Matrix Orbital GLK12232-25-SM Legacy - Manual (Page 5)

1 Introduction
The GLK12232-25-SM comes equipped with the following features;
• 122 x 32 pixel graphics display
• Text display using built in or user supplied fonts
• Contrast is adjustable by software control
• Backlighting is adjustable by software control
• Keypad interface
• RS-232 or I
2 C communications
• Extended voltage module available (-V). This module is equipped with a constant current source to
ensure consistancy in backlight brightness from unit to unit. Since this module has a voltage regulator,
the contrast with remain consistant, regardless of the input voltage. The input voltage must be between
7-15 Volts for this module to operate.
This manual describes the basic use and overview of the display. It also describes advanced functions,
which may require soldering. Matrix Orbital expects the user to be proficient with a soldering iron before
attempting to modify the unit. Please be advised any damage resulting from soldering irons or modifications
will not be covered under the Manufacturer’s Warranty.
1.1 What to Expect From the GLK12232-25-SM
The GLK12232-25-SM is designed as the display unit for an associated controller. The controller may
be anything from a single board, special purpose micro-controller to a PC, depending on the application.
This controller is responsible for what is displayed on the screen of the display.
The display provides a simple command structure to allow both text and graphics to be transferred to the
screen. Text fonts, as well as graphics if desired, are stored in the display’s flash ROM and may be regarded
as ’permanent’ in that they survive power-off periods and do not change unless explicitly reprogrammed.
The screen is backlit for low-light situations. Backlighting may be turned up or down under program
control. Contrast is software adjustable to compensate for differing lighting conditions and viewing angles.
1.2 What Not to Expect From the GLK12232-25-SM
Since the display is intended to be used with a controller, it does not have any built in text editing func-
tions. If a stream of ASCII characters are inputed they will be displayed. However, the CR, LF, backspace,
etc., will be ignored. If the user’s application requires these functions, they must be provided by the software
in the user’s controller, which can issue the appropriate positioning commands to the display.
1.3 Keypad Interface
The keypad interface takes row / column input and converts it to ASCII characters, which are delivered
out the RS-232 or I 2 C port to the associated controller. Please note that the keypad is not used to directly
control any aspect of the operation of the display, which acts simply as a matrix to serial converter. In order
to use the keypad to control the display, the user must program their controller accordingly.
Matrix Orbital GLK12232-25-SM 1