 below
illustrates the two mounting options.