The DemoComII is a Microcontroller Development Kit for embedded software and hardware design engineers to rapidly evaluate and prototype ScreenKeys programmable LCD key switch technology.
The Microcontroller kit is designed around the Atmel 89C55WD microcontroller (8051 core) and includes two onboard ScreenKeys – one of each LCD resolution (32x16 and 36x24).
It enables developers to familiarise themselves with programmable LCD key switches and to learn how the interface and command set operates. It is delivered with pre-programmed firmware that demonstrates the ability to display text, graphics and backlight colours on ScreenKeys.
The DemoComII Microcontroller kit is offered in two different backlight LED options (see large RGB DemoComII image):
Connection points provide the ability to add another two ScreenKeys (of any LCD or LED type), thus controlling up to four LCD keys.
A full schematic diagram is provided for the DemoComII microcontroller. An Application Note and Firmware Source Code are also included on the CD provided, or alternatively it can be downloaded here. This hardware design is recommended as a preferred method to interface to ScreenKeys.
The firmware source code is written for the free GNU public licence SDCC cross compiler. This can be downloaded from sourceforge.net. This code demonstrates how to implement the different ScreenKey interface commands. It also shows how to implement a text-to-graphic conversion and demonstrates how to display graphics on a ScreenKey, etc. The low-level core of this code may be used to facilitate rapid application development by reusing the low-level and hardware-specific functions.
The DemoComII source code and schematic are easily translated for other microcontroller families.