Large scale LED video display data flow management

The development of flexible and inexpensive controller for large scale light emitting diode (LED) video display image rendering is presented. The concept and system components of such system are presented. Controller is capable of discrete pixel intensity dimming by using the pulse width modulation (PWM). It can control the LED boards containing pixel arrays or the individual pixels/pixel strings. High dimming resolution usually contradicts with high refresh frequency and number of controllable LEDs. Thanks to novel dimming technique the dimming resolution can be varied without significant loss of refresh frequency or number of controllable LEDs. Data between the structure blocks circulates in a series fashion using the conventional shielded twisted pair (STP) cable. The structure and functional diagram of the serializer and deserializer needed for data transmission are presented. Control is accomplished by personal computer (PC) via a high speed universal serial bus (USB2) interface. Video data is transmitted via USB. All the controlling state machines were implemented using inexpensive complex programmable logic (CPLD) integrated circuit (IC) combined with static random access memory (SRAM) instead of field programmable gates array (FPGA).