28 Nov
2005
28 Nov
'05
12:03 p.m.
Hi Dirk,
Dirk Jagdmann wrote:
Just read http://llg.cubic.org/dmx4linux/coding.html, and some stuff at
http://www.dmx512-online.com
Say I plan lighting for a specific club : is it like each lamp, effect, motor
will be assigned a to given channel ? I'd then ask the club's technician :
"what
channel is this lamp assigned to ?" (or he'd give me specification)
For example : 4 lamps, on channels 1,2,11 and 12
I would then have to configure my app to issue something similar to :
dmx_t buffer[4] = {0x80, 0xFF, 0x80, 0xFF};
fd = open (DMXdev(&argc, argv), O_WRONLY);
lseek (fd, 0, SEEK_SET);
write (fd, buffer, 2 * sizeof (dmx_t));
lseek (fd, 10 SEEK_SET);
write (fd, buffer, 2 * sizeof (dmx_t));
That would set two lamps to half brightness, and the other two lamps to full
brightness... Is this right ?
All of this sounds great. But how stable is dmx4linux ? Already used it on real
live shows ? (I'm not talking about big/huge shows)
[The following is quoted from your previous answer in this thread]
The idea would
be to modify my application (Jackbeat) to control light in
addition to sound, using dmx4linux (see:
http://llg.cubic.org/dmx4linux) and a
supported DMX controller.
Should be very easy, as it's essentially just an 8 bit value for each
"lamp" you'd like to control which directly drives the lamps intensity.
I just checked
this 55 EUR Enttec USB controller :
http://www.enttec.com/opendmxusb.php
This firm seems to officially support Linux. Looks great...
I would suggest this one. It's cheap, supported and plug'n'play.
A Linux 2.6.x version of dmx4linux will be out in the next weeks. You should expect that lighting equipment should be
DMX controlled today. So
this technically solves to connecting your DMX controller (from laptop) to the
DMX cable of the lighting console at the location. However be prepared that they
might have more than 1 DMX universe/cable due to the local installation so to
use all lights you'll need more than 1 universe on your DMX interface. Or two
interfaces with 1 universe each. That's the reason why you should contact a
local technican beforehand.
Got it. If DMX is a such common standard, I can safely be dependent on it. I'll
forget about the few DMX-unfriendly places I find. And if I really want to play
in some of these non-equiped place, I'll try and rent dimmers and lamps.
For a second universe, is it simply a matter of plugging a second Enttec device
and accessing channels 513-1024 ?
If they don't own a DMX controlled lighting
evironment I won't make myself any
trouble trying to connect to "their" lighting equipment with my own dimmers,
unless you're prepared to spent several days ripping their whole installation
apart (which they probably would not allow anyway).
Okay, let's forget about that. All I need is a DMX controller and the club's
equipment spec.
Thanks a lot !
--
og