So i’m in the “I have a great idea” phase and have done next to no research on actual products yet, I figured this place would be a fantastic place to start. I’ve read through the wiki on the different supported chipsets and power requirements and stuff like that, but I’m wondering if someone could tell me how possible this would be?
I’m looking to basically animate a 16x32 board of LEDs. I’d want to solder them so they’re about a half inch to an inch apart, haven’t settled on a spacing yet. The trouble is, I need to be able to control both the arduino and the LEDs from a portable power source of some kind. I’m open to buying one (or more) of the really beefy phone charger types or even a small car-battery-shaped thing to carry around if needed, but portability is 100% needed on this.
Any chance there’s a chipset/product I should be looking at specifically, and maybe a power source to run it? The code is (for once) the easy part for me here.
I had seen a costume where a guy made Pac-man animations using WS2811’s and got 12 hours out of a 7800 mAh battery, using 170 LEDs. My thought then is that I could at least in theory get 4 hours or so from the same idea.
Couple more direct questions - does FastLED work well with power injection, i.e. having all 512 LEDs in a single addressable group in the code but having the power and ground to the strips themselves actually running to like, 5 different power sources?
Also, maybe I missed it in the Wiki but are there any references out there as far as calculators for like “if you have this many LEDs at 100% brightness, you need a power source that supports X amps of current” or something? I mean I know that’s basic electrical knowledge but I didn’t know if there was a calculator for this specific purpose out there or not.
I created a top hat with 722 neopixel and controlled by a Teensy 3.2. I powered the controlled with one 1200mAh battery and the LEDs with a 2500mAh battery. It lasted about 5 hours at around 50% brightness. Mind you it it depends on your sketch. Here’s a video of it https://youtu.be/iFmmPalj9ls https://youtu.be/iFmmPalj9ls
@Tim_Lukasik That is fan-bloody-tastic! You wouldn’t by chance happen to have a link to the exact product you bought for the LEDs or anything would you? I think I have just about everything else figured out but that. i plan on buying a couple 20,000 mAh batteries in hopes they’ll last all day on a cosplay.
Yes, you will definitely want to have multiple power injection points with that many pixels. If using a single power source you can just run more pos/neg wires to additional points down the line. If using multiple power supplies just make sure all grounds all connected.
You can probably estimate around 40-50mA per pixel when running full white. (Different people use slightly different values here when estimating.) So for 512 pixels you’ll need around 20+ Amps if you wanted to run them all full white at the same time. But it’s also a good idea to have a power supply that’s a bit over rated for what you actually need, so consider that as well. You can probably get away with a LOT less depending on what sort of patterns you plan to run (how many pixels are actually on at any giving moment) and the master brightness you use.
@marmil Thanks for the input. I would say at any given time, about 80% of the LEDs would be on, always at half or less brightness, and most of the time the LEDs would be blinking on and off in mostly red, pink, yellow, and a few other “solid” colors. Any idea what kind of power I’d need for this thing? My first thought was to get 2 20,000mAh batteries and do power taps every 25-50 LEDs, and split the power into 2 sections of 256 while still controlling them from the board as one set of 512. Doable?
Also, either of you have any opinion on the 12mm ones I linked? The guy that did a similar project to the one I’m looking at used them to great effect, he just had 1/4 of the LEDs I plan to have so I’m trying to beef up my power inputs.
@Nathan_Hejnicki Totally doable. Power injection every 50 pixels would be good.
Those 12mm pixels are most likely exactly the same as the smaller versions, but just have a different size “case/dome” on them.
Sounds like planning for about 10A would probably be safe (with a little safety buffer). You might look into batteries used for R/C cars and planes, as those are usually rated for high current output.
I think I’ve done exactly what you’re asking for: http://marc.merlins.org/perso/arduino/post_2018-05-29_EDM-Party-Shirt-powered-with-FastLED_NeoMatrix-and-Adafruit_GFX_-plus-160Wh-10Ah-4S-worth-of-lipos.html
I even wrote a pacman animation for it
768 LEDs, I get about 10-12H out of 10Ah of 4S (16V) lipos. This is not at full brightness.
I’m using WS2812B which actually suck non trivial power even if they’re off. I just found out that WS2813 uses a lot less power when the LED is off, but I haven’t found matrices that use them (yet).
My recommendation to you: don’t waste your time soldering the matrix yourself, just use a premade one like I did (although if you wanted to, you could lay out 16 strips of 32 LEDs on a board, and solder between them, which isn’t as terrible, but still takes a while).
I created the LED matrix myself by cutting and gluing the strips to a black foam backing which made it more flexible to fit around the hat. I ran power to both ends of the matrix, that’s it. https://www.amazon.com/dp/B00VQ0D2TY?ref=yo_pop_ma_swf
@Tim_Lukasik $35 for 300 LEDS is not a terrible price, it’s more or less what I pay too and you won’t get that much cheaper when ordering from china with long mail delays.
Note too that the cheaper you go, the more likely you are to get crappy LEDs with failures that you don’t want or need.
