Page 24

EETE OCT 2013

Displays & Interfaces Fig. 2: Typical power-on sequence for display control. Source: Distec A second DVI/HDMI input could be implemented on the internal AUX-connector. The VGA input performs a resolution up to 2128x1200 (at 60Hz and reduced blanking) and provides 205MHz of bandwidth. In addition, up to eight Composite Video or eight S-Video and Component Video (1080p) channels are available. The board can be remotely controlled via an infrared beam (RC5 codes) as well as through an RS-232 serial protocol. IR remote hand control and the required IR receiver are available as accessory kit. Finally, the eight GPIO inputs and the I²C-input offer a wide range of customizable in/out functions. Flexible firmware is the key to customization Now Distec offers its customers the flexibility to program their own display specific parameters. Using the configuration software MarsRover, characteristics like timing, LVDS positions power and back light sequencing can be defined and adjusted without restrictions – see figure 2. The firmware configuration via software, in contrast with the old fashioned DIP-switch or soldering bridge, provides higher operational security. Also the flashconfiguration board by board can be executed much faster in the customer’s assembly area than via hand-work with DIPs and jumpers. The MarsRover software provides the option to update the EDID data for each single input (VGA, DVI, HDMI). Additionally, the Prisma-IIIA can serve as a “blueprint” for dedicated OSD settings (colour setting, brightness, etc.). Via the copy- function of the MarsRover software, the programmed configuration can then be transferred to any other Prisma-IIIA. In future releases, MarsRover will enable users to manage calibrated colour and gamma values. Interfaces for industrial use Designed for industrial use, the Prisma-IIIA provides a serial RS-232 interface. USB access is done via a USB-RS-232 converter. Within the next few weeks Distec will finalize the development of an industrial and longtime available serial to USB interface. To implement a remotely controlled system via RS-232 or USB, both a user software like for example Docklight or the user’s own Linux or WIN interface and the description of all commands in a serial protocol are necessary. The serial protocol command set provided by Distec can be expanded with customized functions like access to GPIOs or integration of I²C sensors, such as temperature and ambient light sensors. Access to internal memories provides storage for information such as configuration data or serial numbers. Another extension allows users to switch between different presets for brightness and colour adjustments. CE/FCC certification Electromagnetic compatibility for CE, FCC certifications or even stricter regulations is a key-point. During the development, specific attention must be given to the lowest emissions and the highest possible noise stability. Even without any shielding, the TFT controller board meets Class-A requirements according to EN55022, allowing a straightforward integration into custom systems without elaborate EMI measures. To support the EMI approval process, users can adjust the LVDS levels and slopes as well as the spread spectrum clocking. This is done directly through the MarsRover software interface. Fig.3: The Prisma-IIIA in an EMI test set-up. Source: Distec. 24 Electronic Engineering Times Europe October 2013 www.electronics-eetimes.com


EETE OCT 2013
To see the actual publication please follow the link above