$20 OpenDMX dongle

[DynamoBen]

SparkFun has an OpenDMX compatible interface for $20, enjoy. (it will also work with the OpenRDM software Henne created)

http://www.sparkfun.com/commerce/product_info.php?products_id=9822

[dmcole]

Even comes with a place for an RJ45 jack ... I couldn't tell if the pins were the "Christmas Lights Standard."

\dmc

[n1ist]

Unfortunately, they have the signals on pins 7 and 8, and they hit the RJ45 before they get to the A, B, G pads. The best way to use this board is to wire up an off-board connector or a pigtail with an RJ45 plug on it.
/mike

[DynamoBen]

Unfortunately, they have the signals on pins 7 and 8, and they hit the RJ45 before they get to the A, B, G pads. The best way to use this board is to wire up an off-board connector or a pigtail with an RJ45 plug on it.
/mike

I'm thinking that I might just use a screw terminal connector then I can make a whip for an RJ45 and one for XLR.

I may email sparkfun and see if they are willing to update the pinout, or maybe I will just cut the traces and run some mod wire. ;)

[hartlove]

I was looking at this a couple of nights ago, since I was already ordering some stuff from them, and I'm looking for a rs485 adapter.

Would I just use the OpenDMX driver from Entec's website, instead of the VCP drivers that it comes with? and then have DMX that I can send to my Ren24s? Or am I missing a step or three?

[DynamoBen]

Would I just use the OpenDMX driver from Entec's website, instead of the VCP drivers that it comes with? and then have DMX that I can send to my Ren24s? Or am I missing a step or three?

The VCP driver is what you need, its FTDI's Virtual Com Port Driver. That in conjunction with the OpenDMX plugin and DMX addin gets you DMX.

[hartlove]

OK, thanks. I think that's the way I'll go then.

[bonuts]

I'm probably smoking crack, but from reading the sparkfun site, it sounds this gizmo and the Ren-T perform similar functions, i.e. output RS-485 communication.

I know this is a stupid question, but could the Ren-T output DMX with the right type of plugin or something? Thanks.

[DynamoBen]

I'm probably smoking crack, but from reading the sparkfun site, it sounds this gizmo and the Ren-T perform similar functions, i.e. output RS-485 communication.

I know this is a stupid question, but could the Ren-T output DMX with the right type of plugin or something? Thanks.

This device is just a USB-->RS485 converter.

DMX is a protocol that communicates via RS485. The Renard is a protocol that can communicate via RS485. The Renard can be controlled with both its own Protocol and DMX Protocol.

So this is a multipurpose dongle then can do both. Make more sense?

[bonuts]

This device is just a USB-->RS485 converter.

DMX is a protocol that communicates via RS485. The Renard is a protocol that can communicate via RS485. The Renard can be controlled with both its own Protocol and DMX Protocol.

So this is a multipurpose dongle then can do both. Make more sense?

Thanks. It does make sense. But I still feel like I am missing something. Based on what I've read and based on your response, I ought to be able to use my Ren-T as a DMX dongle. If the sparkfun device is a USB > RS-485 converter and the Red-T is a serial port > RS-485 converter, they both ultimately spit out a communication protocol over RS-485. If I'm doing Vixen > Renard Plugin > Ren-T > RS485 > Ren24 with Renard firmware, why can't I do Vixen > DMX Protocol > Ren-T > Rs485 > Ren64 with DMX firmware. But I'm guessing its actually more complicated, that there is no way my Ren-T can do that.

[DynamoBen]

...why can't I do Vixen > DMX Protocol > Ren-T > Rs485 > Ren64 with DMX firmware.

Because of the below


...the Red-T is a serial port > RS-485 converter, they both ultimately spit out a communication protocol over RS-485.

DMX has a baud rate of 250K. A PC typically can't do 250K because it isn't a "standard" rate. However the FT232 chip on the USB interface can do these odd baud rates. So a standard serial com port can't do DMX, but a USB interface that allows non-standard baud rates can.

[aususer]

For what its worth, I bought an arduino to play around programming with and then found a link to someone who had turned it into an openDMX controller (http://www.arduino.cc/playground/DMX/Opendmx); built a simple max485 "shield" (http://www.arduino.cc/playground/DMX/DMXShield) (or you could buy one).. and then I had a simple openDMX controller (just download the drivers from entec).
Worked brilliantly (I'm advised that there can be frame dropping with openDMX but I didn't see any).

I started playing with a few of my "MPH Pixels" in vixen, then found some code for the arduino that ramped RGB over all channels... ended up getting the arduion driving my pixels standalone (http://www.arduino.cc/playground/Learning/DMX)! (great for testing).

These arduino-clones are not $20... (more like AU$32 clones (http://www.littlebirdelectronics.com/products/DFRduino-Duemilanove-328-%28Arduino-Compatable-Clone%29.html)) but as part of your toolkit they might give you a nice "bang for buck" and excellent fun for the DIY'r (I've since bought the ethernetshield and looking for some ACN/E1.31 methods ;))

just a thought.
Mike

[bonuts]

Because of the below



DMX has a baud rate of 250K. A PC typically can't do 250K because it isn't a "standard" rate. However the FT232 chip on the USB interface can do these odd baud rates. So a standard serial com port can't do DMX, but a USB interface that allows non-standard baud rates can.

Thanks for the explanation, makes sense now.