School of Medicine, Aberdeen University
by Ron Haselden, 2009
Ron's concept and brief to Nusoft was to produce moving horizontal and vertical coloured bands to backlight snippets of text from from the Hippocratic Oath.
The concept we used to archive this was to have a low resolution video display shining its coloured light through a fixed stencil of text onto a frosted glass front sheet.
The video display required us to design, develop and manufacture an LED display matrix using 4,160 coloured (RGB) LED's. The approximate size being 2m x 1.5m. The matrix was built up using 130 individual circuit board tiles, each with 32 RGB LED's.
Complete LED Display Matrix
Maxim 6974 RGB LED Tile
MOD5270 & Xilinx CPLD Video Controller
The video bit stream signal for the display was daisy chained through each of 130 circuits. Since each pixel of the display required a 36 bit colour value this thus required a controller capable of putting out a video bit stream at about 4Mhz to archive a flicker free frame rate.
The video controller was designed such that a NetBurner MOD527 microcontroller could generate video frame images within a 128k dual port static ram. A Xilinx CPLD was developed to do the high speed reading of the video frames from the dual port memory and generate the video LVDS bit stream to the LED display matrix.