To control a lot of Troia pixel modules from one PC, we developed the Troia distribution module. It is connected via USB 2.0 to the PC and gets controled by a Linux-kernel-module.
The task of the module is to distribute the incoming data into 32 streams of serial data with 38400 bps. Then up to 32 Troia pixel modules and therefore up to 1024 pixels can be activated by one distribution module. Via USB 2.0 then 20 (or more) Troia distributing modules can be connected to the PC to control more then 20.000 pixels at once.
The whole thing is realized with a microcontroller by Cypress, which puts out the serial data on 32 port-pins. These are boosted through usual HCMOS bus drivers (74HC540, 74HC541) and provided for the transfer with 10 mA Current Loop.
The mode of transmission 10 mA Current Loop was chosen, because of using twisted twin wire, it is possible to realize distances around 20 meters without interference. In addition the sender-site is assembled very simple with two HCMOS-bus drivers and even the reciever-site is actually just an opto-coupler, which is directly guaranteeing the galvanic isolation.
- distribution module circuit diagramm (version 2.5, pdrteilerModul/f)
- distribution module pcb (png)
- distribution module schematic (png)
The Troia distribution module was successfully tested with 6 Troia pixel modules in the TROIA Prototype.