Raspberry as a DMX Device

[Jim JKla]

I have struggled long and hard on which section I should put this in and finally decided best place is here in software & hardware.

There are a lot of posts about using a RaspberryPi as a controller of DMX devices.

For those that do not know DMX is a way of controlling lighting used in theatre and discos and live music venues. There are other uses but these are the main ones.

A DMX cable consists of three wires 1 2 & 3 where 1 is a common ground and 2 & 3 are data lines commonly referred to as cold (2) and hot (3).

The signal typically carries 512 channels each with a value between 0 and 255 and the cable is daisy chained through a number of devices each with an address a device may have a block of addresses for example a Martin Mac2000 moving head light uses a block of 24 to control a number of aspects this light is capable of performing.

Now there are a number of devices capable of taking a signal from a USB port and turning it into a DMX signal and personally I use the Velleman kit K8062 it’s cheap simple and to all intents and purposes does what it says on the box “USB Controlled DMX interface”.

There’s a rather nice piece of software Freestyler which is and this is fairly crucial FREE and this is capable of controlling a lighting rig and is fairly simple to program and use and has it’s own Wiki and support forum.

What I would like to do is take the signal from the DMX line and have the RaspberryPI display on the screen the values that are coursing along my DMX cable

Freestyler has a mode where it will emulate what the output of your controller is doing what I want to do is listen on the cable and detect the values.

A chain of DMX devices is usually terminated with a plug containing a 120 ohm resistor between pins 2 & 3 and it would be useful to have the option of incorporating switched termination.

If this works it would also be nice to have a display that takes this output and uses it to display the values as coloured dots on a 256 x 256 grid with each dot in a colour representing the value between 0 and 255 one dot for each channel.

Rather than have some USB device I would also like this to make use of the I/O capabilities of the RPi.

[jcoopa]

Hi there, wondered if you could help me

Iv been looking into this dmx dongle. i have even spoken to Vellaman about it, and they said they don't think it would work with a pi. Im hoping that you proved them wrong!

what i am aiming to do is to be able to control dmx fixtures using a pi. So that one the pi receives an input (from a buttons or a motions sensor, it triggers the pi to run a dmx light scene... do you know if this is possible?

Hope to hear from you soon

regards
James

[DynaSpan]

Hi,

I'm using a DMX dongle for my lightning at home. I use lindmxd for controlling the DMX dongle. Maybe you can do something with this program?

DynaSpan

[Arjan]

Hi,

I have a simple DMX512 isolated break-out board which can be used as a DMX Receiver or as a DMX Controller. This board is connected to the UART (PL011).

Details about the Raspberry Pi DMX512 Receiver can be found here : https://sites.google.com/site/rpidmx512

Thanks, Arjan

RPi_DMX512_Receiver.jpg (60.41 KiB) Viewed 22737 times

[Arjan]

Hi,
There is a Raspberry Pi DMX shield available from http://www.bitwizard.nl/catalog/

IMG.jpg (51.55 KiB) Viewed 19712 times

Raspberry Pi open source DMX512 RDM solutions for the shield:

• Raspberry Pi DMX USB Pro (RDM Controller)
  Raspberry Pi RDM Responder (DMX Slave)
  Raspberry Pi DMX512 Receiver (Slave / Analyzer)
  Raspberyy Pi OLA DMX512 Sender
  Raspberry Pi Logic RDM Sniffer

For more information, see https://sites.google.com/site/rpidmx512 ... dmx512-rdm