kodyaudette
New member
Hello everyone! I'm really glad I stumbled upon this forum, I've been looking for a method to build a large LED display to serve as a backdrop for a band, and I think I've finally found a good way to do it. I needed a way to show video clips (albeit at very low resolution) for ease of making animations for a live show and it seems like using a pair of Teensy boards with the OctoWS2811 Library and the Processing movie2serial Program would be a fairly solid approach.
I have a couple questions for you before I start ordering parts though, as this will be a fairly expensive project and I don't want to run into any avoidable issues.
Here are my design targets, most of which are flexible based on ease of build and practicality:
Overall screen dimensions: ~10' wide x 6' tall, or in metric, around 317cm wide x 125cm tall.
LED pitch: 30 LEDs/meter, or 3.3cm. I was initially looking at some pre-strung LEDs at 5cm pitch, but after drawing out a grid on the floor, I don't think that would really work too well without some sort of diffuser,and I think that the 3.3cm spacing of the 30 LED/m strings should work fine without diffusion, the viewing distance for this screen will be 5+ meters and it's acceptable for people to see the individual pixels, not to mention that fog/haze on stage will help to diffuse things a little anyway.
So as far as pixel resolution, that equates to roughly 96x56. These numbers are flexible in both dimensions if it makes more sense to group the strings differently, etc. but that's the approximate number I'm moving forward with. This means a total of ~5376 LEDs. As far as I can tell, two Teensy 3.2 boards should be adequate to control this many LEDs at very acceptable speeds, correct? I see that for a 3.0, a limit of 1000 is recommended, but that a 3.1 can handle 4000. Am I mistaken here? That would be 16 banks of 336 LEDs each. I know that power distribution can be a concern with such long strings of LEDs, however each vertical column of LEDs will be 56 LEDs and I will apply power to each column, while every 6 columns will comprise one "Bank" as far as Data goes. I estimate around 1300w of power draw at full white brightness and will be providing plenty of extra power supply and wire guage headroom to handle the currents required for so much power.
My total budget for this project around $1000, though I was really hoping to target closer to $800. The biggest costs are the LEDs, the wire, and the power supplies. Now I have received a quote for 180m of the 30 LED/m strip for two different voltages, 12v and 5v. Now I can see that it would be simpler to use all 5v since the Teensy Boards are happy with 5v, as is a Raspberry Pi which I am considering eventually using as the video source, but the difference in price between equivalent amounts of the 5v and 12v LEDs is substantial when buying this amount. I was quoted $504 shipped for the 12v and $792 for the same amount of 5v LEDs. Both are individually addressable WS2812, I assume the 12v ones just distribute the power in groups of 3 LEDs, but the Data signal should have the same voltage requirements as the 5v LED strings, correct?
After specing out the rest of the parts necessary, the difference in total approximate project cost would be ~$795 for the 12v strings, or around $1100 for the 5v Strings.
So my biggest question is, do you see any issues with running the Teensy boards off of USB power from a laptop, then getting an appropriate number/wattage of 12v supplies for the LEDs? If this works, it would have the added benefit of lowering the current on each of the power wires which would lower wire cost a bit and also give me the warm and fuzzies about being able to overspec my wire gauge.
Thanks for any help you can provide! I will definitely be documenting this whole process, and since it will be used as a backdrop for a band, there will be plenty of photos and footage of it in action.
Sorry for the long post, but I figure it's much better to be thorough!
I have a couple questions for you before I start ordering parts though, as this will be a fairly expensive project and I don't want to run into any avoidable issues.
Here are my design targets, most of which are flexible based on ease of build and practicality:
Overall screen dimensions: ~10' wide x 6' tall, or in metric, around 317cm wide x 125cm tall.
LED pitch: 30 LEDs/meter, or 3.3cm. I was initially looking at some pre-strung LEDs at 5cm pitch, but after drawing out a grid on the floor, I don't think that would really work too well without some sort of diffuser,and I think that the 3.3cm spacing of the 30 LED/m strings should work fine without diffusion, the viewing distance for this screen will be 5+ meters and it's acceptable for people to see the individual pixels, not to mention that fog/haze on stage will help to diffuse things a little anyway.
So as far as pixel resolution, that equates to roughly 96x56. These numbers are flexible in both dimensions if it makes more sense to group the strings differently, etc. but that's the approximate number I'm moving forward with. This means a total of ~5376 LEDs. As far as I can tell, two Teensy 3.2 boards should be adequate to control this many LEDs at very acceptable speeds, correct? I see that for a 3.0, a limit of 1000 is recommended, but that a 3.1 can handle 4000. Am I mistaken here? That would be 16 banks of 336 LEDs each. I know that power distribution can be a concern with such long strings of LEDs, however each vertical column of LEDs will be 56 LEDs and I will apply power to each column, while every 6 columns will comprise one "Bank" as far as Data goes. I estimate around 1300w of power draw at full white brightness and will be providing plenty of extra power supply and wire guage headroom to handle the currents required for so much power.
My total budget for this project around $1000, though I was really hoping to target closer to $800. The biggest costs are the LEDs, the wire, and the power supplies. Now I have received a quote for 180m of the 30 LED/m strip for two different voltages, 12v and 5v. Now I can see that it would be simpler to use all 5v since the Teensy Boards are happy with 5v, as is a Raspberry Pi which I am considering eventually using as the video source, but the difference in price between equivalent amounts of the 5v and 12v LEDs is substantial when buying this amount. I was quoted $504 shipped for the 12v and $792 for the same amount of 5v LEDs. Both are individually addressable WS2812, I assume the 12v ones just distribute the power in groups of 3 LEDs, but the Data signal should have the same voltage requirements as the 5v LED strings, correct?
After specing out the rest of the parts necessary, the difference in total approximate project cost would be ~$795 for the 12v strings, or around $1100 for the 5v Strings.
So my biggest question is, do you see any issues with running the Teensy boards off of USB power from a laptop, then getting an appropriate number/wattage of 12v supplies for the LEDs? If this works, it would have the added benefit of lowering the current on each of the power wires which would lower wire cost a bit and also give me the warm and fuzzies about being able to overspec my wire gauge.
Thanks for any help you can provide! I will definitely be documenting this whole process, and since it will be used as a backdrop for a band, there will be plenty of photos and footage of it in action.
Sorry for the long post, but I figure it's much better to be thorough!