DMX address and values translation device?

[Apspete1]

Hi blueroomers,

I'm looking to find a DMX translation device that is readily available and can be bought in qty (80) in the next 1-4 days

Ideally could be powered from 12v dc

The device must have DMX in and loop thru (ideally on 3 pin xlr), must be able to set a start DMX address on the unit and Have a separate DMX output that outputs the incoming start address DMX data values but translate to start at address 1 onwards with the live data.

So say DMX 100 is the listening address and I have 96 channels with 32 rgb led pixels at the location, it would be translated like this.

100->1101->2....195->95196->96

If anyone knows of a complete device or indeed an off the shelf pcb that could do this, I would love to know.

Ps I'm based in the uk.

Thanks in advance

Pete

[ddproduction]

I'm curious where the need for this arose from?

[Apspete1]

We have strings of led ball pixels that we are using that are spaced at 5m intervals, they self address down the pixel string from the first DMX address they see.

Whilst it is possible to link the ball strings when they are next to each other so linked strings just take next DMX address and allow a whole univ to be used, they do not like being spaced apart by 5m due to the design of the cable used in the strings.

So manufacturer came up with special board that you can set start address and sends out as DMX address 1 on but with the data from start address onwards.

But as I mentioned the boards are dead!

I could of course use 80 artnet universes! But would need to find 7 more 8 port luminex artnet to DMX units if supplier can't make board work. I have 3 luminex units already.

Bit of an odd requirement but that's what happens when your trying to innovate with the design of an event, and push items beyond what they were originally designed designed for.

Hope that helps explain why I need a solution.

1411208564[/url]' post='507618']

I'm curious where the need for this arose from?

[gyro_gearloose]

So if I understand you correctly, you have a few hundred LED pixels that you want to have individual control over? If that's the case then you'll need your 80 universes of DMX data. No amount of address translation will get round that fact. Of course if you don't mind having different strings doing the same thing, then just set them to the same DMX address. Or have I missed something?

 

Edit: What make are the LED strings. If they use some of the WS28xx family of LEDs, then there are several people selling controllers on ebay.

[musht]

Insert null pixels to bridge the gap and alter the prgramming to ignore them?

[dosxuk]

Of course if you don't mind having different strings doing the same thing, then just set them to the same DMX address. Or have I missed something?

 

I think the problem is he can't set the DMX address - they only run on address 1. Meaning he can put each string on it's own universe (not using all the channels), or re-map the correct channels from a smaller number of universes to the 80 odd strings.

[Apspete1]

James,

 

you have hit the nail on the head.

 

there are 78 strings of 6m in length made up of 2 x 3m strings. there are 32 led balls in each 6m drop.

 

what happens is that these ball strings accept only DMX, they are indeed internally ws2811 but have a DMX driver included.

 

If I link one 3m string to the other, each string uses the next 48 channels. so for each of my 6m strings its ch1-96.

 

what we wanted to do was use a universe per 5 drops of balls, this would use 480 channels neatly in one universe. Requiring only 16 universes however the drops are spaced 5 metres apart.

 

unfortunately the way the strings are manufactured means that the cable is unshielded, so once the DMX has been down the string (6m) and looped back up the string (6m) and linked to next location (5M), with 5 drops this ends up as 74metres and that is outside the products operating conditions! DMX is trashed.

 

So hence the need for the PCB to split the universes down to ch 1-96 per string.

 

I can as a back up plan just use 10 off luminex Ethernet-DMX8 MkII but thats 80 universes of artnet!

 

Anyone got 8 more luminex Ethernet-DMX8 MkII for hire for a week starting this monday?

 

Hope thats a bit better explained this time, thanks everyone for your help so far.

 

P.

Of course if you don't mind having different strings doing the same thing, then just set them to the same DMX address. Or have I missed something?

 

I think the problem is he can't set the DMX address - they only run on address 1. Meaning he can put each string on it's own universe (not using all the channels), or re-map the correct channels from a smaller number of universes to the 80 odd strings.

[dashroom66]

Quite a lot of these type LED products (assuming they are one of the made in china variety) are just standard WS28XX or LDP88XX pixels with a tiny DMX decoder at the start, and they usually sell an address programmer dongle thingy that you can plug into the DMX in (or elsewhere) and change the address. Try asking your supplier and they might have one for your pixels.

 

George

[gyro_gearloose]

Or if you can live with drops of 30 pixels, cut the first one off each string and use an addressable DMX ws28xx driver. Should cost about £10 per driver board if you buy in bulk from Israel. Theres a guy on ebay who sells them.

[maeterlinck]

I would be surprised if each node was regenerating the DMX signal, removing the first slot and transmitting DMXin-1 slots. As suggested more likely there is a WS28xx or similar (lots of options here - WS28xx is just the one most people know!). As such the DMX transceiver will be in the first node with others getting a serial input in greycode or similar. In either case the max signal run is 11m, last node > up string > along to next drop. Easy for DMX, doable for serial WS type signal as well.

Things to note/check:

Is the power supply the same for each drop. You will need to tie -ive together at the least. They generally perfer to share the same power supply, even if it's tapped at source.

Check for voltage drop, if you're running 11m at 5V and drawing a few amps on maybe 0.22 / 0.5mm2 cable there will be a drop. Mostly these chips won't work at less than 4.5VDC.

Does each start string accept DMX?

 

Any link to what you have might help focus suggestions.

 

HTH

[Apspete1]

We have a meanwell 12v power supply powering each set of 5 strings that is to run on a universe, using 2.5mm 2 core cable for the power interlinks, the power supplies are trimmed to provide 12.45v which means the end of last string gets right voltage.

Each of the 3m strings we own can accept DMX into the start, they are wired with a 4 pin connector, +ve, -ve, Data, and return data if you use a special loop back plug on bottom of string to run DMX back up it.

The chip inside the led balls is DMX512A T124596.

 

 

LED TYPE: SMD 5050

LED QTY: 2

LIGHT HOUSING & STRUCTURE: Mold Injected with TPEE

BEAM ANGLE: 360 deg

INPUT VOLTAGE: 12v

POWER CONSUMPTION PER BALL: 0.6w

PROTOCOL: DMX512

 

I would be surprised if each node was regenerating the DMX signal, removing the first slot and transmitting DMXin-1 slots. As suggested more likely there is a WS28xx or similar (lots of options here - WS28xx is just the one most people know!). As such the DMX transceiver will be in the first node with others getting a serial input in greycode or similar. In either case the max signal run is 11m, last node > up string > along to next drop. Easy for DMX, doable for serial WS type signal as well.

Things to note/check:

Is the power supply the same for each drop. You will need to tie -ive together at the least. They generally perfer to share the same power supply, even if it's tapped at source.

Check for voltage drop, if you're running 11m at 5V and drawing a few amps on maybe 0.22 / 0.5mm2 cable there will be a drop. Mostly these chips won't work at less than 4.5VDC.

Does each start string accept DMX?

 

Any link to what you have might help focus suggestions.

 

HTH

[musht]

Idea behind a null pixel is just as a repeater,in middle of 11m between strings might make it with one, either cutting the LED away from its card or wrapping gaffer round it to black it out.

 

Still occupies an address slot which needs to be accounted for in programming.

[gyro_gearloose]

Okay, since the DMX translator you're looking for probably doesn't exist you're going to need lots of universes. Do you really need individual pixel control over each string? Can you not pair some of them up? If you can't, this sACN/Artnet to DMX convertor might be worth a look. I haven't played with one myself, so you might want to buy just one to see if it suits your needs.

[dbuckley]

The perhaps frustrating thing is that I could code up such a translater in under an hour, but then you need hardware upon which to run it.

 

If you are looking for PCB level stuff, then perhaps this would be a good place to start; the Christmas light crew have many similar items of kit, and also stuff to directly drive pixel LEDs. This particular board uses a propellor chip, which is what I'd use by choice, and thus changing its code to split up a universe would take minutes.

 

This assumes, of course, your controller can output sACN (E1.31)...

[rob_cheese]

I'm sure it *must* be possible using an Arduino/Raspberry Pi with someting like this:

 

http://www.tinkerkit.com/DMX-master-shield/

 

Probably not a sensible suggestion, given the time and effort involved to get a lash up solution, but I thought I'd throw it in.

 

Rob