Lots of discussion on this in other posts. It really depends on the pattern and what level of FPS is acceptable.
One example:
There are multiple bottlenecks, processing is just one of them. On a v3, I think in most cases, if you go over 1000 pixels in untuned patterns, you’ll see some FPS drop purely from rendering time… Could be more or less, YMMV
Depends on the pattern, using the shipping patterns average is 48k pixels/sec.
Data rate of expander is 66k/sec.
Good FPS would need more than a solo PB for something like that.
How can you tell the Fairy lights on AliExpress have fixed addresses? The ones I have bought there are labeled as WS2812, for what that’s worth, and there are several versions available. Would it only show itself if you tried to attach a second string in series and it failed or as you suggested, cut one up and wire them in parallel, in which case they would work as expected?
… I have this perhaps irrational focus on something other than the bullet strings because I so much like the more linear arrangement found in Fairy Light strings. I’m just not so much a fan of the “jaggedy” aesthetic of bullet strings (reminds me too much of Christmas lights?) , though in a net the bullet could conceivably be arranged co-parallel with the conductor. That seems to be a basic hurdle that I might have to get over, dunno yet. As yet, I’m focusing on Fairy Light strings which does engender its own beautiful nest of issues.
I get the arrangement, thanks, have not built anything yet. But I’m also not so partial to zip ties for the above aesthetic reason. I know, picky, picky, picky. Again, dreaming of the fastenerless fastener. Let me know if you find one!
The fixed address ones have the data on one of the outside wires. The pixels are a bit larger too.
@Booli, the fixed-address fairy lights are usually advertised as “SK6812”, they’re connected by 3 copper wires, and all of mine have come with the same packaging:
Two definitive ways to tell that they have fixed addresses are:
Signs that a fairy light string is NOT fixed address – that it follows the normal WS2812B addressing protocol – include:
Four connecting wires to each LED:
Three connecting wires, but each LED has four pins:
Three wires, but each LED is mounted on a carrier board with separate Data-In and Data-Out pins:
…and returning to the subject of large-scale nets, I saw this on AliExpress:
though I haven’t tried one yet. It’s not clear from the photos whether the vertical strands have sequential or parallel data paths, but even if they’re parallel that could be fixed by cutting the data wire at the top and jumpering across the bottom of alternating strands.
Thanks for all the great answers, folks! Really worthy, interesting and appreciated. In short, just a few notes -
@pixie you found the prior discussion of nets Nets Awesome!, and from the pics there I now see that bullets can be co-parallel with the wiring. Some tasty looking translucent shell (cubeoctahedron or higher poly shape perhaps?) might spice it up. @jeff 's reference to 10 x 30 nets from Ali Express Ali Express 300 LED Net shows them now at $240 including shipping. Worthy of consideration, but not “cheap” either. At the bottom of that listing page are several interesting arrays and net-like arrangements including Net-like Array and LED Array on Translucent Film.. This latter much like @gmcmicken filmed array Fairy Light Matrix on Clear Sheet, but his is better!
@gmcmicken, your matrix on a sheet is just really great. I love the whole approach… diffusion, effectively strain-relieving the strings, hot melt to clear sheet yielding wide angle viewing… that vinyl sheet though, did you see any puckering or melt behavior there? Could you reveal what type of sheet you used?
Finally, my fairly elementary observations about bottlenecks and such is that watching framerate behavior real-time is a great teacher and reality check for any given pattern/system combo. Multiple PBs and expansion boards can do a lot! Its not so difficult to wire this stuff up, as long as atention is paid to volts drop, and grounding grounding grounding That is IMO. Also there’s the alternative of running things from @zranger1’s ExpanderVerse, which opens up, well, yet another Verse.
ANd @Pixie thanks for running down the different Fairy Light strings. I have been running two types BrizLabs 200 LEd Fixed Address Strings and those 3-wire strings, where the data line hops back and forth. The former have much heavier wire then the latter. The 200 light strings seem to run fine without power injection, though there is some brightness drop.
Well first I looked on amazon for vinyl sheets and the reviews were all terrible so I had my wife look at the fabric store in town while she was there for something else. She said they had two thicknesses and bought me the thinner one. I almost guarantee this one (6mil?) from the fabric store is 10x better than the ones on amazon. It’s advertised to cover furniture, tables, etc. It did not melt, I didn’t have to be careful, and it didn’t pucker much at all. Though the glue is permanently bonded to the vinyl there’s absolutely no way to scrape it off now.
Thanks for the crystal clear clarification…I just went and check and I have versions of all of them, including 3 wire ones which I now suspect have fixed addresses.
This looks really good… and cheap! Someone please be the guinea pig!
Caveat emptor. It looks like each string might be run in parallel. In the video they are mostly doing the same thing on each string. There’s a little color variation but I suspect that might be incidental.
There’s also some minor flickering/glitches in the video, and complaints about that in the reviews. Reviews also mention setting the controller to 30 LEDs to get things to work.
On the other hand, if these do speak ws2812 you could hack them into separate strings by the connector and run them to a splitter to get things fully addressable.
I noticed in the buyer submitted photos that they are not parallel, at the bottom they are connected in a zig zag.
For anyone interested, I had ordered these, and they are in parallel. It definitely would be easy to make them into a zig zag as suggested by connecting them at the bottom and cutting the top connection, but I haven’t tried yet.
Okay so I ordered these which are almost exactly like the ones linked above. The power/controller, the wire, the led size/shape/construction all look identical except for the shape of the junction boxes (with hooks) for each drop.
Anyway - the million dollar question - how are they wired and what protocol do they use. I’m happy to report they are all wires in series with a “return wire” running from the end of each drop back up to the top to continue onto the next drop. Despite 4 wires from the USB, one is not connected. So it is 3-wire, WS2812-like protocol with GRB order.
Can you simply chop off the controller and run it direct from a pixelblaze - yes you can.
Good detective work; thanks for the report. Is the return wire a single conductor? That would make the power and ground to each string run in parallel, but with the signal line returned, it wires the data in a zigzag serial fashion That would account for the fourth conductor in the string plus cleverly shortening the overall length of the power line and reducing the voltage drop. They are effectively injecting power into a serial string at the top of every drop.
It’s 4 wire throughout, the 4th on the drops is the data return wire, and the 4th wire on the mainline is not connected.
Ya exactly, parallel power for each drop, and series data from the bottom of one drop to the top of the next.
This is great! Thanks for following the rabbit down the hole on this, and detailing it out!
Question, about how long was it from order to delivery?
Great work! Thanks again! We’ve been looking for something like this for a good while.
I ordered on Jan 7th, it was shipped on the 9th, and arrived at my door (in BC, Canada) on the 26th.
Not too bad…
But I went to order and they said 49 days to deliver… maybe delivery to US is way different than Canada!!!
