# Gemmy Fire & Ice...& Water & Grass & Sun & UV Tanning &...



## corey872 (Jan 10, 2010)

Quick rundown on my weekend project. (I'm using the term 'weekend' as I started this ~2 years ago, got one finished last year and finally hammered out the second one this year...but that is a blink of an eye compared to my ~17 year Plasmaduino project!)

So where to start...I wanted a couple of these Gemmy 'Fire and Ice' projector lamps ever since seeing the neat twinkly pattern in the store. But I didn't want them at $20+ each! So I finally found a couple on half price sale after Christmas. The only downside is these made twinkles of two shades of white...not a terribly useful color combination - but we can fix that!










So the project starts as most do... spill out the guts and see what is going on. Inside is a small motor to spin a prismatic disk (disk not shown). A small 'mains dropper' powers the board of 12 LEDs.

I went about setting this up, taking photos, moving the disk, etc - then decided to take a voltage reading on the power supply to see what I would need to take into account for my board. 40 volts!! Well, I guess that is one way to make sure each LED gets 3.3 volts - just stick them all in series!










That wasn't really usable voltage for my design because I was planning to have any possibility of LEDs from a single color group (4 LEDs) up to all six color groups (24 LEDs). So my LEDs really needed to be in parallel with 3.3V across the whole array. The only issue was the 3.3V supply I scavenged from a wall wart was bigger than I could fit in the case.










But this also gave me an opportunity to work on the 'two birds one stone' issue as I also needed a spot to mount some switches. So a quick 3D print build later and I had an extender / adapter to solve both problems. Just cut the original housing in two, insert the adapter and patch up with superglue.










Next up, dealing with the circuit board. I had originally planned to just mount everything on perf board, but trying to keep track of 24LEDs, anodes, cathodes, color groups, parallel strings, etc and pack it all into the tiny space turned out to be a headache. A couple rounds of magic smoke and I said 'heck with it', loaded up EAGLE and sketched out a board. In a couple weeks, it was back from the fab shop and ready to be soldered.










Just enough space to cram in 4 LEDs of each color...red, orange, yellow, green, blue and violet /UV. No fancy programming here, just simple switches to control each color on or off. Though I am breaking into my stash of flicker LEDs - where I broke down and bought a couple dozen in each color to have for 'special purposes'.

I suppose someone could get really fancy with the new 'neopixels' and have a fully computer controlled / multi colored / animated light show out of it. But I just wanted something simple and relatively static.

Well that is 5 pics for now - catch me in the next post!


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## corey872 (Jan 10, 2010)

So here is the end result of all the slicing, cutting, soldering, etc. Looks about the same from the outside, except for the row of DIP switches...one for each color, plus a couple of spares.










...and a quick video to demonstrate some of the features.






PS - yes, the video is upside down! I flipped it right side up in my phone, downloaded it and it was upside down again. Flipped it right side up in a video editor and uploaded to youtube where it went upside down again. So at this point, I give up!.


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## RoxyBlue (Oct 6, 2008)

I am in awe of your technical capabilities.


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## Pumpkin5 (Aug 8, 2010)

Cool, cool!


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## corey872 (Jan 10, 2010)

RoxyBlue said:


> I am in awe of your technical capabilities.


Surely, tongue-in-cheek referring to my lack of video capabilities, lol! But thanks!!


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## 10carmoc (Apr 16, 2017)

corey872 said:


> I suppose someone could get really fancy with the new 'neopixels' and have a fully computer controlled / multi colored / animated light show out of it.


On that note, I've actually experimented with sticking Neopixels inside those cheapo rotating "disco bulbs" from eBay, and while it's cool in theory I'd say you're better off using individual LEDs in this case. Each "pixel" is really just three separate LEDs (or four, if they're RGBW) crammed really close together - if it's under a diffuser you can mix custom colors just fine, but if you put it under a lens and project it onto a wall, the distance between the emitters becomes much more apparent and you end up with separate points of red, green and blue.


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## corey872 (Jan 10, 2010)

That is a good point on the neopixels or RGB LEDs in general. 

I actually ran into the same issue with some RGB flood lights a few years ago. The individual red, green and blue LEDs created a rainbow fringe when the light hit a wall due to actually being three separate elements inside the bulb. That was easy enough to fix by fogging the lens of the bulb.

But in this application, the prismatic elements would definitely split the colors more, so you would need to have a neopixel with good, color diffusion at the LED. 

Though I have not tried, some look like they might be OK... 5 and 8mm 'straw hat' LEDs ...and some aren't diffused at all... 3535 and 5050 SMT chips. So choose carefully!


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## bobzilla (Nov 13, 2008)

Nice job! Very cool


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## jdblue1976 (Nov 18, 2010)

Nicely done. I have several of these for ambient lighting and one stopped working so I may try this on that one. Generally, you can find a few of these at the big box stores for half off the day after Halloween. I bet there will be plenty of bargains to be had be this year.


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## ncdodave (Sep 12, 2020)

Thats pretty cool! Im not an electrical wizard by any means but Now I know how to change colors around on those fire and ice lights to work better for my graveyard


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## Fright Boy (Oct 1, 2014)

Wow!! I wish I had the electronics know how to hack things like this. My soldering skills are _Poo_. I have a multimeter, but barely know how to use it. Wonderful job.


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