As a little kid, I remember the Glow in the Dark stars and shapes one could stick on their ceiling for night time view, frankly I remember the shapes being extremely boring

Older, equipped with some basic electronics knowledge and a deep interest in innovative display systems, I thought of a way of transforming my Rooms wall into a dynamic glow in the dark canvas.

While doodling on a Vinyl Glow in the Dark paper with a bright white light, i realized an interesting display could be built from it: GLO.

GLO consists of an array of 5mm UV LEDs that run on a simple linear axis, powered by long thread and a Stepper motor. The UV leds act like pixels, turning on at the right time, and drawing our desired text on UV sensitive surface such as my Wall (paper).

The result is a cool mystic, message board that glows in the dark and displays Twitter Trends, RSS Feeds, and Custom Text on my wall…slowly fading out.

Warning: Lying in bed watching  favorite news slowly fade out, can make you (me atleast) very sleepy.

Here is a Video of it, pulling and printing a Sports Headline from BBC on my wall:


This is also a contest entry, if you like it please vote for it :)

Step 1: Building the UV LED Array

I am building this as per my resources and what I think is the most efficient way to implement this. When you are building  be sure to let the Inventor in you come out,  do stuff the way it suits you. Nevertheless this is how I implemented mine

So in this step we will be focusing on building the UV Led Array that will act as our Drawing Pen.

Parts you need for this step:
1 x 2” by 3” Perfboard
12 x 5mm UV Leds
12 x 220ohm Resistors
2 x 74HC595 Shift Registers
2 x IC Mount/Holder
1 x Some hookup wire
1x  7 wire Ribbon Cable (the length should be a a little longer than your display length)

Tools you need:
Helping Hands
Soldering Iron
Wire Cutter
Wire Stripper

Start by placing everything on the perfboard, and think about how you are going to solder everything in place, it’s a small perfboard, so everything will be quite snug. You might find it easier to use Helping Hands to hold everything while you solder.
The leds have to be positioned at the centre of the board while the other components at either side of these.
Before you start soldering everything, just place all the components in their places to make sure everything will fit well and will conveniently connect together when needed.

Here is the important bit, the leds will only leave a sharp impression on the UV sensitive surface if they are right up against it. Currently, as it stands, the Shift registers in their Sockets protrude out, however we want the leds to protrude just a few millimeters above the IC’s

Keeping that in mind, let’s begin soldering, I recommended removing everything from the perfboard and soldering the component in this order.
Place the IC sockets in their place, and solder them. Next place the resistors, and ONLY solder their common leads. Next bend the resistor leads and solder to achieve a common ground connection between each resistor. Snip the excess.

Next place the leds in place, ONE BY ONE, it is important that you get their orientation (Short lead -, Long lead +) and height right. They should protrude about 2-3mm from the ICs. Now solder each LEDs negative, (short lead) to its respective resistor.
Repeat this for each LED, carefully making sure they are all level with each other.

Now follow the schematic and make all the required connections, because the board is quite small you will have to come up with innovative ways to make the connections (messy). The Terminal Block in the diagram is a representation of the Ribbon Cable.

Solder your ribbon cable at one end of the perfboard, and connect all the wires that will be connected to the arduino to it.

The order of the connections on the ribbon cable are not important as long as you remember (label them!) which one is which. For me, the order was dictated by which connection was the easiest to form.
I ended up with:
Master Clear, Ground, 5v, Clock, Data, Output Enable, Latch

Yours may differ.

Once everything is soldered, you need to divide the 12 LEDs, into a group of 6 LEDs, this will form 2 lines of text. Gently push the leds apart until you have 6 at either side with a little gap in between.

If you are getting confused about any step, do check out all the photos, i have attached loads of them.

Once that is done, give yourself a pat on the back and lets move on to testing.
<p>Can you use any stepper motor for this?</p>
<p>See <a href="http://shrimping.it/shrimp/project/pov/font/" rel="nofollow">http://shrimping.it/shrimp/project/pov/font/</a> for some alternative pixel fonts, although they are a bit larger, they could be useful for larger LED arrays. In particular there is a bitwise export of fonts into Arduino code at <a href="http://shrimping.it/shrimp/project/pov/font/fonts.h" rel="nofollow">http://shrimping.it/shrimp/project/pov/font/fonts.h</a> with <a href="http://shrimping.it/shrimp/project/pov/" rel="nofollow">http://shrimping.it/shrimp/project/pov/</a> as a reference example for the use of this Arduino-code representation.</p>
<p>i had a similar project in my mind for ages. i really enjoyed reading your instructable and looking forward to build my own now! </p><p>i got some questions: </p><p>- how and why are you editing the format of your bitmap font? i don't understand the changes. maybe you can describe the process of editing more.</p><p><em>0x7E, 0x81, 0xA5, 0x81, 0xBD, 0x99, 0x81, 0x7E, // Char 001 (.)<br> -&gt;<br> {0x7E, 0x81, 0x95, 0xB1, 0xB1, 0x95, 0x81, 0x7E}, // Char 001 (.)</em></p><p>- why are you using a stepper-motor? wouldn't it be much cheaper to drive a dc-motor?</p><p>-third: i dont see the advantage of using a 6x5 font. can u explain why you havent take a 8x8 or 5x5 bit pattern?</p><p>-and last: i dont understand why you are so complicated whith the shift registers. you could easily do the first line of text with the one, and the second line of text with the other shiftregister. i dont see the advantage of splitting your letter up.</p><p>id would be nice if you could answer my questions. im sorry for my bad english.</p><p>best regards, norman</p>
<p>I am glad you liked my project. Now to answer your questions:</p><p>As you can see i am using 12 LEDs, i would ideally want 2 lines that would have the same size of characters therefore i split the leds into pairs of 6. That is, 6 LEDs for the first line and 6 LEDS for the second line. For this reason i needed to make my own font, 5x5 Fonts are common so are 8x8, but as i couldnt find a 6x5 Font i made one. My font is simple, each character has a length of 6 pixels (6 LEDS!) and a width of 5 pixels. </p><p>This leads me to your third question, Shift registers usually work with 8 bit inputs and 8 bit outputs and that is how the function Shiftout is designed, but here my character pattern is only 6 bits (6 LEDS) so rather than writing a function that accepts B111111 (six bits) and only writes to the first line, i just merged both lines so each time i would have 8 bits to shift; that is 6 bits for the first line and 2 for the second line, and for the second shift register the remaining 4 bits for the second line. So this makes the process much simpler. </p><p>And now the second question; frankly speaking i used what i had lying around, but i also thought that having a stepper motor would give me room to add functionality in the future as i would have precise position control. I don't see any problem in using a geared DC motor though.</p><p>If you do build one, post the link here! :)</p>
<p>So you use a 6x5 pixel-font because you had 12 LEDs. i just wondered because its unusual.</p><p>I already found out that the chars are signed/unsigned (first question).</p><p>The shiftregisters also work with 6 bit in-and output. so i dont see the benefit in splitting the second line up. its just more work to code.</p>
PS i just remembered one of the main reasons i did this: My circuit, i had used 8 Led's for the first register and only 4 for the second one, meaning 2 bits of the second lit of text was controlled by the first register. Yes i could fix that by rewiring but, software? why not ;)
i urge you to try it out and you will understand. its fine you can write 6 bits to the Shiftregister but that would by default set the 2 unused bits to 0. Nevertheless have a go, i would like<br>to so your implementation.
<p>and thanks for the fast response. i will let you know if i build one!</p>
<p>Wich torque has your stepper motor. Can you tell me the motor you are using?. </p>
<p>I love your project!</p>
thankyou :) i love your project too !
<p>I've visited instructables.com for the last... well, a long time anyways - never once have I ever felt the need to sign up or comment on any project. <br>But this, this is truly amazing and I felt the need to let you know that! <br>I have voted for this project! </p>
wow thankyou so much :) this means a lot as this is my first published project. thankyou for your vote :)
Very cool project! Well written, approachable, unique concept, and cool looking! I've always had a soft spot for glow-in-the-dark things. <br> <br>I like the idea of &quot;printing&quot; on the back of the paper, could make a box with the paper held in a frame with the writer behind it. This would make it more portable, and allow for uglier but more solid &quot;print-head&quot; drive, like a threaded rod, CNC style. Could even have a second rod for stability to keep the LEDs as close to the paper as possible. <br> <br>I have a couple of questions: <br>Do the UV LEDs flash visibly for the human eye as they do on the video? <br>If you &quot;print&quot; faster, I'm sure it will fade faster, did you try to find a balance here or was there a different limit to the &quot;print&quot; speed? <br> <br>Got my vote! Thanks for sharing! <br>
Thanks very much for your kind words. I initially was thinking of a box/frame style display, but the only problem is the short text length,even a decent sized frame could display a 10-12 Chars at a max! One way around this is to use SMD UV Leds, but i had trouble finding them; who knows maybe version 2.0 ;). <br> <br>As far as glow life is concerned, there are 3 ways you can control it: <br>1) Material, as mentioned in my instructable, use a Red Glow in the dark surface for the shortest glow time. <br> <br>2) Light Intensity, again as i mentioned this is what i went for, currently with no dimming i was getting 5 min rewrite time, which is decent. If i reduce the brightness it can be even shorter <br> <br>3)Speed, as you rightly mentioned, moving it quicker means less exposure so yes shorter glow time. But with this setup its quite hard achieving fast speeds as im not using any pulley or gears. <br> <br>and no, there isnt a strict balance, because one way of the other, you get a glow life about a couple of minutes, so currently i just ran it at a maximum safe speed. <br>i hope that answered your question :)
<p>I'm also interest to know what the human eye can see in a darkened room from the UV LED's? I assume there may be a very slight purple-ish flashing but nothing as obvious as the camera picks up? Is that right?</p>
<p>Yes Exactly, there is only a slight glow visible.</p>
<p>I like it good idea and well written instructable.</p><p>Two things I thought of are:- If you didn't want to use a stepper motor you could use a synchronous motor (search for mirror ball motor in Maplins) these will run at a pretty constant speed and run off the mains so no controller needed. Getting the right timing for the messaging can be achieved by using a timer as the motor speed is fixed to a fraction of the mains frequency it wont change much.</p><p>Another thing is rather than move the LED's, move the UV paper. Put two rollers on the wall and make a band out of the uv paper. Make the band long enough so the image has reached the right fade before reaching the end roller. That way you can have continuous messages. Also the leds can be set up accurately to almost touch the paper as it goes around the roller. </p><p>Anyway these aren't improvements as your idea is fine as it is, they are just food for thought. </p>
i looked at all possible ways to do this, and that was one. however this was the most easiest and approachable way to do this. the problem with the ghost writer (cool name!) is suspending the paper so it doesn't move when the uv array is moving across it.
Do you mean when the paper is stuck to the wall or if made in to a band like my suggestion ?<br>If it is made in to a band then the UV array doesn't move at all and stays at one end aimed at the paper as it travels around the roller and so is nice and steady and close to the paper. If the glow time is say 1 minute then you can adjust the speed of the band to give you pretty much any length (with in reason) of display you want and of course continuous text with no need to fly back. Anyway like I said good idea and it got me thinking. You have a vote from me.
Hmmm, interesting! I like i your idea, but i think if one were to implement that, the only constraint i see is Money. UV Sheets costs quite a bit! &pound;5 for one A4! <br> <br>Thanks for the Vote :)
I suppose as it's a band you would use twice the length of paper for the same length display but then you could get three strips out of an a4 sheet. I'll have to get some of this paper to play with. Ever since I read this I've been trying to think of where I could use it, I haven't come up with anywhere yet but I'm sure the right application is out there somewhere :)
<p>wow good one i had a doubt:you used stepper motor i <br>believe that the speed of stepper motor is not much as dc motor &amp; i <br>have done a similar project called persistence of vision where we <br>rotate a display at-least with 30-40 rotations per second to cause the <br>persistence otherwise it will not display the characters but, how is it <br> that characters are displayed in your project. Can you explain?</p>
<p>This is not a Pesistance of Vision Display. It Writes text on a special glow in the dark surface..Hope that answers the question. </p>
<p>Genius idea! Got my vote. <br>Think I might have to make this!</p>
<p>Thank you so much :) Do share it here, if you decide to make it.</p>
Your featured on hack a day too! Great project.
<p>Thankyou so much :) Can you please give me a link to that? I cant seem to find it..</p>
<p><a href="http://hackaday.com/2014/01/11/i-am-the-midnight-message-board-what-messages-at-midnight/" rel="nofollow">http://hackaday.com/2014/01/11/i-am-the-midnight-m...</a></p><p>Nice work.</p>
Google hackaday.com your right on the front page :)
very cool
thank you :))
It might be fun (for some values of &quot;fun&quot;) to write the next string backwards from right to left (just the drawing done in reverse order; personally wouldn't want the text to appear backwards) instead of moving the &quot;print head&quot; back to the left edge. <br> <br>Very cool/cute project!!
this was a dilemma for me haha. in the end i decided to make it go back and write the second line again. i figured, right to left would feel very weird, because we would naturally try and read it before its finished.
<p>Very cool!</p><p>... and yes, 6-pixel fonts are a pain in the ####, I needed to make one for my LED dance floor :-/</p>
it was quite hard, yes. but if you look at my Sketch i have attached 6 Led font, including Upper case, lower case and symbols. Perhaps you could use them :)
cool... got my vote...
When you charge the Vinyl paper with the UV light, does the glow penetrate to both sides of the paper? Could you run the stepper motor and UV LED on one side and see the glow on the other? It would be nice to build a display board that would &quot;ghost write&quot; messages.
Yes Precisely! infact by lighting it up from the opposite &quot;plain&quot; side you can achieve an even shorter glow life.
Nice instructable! Sorry I didn't read the entire instructable and this might be a stupid question but I was wondering if the paper is reusable
Yes it is, if you read the &quot;On the wall&quot; section, it make make it clear :) the paper has a glow life, so your message fades away in about 5-6 minutes, then you can display a new message. You can also control the brightness of the LED's to achieve shorter glow lifes. Thankyou.
Well done! Amazing work, deserves to win!
Thankyou :)
Really, really nice. Not so pleased about Walcott being out of the world cup though..
Haha, neither was i, but im happy about these positive comments :) thankyou
At first glance I thought this was a persistence of vision project. I was so very wrong! I've been working on a project with UV LED's and Lasers with phosphorescent surfaces for a while now and never seen this imaginative application! Thanks for sharing!
thankyou so much :) Your right, its like a Slow Memory POV if you think about it.

About This Instructable


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Bio: Im a Student in A levels who is deeply into Electronics and Computing. Most of my electronics knowledge has been achieved through tinkering around with ... More »
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