Old-school Projector Turned Digital

Who hasn’t thought about turning a 1950s slide projector into a digital projector? [Matt] did, but unlike most of us, he actually did it.

[Matt]’s friend [Angus] found an old, single-slide, sans-carousel slide projector in the trash. It’s a wonderful piece of ancient technology with a fabric insulated power cord and bakelite lamp socket. This projector was upcycled to the 21st century by adding a 10 Watt LED and a Nokia 1200 LCD.

For the electronics, [Matt] used an ATmega88 microcontroller. There’s an infrared receiver so the remote from an in-car CD player can be used to advance the slides and turn the projector on and off. The LCD is controlled by a bit of bit-banging from the Mega88, using hard-coded images of Che Guevara, Hendrix, Space Invaders and some old-school Macintosh/Lisa icons. Unlike the screen printed t-shirts at American Apparel, Che is the only authentic image in this project; this projector might have been made after Guevara came to prominence.

With a 10 Watt LED, it’s not the brightest projector on the planet and the picture is a little washed out in a bright room. With dim lighting, it’s a very good project even if the images are static.

21 thoughts on “Old-school Projector Turned Digital

    1. He published the schematics from the CAD package “English”. You probably learned to use this one early on at school; and maybe your parents spoon-fed the package to you. Conversion into other formats should be no great problem once you get the hang of the “English” CAD package.


  1. I did a similar build with a slide projector and a “Pustom” LCD from DX. I used the original bulb though, and the LCD began to warp slightly after watching my treasured Wrath of Kahn VHS the night I completed it. I added some extra cooling and everything was OK after that.

  2. Great project, great build. I love seeing old technology re-purposed. But…

    The test images… Che Guevara? Really? Of 10e+100 possible images, Che Guevara?

    If Che is to be considered a “luminary,” then where are the others of the same ilk? Where’s the Pol Pot slide? Stalin? Idi Amin Dada (he’s got the cool shoulder boards) Where’s Gadhafi?

    How ’bout Hitler’s face? Whoops. There… now you made me use the “H” word. I guess this discussion just ended.

  3. “hard-coded images of Che Guevara”
    I guess they were fresh out of Hitler images.

    “To send men to the firing squad, judicial proof is unnecessary … These procedures are an archaic bourgeois detail. This is a revolution!” – Che Guevara

    “The [derogatory term for a black person] is indolent and lazy, and spends his money on frivolities, whereas the European is forward-looking, organized and intelligent.” – Che Guevara

  4. Hey guys, thanks for the comments! Well, I was going to use a good ol’ cock&balls for the test image but quickly googled for something posterised, monochrome & recognisable … So oops, sorry for the Che, I will try to use e.g. Stalin next time. (It was not used out of reverence, but perhaps flippant use is worse? Discuss.) ;)

  5. I did that long long time ago as a challenge with some bachelor friends. In the afternoon, I bet that I would be able to show them a movie on an home made beamer during the evening party. So I took a Carena slide projector and a Casio LCD TV and tried to mary them. By adding watercooling (a glass sandwich with water in between) and a shitload of cooling fans, the monster was operational within 3 hours, making me win the bet. The picture was not really 1080p but it was about 25 years ago ;-)

  6. Dismantle a broken Ipod 3G (i.e. video) and replace the broken HDD with a flash card.

    Then remove the LCD’s back panel and leave the polarisers intact, and put the panel “backwards” into the projector at the correct distance.

    Using 10W LEDs would work well, the trick is to turn up the contrast to max in order to increase light throughput.

    There is apparently a hack where two pins on the LCD panel control scan direction and picture inversion are cut and shorted to +V to mirror the picture.

    This also works with cheap LCD TVs which would otherwise be useless :-)

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