spiralphenomena
Posts: 4
Joined: Fri Dec 30, 2011 9:47 am

Re: DMX Lighting Controller

Wed Apr 11, 2012 9:05 am

I'm looking at making a lighting controller out of a pi for my third year university project (masters in electronic and communication engineering). Was thinking of having a bank of potentiometers and buttons as an interface for a programmable DMX controller. Haven't really thought of any of the specifics yet it's just thoughts in my head with nothing written down as of yet.

mole125
Posts: 228
Joined: Tue Jan 10, 2012 2:01 pm

Re: DMX Lighting Controller

Wed Apr 11, 2012 9:22 am

Sounds fun, though I'd be tempted to skip the physical buttons and have it all controlled electronically - shove a wireless dongle in their, have some simple software running on the box and allow you to log on and control it remotely - either using a simple web interface or VNC to access a local gui app. You would then be able to connect via your phone/tablet when you are up the lighting rig to turn on/off the lights as you are adjusting them.

Then again I'm a software guy rather than an electronics engineer so preferences may vary

Either way let us know how it goes.

spiralphenomena
Posts: 4
Joined: Fri Dec 30, 2011 9:47 am

Re: DMX Lighting Controller

Wed Apr 11, 2012 9:29 am

The wireless idea does sound like a good idea but I need an element of electronics due to the course I do I'm trying to work out the best way to interface with DMX too, not sure whether to buffer the output or just have a straight connection to the pi through the SPI. I may end up using a wireless dongle for networked control though.

XAPBob
Posts: 91
Joined: Tue Jan 03, 2012 2:40 pm

Re: DMX Lighting Controller

Wed Apr 11, 2012 9:49 am

No reason not to have - or at least propose - both.

mole125
Posts: 228
Joined: Tue Jan 10, 2012 2:01 pm

Re: DMX Lighting Controller

Wed Apr 11, 2012 9:52 am

Pesky exam rules

I've no idea how complicated to interface with DMX it is to know how much electronics that counts as. You could always complicate it by choosing to support multiple DMX channels rather than just one if that makes the electronics more challenging/appropriate.

Another option (though more expensive) may be to go for a pure touch screen approach for the control - though again I'm speaking as a software guy pulling the control problem up into my domain rather than a hardware guy.

spiralphenomena
Posts: 4
Joined: Fri Dec 30, 2011 9:47 am

Re: DMX Lighting Controller

Wed Apr 11, 2012 9:59 am

I need to research the DMX interfacing a bit more, other way of making it more complex is to transmit the DMX signal over ethernet and have the pi controller one end and a decoder at the other end. As I said I'm just throwing ideas round as to what's possible.

redman684
Posts: 48
Joined: Fri Dec 09, 2011 5:25 pm

Re: DMX Lighting Controller

Thu Apr 12, 2012 4:17 pm

DMX is an easy protocol, but old and at many points open to interpretation. Over the years many variations have appeared. So while you might be doing all the right things, it might still be hard to get a certain dmx device to work.

There's even an oversight in the protocol specification (I believe it was something like the delay between frames being shorter than the delay between the block inside the frame), forcing everybody to deviate from the original spec.

DMX512-A has solved many of the problems and is more versatile, but also more complicated.

If you only have a few DMX devices available it might be more fun to work with a digital RGB LED strip. http://www.ladyada.net/product.....index.html

I haven't looked into the protocol of the LED-strip (yet) but I expect it not to be very different from DMX.

You'll have 32 RGB LED's per meter to control, which I personally find much cooler than a single moving head. And it's more high-tech compared to the 25 year old DMX.

tank
Posts: 64
Joined: Thu Dec 15, 2011 5:51 pm

Re: DMX Lighting Controller

Thu Apr 12, 2012 4:43 pm

Take a look at the Velleman K8062 kit (http://www.velleman.co.uk/cont...../p310.html). That shows how to interface to the DMX line with 1 IC. 

Reink
Posts: 3
Joined: Fri Apr 20, 2012 9:06 am
Contact: Website

Re: DMX Lighting Controller

Fri Apr 20, 2012 11:05 am

I think there are many DMX appliances for a Raspi and there are several ways of interfacing to DMX.

In my opinion is a new expansion-board with the nessesary hardware to make the nessesary signal conversion from the Raspi to the DMX (RS485) signal. I see three ways of interfacing this hardware to the Raspi.

1) UART (Simple optocoupler with line driver)

2) SPI

3) I2C

With the PSI and I2C the extra hardware must be more "intelligent" but should move the creation of the DMX data from the Raspi to the expansion-board resulting in a more robust DMX signal.

When the drivers for this new hardware are be hooked into the DMX4Linux/OLA framework, they are very wide usable.

An other option is using a (commercial) 3rd party DMX USB interface connected to the Raspi, but this doesn't look as a nice solution to me.

michaelstickel
Posts: 2
Joined: Tue Jul 03, 2012 2:03 pm

Re: DMX Lighting Controller

Tue Jul 03, 2012 2:07 pm

Hi,
I have the same idea as you to use the RPi as one base for a lighting controller.
Michael
spiralphenomena wrote:I'm looking at making a lighting controller out of a pi for my third year university project (masters in electronic and communication engineering). Was thinking of having a bank of potentiometers and buttons as an interface for a programmable DMX controller. Haven't really thought of any of the specifics yet it's just thoughts in my head with nothing written down as of yet.

michaelstickel
Posts: 2
Joined: Tue Jul 03, 2012 2:03 pm

Re: DMX Lighting Controller

Tue Jul 03, 2012 6:27 pm

The problem with a lighting console is that it is 90% Software and at most 10% hardware.

The complexity is not in having more DMX outputs. If the RPi would have more UARTs, it would only be a matter of duplication, both in the hardware and the driver.
Writing the DMX driver is a matter of not more than a weekend.
Writing a driver that supports RDM is a matter of two to four weeks.
Implementing the RDM protocols is a matter of weeks to months.
Writing a compettetive lighting desk is a matter of months to years.

But as you are doing a master in electronic and communication engineering, RDM might be interesting for you. The hardware is nearly the same, but with a half duplex bidirectional comunication initiated by the master.

- Implement a driver that can be used as a DMX512 transmitter and receiver and an RDM master.
- implement a driver that is used as a DMX512 receiver and an RDM slave.
- write an RDM protocol master implementation.
- write an RDM protocol slave implementation.
- implement an RDM protocol analyzer, that sits in the middle and analyzes the comunication.

But this is a lot of softtware and only little hardware (RS485 transceiver with RDM network).
If you have a bit layout experience, you do it on a weekend.

I have planned to implement a DMX/RDM driver for the RPi and this may be a motivation to rewrite DMX4Linux, as it is a mess and got a bit old.

Reink
Posts: 3
Joined: Fri Apr 20, 2012 9:06 am
Contact: Website

Re: DMX Lighting Controller

Tue Aug 07, 2012 9:19 pm

@michaelstickel

I have the very same idea, and as soon as I get my own RasPI I will get started building my own DMX interface on directly the UART of the RasPI. (Offcourse no hardware limitation to support RDM)

My first thought was also to hook the driver to DMX4Linux, but this seems to have shifted to "Open Light Architecture" thats why I think "OLA" is the better option to hok the driver to.

edwinfb
Posts: 1
Joined: Sun Sep 16, 2012 8:06 pm

Re: DMX Lighting Controller

Sun Sep 16, 2012 8:25 pm

The electronic could be enhanced by a series of output devices
lighting seems to be a limited application for theatre and studio automation

flashular
Posts: 3
Joined: Fri Aug 03, 2012 9:15 pm

Re: DMX Lighting Controller

Mon Oct 01, 2012 2:38 pm

Along similar lines I have created a DMX interface on the raspi to control RGB colorwash units, but it really just serves as a starting point for developing other applications. In my mind one of the huge advantages that the raspi has is its build-in HD screen output, which allows one to create a complete lighting control panel without the need to have a craptop or other device in the loop.

The simple application that I wrote (DMXWheel), kind of demonstrates this principle by using the native LXDE windows environment in the standard raspi distro to open up an HSV color wheel that lets an attached DMX controller ( K8062 ) and LED color wash unit to match the color set on the screen. If there is any interest I can post the source code and and video demonstration.

flashular
Posts: 3
Joined: Fri Aug 03, 2012 9:15 pm

Re: DMX Lighting Controller

Tue Oct 02, 2012 8:31 pm

I have created an instructable for my raspi -> dmx project:

http://www.instructables.com/id/Raspber ... ontroller/

User avatar
TonyD
Posts: 445
Joined: Thu Sep 08, 2011 10:58 am
Location: Newcastle, UK
Contact: Website

Re: DMX Lighting Controller

Wed Oct 03, 2012 12:21 pm

Nice :-)
Tony

powersupplyguy
Posts: 2
Joined: Mon Apr 15, 2013 7:04 pm

Re: DMX Lighting Controller

Mon Apr 15, 2013 7:11 pm

Take a look at the following link as this company offers a really great range of digital SPI RGB LED strip and also a wide range of controllers, accessories and power supplies

http://www.led-supplies.com/product-ran ... gital-tape

They also offer DMX to SPI decoders for the LED tape and there is a video on the product page showing it in use. There are a few versions of the digital LED tape allowing you to control the LEDs either individually (5vdc input stuff) or in sets of 6 (24vdc input version)

I hope this helps

alanwang
Posts: 1
Joined: Wed Jul 09, 2014 2:47 am

Re: DMX Lighting Controller

Fri Sep 12, 2014 3:57 am

I have buy dmx led strip from LED COLOR, Their dmx led strip max 485 is inside 512ic, so their signal is dmx signal ,not SPI ,no need decoder
http://www.szledcolor.com/product.asp?sid=198&i=1&j=13

User avatar
Arjan
Posts: 255
Joined: Sat Sep 08, 2012 1:59 pm

Re: DMX Lighting Controller

Mon Jun 08, 2015 2:22 pm

A DMX512 / RDM shield is available from http://www.bitwizard.nl/catalog/
There is also a version with USB (FT245RL). This shield is compatibility with software that supports Enttec USB Pro.

For more information, see https://sites.google.com/site/rpidmx512 ... dmx512-rdm
IMG.jpg
IMG.jpg (51.55 KiB) Viewed 5422 times
http://www.raspberrypi-dmx.org/
Open Source DMX/RDM/MIDI/OSC/Art-Net/sACN solutions

BURevisfan
Posts: 1
Joined: Fri May 18, 2018 9:11 pm

Re: DMX Lighting Controller

Fri May 18, 2018 9:15 pm

Hello All!

I have an idea I'd like to play around with and I think a Raspberry Pi is the best method to accomplish it.

I'd like to be able to read an incoming DMX signal, manipulate part of the message, and then pass it on to the fixture.

My thought is to control a moving light from two sources. The lighting console would control the everything except for the pan/tilt channels. Those would be controlled by a separate source feeding values into the Pi as well.

I'd greatly appreciate any directions / advice on the matter.

thanks,
Robert

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