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Hardware

The Harvard Network Accessible Dartboard 109

Posted by chrisd from the foosball-is-next-in-line dept.
These guys hacked a dartboard to serve scores over a wireless network. There is an OpenGL client that grabs the scores, runs the games, stores the results in a database, and suggests moves based on player's past performance. On top of all this, the client looks exactly like the dartboard, so it can be projected over the real thing.
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The Harvard Network Accessible Dartboard More

The Harvard Network Accessible Dartboard

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  • stats (Score:2, Funny)

    by terradyn ( 242947 )
    lol, they keep stats on ppl!? Not only can ppl know how badly I suck at CS; they can also know how bad at darts I am, with a picture to boot!
  • Wouldn't just been easier to hack a digital dartboard? You know, the one in pubs? Of course that wouldn't give the feel of a classic metal dart/wool dartboard.
    J.
    • It _is_ a digital dartboard, as you can see by looking at the pictures:
      1) The board has obvious cavaties: http://www.people.fas.harvard.edu/~sander/dip/proj board.jpg
      2) I've never noticed anything like this on a regular dartboard: http://www.people.fas.harvard.edu/~sander/dip/boar d.jpg

      Read the article, look at all the purdy pictures and _then_ post :-)

      Not that I bother doing that of course ... hehe

  • I want one of those! (Score:4, Insightful)

    by Hektor_Troy ( 262592 ) on Wednesday February 20, 2002 @07:51AM (#3037177)
    Not because I can play darts - I probably couldn't even hit the board - but because it's cool. I wonder if you could do something similar for a pool table. It would probably be quite a bit harder, as you'd need to be able to recognize each ball rather quickly. Maybe you could even build a program to recognize each ball and suggest the best shot and project it onto the table? Something new to do for these guys :-)
    • That's something I've thought of in the past, and I can't see why it couldn't be done.

      You'd need

      1) A camera mounted above the table, so it gets a fairly flat view of the table, and can see all 6 pockets

      2) A Projector also mounted above the table, which can project over the whole area of the table (ceiling height would probably make this difficult)

      3) A pc in between that runs some kind of image recognition system to spot the balls (I'd think recognising circles of distinct colours would be easy if you're playing english style pool with red and yellow balls. Spots and stripes may be harder to recognise). It could then hook this into a pool simulation engine to work out which is the best ball to aim for, and then plot lines of the ball paths, which would be projected onto the table.

      Al made one of these for Sam in an episode of Quantum Leap :o)
      • "Al made one of these for Sam in an episode of Quantum Leap :o)"

        Which, of course, only Sam could see, because it was a holographic projection into Sam's mind, right?

        Quantum Leap was cool. I especially enjoyed the episodes where he ended up in a woman.
        • though it seems that most problems happen to men, since the "Sam as a woman" episodes came quite infrequently when you'd think statistically he'd jump into a woman 50% of the time.

          Going back on topic, the whole projector thing would only be any use if you wanted to give both players a hand (unless the game is programmed to be able to turn off the hints for the better player). We'd really need some way of making the projection visable to only one player.
          • Maybe you could work out somekind of "handicap" for the program. The bigger the handicap the better hints you'd get. All new players start out with a handicap of, say, 100, and as you play, the computer works out how "good" you are, and manipulates the standard of the hints it gives you. Of course this requires you to register with the computer, but hey - what's the harm in that?
          • We'd really need some way of making the projection visable to only one player.

            Think HMD ...

            Kevin
        • As a woman? It was cool.

          But the best leap was when he was a monkey to be sent in space.

          Oh.. and to stay on topic..
          Imaging a beowulf cluster of dartboards...
          No. Really. Would be nice for tournaments.
      • Did I not see a colour detector as part of the LegoMindstorms set, or does that require one digital camera for each pool pocket?

        If you're using red/yellow balls, plus white cueball and black 8-ball, you should be able to detect all of those using 2 light-sensors, a red filter, and a yellow filter.

        Of course, you can just play pool at games.yahoo.com if you really need the bounce-angles calculated and displayed on the table

    • Im just ranting here, but here is what i think:

      1- Put a camera that focuses on the table and tune it so it just distinguishes circles, not colors.
      2- If you put all the balls in a standard formation in which all the balls are ALWAYS in the same place (for example, number 1 with stripes is always on the tip of the triangle facing the player), so after a shot has been made it shouldnt be too hard for a computer to track all the circles movements so it knows which circle is which ball.

      My guess for calculating the circles movement is to calculate each circle's center for each frame, and if your're using a fast enough camera you should be to calculate the balls movement...

      Disclaimer: I'm not a good pool player neither have i any experience with image recognition systems.

      Me not know english? that's unpossible

      • Re:I want one of those! (Score:2, Interesting)

        by rm-r ( 115254 )
        This could easily be done on a monochromed and thresholded (thresheld?) image to give white balls on a black background and then using Hough transforms to give the ball positions. The area detected could then be sampled from the original image to obtain the ball colour. This is cool! If only I had a pool table so I could do this ;-(
        • And here's a link about Hough transforms ... [susx.ac.uk]

        • Re:I want one of those! (Score:2, Interesting)

          by nat5an ( 558057 )
          Actually, given that you know the positions of the balls at the beginning of the game (assuming that you specify what game you're playing), it's pretty easy to track them if you know where they start. This can even be done fairly well with people, who are much more complex in their movement patterns than billard balls.

          In fact, you could do LOTS of useful things with a system like this. Combine it with two other cameras that get side views of the table, and the computer can get the angle and location of your cue and predict what will happen if you hit the cue ball at this angle with varying levels of force.

          The only thing you'd have a problem with is predicting what would be affected by varying levels of chalk on the tip of the cue, but if you played consistently, the system could be trained to predict very well.

          Hey, this would be a good topic for my thesis, and a lot more fun than some other topics :-D

      • Re:I want one of those! (Score:2, Informative)

        by JohnPM ( 163131 )
        Nice idea, but tracking the ball movements is not going to be feasible unless you have a very fancy high-speed high-bandwidth camera and a lot of computing power to process images many times a second. The problem is mostly with the break, I should think. The balls are moving essentially at random all over the place in just a fraction of a second. The ball tracker would also have to understand the basic physics of the game, because otherwise even two balls colliding head on would present a big problem. The moving ball may appear to pass through a stationary ball for example.

        But all is not lost. I don't see why you can't just track the balls on colour. In pool, each ball has a unique colour and at least some of it is always visible - even on the "stripes" balls (aka bigs or halves). Since you're not tracking movement, you can do all the image processing between shots, taking several seconds if necessary.

        Finally, may I suggest, instead of an expensive projector, you could rig up a laser pointer reflected off some kind of servoed mirror. If your computer could manipulate the mirror accurately and quickly enough it could draw out the line along which you should hit. You may well be able to buy these mirror components as they are already used in laser displays for rock bands, museums, etc.
        • You a mirrored setup as in most lasershows? Kinda like this: http://www.laser-light-show.com/syst.htm

          "Total system cost is only $8995 complete (Low power 5mw).
          Medium power 50mw system $9995 complete.
          High power 100mw system $10,995 complete.
          Includes Pent III desktop computer. Laptop available at additional cost"

          Not entirely sure that this is a bargain ... hehe :-)

          • Re:I want one of those! (Score:2, Informative)

            by JohnPM ( 163131 )
            Nah those are with huge lasers for open-air displays. All you would need is a good laser pointer. The page you want is here [laser-light-show.com] where they have a bunch of cheap components like mirrors and "General scanning 124 Galvo" for a couple hundred.

            Also they have a "hackers special" which includes the laser and stuff for $2700, which is almost getting down to the price-range. It looks like the galvo (motors) + mirror subsystem goes for around $1000 though - still pricey.
    • I believe this was a slashdot story a long time ago, but there was a "Snooker Playing Machine" built by the University of Bristol (UK) back in '98.

      The only information I could find about it now is at: http://www.bmc.riken.go.jp/sensor/Ho/chicago/Robot ics/Snooker/snooker.html [riken.go.jp]

      The site includes some pictures and a couple very limited technical details.

  • Announcements (Score:3, Funny)

    by Maiko ( 534130 ) on Wednesday February 20, 2002 @07:54AM (#3037182) Homepage Journal
    I know from UK Darts TV coverage that the announcer says the scores after each set of darts thrown. Does the machine spout "Whon Hunderud hand eIIIIIIghty!" every so often?

  • Geez! (Score:3, Funny)

    by Tazzy531 ( 456079 ) on Wednesday February 20, 2002 @08:02AM (#3037191) Homepage
    Geez..they go to harvard and they have enough free time to build a "wireless dartboard" ... meanwhile I'm still up a 7am working on my Programming Languages and Translator class project...UGH!
  • Drunk geeks with sharp instruments. Great.

    Anyone smelling a hoax? It looks good and even possible, but the dartboard shown looks like a standard horsehair board and not one of those electronic pegboard types, so how does a hit register? A normal dartboard is a damned good insulator with a wireframe over it. Sections don't move, so switches can't be pressed.

    woof.

    • Copy/paste from another post I made earlier. Maybe you too should drink a couple of cups of coffee:

      "It _is_ a digital dartboard, as you can see by looking at the pictures:
      1) The board has obvious cavaties: http://www.people.fas.harvard.edu/~sander/dip/proj board.jpg
      2) I've never noticed anything like this on a regular dartboard: http://www.people.fas.harvard.edu/~sander/dip/boar d.jpg"
    • Nope, this is real. if you read the article they say "Our first goal was to understand how our Sportcraft dartboard translates a single dart hit to an electronic signal..."

      and a quick search of sportcraft on google finds www.sportcraft.com [sportcraft.com]

      Which has electronic darts boards exactly like the one they've hacked.
    • Dart board? We don't have one anymore. There was a horrible accident. Drinking and darts don't mix.
      --Mancomb Seepgood

    • You could use a horse hair dart board using a pair of cameras and a little triangulation algorithm. The result would be a little bulkier, but probably more fun (soft darts suck!)..

  • Watch out for... (Score:3, Funny)

    by mikeage ( 119105 ) <{slashdot} {at} {mikeage.net}> on Wednesday February 20, 2002 @08:05AM (#3037197) Homepage
    ...network accessible _darts_. Now those had better be secured-- I don't want anyone cracking into my sharp pointy object collection

  • Bonus scores? (Score:3, Funny)

    by Frank of Earth ( 126705 ) <frank@fper3.14kins.com minus pi> on Wednesday February 20, 2002 @08:19AM (#3037215) Homepage Journal
    How many points is it when you get the dart to hit the parallel cable. [looks like shielding doesn't cover everything completely]

    Very cool guys.
  • This is so cool, although the guys are obviously not that great at darts strategy - look at the stas for the doubles. Double 20 is at the top as expected but double 16 is way down the bottom. Watch the pros play, they will always try and leave themselves double 20 or double 16 to finish. The logic should be obvious to most slashdotters - you can keep splitting the double 16 all the way down to double one if you miss the double and hot the single. Double 1 is the next highest double in the stats so maybe they are doing tjis, but just not very good at getting the doubles!!!
    • Where the computer works out the most optimal target to hit next and highlights it for them on the projection.

      That would be sweet!
      • It actually does do this. If you look at this image [harvard.edu], you'll see a box that says "Aim for Triple 20" in the bottom right corner. When playing 301, the computer calculates the best next move using a simple dynamic programming algorithm and displays it there (assuming perfect players -- we are working on a version that considers a player's probability distribution).
        • I'd like to see what they think is the shortest way to finish 501, nine darts is the answer. saw John Lowe do this once :-) Two darts from 101 etc.

          I also wonder if the tutor is smart enough to realise that John is crap and should always aim at triple 19s. Clive is playing and it just lights the whole board up as a guide:-) etc

          Lastly, whatever happened to KISS, there is more hardware here than they took to the moon :-)

  • Two things we can notice here: (Score:3, Interesting)

    by ksp ( 203038 ) on Wednesday February 20, 2002 @08:30AM (#3037234) Homepage
    1)
    "Pedro V. Sander" desperately needs to get a life according to the stats!

    2)
    You can be no good at darts as long as you play alone, it is easy to cheat since the PC never notices when you miss the board altogether.

    BTW: Pedro, I am not suggesting that there is a link between 1) and 2).

  • We can even track the slashdot effect. (Score:3, Funny)

    by Hektor_Troy ( 262592 ) on Wednesday February 20, 2002 @08:32AM (#3037238)
    When I read the article the first time, the counter (at the very bottom) said 865 visitors, now (~50 minutes later) it says 4589. That's obviously not enough to slashdot the server, so let's show them what we can really do - slashdot the server. Or just slashdot the fastcounter.bcentral.com server (they're the ones hosting the counter) :-)
  • We built a parallel port onto a dartboard. We connected the dartboard to an old laptop, which we call the dartboard server

    I'd have thought they could have come up with a better name than 'the dartboard server'. How about 'Jocky [darts-import.nl]', 'Eric [planetdarts.co.uk]', or 'Tricia [planetdarts.co.uk]'
  • Seems like every great game will eventually be ruined by cheaters, see Starcraft, CounterStrike, ARC... I wonder if this wireless dartboard can detect cheaters (e.g stand in front of the board and stab it point blank, in order to up your stats). Hope the AI is smart enough to /ban such users. And maybe literally "kick" them by ways of a 10 ton hydrolic metal boot nailed behind the player's spot.
  • >> the client looks exactly like the dartboard

    I heard that version 1.0 was done as a dodecahedron. When that didn't work too well they tried the classic "Circle with some pie-slices" approach and found success.
  • Check out an Etch-A-Sketch that you can draw on by submitting moves to a form. The server is an 8 bit Rabbit 2000

  • Someone I know finally made it onto slashdot (Score:4, Funny)

    by DoorFrame ( 22108 ) on Wednesday February 20, 2002 @09:40AM (#3037375) Homepage
    Ok, so I've known a number of people in my life, but this is the first time any of them have ever did anything which warranted their appearance on the infamous slashdot. So, with my knowledge of a grand total of TWO of the players [harvard.edu], I want to ask you, what do you think this guy [harvard.edu] is up to?

    Ok, sure, it's a cool hack... blah blah blah, but you're all missing the most important point of discussion, does or does not Marco Carbone look like Jon Favreau [imdb.com] (of Swingers fame):

    Picture of Marco Carbone: here [harvard.edu].
    Picture of Jon Favreau: here [imdb.com].

    There's almost certainly some sort of conspiracy afoot.

    PS. I attempted to find a picture of Marco Carbone as a dog, but alas the wayback machine failed me [archive.org].

  • Also some game theory on the matter... (Score:4, Interesting)

    by mcarbone ( 78119 ) on Wednesday February 20, 2002 @09:58AM (#3037444) Homepage
    We also applied some game theory to the game 301 and to a game we invented called 30-Block, which you can read about here [harvard.edu]. We can solve 301 fairly easily, but 30-Block turns out to be quite intractable.

    The more interesting part of this paper discusses probability models we use to predict where players will hit based on where they aim. It's interesting: if you are a perfect player, you have the highest expected value when aiming for Triple-20 (obviously), but the worse you get, the best place to aim in the boards spirals inward until it gets to double bulls-eye (which minimizes how often you miss the board).

  • deamon (Score:2, Funny)

    by davidhan ( 539718 )
    We wrote a dart
    deamon to poll for dart hits. The deamon accepts multiple simultaneous TCP connections and sends the dart hits to all connected clients.


    And these guys go to Harvard?
    • Eighty percent of Harvard students graduate "with honors." Eighty percent. Please remember that when you're looking at resumes from Harvard alums. Grade inflation is so rampant that C's are very rare. Meanwhile, I graduated - without honors, and with lumps -from an affordable public university with an attrition rate of over 40% (OK, it's still a top-tier school, but it *is* a state school.) And still Harvard gets the hot rep - and we still end up working for the Harvard boys. It's just not fair, I tell ya.
  • A while back, the wall street journal did an experiment they had group consisted of seasoned investment managers square off against chimpanzees who would select stocks by throwing a dart at a dartboard. 50% of the time, the chimpanzees picked better stocks.

    The Harvard guys should get themselves a few good chimps and use their networked dartboard to serve up a website that well-informed chimp-picked stock tips. They can then sell ad space to financial

    Hey, there have been crazy dot.com business schemes.
  • The laptop and wires are protected by a dart-proof cover... but what about the webcam itself?
  • This is by far one of the niftier hacks i've seen lately, but its a shame that it is an electronic dartboard. I mean, if they had figured out how to do this with a standard dart board (which would probably be hard as crap) I would seriously go out and purchase one today (and yes i know they're not trying to sell it, i'm just saying). Having played on electronic dart boards before, i can tell you that half of my shots never stick in the board. This could be because i suck and have an unorthodox throwing style, but more over its just because its damn hard to get the darts into the tiny little holes. Can anyone think of a way to do this using a real dart board. just some food for thought.
  • This project is impressive -- i saw that they're not EE's, so they had a hard time figuring out how the contact sheets are picking up dart throws. They came up with a good work-around, but i'll explain how the thing was supposed to work -- (i'm doing a similar implementation to this for my senior EE project).

    WIRING:

    Contact sheet 1:
    Basically, the grid is broken down into two halves. one of the contact sheets connects full wedges (ie, 20, 19, etc) across the single/double/triple boundaries together with another wedge on the other half. Therefore, there's 10 wires (20/2 = 10)

    Contact sheet 2:
    contact sheet two connects all the point values on each half...so, for half #1, one wire connects all singles, one wire connects all doubles, etc... one wire connects all singles on half #2, etc...there's 7 wires total, because one of them is used for bull's eye

    Implementation (time division multiplexing):
    send a logic pulse down each of the 10 wires in contact sheet #1 really fast, in a loop. Read as input on the rings...so, if you read that there was a single scored on the first half, just check where you sent the last pulse down -- deduct which was hit.

    i dunno, i guess this is boring, but in case anybody was interested :)

    - blake
  • Well the usefulness of this technology escapes me at the moment. It is kinda interstings , but what next a web active foosball? I have a hard enuf time keeping up with that little ball as is. Maybe air hockey? Well in the spirit of spirits , networkable drinking games. Try one at your next lan party. I am running thin on those so far. But i do know you can hook up a lan while totaly enebriated.

    I know that alot of breakthrows in computing and hard ware have happend do to people just fooling around. This could if used right turn into something workable in another feild , maybe your next SAT prompter will be a camera and use of specal pens so it can track cheaters.

    But i kinda want one in my home sounds kinda fun.

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