arfink
Offline
Minneapolis

So, I'm not sure if this is the proper place to post this, but here goes:

While I've been waiting ages of eternal days for my NTRQ NVSRAM bank chips to arrive my mind has wandered back to a previous project of mine, which is a DIY video projector built inside of an old slide projector. Slide projectors are easy to get and very cheap, and their replacement bulbs are also very cheap. I found a Kodak 500 Ektagraph for $4 at the thrift shop and brought it home.

I previously experimented with a stripped down Gameboy pocket LCD, but in relocating the ribbon cable I managed to partially damage the LCD, rendering the experiment useless, even though just knowing that it worked was fun.

So now I have a different screen in mind, a 2.5 inch Audiovox display:
http://cgi.ebay.com/ebaymotors/Audiovox … ccessories

This thing can take a standard NTSC composite input and runs off 12v DC. Removing the backlight should be simple, and then I might also remove the anti-glare layer on the front, assuming it has one.

Today I ran some pretty extensive heat buildup tests to find out whether it would get too hot inside. My very un-scientific method was to tape plastic food wrap to the closed slide aperture, which is where heat buildup would be a problem for an LCD panel. I left it installed in the running projector for over an hour and the plastic didn't melt, so I'm going to assume that it'll be safe for the LCD.

I'm going to post more progress and pictures here as I do this project, and please feel free to leave comments. If this works then my total cost for this video projector will be a whopping $19, not including the dead Gameboy pocket I killed in my first attempt.

Last edited by arfink (May 12, 2010 7:44 pm)

fluidvolt
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This is an interesting experiment you're working on, I'm looking forward to seeing what happens!

SurfaceDragon
Offline
USA

If you get this working you should make a video and/or a video+tutorial. I would love to see you get the Game Boy projector working. You should try again. and Good Luck with your projects!

arfink
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Minneapolis

Yes, seeing as it's a video projector and so seeing a video would be... uh... good?

Well, as for doing a projection with a gameboy, that's going to be very tricky. I would use either a Gameboy Pocket or a Gameboy SP AGS-101. See, the deal is that except for the AGS-101, all gameboys have ribbon cables going behind the screen, which requires that they be desoldered and moved. Something I have never done successfully or seen done by anyone else.

And I don't have any spare gameboys right now. Not that I'm willing to cut up, that is. My GB pocket is precious to me, what with the working homemade backlight which was a total PAIN to get in there. Projected DMG would look like garbage since it's got tons of ghosting problems and would make the image far too dark.

Also, I'm changing screens for one that will be easier to hack up and has slightly better specs:
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi … ink:top:en

This one, unlike that Audiovox, isn't refurbed. Resolution is supposedly 480x234, which is... not exactly standard resolution. Picture quality will not be very high, but this is supposed to be a super cheap projector project. It'll be good enough for the NES, which is what it's for.

EDIT: found a lovely bunch of pictures of the insides of this screen, courtesy of the guys over at BenHeck forums:
http://www.forums.benheck.com/viewtopic … mp;start=0

Looks quite dandy, should work perfectly for my use.

Last edited by arfink (May 13, 2010 5:22 am)

arfink
Offline
Minneapolis

Hey, great news! I got everything put together pretty well and it looks OK. And by looks OK, I mean the corners are slightly blurry, the image gets a little washed out in places, and the pixels are HUGE. But it's stable even when it gets hot, and the image quality is just fine for Super Mario Bros. and GlitchNES, though I'd go nuts if I had to use NTRQ on this, or anything which required alot of reading.

I haven't tried my projector with anything besides the NES, so I'll let you know how the VCR goes! Wrath of Kahn, here I come!

arfink
Offline
Minneapolis

OH yeah, I promised some pics and video and stuff. I'll get to it this evening.

fluidvolt
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Sounds like it's progressing nicely, and it's great that it passed the heat benchmark; Handling the heat was what sounded like the biggest concern. Looking forward to footage/images!

arfink
Offline
Minneapolis

Yes, but in this case handling the heat means pointing another fan at the projector, so it's a bit of a hack job. The whole thing is really one big hack job, held together with hot glue, believe it or not! Anyways, with a little patience and some jimmy rigging, I think I'm all set to watch Wrath of Kahn on the big screen tonight. The big, pixelated screen! smile I'll take some video of that. I have a video of my projector running GlitchNES as well, but no audio because I realised after the fact that the camera has no mic. I'll have to see about uploading it this evening.

Also, I got a special surprise from my sister today. She works at the university of St. Thomas chemical stockrooms, and while cleaning out a little used storage room she came across a nice little 25" projector screen that stands on the table top. It's really neat to use with the projector, because bringing the projector closer results in a very bright picture.

arfink
Offline
Minneapolis

OK, got video and pics!

Video:
http://www.vimeo.com/12113411

Here is a shot of the screen I used before ripping it apart. Shown with the NES for size comparison.

Here are some shots of the final output:

arfink
Offline
Minneapolis

So, the real question is, given the kind of output this makes, and the very attractive price of the hardware needed, does anyone want a tut? wink

I'm quite pleased with it, for a less than $20 projector solution. Now I just need to case it up better. You can see in the video, I have a spare mini-fan pointing at the thing to help reduce heat buildup near the LCD.

Last edited by arfink (May 29, 2010 2:14 am)

LastKnight
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Middlesbrough, UK

THAT IS AWESOME! .... similar to something i did.... old LCD monitor... Overhead acitate projector. same idea. bit of higher res output

ohmtek81
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Riga

cool and awesome

arfink
Offline
Minneapolis

So, my ancient slide projector also came with an ancient bulb. Which is now burnt out! smile

So, I'm debating whether I should spend the money for a new GE CZA bulb, which would be maybe $20, or upgrade to a 100 watt white LED star, which would put out more lumens with less power and less heat for $35. Hmmm...