Newb Needing direction on a new project

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damonpence

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Hello everyone,

I am laying out a LED Screen project and would like some advice.

Project

Building LED screen 60LEDs per meter.

Width will be 120 LEDs or 2 meters x height 64 LEDs or 1 meter
I was wanting to use the new Teensy 3.6 because of speed and SD card but was unsure on the LED limit. I was trying to determine if the 3.6 would allow more than 8 LED strings. Also, would I need to use 1, 2 or any of the OctoWS2811's on the 3.6?

Or would i be better using multiple Teensy 3.2's on my project?


thanks in advance,

Damon
 
So I have ordered (30) 5 meter LED strips. 60 LEDs per meter. I have ordered a teensy 3.6 and i am trying to work out my build.

so I am trying to figure out how to build my display and how many LEDs to use.

I will have some questions but starting out trying to decide how i will build this system. so on the Octo webpage it shows the LED strips lined from left to right on one Teensy and right to left on the other to construct the display. One question is can i layout my display running bottom to top? I am looking at maybe building (16) columns that are 2 meters in height and (4) LED strips in width. So with all 16 columns connected my display would be 2 meters by a nudge over 1 meter. 7680 LEDs.

I know the columns thing probably sounds strange but let me explain why. This would be a back drop for a stage and I would split the 16 columns across a 15 foot to 20 foot distance. Then from time to time i would need a single display and the columns would allow me to stack them on there side to get a 2 meter wide x 1 meter high display.

So I realize i may need to use (2) Teensy 3.6's for this project which brings me to my second question. I have searched and not really found the answer as it has been asked in other Threads, I know Paul has updated the Octo Library for the 3.6 but can you use 2 Octo's on the 3.6 to get 16 outs to the LED strips? I still have to order my Octo's and was trying to find this answer before i do as i need to know if i need another 3.6.

I will have many more questions and will post pictures as this project rolls along. I do invite any opinion or experience that anyone may have that would help me in this project.

thanks,
Damon
 
Don't believe you can double up Octoboards without fun adventures redoing the DMA. The orientation doesn't have a straight out rotate option so you would need to remap the pixels either on the Teensy or at your source, whichever was easiest to do. Depending on what you are doing Teensy 3.2s will probably be fine for this since the choke point is more the speed you can get data out the strips than processing on the board, see side bar on this page: https://www.pjrc.com/store/octo28_adaptor.html
 
A single Teensy 3.6 and Octo board might be able to pull this off. The theoretical max refresh would be 34.7 Hz. I hope you'll give it a try, with the fallback plan of slightly rewiring and using 2 boards if one doesn't cut it.

I'm sure you're already aware, but whatever you do, don't underestimate the power requirements for so many LEDs.

When it's built, please please please post a photo!
 
Paul, I will give it a try with the 3.6 and the octo just to see how it does. I will also post pictures and possibly videos.

For Power I am figuring (8) 60AMP 300watt power supplies, one for every 2 columns (960 LEDS). does my math sound correct? I was figuring 6 would be good but since i was putting 480 per column then one per every 1440LEDS would not be enough power. I have 1/4 watt LEDS.

my math
2 Columns @ 480 LEDS per column making 960 LEDS
.25 x 960 = 240 watts -- finding 300 watt power supplies seems pretty easy.

3 Columns @ 480 LEDS per column making 1440 LEDS
.25 x 1440 = 360 watts -- I noticed these power supplies are a little harder to find

If i were to parallel the power supplies would this cause major problems or do i need to keep the power separated to each set of LEDS. I do realize from reading i will need to combine the grounds on all power supplies and teensy.

thanks,
Damon
 
damonpence said:
If i were to parallel the power supplies would this cause major problems
Click to expand...

Depends on the design of the power supply. Some are explicitly designed to run in parallel, but it's unlikely you'd be using those types.

Simpler forward mode or flyback designs usually can run in parallel without too much trouble, even though they aren't designed to run in parallel and connecting them together isn't great. These are the type commonly made for very low cost designs (where the cost of cooling is passed on the chassis). Typically they have 65-70% efficiency for lower voltages like 5V.

Synchronous rectification or resonant mode designs could end up doing rather bad things if connected in parallel. These types are usually more expensive, and usually offer 80% or better efficiency.
 
I am looking at ordering my power supplies for my project. What should i look at when selecting a power supply? I have purchased one already but i want to make sure this one would be good or if I need something better.
https://www.amazon.com/gp/product/B017YEOAPA/ref=oh_aui_detailpage_o01_s01?ie=UTF8&psc=1

Does anyone have a suggestion for where i can get information on wiring size for 480 LEDS? I am looking to run one power supply to LEDS(480) using 16 gauge wire with a 30 foot length. I feel the length and gauge of the wire is not correct but i tend to go overboard on wiring size so i am trying not to this time but afraid its to small. My overboard figuring on 60Amps is 4 gau wire for 30 foot.

thanks in advance.
Damon
 
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