Crystal Garden

Rayman

Well, seems I can't finish one project without starting another...
Anyway, check out the attached photo. It's actually hard to get a good photo of this thing...

So, the idea here is to take my old PropRGB (8x8 RGB Led Array driver, Prop Based) and light up "crystals" AKA clear plastic things above each LED. It's actually working out not so bad.

I've printed a few crystals with SLA 3D printer and it's not so bad. But, I think getting laser cut PMMA would be much better and less expensive. Will be squares instead of circles, but I think that'll be OK.

Anyway, work in progress...

yeti

Crossbreed that with BlocklyProp and let different crystals act as different instruction blocks. I bet the kids will like coding the Stargate way by swapping crystals... \o/

JohnR2010

nice. Bet a video would be cool. Do they change in color and brightness?

MIchael_Michalski

Reminds me of "Land of the lost" with the crystals that opened the time portal.

How About,instead of laser cut pieces or 3d printed pieces, just go down to your local plastics shop and buy a rod of acrylic. Cut it at angles in a mitre box,then polish the ends with various grits of sandpaper, finishing with a polish. (try toothpaste).

Rayman

We can change color and brightness, no problem.
I've changed the current limiting resistors from 100 to 33 ohms to make them brighter.
But, the regulator overheats now if they are all on full...
So, until that is fixed, can't do all on full..

Acrylic rod might be the way to go. Certainly the lowest cost way.
Since I need 64 of these, that makes the most sense...

mikeologist

The RGB matrix is cool but you'd get a wider brightness range from an 8X8 WS2812 5050 array using an external psu.
When I was a kid we'd grow crystal shards out of sugar or salt in cheap test tubes. Spray on a bit of poly and they won't melt.
How cool would it be with real crystals?

edit: The test tubes are likely to break in the process.

MIchael_Michalski

I think the acrylic rod would be the best way. It has a really nice clear look to it. Just cut carefully and slowly with a sharp fine toothed hacksaw so as not to chip or melt it,and polish it up really nice. I get some thick masking tape and roll the rods in it before cutting to prevent scratching up the sides.

I wonder if this crazy idea might work. They of course make various colors of plastic. if you cut the plastic at the right angle, not only will it give you that cool glowing effect, it will reflect light back from the end toward the light source. Place the led lights in "Holes" in a piece of black plastic and a photodiode in another hole so it cant get the light from the diodes directly. Now it can only get the light reflected off the near or far end of the diode. You can make "crystals" of various colors and various lengths, say long, medium and short in pink,red, light blue, dark blue light green,dark green, yellow, orange, light purple and dark purple, (and perhaps a few others). When you drop a "crystal" in a hole, it detects the change in light on the photodiode and goes through a detect algorithm. It lights each color (r,g,b) in turn and measures the response of the photodiode. The hope is that you can get a unique signature for the different colors and different lengths of crystals. You could then make a "Crystal User Interface" to control something.Im thinking the microwave. You'd have that mounted instead of the control panel. It would control an array of optically isolated relays that connect the buttons and it would read the segments of the display. Then you would encode numbers and power settings into the crystals Probably some sort of base 6 number system. When guests come over, you go over to your microwave, put a bunch of crystals in, and it starts up and counts down lighting up crystals as it goes and your guests would be all "WTF?!"

Or a security system. You put the key in the ignition or hold your hand over a photo sensor of for a few seconds on your front porch or whatnot,and a console folds out of the dash or the front door of your house. and there are a bunch of crystals in it. It sequences through a random pattern of them then lights up a certain sequence of them. It would be an algorithm that depended upon which crystals were in which places at the start (which would be the last configuration you left it in when you last started the car). You then take then number it gave you, and do whatever it is you do. Im thinking something like , dark color + light color = clear. Clear + color = same color. red + blue = purple, blue plus yellow = green. blue + purple = red. blue plus green = yellow, etc, such that all permutations are used (add or remove colors as necessary to make this closed under the operation, that is, any color plus any other color has a defined result) SO maybe you add the secret code to the number it gave you and put that in. Would confuse the heck out of people.

MIchael_Michalski

MIchael_Michalski wrote: »

I think the acrylic rod would be the best way. It has a really nice clear look to it. Just cut carefully and slowly with a sharp fine toothed hacksaw so as not to chip or melt it,and polish it up really nice. I get some thick masking tape and roll the rods in it before cutting to prevent scratching up the sides.

I wonder if this crazy idea might work. They of course make various colors of plastic. if you cut the plastic at the right angle, not only will it give you that cool glowing effect, it will reflect light back from the end toward the light source. Place the led lights in "Holes" in a piece of black plastic and a photodiode in another hole so it cant get the light from the diodes directly. Now it can only get the light reflected off the near or far end of the diode. You can make "crystals" of various colors and various lengths, say long, medium and short in pink,red, light blue, dark blue light green,dark green, yellow, orange, light purple and dark purple, (and perhaps a few others). When you drop a "crystal" in a hole, it detects the change in light on the photodiode and goes through a detect algorithm. It lights each color (r,g,b) in turn and measures the response of the photodiode. The hope is that you can get a unique signature for the different colors and different lengths of crystals. You could then make a "Crystal User Interface" to control something.Im thinking the microwave. You'd have that mounted instead of the control panel. It would control an array of optically isolated relays that connect the buttons and it would read the segments of the display. Then you would encode numbers and power settings into the crystals Probably some sort of base 6 number system. When guests come over, you go over to your microwave, put a bunch of crystals in, and it starts up and counts down lighting up crystals as it goes and your guests would be all "WTF?!"

Or a security system. You put the key in the ignition or hold your hand over a photo sensor of for a few seconds on your front porch or whatnot,and a console folds out of the dash or the front door of your house. and there are a bunch of crystals in it. It sequences through a random pattern of them then lights up a certain sequence of them. It would be an algorithm that depended upon which crystals were in which places at the start (which would be the last configuration you left it in when you last started the car). You then take then number it gave you, and do whatever it is you do. Im thinking something like , dark color + light color = clear. Clear + color = same color. red + blue = purple, blue plus yellow = green. blue + purple = red. blue plus green = yellow, etc, such that all permutations are used (add or remove colors as necessary to make this closed under the operation, that is, any color plus any other color has a defined result) SO maybe you add the secret code to the number it gave you and put that in. Would confuse the heck out of people.

I like the idea of real crystals., There are many minerals that actually are one color under visible light and glow a completely DIFFERENT color under UV light.

mikeologist

MIchael_Michalski wrote: »

I like the idea of real crystals., There are many minerals that actually are one color under visible light and glow a completely DIFFERENT color under UV light.

You can use different food coloring combinations with the sugar or salt crystals as the "freeze" water molecules within the lattice and will carry the dies with them. You could likely add a few drops of tide to make it UV reactive, but I have yet to try that one.

mikeologist

Since it's likely to be a kids toy I'd add a bittergent to the mix as well, or spray one on afterwards.

Rayman

found a website that sells all kinds of rods for fairly reasonable pricing (including shipping).
www.tapplastics.com

Amazon has similar price for single rod, but think can save with multiple rods, we'll see...

TAP has square rods too. This might be easier to cut and maybe look better too...

MIchael_Michalski

That's exactly the place I was thinking of. They are local to me here in Sacramento. I've shopped there for over 30 years.

Rayman

I think I see more potential here with the square acrylic rods...

MIchael_Michalski

Just watch out for sleestaks...

Rayman

Hmm... That also looks like an 8x8 array...