General Pixel Questions as they Pop into my Noggin'

toodle_pipsky

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I think this will work for me . . . hopefully someone else will find it helful too! As I have questions about pixels I'll ask here so they're all in one place.
First off, thank you to those who have written/starred in the awesome guides around the site, they've answered so many questions already. Hopefully I'm not being redundant.
First question, possibly obvious, how long is a string of pixels, or at least the length between pixels? Is there a standard length or is there a measurement I should be keeping an eye out for?
Thanks guys.
 

Skunberg

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There is no set length or spacing. You can have one pixel or a endless string limited by your controller and power injection. Some strings are used for signs so they may not have the same spacing on the same string. Spacing is only limited by the pixel chips ability to pass the information to the next pixel (several feet) and that can be extended if needed by null pixels (chip to pass data but not light up). I hope this opens your eyes rather than cloud your head :)

Brian
 

AussiePhil

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To further add to the cloud :)


It is generally accepted the default average spacing is 100mm or 4" with spacings as short as 80mm and as long as 140m being received by people.
Always good to specify the actually spacing you want when ordering.


The default string length for puchasing from China is 50 pixels, so a string is generally though of as 50 pixels..... you will notice though that we often talk about specific string lengths when things vary from the expected defaults


Cheers
Phil
 

AAH

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The strings are normally bought in lots of 50 as Phil says but they can be cut shorter and/or joined to suit the application or controller. I think i saw Ed/J1_sys say in chat that some of his controllers can drive the pixel data out to maybe a few hundred pixels. Power would have to be injected every 25 or so to provide accurate colours and there is the risk of a dead pixel early on taking out the rest.
 

fasteddy

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Another thing to be aware of if you plan on building a mega tree and you need the spacings of the strings to be the same then it is best to order all the strings at the same time as there has been consistency issues between bought batches when people have been building mega trees.
 

toodle_pipsky

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Just researching computer power to run pixels. Is my understanding correct that it's usually the visualiser in what ever program you use that requires the big processing power not the acutal running of the show itself? For example the old P4 machine I bought last year as a show machine would run the show alright again, but I'd have a hard time sequencing on it using a visualiser in say Vixen or LSP.

A bit of background - my plan is to add somewhere between 4500 and 7500 channels in pixels (depending on final budget) with maybe the usual 500+ non pixel channels. Not a very high channel count over all I didn't think.
 

Superman

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Yes the show computer doesnt need to be that big at all to run.

I ran both sequencing and show on an old duel core laptop. Sequencing was painfull at times with that.

I dont think your going to have many issues with the P4
 

fasteddy

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Sequencing may be the problem part with that computer and that many channels, the best way is to just try it and if it is too painful to use, then you know you need an upgrade.

Your plans have definetly grown since the Brisbane mini, it looks like your planning a mega tree for 2012
 

toodle_pipsky

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Ok, I need to stop relying on my faulty memory. The PC is a Pentium D . . . not 4, sorry. 2.8Ghz and 1GB Ram.
Mind you by Phil's response, crappy old machinces won't cut it - what's a bare minimum suggestion? (I do kinda have a vague recollection hearing something about computers, was it talked about at the mini, or did I overhear a conversation about it???)
 

toodle_pipsky

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Just deviating from my computer question . . . .

Say I purchase 10 strings of pixels and the length is 5 m - the spacing between the pixels is as I want, but the string length is too long, can I:
Cut the extra pixels off without effecting those left? Like are there addressing issues?
Can I join "off cut" pixels to make the 11th string?
Is there polarity to take into consideration when joining?
Are there any other considerations when chopping a length of pixels?

Thanks guys.
 

fasteddy

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toodle_pipsky said:
Just deviating from my computer question . . . .

Say I purchase 10 strings of pixels and the length is 5 m - the spacing between the pixels is as I want, but the string length is too long, can I:
Cut the extra pixels off without effecting those left? Like are there addressing issues?
Each pixel is individual, so you can cut 1 off with no effect. The way the data is sent is in a cascading way, so all the first pixel does is strips its data it needs and then sends the rest onwards, so the pixels are not individually addressed in hardware. So this allows you to chop, swap and change without issue on an individual or section basis. Refer to the ACL 101 manual page 22 for further information.

toodle_pipsky said:
Can I join "off cut" pixels to make the 11th string?
yes as explained in the previous question

toodle_pipsky said:
Is there polarity to take into consideration when joining?
yes +V and Ground must be always correct. Then depending on the type of pixel you purchase then there is the data and clock wires which need to be the correct way. The 2811 which i think you were interested in only has the data wire and no clock. So its important that you get the wires connected correctly


toodle_pipsky said:
Are there any other considerations when chopping a length of pixels?
Not really except for when connecting strings together, you must take in voltage drop as a consideration
 

toodle_pipsky

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Thanks Eddy, I had read your manual - obviously not sinking in enough!

With polarity I meant . . . and I hope I'm explaining it right . . . does it matter which side the data/power goes in? Can you tell if it's meant to go in on particular side or the other, or does it even matter?

I really don't know what I'm doing yet other than to say I know I still want to "convert" my mega tree, but I'm just really trying to learn what I can at the mo. :) You're a great help.
 
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