Hackaday Prize Entry: Glow In The Dark Plotting

We like big displays, whether they’re gigantic LED displays, CNC whiteboards, or a gigantic laser projectors. For his Hackaday Prize entry, [nilo] has come up with an easy way to create a huge graphical display. It might only work at night, but the Glowboard Plotter is still really cool.

[nilo]’s display is simply a very large glow in the dark sheet wrapped around two rollers, controlled by a stepper motor. By running the motor, the blank glow in the dark sheet slowly scrolls across.

To add some color to this display, [nilo] fixed 64 UV LEDs to one end of the display. By lighting these LEDs up at specific intervals and specific intensities, a ghostly green glowboard image appears across this display. Is it useful? About as much as any other gigantic LED matrix. Is it cool? About as much as any other gigantic LED matrix.

Right now, [nilo] is working on mk. 2 of the Glowboard Plotter, upgrading the control system and increasing the number of UV LEDs to 128. It may seem useless, but it’s still very cool and an excellent entry into the Anything Goes portion of this year’s Hackaday Prize.

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79 thoughts on “Hackaday Prize Entry: Glow In The Dark Plotting

    1. Having the paper move instead of the print head was actually what I thought this would be before reading, do you have anything up online from your build? Sounds cool! I’d love to do something like this for an outdoor installation (the paper/vinyl goes outside while the electronics etc. stay inside).

          1. Haha, thanks! What’s not apparent in those pics is I covered the bottom (LED side) with a stip of packing tape to keep dirt out and there’s a wire running over that to collect static, finally wrapped in antistatic plastic. Otherwise I’ve just built a Van de Graaff :o

          2. @ Erik Johnson
            Very cool! It does look better than described. I instinctively looked away at the 36 second mark, don’t want to get blinded!
            I like that we can see it ‘writing’. Of course somebody’s going to make one the size of a billboard now.

            P.S. Good idea on static control! I play with arcs all the time, but I wouldn’t have thought of that. :)

  1. this material has so much potential

    I built an audio “delay” thingy with a 30mm wide strip attached to a 12″ PVC end cap, rotated by a Mabuchi 540 motor.

    Green LEDs seemed to give the best results, I had a green LED modulated by incoming audio, then used LDR’s to “pick up” the sound, 7 0f them 45 degrees apart to get a variable delay.
    Mixing the signals coming off the glowing strip back into the input LED mad some great sounds! (or god awful, made the dogs howl racket, but hey that can be fun as well!)

    The very best thing I’ve ever seen done with this stuff was a wall, 20′ long, 8′ high covered in glowy goodness, with strobes going off as people walked in front of it.

    When we got home from seeing the glow wall, we tried slides, negatives and pretty much anything at hand placed on the glow vinyl, then “exposed” with a flash gun.

    Images from negatives and transparencies were quite clear and sharp, that hung around for ages.

    1. Are you sure they were green? Glow isn’t really reactive to anything lower frequency than blue. It work best with UV, some blues. As you go into the longer waves towards and into infrared, you actually begin to remove the glow, I think causing it to more quickly emit and reduce its stored energy.

      1. yep, definitely green!

        I tried red, yellow, orange, IR and green worked best.

        Bear in mind this was the mid 80’s, LEDs were not as bright as the ones we have these days.

        1. Of those colors, green would certainly work the best.

          To the naysayers, remember that blue and UV LEDs (they emit light through very similar mechanisms) were invented in the 90’s. RGB LED goodness hasn’t been available for very long.

          “The 2014 Nobel Prize for physics has been awarded to a trio of scientists in Japan and the US for the invention of blue light emitting diodes (LEDs). Professors Isamu Akasaki, Hiroshi Amano and Shuji Nakamura made the first blue LEDs in the early 1990s.”

          1. “Of those colours”, sure, but you’d have to be pretty damn bright with green to get any decent contrast, and LEDs from that era were only really bright enough to be used as indicators…? With what was available then, I’d have used incandescent bulbs, like form a christmas string

      2. seriously?
        how about getting some glow vinyl and, god forbid, actually perform a few experiments???

        I did try a light bulb, one of the Fisher Technik ones that had a little lens on the top, it didn’t work nearly as well as a GREEN LED!!!

        I must say though I am surprised that the “usual suspects” here haven’t made any of the usual dumb/shitty comments about using LDR’s for audio and for bonus butt hurt, 741 op amps driving the LED, amplifying the LDR’s, as well as the 7 channel mixer.

        “Thought experiments” only go so far, at some point you need to actually get your hands dirty/busy and do a few experiments

          1. I give up…

            I’m talking about having a bit of fun with electronics and you’re “pissing in my ear” about quantum mechanics and Planck’s constant.

          2. OK so it hurt your head, just say so! The take home message there is that photons that are absorbed are down converted when the energy is emitted again so the colour is always further along the rainbow toward the red end.

          3. nope, not even close.

            you are just being a fuckwit, trying to make yourself look big and manly and all knowledgeable.

            the challenge around here and at a few of my other friends places is to “make something cool, with what is at hand”.

            And from your recent posts, we all know what is in your hand….

          4. That is pretty lame and childish, are you seriously trying to deny the laws of physics? Which BTW have nothing to do with me as they have always been that way LOL! That pathetic rant suggested nothing other than that your intelligence is rather low, including your emotional intelligence if your shame triggers outbursts like that.

            If you wan’t to believe the earth is flat go ahead, just leave me out of your delusions.

          5. STFU. We get it. You are the smartest person in the whole fucking world.
            Does evey other article have to devolve into a shit fight?!
            Dammit! I didn’t want to believe it but it appers that it just has to happen. This must be what happens to all the newbies; laugh and learn for awhile and then see the same dicks pissing in your soup.

            Bring back the trolls. At least we all get a good laugh at them.

            I’m staying out of HaD for a week. Too fucking toxic.

            Dan, if you’re not a dick than you sure do a good job pretending to be one. I frown when I see your username show up.

            I’m outa here. Unless something with high voltage shows up. If it does stay the hell out of it please!

            See you soon everbody else.

          6. No you don’t get it, people are arguing over how pumping fluorescent materials works when there is absolutely nothing to argue about, they all follow very clear rules and if they didn’t your computer (chips) would not work either.

            I didn’t discover or invent any of this stuff, I’m just pointing it out, in context because people are arguing as if they have no idea about it. I have given people a good reference, and even videos, because they will benefit from it.

            I don’t give a crap about your fragile ego because I have never seen any consideration from you in that regard either. If you are better off for the knowledge I have shared good, but can you seriously make the same clam? No you can’t. I’m not a dick for not giving you what you want, if I know what it is you really need, something you can’t see for yourself due to your ignorance. You want to know what a dick is, other than a sexist term, a person like you who (as you have admitted you do) gives people a hard time about presentation while ignoring the value of the content. That childish crap is what makes a “dick”.

          7. what the problem here is my project work, against all odds.

            green light on fluorescent vinyl works.
            a colour slide exposed onto fluorescent vinyl gives a sharp image, for all colours.

            I’m surprised you didn’t say a word about me using LDR’s to read the audio signal off the fluorescent vinyl, most would say the slew rate of an LDR is way too slow.

            When I built the audio delay thingy I did try all the available colours of LED available, AT THE TIME

            Later we tried a 4mW HeNe laser, it worked ok, even though the beam is red.

            If you act like a dick, expect to get called out on it

          8. Are you still going on about it? THEY ARE THE RULES THAT GOVERN THE ENTIRE UNIVERSE!!! What the other person initially pointed out to you was correct, the physics backs him up. You really need to get over that and wake up to the fact that I did not make the original comment either, I have no idea who that person is, except that the point they made seems to be correct.

            Grow up, it will accelerate the speed at which you learn.

            One other thing, you can call people what you like, but it has no effect if you also demonstrate that you opinion is worthless, which you did by acting like such a shallow fool. Do you think your judgement matters to me when you have acted like an idiot? No, all I feel is sorry that you have hobbled yourself with such psychological defects and that you waste your time trying to hurt people who are untouchable rather then using your energy to learn more about the subject. Did you even take a peek at those videos?

          9. @cyberteque
            It’s called a delay line and they are awesome! I’m sure your build doesn’t need a scientific writeup and maximum efficiency to be practical and an awesome use of available materials.

            You keep digging deeper into dick-land. Do you enjoy pissing off people? Your super good at it; you deserve an award!
            I’ll call around and see who gives these out, lol.
            Rant over.

          10. I think I’ll revist this project, with a blue LED!
            it would go well with the analog synth series HaD ran.

            I might even update the whole thing, blue LED to write with, photodiodes instead of LDR’s and modern op amps, these days my goto op amp is the TL081

          11. Dan: You are saying that cyberteque’s experimental results must have been wrong. The foundation of physics is that we observe things, we formulate laws that describe these observations, and we test these laws with new observations. If an observation contradicts the laws, then either the observation was faulty or the law is either wrong or at least incomplete. Since at the time of cyberteque’s observation, he couldn’t possibly have been using a blue LED, I invite you to offer other explanations for his observation, or just call him an outright liar.

            Everybody else: Dan has learned everything he knows about physics (and science in general) from YouTube. He is the world’s foremost expert. This is typical of his opinions expressed here in HAD comments. I always take this into account when reading his posts. I’m afraid he must be having a difficult time in middle school.

          12. No, you pathetic liar, I did not say that. I said what I actually said, that if you design the experiment with that knowledge in mind it will be better. For a start you track the spectra of the sources (and they change a bit with temperature and power too) and you look at the spectra of the resulting light.

            I refer you back to my previous observation, that the problem with you is that most of your comments are worthless, just useless noise. You could use any name on here and I could detect you, I’d just need to set up an MQ-4.

          13. Oh, and Dan, you might want to look into quantum tunneling. I’m sure there’s a YouTube video about it. I’m afraid the laws that govern the universe are not limited by your understanding of them. I also suggest you look into laser frequency multiplication. The short version is, you can combine two photons and end up with a photon of higher energy (frequency) than either of them.

          14. Why would I mention something that is irrelevant to what they were doing and the materials used, that is just idiotic, the typical sort of useless distraction that you fill this site with. You are a very low value human.

          15. be really careful making ZnS!!!

            The first time I set myself on fire was with powdered zinc and sulpher!
            I was at a hardware store buying lawn mower wheels for a gocart, saw a 2 pound tin of zinc powder on the shelf, immediately grabbed it!
            The hardware shop bloke asked ‘What are you going to do with that?”
            First thing that popped into my head was “Paint my plywood canoe”

            I mixed up enough zinc and sulphur to fill a toilet roll tube, with a bit too short piece of magnesium ribbon for a fuse.

            Later when I got home from the ER I noticed the white powder had settled over most of the yard, I got out my 6″ Wood’s Glass fluorescent tube (blue and UV LEDs hadn’t been invented yet) the lawn, fruit trees and what was left of the clothes I was wearing had this really cool greenish, white glow.

            before you ask, I lost most of the skin on the back of my right hand and wrist.

          16. a few times…

            nothing more than “superficial burns”, which is not too say it didn’t hurt.

            Worst time was pulling 3 adults from a burning car

            the other times I had help, me being careful, idiots using naked flames when they had been told not to

          17. it burns pretty fast, I’ve heard from a couple of people between 7 – 14m/s.

            with the right binder is great rocket fuel, what hobby rocket motors use.

            I tried some local acacia, wattle and eucalyptus gums, ground up dissolved in IPA.

            Using that 6″ wood’s glass flouro, which is powered by a 6V lantern battery, launching rockets at night is pretty!!!

          1. did the patch that “dimmed’ with the green laser recover?

            I found that with a big enough flash gun you could make a “dim” patch that was forever darker than the area around it.
            That was using a huge old Metz flashgun, on it’s highest setting, it was rated at 100′, with 80ASA film.

            The other thing to consider is this WAS 30 odd years ago, is the vinyl additive that makes it glow the same compound?

            I had my green LED in a short piece of 5mm brass tube, after stuffing around for a bit I made a mask so the output was a thin line 5mm wide and as thin as I could cut with a #11 scalpel blade.
            With my drum turning and the LED modulated by some audio it was a lot like looking at a CRO trace.
            The LED aperture was as close as I could get it to the surface, same with the LDRs.
            All the “pick up” 741s were set to a gain of 100 and the whole thing was in a box that was painted matt black on the inside.

          2. I think I know what youre talking about; it didn’t. Youll see I ran the laser on an uncharged section first to no effect. I have some 3W uv dies i use for doing glow shadows with kids from a couple feet away, much like a flash gun would do- if i put the bulbs right up on the vinyl it does create dark spots centered on the dies surrounded by intesnse glow which do “recover”. That effect is like an integer overflow on a cpu: like it was so intense it wrapped back down to 0

          3. You could always just spread sunlight with a prism and expose the material to the spectrum it creates, then you will literally see exactly what it’s absorption spectra is. Use a quartz prism with sunlight if you want to also investigate the UV end of the spectrum. Isn’t 300 year old science just awesome? :-)

          4. if you’re doing UV ink stuff, have you discovered laundry detergent yet?

            liquid or powder glow really well under UV light, with the added bonus of being able to spray on .

          5. Dan occasionally has a good idea when he’s not too busy alienating people. Exposing the material with a whole “rainbow” lets you see immediately where the spectral absorption peaks are, along with their relative sensitivities. If you don’t happen to have a quartz prism lying around, though, you can use a slit and a diffraction grating. You almost certainly have one of those lying around – you can use a compact disc. Here’s an example of how to set this up: http://coolcosmos.ipac.caltech.edu/cosmic_games/spectra/makeGrating.htm, or just google “CD spectrometer”.

            As with glass prisms, the CD will attenuate UV, though. If you want to avoid this, start with a blank CD-R disc with no label or anything printed on the label side, and strip off the lacquer layer with alcohol. this will also remove the aluminum layer so it won’t reflect as well, but it will still work. Be sure the label side is what is in the optical path.

          6. But I have always considered that you were full of shit, it just took you a while to work it out, because you have such a massive ego and couldn’t contemplate the thought that people actually see you as a pretty worthless specimen as far as humans go. Seriously I’ve had more intelligent (and honest) conversation with people who work as janitors that I’ve ever got out of you.

          7. The transmitted spectra would give a good indication of absorption, but the upper state lifetime of the phosphor in this case is quite long, and once saturated, would no longer absorb the pump photons. The host material also has it’s own spectral characteristics that would need to be measured (without phosphor) to properly characterize the material.

  2. Strontium aluminate or zinc sulfide?
    Looks amazing, and I’m jealous. :) So flippin cool!
    Is there a clock mode (every 5 min), or just upload a picture of the time manually?

    1. Hey,

      first, thanks for the feedback. What do you mean with „Strontium aluminate or zinc sulfide“?
      And about the last question: If you mean the way of proceeding that randomly chooses an image and uploads it to the board, there’s a counter in a loop that increases by 1 when the execution is at the last command in the loop. When the counter is equal to 1000, the script will pick the information image and insert it into the queue. When the counter is equal to 2000, it will reset the counter and randomly choose an image from an image pool and upload it by inserting it into the queue. So the interval the machine uses to space uploading images(when uploaded by the script) depends on the speed of execution. If you still got questions, don’t be shy :)


      1. Most likely zinc sulfide then.
        I was thinking about purchasing the other strontium stuff, it’s way more expensive but bright as hell!

        I think it is too cool! Looks radioactive, like one of those x-ray detection screens that nobody uses because of the dangers of radiation poisoning!

        Nice piece of art! :D

    2. Hi,

      what do you mean with your first question?
      And about the last one: If you mean the interval that is used by the script to upload images automatically, there is a counter(called “waiter”) that is first set to 999. Then, the script enters a loop where it first increases the waiter by 1. Next it checks if the waiter is equal to 1000, and if yes, the information image will be inserted into the image queue. Then, it checks if the waiter is equal to 2000, and if yes, a randomly chosen image from a specific image pool will be inserted into the queue. And finally, it sleeps 300 ms. In the end, the interval(when multiplied by 1000, because you have to wait 0.3 s 1000 times) is 300 s / 5 min. Take a look at lines 465 to 482 here: https://github.com/Eigenbaukombinat/glowboard/blob/master/webserver.py

      If you got any questions, don’t by shy :)


      1. The chemicals he mentions are both used to make things glow in the dark. I think he was asking which one does your board use. To which, from what you’ve said, the answer is probably “I dunno, I just bought the stuff, I didn’t make it”.

  3. I was expecting a laser and a galvo but presently surprised.
    I wonder if with intensity control the image could be drawn from light pipes and built up in layers from the edges without moving the canvas material.

  4. The project could even go color if one wanted to go through the painful process of painting alternating rows of paints that glow in red, green, and blue, which ARE available. You’d have to get it aligned correctly.

  5. Reverse the picture to negative and you could print cyanotype photograph with this, making the paper and developing them is easy and they can be exposed with UV light just like this thing uses, this could be a huge “instant” photo printer.

    1. Or you could just expose an electrostatic drum and attract black resin dust to it that is then transferred to the paper and melted so it sticks. This would let you print multiple copies of the same black and white image, but you’d need some sort of dithering scheme to get good tonal reproduction. It would also help if you put it on the network and had it accept jobs in some common format such as postscript…..

  6. I think I’m missing something… Why not just one LED on a 2-axis plotter instead of a line of LEDs? Then you could cheaply & easily have resolution far higher than 64 vertical.

      1. which is why if you are RECORDING AUDIO onto a spinning drum you don’t want you need a really bright light source, it needs to have faded by the time it completes a revolution…

  7. Here’s an earlier HAD article that did a scrolling text display in similar fashion: http://hackaday.com/2011/07/13/faux-led-scroller-using-phosphorescence/ The reason I bring it up, though, is that in the comments for that thread, it is claimed that you can reset a phosphorescent sheet by flooding it with infrared, which stimulates it to give up all of its residual energy.

    There was also another article on HAD, but I can’t seem to find it now, that used a rotating phosphorescent band as delay line storage for a (very slow) computer. Anybody have a link to this?

    1. I tried. Couldn’t find exactly. Found something close searching ‘glow in the dark’ on HaD but no read stage. I’m going on a vacation, you’ve been awesome.

      I want to see this delay line. How about a Möbius strip? Lol
      They make some conveyor belts that way. Crazy awesome, just learned this seconds ago! Happy travels. I’ll be back soon.

  8. Brian Benchoff!

    This needs a ‘glow in the dark’ tag. Was just searching for articles and it is missing. Thank you for being awsome.
    Great article, I have a scanner to destroy now. :)

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