Personal tools
The Open Lighting Project has moved!

We've launched our new site at www.openlighting.org. This wiki will remain and be updated with more technical information.

Talk:Open DMX USB

From wiki.openlighting.org

Revision as of 11:52, 30 May 2009 by Beier (talk | contribs) (how to build it?)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

According to the Enttec page this unit doesn't support receiving DMX and there are no OS X drivers available from Enttec.

Electrical design

As pin 4 and 5 in the XLR5 plug is not connected to the RXD input pin of the chip, it cannot be used for the RDM protocol. But if DMX signals are fed into pin 1 and 2 (with the help of a plug gender changer), the software should be able to set the RTS line low and poll the chip for incoming serial data.

I wonder if some DMX-serial drivers for this interface requires this exact FTDI 232BM chip (e.g. the one in Freestyler, that I could not get to work with other USB-to-serial converters.

In general this system only requires that the app can set the serial clock speed to 250 000 baud, and be able to control the RTS line (is relatively good timing required?). The data are transferred and buffered in the chip one byte at a time, I assume (so here the timing is not as critical, if the bytes are delivered within time).

Building instructions where?

The schematic diagram is available.

But the interfaces that Enttec build comes with some code in the EEPROM.

  • Is this code necessary? Or does it depend on how critical the device drivers are?
  • What is the code, what does it tell?
  • newer versions of the FTDIchip 232 have built-in EEPROM. Do they work just as well?

Are there device drivers that can use any serial port, given that the speed can be set correctly?