Illuminated Touchscreen Poster Frame with Subliminal Message!

Ever since Think Geek first posted a set of five Serenity/Firefly-inspired "travel" posters, I knew I had to have a set of my own. A few weeks ago I finally got them, but was faced with a dilemma: how to mount them on my wall? How to do them justice?

Well, as often happens in my brain, complexity increased at a geometric rate and I came up with this mother-of-all-poster frames. It is illuminated using 28 super-bright white LEDs, mounted along both lengths of the frame. It is activated using a capacitive touch sensor. It uses surface mount technology. And best of all, you can activate a subliminal message from the Serenity movie that *could* cause you to flip out and beat everyone in the room to a pulp.

Interested? It's your lucky day! I will teach you how to make one. You can use any poster you like, but this Instructable is based heavily on the "Miranda" poster from the set.

EDIT: Please vote for me in the Epilog Contest! Why? Because if I win, I will be donating the laser cutter to the fledgling Maker group starting up in my city. It would go a long way towards our goal of a Maker/Hacker space in Waterloo!

Step 1: Materials and Tools

I tried to keep this project as Green as possible. First off, by illuminating the poster using LEDs instead of fluorescent light, I'm avoiding the use of all the toxic chemicals that go into making fluorescent tubes and ballasts. LEDs also consume less power. All of the components purchased at Digikey and Mouser are ROHS-compliant. I used lead-free solder. Lastly, the polycarbonate plastic sheets I used were scraps purchased from a second hand store - much cheaper!

MATERIALS

From the Hardware Store:

- Three sheets of acrylic, Lexan or polycarbonate sheet, at least 2.5mm thick. Two should be the same dimensions as the poster, and one should be 2 inches larger in each dimension.
- aluminum duct tape (the stuff that is actually made of aluminum) - make sure it's shiny on the adhesive side, too!
- regular grey duct tape
- electrician's tape (any colour - I used yellow to match the yellow of the poster)
- masking tape
- four machine screws with matching washers and nuts
- epoxy or other glue that adheres to plastic and dries optically transparent

From Digikey or eBay:

- 34 3mm or 5mm bright white LEDs
- 14 3mm or 5mm bright red LEDs

From Digikey:

- 2 QT100A touch sensor ICs (427-1135-1-ND)
- 1 D-type flip flop IC (296-9851-1-ND)
- 1 5V regulator IC (497-1171-1-ND)
- 2 N-channel logic-level MOSFETs (ZXMN6A07ZCT-ND)
- 1 inverting buffer (296-8483-1-ND)
- 8 68 ohm resistors (regular 1/4W through-hole type)
- 3 150 ohm resistors (regular 1/4W through-hole type)
- 4 51 ohm resistors (regular 1/4W through-hole type)
- 2 100k surface mount resistors (RHM100KECT-ND)
- 1 1k surface mount resistor (RHM1KECT-ND)
- 4 10 ohm surface mount resistors (RHM10ECT-ND)
- 2 10nF surface mount capacitors (311-1173-1-ND) ******** depends on sensor!
- 2 100nF surface mount capacitors (311-1179-1-ND)
- 2 10uF tantalum surface mount capacitors (718-1044-1-ND)

From Mouser:

- 1 "SchmartBoard" Discrete #2 protoboard (872-202-0035-01) (or you can make your own PCB)

From... Somewhere...

- 1 12V AC/DC adapter
- 1 socket to match the plug on the adapter
- assorted wire (I suggest 26 AWG stranded wire with Teflon insulation)
- solder
- solder flux
- Kapton tape (or masking tape in a pinch)

TOOLS

- A table saw or band saw (for cutting plastic panels)
- A drill press
- An oscillating palm sander
- A belt sander
- A Dremel tool with engraving bit, or an engraver (or better still, a laser engraver!)
- a metric ruler
- a nice precision soldering iron
- other assorted hand tools, as needed

Comments

[BATMANG]

This is fantastic! From one Firefly/Serenity fan to another: great job! I am definitely going to try this once I round up some funds. (I might end up just using the same poster and image as you, just because I like it so darn much!) Where do you think I could get the polycarbonate sheets? I looked and the most readily available ones are from Lowes or Home Depot, but they are sold in weird sizes and undesirable thicknesses. Also, how long did it take you to make this?

[jeff-o]

The polycarb sheets can be found at lots of places. I got mine at a local surplus store. If the city you're in is big enough, there may even be a plastic store nearby. I suggest calling around until you find someplace that has them. It took a couple of hours to make this. Gee, it was so long ago. Maybe 8 hours total?

[mneufeld623]

 Do you mind if I ask your approximate cost of materials?

[jeff-o]

Hmmm, I'd estimate somewhere around $50.  The most expensive part was the polycarb sheets, even though I got them from a surplus store.  The next most expensive is the LEDs, especially if you get them from Digikey instead of eBay.

[mneufeld623]

 Thanks, I found some online sellers that had the polycarb at about 15 bucks a sheet, but i'm going to look around and find some scrap/surplus since i don't mind cutting it all myself.

Oh, also, would having a little extra thickness on the sheets help, I just want to make sure the led's stay flush in their slots, and also, I think I might get slightly better refraction for the backlight with a thicker sheet, so I might go up a size for the back-most pane.

[jeff-o]

Yup, thicker sheets probably would help.  If you can get 'em for a good price then go for it!  I used thinner pieces to keep the cost and the overall thickness down.

[superjames]

Cool! I'm doing something very similar but using the QPROX 100a demo board from digi key (uses the same touch sensor as your project). I'm having some problems with getting the electrode to obey the touch. Sometimes it doesn't sense my touch, and sometimes it fires off without even touching the sensor!? I am completely new to this so I have no idea what the problem is. I am using a 100uf capacitor...and it makes the touch very sensitive. I can't figure out what's making it misfire. Any help apprecaited. Thanks!

[jeff-o]

100uF??? That's way, way too big, and electrolytic to boot! You need to drop that down to between 10nF and 33nF (ceramic) for it to work properly. Do that first, and if it still doesn't work then you need to examine what's going on around the electrode. There should be no other traces running behind it, and there must be no connection to ground.

[superjames]

You know it may not be 100...it's been a while since i was playing with it. But it's going through 1/4" glass, so it needs some sensitivity ;) The electrode is taped to the glass...is it possible that the glass has some grounding?? Also, i don't the the wire is shielded, could this be the issue? thanks alot for your help!

[jeff-o]

1/4" glass is nothing. A cap in the range I mentioned will cause it to trigger before you even touch the glass. And no, the glass wouldn't be grounded in any way. The wire doesn't need to be shielded, but it should be kept as short as possible. Like, less than an inch. If it's going a long distance then it will cause problems. It helps a bit to reduce the value of the capacitor. Read over the documentation on qprox's website, they give lots of onfo on proper electrode and circuit design.

[superjames]

okay thanks alot. your wire is way longer than an inch though isn't it? i need 8" of wire between the board and the electrode (a 3" diameter) because the board can't be mounted to the glass. any ideas? thanks again.

[jeff-o]

You know, you're absolutely right. My wires are longer! My mistake. But, I'm fairly certain I reduced the capacitor to compensate. So yeah, go ahead and keep that 8" wire, but change the cap. Just make sure the wire isn't passing any ground planes because they will kill the signal.

[superjames]

thanks! gonna see what I can do :) Gotta order a couple new caps...which one's should I order to try out?
- 2 10nF surface mount capacitors (311-1173-1-ND) ******** depends on sensor!
- 2 100nF surface mount capacitors (311-1179-1-ND)
- 2 10uF tantalum surface mount capacitors (718-1044-1-ND)
???

Thanks so much for your help jell...I mean jeff-o ;)

[jeff-o]

Here's a good document to read to help you choose the capacitor you need, and in general help you design your project:

http://www.atmel.com/dyn/resources/prod_documents/doc10620.pdf

But, I would suggest the following numbers. Get both and see what works. Each has a minimum quantity of 10, that'll be plenty!

399-1237-1-ND (10nF X7R, 1206 size ceramic)
478-3790-1-ND (33nF X7R, 1206 size ceramic)

[superjames]

Huh, those are way different than what I got...those look like blocks compared to my ones with legs. Here's the one's I got, perhps this will give you an idea of what's possibly wrong with my setup:

P4923-ND CAP CERAMIC MONO .1UF 50V 10% (this is the one that make's it very sensitive..not sure what .1UF means)
445-2883-ND CAP CER 47UF 6.3V Y5V RAD (this one didn't seem to do much)

Seems like the CAP's with legs would work better for my demo board because of the solder points on the board.
Here's the Eval Board I got:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2622557&k=E100S

Any input appreciated!
thanks

[jeff-o]

Ah, the ones I spec'd were surface mount parts, the same as the first set you mentioned. But, the second set is indeed through hole (and rather tricky to solder to those tiny pads, eh?) I still think your main problem is that you're using caps that are too big. You're pushing the limits of the sensor so that sometimes it works, and sometimes it doesn't. Try something like this instead: 490-3813-ND (10nF) 490-3845-ND (4.7nF)

[superjames]

can those 399-1237-1-ND fit onto those pads from the demo board? maybe the ones with legs are not correct. so do i just have to solder it to a single pad? cuz i have the each leg stretching across the pads. as you know, i have no idea what I'm doing! haha

[jeff-o]

Well, you'd have to replace the "Cs" cap that's on there with one of the new surface mount caps. But, that's kinds tricky. You had the right idea with using a through-hole capacitor. Cut the legs short, put a small bend on each one, and solder one leg to each pad. Question though; what happens if you don't attach an extra capacitor at all?

[superjames]

ah good idea bout the bend :) if i don't attach one at all, i get no response through the glass

[jeff-o]

Wow, none at all? It's got one of the highest dielectric constants so it should work really well. What happens if you set the glass on top of the existing "key" on the demo board? I read one very interesting note in the application notes, that the electrode should be secured to the glass as securely and closely as possible. It says that a gap of even 100 microns will adversely affect performance. They recommend attaching the electrode using double-sided adhesive film.

[superjames]

ah interesting. i gotta find some double sided adhesive film, that will work well. i'm still a bit concerned about the mis-fires though. gonna order those other capacitors. thanks for the tip

[jeff-o]

Double-sided tape will work fine too, as long as it's transparent. Try pressing your electrode between the glass and another flat surface and see if that makes a difference.

[superjames]

Thanks so much for your help. Gonna order them now :) If I have problems, I'll track you down...haha j/k. cya

[superjames]

Awesome, thanks!

[denanderen]

this is one great instructable! i'm definitely going to make one of these (with a few adjustments) but i think you can reduce the chances of the plastic breaking because of the screw by just using a washer. (at least i think i'm going to use one) but still a very nice design in which you obviously put a lot of effort.

[jeff-o]

Thanks for the kind comments, I appreciate it. :) I look forward to seeing what you come up with!

[Generik99]

Hehe damn that's pretty cool :) May have to work on some of these posters.

[jeff-o]

You can use pretty much any poster you like, too. Use different colours, light up different sections, even animate sections! Imagine a poster of a street scape, where the neon lights blink and flicker. Or Van Gogh's "Starry Night" with stars that light up. There are limitless possibilities!

[jolshefsky]

That's really clever. I like it a lot.

[jeff-o]

Thanks! :)

[Sandisk1duo]

pretty legit how does the capacitive sensor work? what is it attached to?

[jeff-o]

There are two electrodes on the back. They are each connected to a special capacitive sensor IC. When your hand (or another conductive object) comes close to the electrode, the capacitance "seen" by the sensor changes, triggering the output of the IC to go high. I'm sure the datasheet on the last page explains it better than I do!

[aaron2a]

could you change how close someone has to be to activate it

[jeff-o]

Yes, to an extent. You can vary the sensitivity by changing the capacitor that is tied between pins 3 and 4 on the touch sensor IC. A higher value (up to 50nF) makes it more sensitive, so that a person's hand can be a few inches away. A lower value (down to 4.7nF according to datasheets, but more like 10nF according to my experiments) means that a person will have to physically touch the panel to activate it.

[thinkgeekmonkeys]

I watched your videos ... and for some reason I feel like eating people alive. And maybe making clothing out skin? Hmm. That's odd.

[jeff-o]

I must admit, my poster has not been tested on people exposed to the PAX. However, if you feel that you have simply been brainwashed by the Government, then a few hits from a Van de Graff generator should fix you right up!

[thinkgeekmonkeys]

Awwrgh gawwrgh arggh!!!!!!

[jeff-o]

I should have mentioned; remove any chunks of metal that you may have embedded in your own skin, prior to the Van de Graaf generator treatment.

[technoplastique]

The finished effect is fantastic. These would be so perfect in a home theater kind of room - so much better than anything that 'home theater companies' come up with. Great job.

[jeff-o]

Thanks! Every time I walk past I can't help but play with it. :)