BY THOMAS KIBALO
USING A 128x64
GRAPHICS DISPLAY
WITH YOUR 16-BIT MICRO
EXPERIMENTER
We’ve discussed a number of features on the 16-bit Micro Experimenter since
introducing it in the Dec ‘09 issue. This time, we will extend Experimenter
applications with graphics. We are all familiar with character-based LCD
displays. They have been around for quite some time. But what if you could
have both characters as well as graphic displays at the same time? Using
graphics enhances the user’s experience. We’ll show you how easy and
inexpensive this technology can be with the 16-bit Micro Experimenter.
This article introduces a low-cost hardware solution and ‘C’ software library
that works with our 16-bit device. Figure 1 shows an example of this
graphics capability.
■ FIGURE 1. Experimenter with Graphics display.
Introducing the EA DOGM 128x64
Graphics Series LCD Display
We will be using the EA (electronic assembly) DOGM
Graphics series display. The display has a matrix of 128
horizontal pixels by 64 vertical pixels, for a total of 8,192
pixels. This display provides a significant capability for
displaying pictures, graphics, and text. Designed for
commercial hand-held devices, it is extremely compact
with a large viewing area. The + 3. 3 VDC display is a
perfect addition and is easily mountable onto a solderless
breadboard.
A good choice in the EA series is the DOG128W- 6
display when used with the white backlight EA LED55X46-
W. This combination creates a monochrome display of
black pixels on an illuminated white background. The EA
LCD display and backlight modules are configured as a
single unit. The DOG128W- 6 display plugs in and sits on
top of the backlight LED55X46-W. Both parts are soldered
together and are then plugged in as a complete assembly.
Hardware and Interfaces
The DOGM has internal memory to support each of
the 8,192 pixel states. A block diagram of its internal
32 April 2010
memory is shown in Figure 2. This internal memory is
organized as eight pages of 128 bytes each for a total of
1,024 bytes ( 8,192 bits). Each bit in the row corresponds
to a unique column or horizontal (display pixel) x position.
There are 64 rows, so selecting a row corresponds to a
unique vertical y position of the pixel on the display.
Figure 2 is marked with the individual pixel addresses (x,
y) representing the four corners of the display for a pixel
reference map. Setting or resetting a bit for a particular
pixel will turn it on or off during display.
