Pixel Matrix Config Help

[joeengler]

I have 8 rolls of 5m led digital strips, DC5V input WS2801 left over from last year. I was thinking they might make a nice matrix. They have 32 LED's per meter and I'm looking for some help in the layout
Options
1) 32 rows by 40 pixels
2) 24 rows by 53 pixels
3) ??? ???

 

[JonB256]

Those are very close spacing between pixels. The 40 by 32 would be a very useful size but not very large.

 

[joeengler]

If it will be better I can add a few more strips to the project.


with a 32 x 40 I calculate the size to be 49" wide by 39" tall the pixel spacing would be 1.25 apart.

 

[JonB256]

My 40 pixel wide by 24 pixel tall matrix has a 2 inch or 51mm "square" pitch.


I like the overall size of it, but with a 2 inch pitch, it looks better from a distance. Your pitch is tighter, approximately 30mm, and should look better close up (though it will be BRIGHT).

 

[joeengler]

My 40 pixel wide by 24 pixel tall matrix has a 2 inch or 51mm "square" pitch.


I like the overall size of it, but with a 2 inch pitch, it looks better from a distance. Your pitch is tighter, approximately 30mm, and should look better close up (though it will be BRIGHT).

So do you think a 24 x 40 or 24 x 52 would be better then the 32 x 40. I just want to try and use the strips I have.

 

[fasteddy]

Something that is wider rather than taller may be best because you can then use it much more effectively for text and use it for things like a showing the tune in channel and so. If you want to do 3 lines of text then effectively you only need 17 rows.

 

[robt]

This still eludes me, are there no pixel strips that allow control of each led individually?

 

[burner]

There is, but it's much more expensive and will chew up your channel count quickly:
http://www.aliexpress.com/store/product/5m-led-digital-strip-DC5V-input-WS2811IC-256-scale-32pcs-IC-and-32pcs-5050-SMD-RGB/701799_585177065.html

 

[fasteddy]

This still eludes me, are there no pixel strips that allow control of each led individually?

yes there are as burner showed, there are many variations, but there is a compromise, with indivisual control you will be dealing with higher currents a higher % of voltage drop and also aa individual 30 LED/M controlled is 3 channels per LED so that equates to 450 channels per 5 metre strip as apposed to the 12vdc strip which is 150 channels per 5 metre strip and uses less current and suffers from less % voltage drop.

What this means is that if using individual controlled 5vdc pixel strips then it will cost you more in $, power, cable and channels. This may be worth the effort if you have people close to the display, but if you have people viewing the display from some distance then i wonder if its worth the cost and effort of using 5vdc

In the end their is no perfect solution, 12vdc has its benifits and 5vdc has its benifits, what you need to look at is what is the best fit for a particular application.

Personally ive been happy with using 12vdc strip over the years and doubt my audience would even notice or care if i had used 5vdc or 12vdc strip, im looking for the best bang for my buck. But now the 2811B 30 LED/m strip from ray is very tempting at only $32 compared to that of the 12vdc strip which is $30 so it can be hard to choose, either way there is choice for you.

Refer to this thread for a list of different strip and their current draws http://auschristmaslighting.com/forums/index.php/topic,3812.0.html

 

[robt]

Yes, the individually controlled leds (one pixel per LED) is what i need, i figured i would just happen across info eventually, but noone seems to be talking much about it, i'm sure because of the downsides. Thanks for posting that thread. I take it, when you see them for sale, they'll say in english that each led is individually addressable, or is there tech jargon? The first set i bought said each led was, but i didn't know the difference between a pixel and an led at the time, and i think neither did the person that wrote the description.

Yeah burner, from looking there, that's a ton more expensive, i'll have to get a strip and decide later if it's worth the extra cost. Something similar i need to do is get a few dozen very bright LEDs (5w, maybe more) and work out how to hook them together in series, i'm hoping there is a controller that will let me use (address) them just like they're a pixel strip, that would solve nearly every problem i have now.

Thanks for those videos you posted btw, i keep going back to them to watch different sections again, and this forum is an amazing resource itself. Things are changing so fast with pixels/controllers/leds, i think forums like these are a huge asset to both the industry as well as the diy guys like me.

 

[burner]

Look out for the words 2811 (which is the little black IC chip on the board and the controlling device). The number of these chips is equal to the number of pixels. Also look out for the words 5050SMD, which is the tri colour LED. Each LED (or bunch of LEDs) that 1*2811 IC controls has 3 channels (a red, gren and blue channel).
Hope that makes sense.

 

[robt]

For any 2811 based strip, each LED is individually addressable?

 

[robt]

I think i see now, it looks like you mean to say, *IF* The number of these chips is equal to the number of pixels, thanks

 

[fasteddy]

Generally if its 5vdc then it will be individually controlled, if its 12v then its will be more than 1 LED controlled per section.

Now to confuse things the new 2812B strip has the IC inbuilt into the LED so you wont actually see any black IC chip

The link I gave before shows you most of the different types of 2811 strip available in both 5vdc and 12vdc

 

[dougd]

Personally ive been happy with using 12vdc strip over the years and doubt my audience would even notice or care if i had used 5vdc or 12vdc strip, im looking for the best bang for my buck. But now the 2811B 30 LED/m strip from ray is very tempting at only $32 compared to that of the 12vdc strip which is $30 so it can be hard to choose, either way there is choice for you.

Eddy, you have a link to that strip, cant find it for some reason.