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Illusionary LED clock 193

Graah writes: "A pretty interesting clock which uses a spinning set of diodes to create an illusionary LCD clock. This page includes everything you need to build your own, except the hardware of course. =)" Note that one item on the list of things you'll need is "[a] programmer that will program a PIC16C84 or 16F84 microprocessor." Often you can find these inside broken VCRs.
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Illusionary LCD clock

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  • by Anonymous Coward
    Do you remember the toy from circa 1982 which was a short hand-held bat with a linear bank of LEDs? You programmed a message into the 'bat', and as you waved it around it would display the message. It worked just like this clock. This toy was a contemporary of the hand-held Coleco football and "Merlin".
  • by Anonymous Coward
    PICs are microcontrollers and have nothing to do with VCRs. The only thing you'll get from the VCR is the motor. Read the page and you'll learn that.
  • Anyone lucky enough to have seen the HipKnowTron at this year's Burning Man knows that it beats out all those other spiny displays. ypn o.html []
  • Sad to say .. this is not new.

    I've seen productions ones for sale in South African electronics shops or months already.
    This it's pretty nifty that you can build your own
  • by Coppit ( 2441 )
    Quick! Somebody patent the "rotating illusionary clock"!
    ----------------------------------------- --------------
  • I saw this at least a year ago. This is quickie material at most.
  • "What I describe has been done and is VERY OLD (> 20 years). "
    Indeed - I still have somewhere a mid-80's Omni with a little piece on this, so it must be a fair bit older than that. Is Omni still going? Whoever imported it into the UK seems to have given up on it, at least. It was like Playboy but with UFOs instead of naked chicks.
  • A PIC is genearally a one-shot deal anyway.. you can't 're-program' it.

    No. A PIC is usually a reprogrammable device. However, they may use the one-time-programmable version in a VCR due to the high volumes....

  • Yup. I remember the wand (a kid's toy) you could type your own message into and wave it around.

    This summer I saw a frisbee with buttons on it so you could program your own message, and it would spell it out as the frisbee spun.

    There has been a pendulum version of this clock (the LED's mounted on a pendulum) for sale in novelty stores for at least 4 or 5 years now.

    I also remember seeing a clock like this (complete with circuits) in a Popular Electronics back in the mid-70's.

    I have personally built pocket gizmos to display signs on moving vertical LED bars, as long as 10 years ago.

    Nonetheless, they are a lot of fun to build. This is about the simplest circuit you're ever going to find. If you use a PIC, it hardly even counts as circuitry.
  • With some way of detecting people on the spinning round bit (obviously not a motion sensor!), and a little extra software, you could have a clock that always pointed the time in the direction that you were. Only good for one person though.
  • Actually, I remember seeing a very similar novelty device in some gift store. It was a want that you waved to get the time. It activated off of the motion of the wand, and would blink out the time in a short burst.

    It's possible, but I seem to remember it being quite expensive for its value. I mean, how do you set that kind of thing?

    Mike Hollinger
  • dammit! want --> wand.

    Mike Hollinger
  • This looks like it could be alot of fun to build. Of course, the first thing I will have to do is build the gizmo to program it.

    Lots to learn=Lots of fun=Lots of free time taken up:(
  • If you were tuned into LSD and knew some party kids you would have already seen this. Now it's time for my drunk ass to fall asleep.
  • Check out - 3 blades mount between spokes on a standard bicycle wheel and generates several different patterns in different colors.
  • I built one of these in my Real-Time Systems class. Everyone else in the class used Ada on 386 machines, but the prof said it was OK if I used Borland Pascal and assembler. It was a piece of cake!
  • the [] are to signify a word or words added to a quotation that were not part of the original quote.
    Richard Nixon, in his famous soundbite, "I am not a crook."
    "[Richard Nixon was] not a crook," according to his famous soundbite.

  • You can get the same effect by looking at a common LED clock from across the room while using an electric toothbrush. I have a Braun electric with the little round head, and I can stand 15-20 feet away from the clock, move the toothbrush to the right part of my mouth and a very stong illusion appears of the LED elements sliding back and forth in relation to each other (I guess the toothbrush is vibrating my head at 60Hz!). Very cool!

  • I camped near these guys at Burning Man... It marked my way home from the other side of the city! Quite cool technology... a lot of thought went into it and it shows.
  • Ah, now that explains why so many of these things looked overbuilt when I looked at them. I thought they looked pretty darned sturdy for a whimsical clock. Now I know... Hilarious post.
  • I was thinking exactly the same thing. I made a version of the Nipkow disk (wooden thing with holes in acting like the lenses in Logi Bird's) when I was at school. It worked if you had a good sense of imagination. It also got me beaten up for being a geek - funny how times change isn't it... Anyway, if you start to think seriously about building one of these things, keep us posted...
  • A friend of mine submitted a similar project to Circuit Cellar Magazine [] as a contest entry. There's a picture here [] and the abstract is here . []

  • Sad to say .. this is not new.

    No, although Mr. Blick did this project years ago (I saw it in about 97 or 98 and was suitably impressed.) I wonder where the guys that made a commercial version got their idea?
  • Bob just posted this to the piclist, a mailing list for PIC microcontrollers:

    Subject: [OT]: Alright, who told them?

    Aargh, my web site has been slashdotted, I certainly hope it wasn't someone
    here who told them, or I'll return the (questionable) favor.

    Hehe, =)
  • by Anonymous Coward
    Setting the time's a bitch with those push buttons spinning around.
  • You could have submitted it, 2 years ago even.
  • Use parts from a VCR to make your illusionary clock and what'll you get? An illusionary flashing "00:00".

    Regards, Ralph.
  • Check out []
  • You can also get 1F caps from custom car stereo shops, they're used for subwoofers or something. If you go cheap and get used, make damn sure it's discharged, since that's a lethal amount of juice.
  • This reminds me of how John Logie Baird's first television worked. It's actually more sophisticated than that really, in that Baird's TV gated the light output by shining it through apertures in a spinning disk. But you get the picture :o)

    The digits apparently floating in the air reminded me that some of the current prototype 3D TV's look a bit like this too. Plus ca change...

    Consciousness is not what it thinks it is
    Thought exists only as an abstraction
  • The ROPOD (ROtating POlar Display) is a similar device, only the screen is a spinning disc rather than a rotating cylinder, making this one of the few displays to use a polar coordinate system.

    These spinny things are all fine and dandy, but what I want is a clock that really is suspended in midair, i.e. a hologram.

    Is there such a thing? And could we make one at home?

  • By steering laser beams at a rapidly rotating helical surface, you can build a 3D display that doesn't require special glasses and can be viewed simultaneously from all angles. Only slightly off-topic. Here's a descri pti on [] of a fancy color version, and the photo at the bottom of this [] page shows one in operation.
  • The device is called The Fantazein Clock at and in PBS-affliated Store of Knowledge. The STK web site says $89. I think it is nifty.

  • Very very cool stuff... I image that with different color LEDs you could also work at simulating color. Though I imagine blue LEDs are hard to come by, you could have some fun with read and green (and the sickly orange the make combined).

    How is the work on blue LEDs coming?
  • Can the Hyp-Know-Tron actually display images? All the photos are just pictures of swirly displays; the ROPOD and even the various clock displays are actual "displays" rather than big light shows.
  • Wouldn't LED clock be more accurate? LCD would indicate a Liquid Crystal Display, like a watch, but this device uses lights, so LED would be more like what it actually is, similar to a desktop alarm/clock type device.

    -Julius X
  • I think I saw one of these coming out of a concert a few weeks ago. It was further fest (guys from the grateful dead), and let's just say that my visual perception had been ... um ... enhanced.

    Somehow, I don't think the police realized the dangerous situation they were creating...

  • IANAPL, but my understanding is:

    First of all, the only thing that patents clearly make illegal is building a device covered by patent and profiting from it either by using or selling that device, without first coming to a licensing agreement with the patent holder.

    Theoretically, if you build this clock for your own use, the patent holder might have some claim (although I'm not sure if there's an exception for non-profit use), but in practice, he would have to sue you in federal court to get anything from you, and would be likely to be awarded zip, so realistically he's not going to sue you, he's going to sue the guys with deep pockets who're making money off his patent instead.

    It's perfectly legal to be discussing it, because patents are public - that's kind of their whole point, they're the opposite of trade secrets. The details of patents are published so that others can decide whether they want to license them, and be aware if they're violating them.

    As for the existence of these other plans, it's up to the patent holder to uncover and enforce their patent, via civil lawsuit if necessary, so the holder should be sending a notice to the owner of that page. I believe if the page owner were to include a notice saying "these plans may be covered in part by U.S. Patent #XXX", he'd be fine, since once again, it's perfectly legal to discuss the details of patents.

    It is most certainly not illegal for Slashdot to link to the plans. The only kind of argument I can think of which might lead to such a conclusion is the as-yet unresolved "Napster argument": because Slashdot profits by linking to information about a patented device, the patent holder might be entitled to a cut of that revenue. However, that issue hasn't been decided in the Napster case, and further, clearly doesn't seem to be extensible from copyrights to patents. In the case of Napster, the actual content is available for download, not mere discussion of it. In this patent case, all that is available is information about building a patented device, which overlaps information in the publicly accessible patent database. In addition, Slashdot has strong rights based on freedom of speech as well as freedom of the press.

  • This product already exists, although Sharper Image doesn't carry it, yet... (I guess "Richard" is being slow on the uptake on this one.) These clocks can already be seen on executive desktops - a CIO I know has one on his. Places like Exploratorium sell them for around $99.

    The one I'm thinking of is the Fantazein clock []. The animated image on that page gives a pretty good rendition of the way the clock behaves in real life. It has a strip of LEDs mounted on a metronome-like arm that moves back and forth fast enough that you don't see the arm, so the numbers appear to float in space.

  • The article says nothing about finding a programmer inside a VCR.. it says the guy got his motor from the VCR..

    There would *NOT* be a PIC programmer inside a VCR, unless I'm completely mistaken. A PIC is genearally a one-shot deal anyway.. you can't 're-program' it.
  • I've seen similar devices in the mall..

    usually a string of LEDs on a stick, that swings back and forth like a pendulum. Works great. Less bulky, and less effort.
  • Yes, it exists. I bought one at DisneyWorld a few months ago when I took my girlfriend down to orlando. It was $20 or $25, comes pre-programmed with certain words, and lets you add your own message as well. It also has a toggle to allow lefties to swing it the other way. (The first time I saw one was at a Sasha/Digweed party, and someone had it writing "Digweed")

    I'm not sure where else they can be bought, nor can I remember the product's actual name, as the packaging is long gone...
  • You don't have to build just spinning clocks. Why not build a spinning game instead?

    A friend of mine did this, among others the games tetris and pong.

    They're described, along with pictures of them in action, on this page on his home page [].

  • If you're interested in microcontroller projects you might want to consider Atmel []'s AVR [] series. Atmel has a selection matrix [] which shows the AVR variants available. Some of the advantages over PICs:
    • You can use Steven Bolt's sp12 [] programmer which requires just a crystal and a few caps and resistors to build a stand-alone programmer, or requires nothing more than connectors and a few series resistors for an in-circuit-programming version.
    • All parts are flash based, not just a select few.
    • A low end established flash based part is available with a UART.
    • Flash parts are available with PWM channels, A/D converters, 16 bit timers, SPI and analog comparators.
    • A starter kit [] is available for $49 USD that comes with an in-circuit programming dongle and a demo board.
    • The series includes devices with between 1KB and 128KB of flash program storage.
    • (My favourite feature) GNU Binutils [], GCC [] and even GDB target the AVR line. It's a joy to have access to a free and Free macro assembler and C compiler. Many micros come with free assemblers but these are often buggy and lack features, and it's very rare to get a free C compiler.

    (Note that the latest binutils release supports the AVR, but the AVR GCC support is available as a patch to 2.95.2 at the location given above, or in the latest CVS & snapshots of GCC. The server hosting the patches seems to be down and has been for a short while, so Google's caching might come in handy. Google won't let me link directly to the cached version so just to to the cache of the first link for this search [].)

  • The 'F' in PIC16F84 stands for 'flash' - i.e., the PIC used here has 2kwords (2048 12-bit blocks) I think of flash, that can be reprogrammed up to 1,000 times.

    Anyhow, they're cheap enough chips to get off of digikey, jameco, mouser, etc.

    And cheap programmers: Amazon Electronics,, click on Amazon electronics. No relation to
  • A coworker of mine picked up something *very close* to this at a gift store in St. Louis. We haven't been able to find it again. It works very close to this, but is different.

    This is a complete clock that consists of a base stand, and what looks like a pendulum (or a metronome) with a bar that sticks upwards. The bar is spring loaded, and in a vertical position. In order to see the time, you move the pendulum all the way to the left, then let go.

    As the arm swings back and forth, it displays the time "in the air" using a single column of LEDs. It has a sensor on it so when it is travelling to the left, it starts up so that by the time the arm is swinging to the right, it displays the time.

    Its really neat. I wish I was able to find one again (did the best internet searches I could) but I have not been able to yet. This rotating clock is even better in that you have to take no action for the time to be displayed. Sounds commercially viable to me. A good geek toy.
  • I can't think of any VCR with either.

    Not that the PIC isn't suited for that kind of application...

    Myself, I built a parallel programmer at first (I also partially wrote KDE software for it). Later on I bought Microchip's serial programmer. I'm glad I got it. I had no trouble finding good software for it, I'll have to make an IDE for it one of these days.

    Interestingly enough, Microchip's Windows IDE has TeX support. It's based on PFE, which I made sure was present on every Win machine I had to deal with.
  • So how do I hook that programmer to my PC? I have just never seen something like that, but maybe I've had my head up the wrong place.

    A friend of mine made a PIC programmer using just a few transistors and probably some resistors and caps, and that was it. I'm sure those parts are probably in old VCR's but what would a VCR use a fully functional PIC programmer for?
  • No worries there, I've built PIC programmers, but I prefer the Scenix chip these days.

    I was just wondering exactly _where_ you would find a programmer in a VCR, and how you would hook that up. And, yes, I was sarcastic... ;)
  • I thought the little network programmers were inside my TV... now you say they are in my VCR, too?
  • go to a mall or theme park, most science stores in malls (world of science, world of knowledge, etc, and even Spensors (or however it's spelt)) have them, parks also have ones that display different messages like Happy Birthday and Happy Newyear, etc..., then there are other kinds like a pendulum clock (as mentioned by AtariDatacenter) , some are cheap, like the ones you spin manually (usually at themeparks) and then there are the more expensive motorized ones (at science stores)... so if you want one but dont want to/cant build one, just look around.
  • by British ( 51765 )
    This is exactly how the Adventurevision worked. It had a row of LEDs and a rotating mirror thing. The result? A cheap display. As the mirror rotated, the LEds flashed to make the image, REALLY fast.
  • Combine this concept with an array of Red, Green, and Blue LED's pointing at the right angles and you should be able to get floating 3D pictures a la 'Help me Obi Wan Kanobi'.
  • For even more fun, instead of a line of LCDs, you can have a 2d array. Spin this to get a 3d display.

    Probably would make an even more hellacious racket.
  • There always HAS been a series (16C84, 16F84) that can be reprogrammed, but there is an equivalent write-only device known as a One-Time-Programmable (or OTP) that is cheaper. That's the one you are likely to find in most consumer electronics devices because they are cheaper in quantity than the reprogrammable ones that would be useful to you or me.

    Even in devices that may be flash upgradable, the PIC isn't likely to be the chip containing the flash where price is an issue to the designer.
  • "A $90 version of the clock you're talking about should be available at the Store of Knowledge in your local mega-mall."

    $90!!!! Jeez, you can get simpler one for $30 at It doesn't seem to have all the features, but it still looks rather cool.

    Here's the address: ion=1&category=15

    If that don't work, just look under toys->desk toys. They have lots of fun and cheap junk that other "science toys" places overcharge for.

  • Just remember to feed the jolt to the VCR in moderation...too much may cause your programmer to blow your VCR to smitheriens...
  • Dammit I have been saving 5-6 of these up for something to use them for and now I have a use for em! I bet all you suckers that got rid of yours are now looking for em...I am heading to eBay to rake in the dough!
  • for your fingers? :) Isn't it like a fan that can cut easily?

  • No, it's not a misprint. 1.0F, not picoFarad, not microFarad, but one whole damned Farad.

    I don't have any at the moment, so I can't read the can. Serious electronics shops have them (i.e., not Radio Shack). Barring that, see if there are any local HAM radio enthusiasts... someone'll sell them along with the mythical blue LEDs at a table.

    The ones I got were a regular electrolytic can shape, with two leads poking out one of the flat bottom of the can. The can was a squat 1" diameter by 0.5" length, not including the leads, which were spaced at 0.1", the same pin spacing as most hobby boards (and the BASIC Stamp's pinout).

    With the bidirectional 5-12V DC regulator on the BASIC Stamp, you can set up solar/capacitor projects easily. The solar cell can power the Stamp all day through one pin, and excess goes to trickle into the capacitor on the other pin. When the cell is in shadow, the voltage flips the other way, draining power from the capacitor instead. The total energy WILL drain the capacitor before dawn, for all but the smallest projects, but the Stamp will just resume or reboot when the solar energy starts up again.

  • Last time I checked, the Stamp used a PIC.

    Yep, and you could probably do a lot more if you knew what you were doing with PICs. I didn't, so I opted for the Stamp, which added a massive layer of abstraction on top of the PIC internals that made it much easier for me to experiment. That's what makes Stamps great for beginners: no need for anything but a parallel cable, a battery and a few LEDs before you can get your first project running.

    It's like saying, "Last time I checked, Linux used a microprocessor." If you wanna write your own code directly on the iron without an OS on it, sure, go for it. If you prefer to have a little bit more support added, allowing for device I/O and such, well, use a microprocessor+software combination.

  • Does anyone remember the Virtual Boy? Made by Nintendo, it worked just like the device you describe, but projected a slightly different image into each eye to make things look 3D. For some reason, no one liked it. I thought it was neat.

  • 7 LEDs -- That's only 4 :CueCats!!!!!!
  • This is fairly simple. What makes it onto Slashdot is whatever [CmdrTaco/Hemos/Timothy/insert one of many slashdot posters here] finds interesting when reading through submissions. There is no pattern, beyond the random chaos in the posters' minds. Any attempt to predict articles may succeed over short periods, but will catastrophically fail when confronted with what is known as "the whiskey effect" (TWE), when CmdrTaco signs on drunk.

    I hope that this clears things up for you.

  • I've seen similar designs at football games. A few LEDs on a stick spell out "Go [local football team]!" when you move your hand and the stick swings about the handle. I thought it was pretty neat. AFAIK, it works exactly like this clock does, except without a motor.

    I'm trying to find a link to anything like it, but I'm not finding anything. ARGH! It does exist, I tell you! I've seen it!

  • one item on the list of things you'll need is "[a] programmer that will program a PIC16C84 or 16F84 microprocessor."

    Actually, you can find these on ebay. Right next to the "programmers looking for a job coding FORTRAN" section.

    After 16 years, MTV has finally completed its deevolution into the shiny things network
  • I wonder if they could find a resonable way to make a giagantic wristwatch with this thing a good novelty item
  • I know I saw something like this at the Discovery Store, Natural Wonders, or one of those similar mall stores that always has huge geodes and stuff in it. You know the kind of store I'm talking about. Their model was pre-assembled, and the LEDs (not LCDs) oscilated back and forth on a light-weight transparent wand. This gave a much more realistic illusion of floating numbers.

    Related--in college I discoverd that an ordinary LED clock, when combined with a strobe light, could be used to create an illusion. Just move the clock slowly back and forth, and it looks like the numbers are sliding off the clock. No psychoactive substances are required to view this illusion.

  • is exactly what I was talking about. Thanks.

  • If i switched the LEDs to all different colors could i give my clock a tye-dye motif? Or would it just look like a mass of ugly colors then?

  • the site is slashdotted already...anyone got a mirror?

  • Why was I not surprised to discover this...
    This one took me a little longer to find than the contest patent.....

    U SP# 5,302,965 [] covers...
    A display comprises a static unit (8) on which is mounted a rotating unit (7) driven by a motor (12). The rotating unit carries light emitting diodes (6) arranged as vertical columns which sweep around a cylindrical surface. The light emitting diodes (6) are controlled by a control circuit (6) in accordance with data stored in a memory (61) so as to provide a cylindrical display. The control circuit (60) and memory (61) are located in the rotating unit 97) and the memory (612) has a capacity for storing several different images for display.

    I'm thinking maybe I should change my .sig to "Mr Patent Search"

    p.s. sorry about the duplicate posting I responded to the wrong message with my first try...

  • This reminds me of how John Logie Baird's first television worked. It's actually more sophisticated than that really, in that Baird's TV gated the light output by shining it through apertures in a spinning disk. But you get the picture :o)

    Nipikow Disk TV sets. Yeah, they were really cool.

    But, man oh man, after watching one of those, I'm grateful for rickety old NTSC. If you think 525 lines isn't enough resolution, try watching Felix the Cat on 50 lines.

    I love antique TV sets, they're fascinating. I've got a collection going; I have 4 from the early 1950s (*not* mechanical), and a couple of early 1960s portables.

    Here's one for you: the original proposed color TV standard was mechanical: a spinning disk, with the three primary colors on it, was to be placed in front of the picture tube and spun in time with the sync signals from the TV station. Thank God RCA came up with the three-gun picture tube.

    Antique TV Museum: MZTV Museum [], part of Canada's MuchMusic and Citytv empire.

  • Wasn't there a really cheap item sold to make a B&W TV look color? It was simply a plastic filter with blue on the top half and green on the lower half that mounted to the TV. (I'm not kidding about this). I guess it was for the days where Westerns were the biggest entertainment on TV. Always a need for blue sky and green grass....

    Absolutely, there was. It was kinda like the screen overlays on a Vectrex video game system.

    But no, that's not the color TV system I was talking about. The color TV system I was talking about (I think it was from Westinghouse, but I can't remember for sure) actually had the primary colors on a rotating disk.

    If you wanted to show the red in a picture, only the red portions of the image would be displayed on the (black and white) TV screen. At this point, the red portion of the disk would be over the screen. When you wanted to show blue or green, same thing - the image displayed on the CRT would switch as the disk came to that point in its rotation. It would have been flickery, but it would have been true color. And the noise and bulk of a rapidly spinning disk over the CRT would have been nasty.

    Part of the issue was that when the NTSC (National Television Systems Committee) was choosing the support for a new color TV standard, the FCC had decreed that it had to remain backwards-compatible with the existing black and white TV standard (they pushed for this back in the late '80s, too, with the proposals for the new HDTV standard). This color wheel system, elegantly simple but unwieldy, would have done that.

    Fortunately for us, RCA invented the color (three-gun) cathode ray tube at about that time, and had come up with a way of encoding the color information onto a black and white image by syncing an oscillator in the TV set with one at the TV station (the 3.5758MHz "colorburst" signal) which was hidden in the horizontal blanking interval (the black bar that you see geting torn all over the place when your horizontal hold is set wrong). The color information then rode over top of the video brightness information. Old TV sets don't notice the color signal, but your color TV set compares the phase of the signal riding on the luminance (brightness) and demodulates it by phase to each one of the three primary guns. And the more saturated the color has to be, the bigger the color signal riding in the brightness info.

    Basically, it's an all-electronic version of the nasty old Westinghouse color system. We should all be grateful to the pioneers like RCA, Nipikow and Zworkin for what we now take for granted. And, of course, to John Logie Baird, whose mechanical TV system is completely irrelevant now, but he got the ball rolling by proving that TV was possible.

  • Hey.. that's a pretty neat idea. I'll call my patent attorney tomorrow and see if I can make their idea my intellectual property.

    Too late. Every Sharper Image store has something similar, though I'd prefer to build my own. (Helps to give me an excuse for keeping all those old VCR head drum assemblies kicking around.)

  • So how do I hook that programmer to my PC? I have just never seen something like that, but maybe I've had my head up the wrong place.

    Havn't you ever seen The Matrix?

  • Actually, it wasn't grey scale at all really, it was just a bunch of red lines. It looked 3D but it sucked, plus it gave you a headache and didn't have many games on it.

    I wonder why it didn't do well?

  • Here's some info on PIC programming:

    ftp://ftp.armory .co m/pub/user/rstevew/PIC/DaveTait/picprog.html []

    This file contains links to plans for building really cheap but functional PIC programmers. I've done it before; it's not too hard.

    These are really cool little chips.


  • I want one on the wheels on my car
  • It was called "The Private Eye", by Reflective Technologies (don't look them up, they've been out of business for a while [and I don't even know if I got their name right!]). It was a monochrome eyepiece meant to be attached to a computer or a diagnostic device. It consisted of a row of minuscule LEDs on one end of a plastic casing about 1.25 inches square and 4 inches long. The other end had a constantly oscillating mirror that reflected the image out through the eyepiece to the user's eye. The image wasn't too detailed (50x60 monochrome red), but it did make for a less obtrusive, more private display device. You could view stock quotes, read a secret document, or even play a game of chess by viewing this eyepiece. However, that was 1990 (the eyepiece was expositioned at my Cub Scout pack meeting [not exactly COMDEX!]), and lack of demand and evolving technologies made this disappear from the face of the earth. Only after seeing the propeller clock did the memory of it get conjured up.
  • Steve Ciarcia did this in his Circuit Cellar column in Byte magazine around 1978. At the time it was a cheap display if you couldn't afford a terminal for your state of the art 8-bit computer.
  • Also see Daryl Bender and Ottawa Canada's page [], where Darly and Ottawa explain other ways to obtain electric motors.
  • Some friends of mine built a couple of incredible LED-based art pieces for Burning Man this year. They both were based on persistence of vision, like the LED clocks, except that you moved your eyes or head instead of the LEDs moving. They've got a web page here [] with some great pictures.

    They made a 32' tall tower with LEDs down the length of it, in full color, with a Linux box controlling it. You could see it halfway across the city!

  • Since the site is slashdotted, here's another propeller-clock sites to look at in the meantime: []

  • This definitely is very cool, I've seen the police with 'wands' like this, basically they have a stick which the wave back and forth and a message appears in the air, it's a cool illusion, I saw a "slow down" message from one of them. I wonder if "you're a stupid moron" is too long to be made out ;)

    I've also seen this technology on TV [] a while ago.

    Very clever.
  • by Anonymous Coward on Sunday October 15, 2000 @03:00PM (#704254)
    This is at least two years old. It's been around for a long while.

    PICs are great little microcontrollers. Get one from DigiKey [] for around $6. A good programmer for them you can build is called the NOPPP. [] It's easy and cheap to build.

    This guy [] built a better version of the propeller clock.

    Hope this helps.
  • by redhotchil ( 44670 ) on Sunday October 15, 2000 @02:59PM (#704255) Homepage Journal
    Most of it is mirrored here. []
  • by Emil Brink ( 69213 ) on Sunday October 15, 2000 @10:13PM (#704256) Homepage
    OK, I'll bite. I'm just a software dude playing around with electronics on the side, so... Anyway, here goes nothing:
    1. Probably something to deal with the fact that the board containing the LEDs for the clock is rotating, so transferring signals to them becomes kind of complicated.
    2. A kind thin board featuring strips of copper and lots of holes drilled on a standardized grid. Dead handy for building circuits without using real printed circuit boards
    3. No idea, sorry.
    4. Likewise.
    5. A PIC 16C84 is a wonderful microcontroller made by Microchip []. It's a RISC design, and uses a Harvard architecture. Commonly clocked at 4 MHz, which lets it execute 1 million instructions per second. Very popular among us hobbyists because it stores its program in 1024 words of EEPROM, thus making it easily erasable and reprogrammable using just electricity--no UV light or anything like that.
    6. A DIP resistor, I would guess, is another name for a "resistor network", which is just a bunch (seven or eight seems common) of resistors mounted in a standard DIP (that's dual inline package) capsule. Very handy when you need lots of same-value resistors for e.g. LED current limiting.
    7. "16C84" is just a shorter form of "PIC16C84", of course. The word programmer in this context referes to a piece of specialized hardware which is used to transfer instructions into the EEPROM of the chip. The net is full of build instructions for those, and they're all pretty nice and simple.
    Um, again, please note that I'm just an electronics hobbyist, not a real expert (TM). Anyway, I hope that clears some of it up for you.
  • by fliplap ( 113705 ) on Sunday October 15, 2000 @03:18PM (#704257) Homepage Journal
    Wee...more spinny clocks:

    Dave Barrett's Clock []

    The Original - Bob Blick's Clock []

    Luberth Dijkman's Clock []

    Andrew Jardine's Clock []

    Ken Staton's Clock []

    Victor Tihonov's Clock []

    Don Zehnder's Clock []

    Come one, build a clock, join the club!

  • by HangHigh ( 183020 ) on Sunday October 15, 2000 @03:47PM (#704258)
    Another interesting twist on this idea is to mount a bunch of LED's on a pole (one long single column). You then use the viewers motion to generate the desired message. Typically this would be timed such that a moving car would provide sufficient motion.

    So at night, a driver passing by in a car would see a message, yet if they stopped to see what the hell was that, they wouldn't see anything.

    What I describe has been done and is VERY OLD (> 20 years). Stiff fun stuff though.

  • by BigBlockMopar ( 191202 ) on Sunday October 15, 2000 @09:19PM (#704259) Homepage

    It allows all timezones to be displayed :-)

    You're a putz, Bob. I like you. I checked out your website, you build really cool stuff. Thanks for putting these neat little projects up on the 'Net!

    Uhhh... I design radar equipment for Litton []; any chance of getting your microwave oven hack schematics, despite the danger warnings? (I've got *no* idea how you'd have handled the waveguide issues, or even how you built the antenna!)

  • by Anne Marie ( 239347 ) on Sunday October 15, 2000 @02:59PM (#704260)
    From the article: If you don't have any way to put the program into a PIC 16C84 or 16F84 chip, you can build your own programmer.

    So if you don't already have a programmer, you'll have to build a programmer yourself. None of this weak "find a programmer in a box" crap -- do it yourself.
  • by squiggleslash ( 241428 ) on Sunday October 15, 2000 @04:27PM (#704261) Homepage Journal
    This is probably ultimately off topic - mental thought process that got me here was "cool, an image generated by a mechanism moving some beams of light, hey, where have I seen that before?"

    John Logie Baird, a Scot, is supposedly the inventor of the television (but not anything we'd recognise today as a TV.) His device, which was experimented with by the BBC in the mid twenties[? I think - any geek historians out there?], was a large wheel with thirty lenses around the edge, all at a slight offset from one another. The transmitter was a light sensitive resistor on one side of the such a wheel. The receiver also had a wheel, and had a light bulb on one side, and a screen on the other. The different offsets for the lenses meant that when the wheel was spinned, the resister would automatically scan 30 lines; on the receiver, the light bulb would illuminate the same positions on the screen thanks to having a similar set of lenses.

    Needless to say, while it was first, it was also crap (30 lines for crying out loud), but it was capable of transmitting something that looked like a human face in real-time, and thus, for the twenties, was reckoned to be the coolest thing since the, well, coolest thing that had come before it. No doubt it was much discussed on Slashdot's predecessors at the time.

    Now we have tiny little leds with less persistance, and can bank them, and presumably are perfectly able to generate wheels with considerably more than 30 lenses, the question arises - is it possible to create a mechanical TV (camera and/or receiver) capable of producing/showing an NTSC or PAL signal?

    Or even have... *shudder* a mechanical VGA monitor?!

    Well I think it would be cool anyway. I'm guessing if we can use leds on a spinning drum to generate a clock from cheap off the shelf components, we ought to be able to out-Logie Baird right now.

    (No, I don't know what that meant either)

  • by Aphelion ( 13231 ) on Sunday October 15, 2000 @02:56PM (#704262) Homepage
    For a moment there, I thought the headline of this story was "Illusionary LSD clock".

    Makes a lot more sense, doesn't it?
  • by egnor ( 14038 ) on Sunday October 15, 2000 @03:18PM (#704263) Homepage

    The ROPOD [] (ROtating POlar Display) is a similar device, only the screen is a spinning disc rather than a rotating cylinder, making this one of the few displays to use a polar coordinate system. It's also capable of quite a bit more than telling time; the resolution is much higher, and the author has software that can decode a compressed animation format for video display. Follow the link for photos etc..

    The coolest thing about the ROPOD is that it's this huge, whirling, rickety contraption that makes bystanders fear for their lives...

  • by SubtleNuance ( 184325 ) on Sunday October 15, 2000 @04:25PM (#704264) Journal
    If you find this project interesting, you may want to also see THIS [] link which has details/schemas on many other Mech.Scanned clocks. None as neat and clean as Blick's - but nice nonetheless. Has a few projects with pretty large units - different formats/methods ect.. have a look.

    Ive been putting off building a mechanically scanned clock like this for some time! I saw this page some time ago, Bob Blick's project is very neat and clean. I stumbled across it while researching about BEAM [] robotics. Meant to comment on the last story here on /. about the Home Robot []. I dug up this [] link which is decidedly more hardcore an offering compared to the Pocket-Bot [] (scroll to very bottom of page) offered by Divent (though _Not_ the bot featured in the /. article - it is the other kit Divent apparently markets).

    Hey Americans: Big Biz has bought your Democracy, are using your gov' and military to enslave you. Wake up. Free yourselves. Do the world a favour; Tell your friends/relatives/neighbours to:
  • by Breace ( 33955 ) on Sunday October 15, 2000 @02:49PM (#704265) Homepage
    Note that one item on the list of things you'll need is "[a] programmer that will program a PIC16C84 or 16F84 microprocessor." Often you can find these inside broken VCRs.

    I'm sure not the programmer but the PIC16C84 itself, right?
  • by NoWhere Man ( 68627 ) on Sunday October 15, 2000 @03:28PM (#704266) Homepage
    Mini Programmers save space and hardware. They feed off the dust inside VCRs and TVs. Unfortunately the heat eventually makes them pass out. Which is why electronics stop working for no reason and then start back up again after you shake them, you just woke him back up.
  • by Speare ( 84249 ) on Sunday October 15, 2000 @04:42PM (#704267) Homepage Journal

    In 1995 or so, I built a simpler model using a Parallax, Inc. [] v1 BASIC Stamp circuit.

    (For those of you who haven't toyed with a BASIC Stamp, it's a 14 pin SIPP circuit board (1.4" x 0.5") with a 5-12V DC voltage regulator, clock, 8 programmable I/O pins, 256 bytes EEPROM memory, and TTL/RS232 control lines. You download programs that are tokenized BASIC, and the program is run whenever power is available.)

    My clock and silent-radio didn't have a spatial sync, but did drive five LEDs to scroll through a message. I trickle-charged a small 1 Farad capacitor to power the circuit for about ten minutes, and spun the whole apparatus around on the end of a pencil to read the display.

    I recommend the BASIC Stamps (v1 or the more capable v2s) for anyone who wants to play with digital programmable circuits for the first time.

    My other 1.0-Farad-powered project was a small sound-effects generator that rode inside a slotcar racer. It used four tilted mercury switches as a crude accelerometer, to provide screech and revving sounds for my racecar.

  • by pmcneill ( 146350 ) on Sunday October 15, 2000 @03:11PM (#704268)
    Would definitely wake me up...

    /me reaches over

    *whap* *whap* *whap*

    /me awakens quickly

Don't tell me how hard you work. Tell me how much you get done. -- James J. Ling