In-progress pic of my latest project

…any guesses what it is?

I’m prototyping it for the moment with a breadboarded A*, but thinking about running it on Cerb, so I can run the blinkies easily, and also add a tunes module (just got a couple in today).

Planning to make three of these. Next year, I’ll probably do more, and have the stars laser-cut. Ran out of time for that this year, so ended up cutting the first with a jigsaw, and the other two oversize on the bandsaw, then flush trimmed with a router. Way too messy. :slight_smile:


Looks great! A Christmas tree star?

@ Architect, @ andre.m -

Good guesses. I’ve thought about using this as a Christmas Tree star, but:

a.) I don’t think I can get buy-in from my wife. She’s not quite as big a fan of the blinkies as I am. :wink:
b.) with the 1/4" PVC sheet backing I used, I think this will probably end up being too heavy. I probably could have easily gone with 1/8" PVC sheet and it would have been plenty sturdy. Live and learn.

Plan is to hang these in some of our windows. That’s assuming I get them done. I’ve got the main strip wired, along with one of the four side strips. Also realized, after I already drilled the holes at each end of the strips, that I really only needed one hole at the far ends, for the signal pin, since I can pull power and ground from either end.

It’s a fun project that has given me an excuse to use both power tools and my soldering iron on the same project. That’s a win in my book, even if this first set of stars aren’t perfect.

Next set I do, I’ll also probably order LED strips with a white background instead of black. The ones I’m using I got on sale from Pololu’s black Friday sale, so they were too cheap to pass up.

@ devhammer - What? No custom 24" PCB? Slacker… :wink: Looks great! Looking forward to a video. What sort of animations do you have planned? Will the three be synchronized across rooms?

Easy there, cowboy! First I have to get at least one working fully. :slight_smile:

Once I’ve got the wiring done on the first star, the next step will be writing up some code that knows how to address the LEDs in a manner that makes sense given the layout. Ideally, I’ll come up with some flashing and fading patterns that work well radially, but I’m letting that cook in the back of my head while I work on the mechanical aspects.

Assuming I can get all three stars working properly in the next several days, they’ll all be controlled by their own mCu. Just for grins, I might even have them each use a different stack (perhaps one A*, one Gadgeteer, and one Espruino). Would be useful in future demos, to show how one accomplishes tasks across different micro platforms.

Synchronization will probably have to wait 'til the next iteration, since it would require wireless and I’ve not yet invested heavily in modules on that front. Would definitely be cool to set them up so that I could control colors/patterns, etc. via BT on my phone, and have one act as a master and the rest follow its lead. But that’s way more than I have time to bite off this year.

Cool stuff :slight_smile:

Sigh. Two steps forward, one step back.

Got all the strips soldered together and working:

But then I was getting brownouts, so I switched power supplies, and grabbed what I thought was a 5V power supply that I recently got from Adafruit. And since my breadboard power supply adapter needs a minimum of 6V, I wired the power supply up directly to the breadboard.

Well, it turns out that the power supply was 12V, 5A. And the first star is now toast. Good thing I have two more blanks.

Lesson learned. Don’t work tired, and ALWAYS double-check the values on your power supply.

Taking a break from this before I trash anything else. :-[



Another lesson learned, this one during disassembly…

Cut edges of sheet PVC are SHARP. Not quite as bad as a paper cut, but I would have been better off wearing work gloves to take this apart.

Oh, and another lesson. Don’t hot glue the wire pass-through holes until you’re SURE that you’re done.



Tore down the first attempt. I tested at a couple of points to see if any of the LEDs were salvageable, but it appears I successfully fried the whole lot. Thankfully, I have more. :slight_smile:

Rebuilt the first star, and it’s working again, and while I would prefer to have avoided frying my LEDs, the rebuild is giving me a chance to fix a few issues with the first build, including properly aligning the strips, and switching to all white wires on the front to minimize the contrast with the background.

Also used my label maker to add prominent labels to all my power supplies so it’s absolutely clear which is which.

Starting star number 2 now. Goes much faster the 3rd time. :smiley:

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Please show us what it looks like when it is powered. :slight_smile:

@ Architect - See the Vimeo link a few posts up…I took that prior to destroying the first iteration, but that’s what it’s looking like now.

Still need to write some custom code to account for the pattern of the LEDs so that it looks cooler. :slight_smile:

@ devhammer - Nice!

Somehow I have missed that link before.

Easy to do. Used to be that the forums supported embedding Vimeo videos, but I think the video tag only supports YouTube now. But given that all my hardware demos are already on Vimeo, seemed easier to stick with that.

Since I was doing some testing of the WS2811 code posted on codeshare for @ Jason, I just plugged in one of my stars to the breadboard connected to my Spider board, and the test code works just fine. So although the codeshare library for WS2811 seems to have a few issues when running on Cerb family, it runs great on Spider so perhaps that’s what I’ll use to run the project.

Just have to figure out how to mount the mainboard, DP module, etc.

Updated video, using FEZ Spider and Nicholas3’s SPI WS2811 library, with a few helper methods to map the LEDs on the star:


(turns out that Vimeo embedding still works, it’s just not obvious that it’s there. Just needed to add “=vimeo” to the opening video tag)

Interestingly, if I power it via USB from my PC, the LED pattern is consistently flawless. If I power it off a 12V supply connected to the USB DP module, however, I get occasional glitching (incorrect colors, stray, random LED lighting up, etc.). Not sure why that would be, unless there’s something about the voltage regulator that is causing it. If I connect both the power supply and the USB, no glitching. Weird.


@ devhammer - Nicely done. Hope I get as lucky.

I like it. If you don’t produce them maybe the Outrageous guys will make a treetop size for next year.

yeah, nicely done ! Can you tell us the point-to-point size of the Perspex ? Of course, bonus points if you use metric :slight_smile:

No plans to produce these. The cost would be prohibitive, I think, particularly to get them to a level of polish that would be worth selling.

That said, I think @ ianlee77 may have had the right idea…if I wanted to make these more polished, then creating a custom PCB might be the way to go…would eliminate the ugly wiring from strip to strip. Not sure what a PCB this size and shape would cost, though. :slight_smile:

Learning a lot of good lessons from the project, both in terms of what to do, and what not to do…

Glad you like it.

It’s actually PVC sheet, not Perspex. I’d probably go with a thinner base next time. 1/4" is totally overkill for this project.

The longest measurement is 29.333 cm (or for us yanks, 11.549 in), so it’s a little taller than a standard US sheet of paper, but not quite as wide as a sheet of paper (7.849 in. / 19.935 cm).

I made the design using Inkscape, so if I’d had the time/money, I could have had the design laser cut. I’m glad I didn’t this time, however, because when I cut out the first attempt at the shape from hardboard (Masonite), I found that it was too small to get the LED strips to fit properly. Would have been an expensive mistake, if I’d had that first attempt laser-cut.

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