Woo! boards for the LEDs have arrived. Now, if DHL can actually get to my address, I ought to have the LEDs tomorrow. Guess I better do the ICs tonight. 
And just like that, DHL just informed me that there is a package at my door. That would be 800 RGB LEDs with black tops. And there was much rejoicing! Caps and stencils should be in my hands on Friday, which will make for a fun upcoming weekend.
These are exactly what I need to finish off my LPD8806 bike light POV project (https://www.youtube.com/watch?v=Cu0mKToSdps) but I have no idea how to properly design them myself in Eagle or the like. Any chance you’d be willing to sell me the schematics that these were printed from? Please? 
They’ve been changed from that original batch. How long and wide do you need them to be? These are very dense, pixels are 1mm apart. Those board in the picture have 12 drivers on one side and 24 LEDs on the other. They can pull quite a bit of amps, especially since I use two of them end to end.
Also, keep in mind that these are double sided which may pose a problem for attaching them to the spokes. But then, one can be creative with that.
I’m looking for strands that would be 8-9 inches long with a width as small as possible, but anything less than 1.5 inches or so would probably work. The density like you have is actually what I’m after, my current setup with pre-fabbed strips is working but I’m not satisfied with the “resolution” they provide at ~2 LEDs per 1.5 inches.
I’m not too worried about the amp draw right now, the platform allows for a pretty healthy rechargable battery and the use case is ~20m at a time at low brightness with primarily black images.
The strips will be encased in a waterproofed enclosure that actually mounts inside the wheel rather than attaching directly to the spokes (allowing a double-sided board to work perfectly). This makes it easier to keep the strips at perfect 90 degree intervals and to have lights facing both sides of the wheel (8 total strips).
What I meant with double sided is that the LEDs are on one side and the LPD8806 drivers on the other side. I can make them just about 12mm wide (or just under 0.5"). However, it’s also possible to make it so there are LEDs on both sides and drives on both sides. It’ll make them a bit wider but probably still within 1". The problem with that is adding the LEDs on the second side as you can’t reflow them and doing them by hand is a royal pain in the behind.
So if you can live with separate boards, you can certainly stick with the design I have now, and put two boards back to back, so you have LEDs on the outside and drivers on the inside. That’s what I’m doing for my POV anyway, except they’re inside of a polycarbonate tube and I have a 4-sided arrangement (four strips) instead of just two. You can potentially to the same, stick two of them inside of a clear tube and them mount the whole thing inside of the spokes.
And you also realize that these are short pieces that you connect end to end to make a longer piece, right? My POV design consists of two of those that then form a full 11.33" length (for 48 pixels.)
At 8.4" you get 36 pixels. The next jump is at 9.5" for 40 pixels.
In the case where you make them with LEDs and drivers on both sides are the circuits (and therefore the addressing of LEDs) on each side isolated?
Wow, 40 at 9.5"? That’s pretty incredible. That might be a little overkill for what I’m doing but I would love to try it out.
They can be isolated, but honestly I wouldn’t want to assemble those. Hand soldering the LEDs on the second side is a pain, not because there are so many, but because it’s very very easy to char and/or deform the plastic on the LED. Especially when you need to come back to fix a stray bridge or a pad that didn’t connect. With two strips back to back, you choose if you want them isolated or if you want to tie them together. The same DATA and CLK lines can go to both strips so both show the same thing, or separate lines so each display something different.
Don’t you run into the same issue with the boards that have LEDs on one side and then drivers on the other? I watched the video where you were preparing to reflow the drivers onto the boards, wouldn’t you then be stuck hand soldering the LEDs on the reverse side?
In that video, yes, and it took forever to fix problems afterwards. Now I do the reverse, reflow LEDs first, drivers second. Much easier and no problems on the LEDs side.
In that case it sounds like the design you’re using now for your POV would work great!
I’d be more than happy to compensate you for a copy of the schematic of the board and the solder stencils if you’re willing. That is unless you have a small pile of pre-assembled boards you’re willing to sell… 
If you’re not interested it’s totally cool, your posts and comments on the FAST_LED group (and here) have already been an immense help and I sincerely appreciate your willingness to help out and share what you know. It’s a huge help to the beginners like myself, so thanks!
I’m all in the spirit of sharing work done, so no worries there. But, I’d rather not send you the left over I have now because of a small oversight on them (they are missing the pull-down resistors on the signal lines.) I am going to send another batch out to be made, so if you’re willing to wait a bit, I’ll get you some of the new boards for you to play with. If you want, I’m happy to populate them and you can then pay me for the components.
Oh wait. If I send you what I’m using, you’ll end up with 48 pixels on 11.3" which is longer than what you want. Hrm.
Ah right, I’ve gotten so used to working with the pre-fab strips that I was thinking you could just cut them into smaller sections but looking at the picture that’s clearly not the case.
At least, not easy. But I may be able to make it so you can. I just have to place the pull-downs after each IC and only populate the last one in the string. Let me do some work on them and see what I come up with. Worst case, I’ll create the smaller ones and maybe make some shorter versions of my design.
Thanks so much! After doing some better measuring I think I’d optimally be shooting for right around 8.5" but there’s always wiggle room
That means 36 pixels at 8.4" … That’s edge to edge, there’s a 1mm space between the first/last LED and the edge of the board. Connector pads are on the back side.
So .6" shorter than the 9" strips I’m currently using and 3x as many LEDs, that’s awesome. I’m getting excited just thinking about how sweet that would look.
You’ve seen the pictures, should give you an idea. ( and if you haven’t: Google Workspace Updates: New community features for Google Chat and an update on Currents )