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Displays Hardware Hacking Input Devices Build

DIY Multi-Touch Tabletop "Surface PC" 78

notthatwillsmith writes "We've all seen the nifty demos of Microsoft's Surface PC. Now Maximum PC details how you can put together your own multi-touch tabletop PC. The article shows how you can build the cabinet and combine that with a standard PC, a decent projector, about $350 worth of assorted hardware (cameras, lenses, mirrors, and screens), and a handful of free apps to build your own Surface-like PC — without giving Microsoft $10,000."
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DIY Multi-Touch Tabletop "Surface PC"

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  • by Anonymous Coward on Wednesday April 08, 2009 @01:06AM (#27500125)
    and now we are discussing it...
  • Already slowish (Score:5, Informative)

    by Anonymous Coward on Wednesday April 08, 2009 @01:12AM (#27500145)
  • by WaroDaBeast ( 1211048 ) on Wednesday April 08, 2009 @01:24AM (#27500191)
    Touché.
  • You'll see a chair come flying out of the left hand side of the screen and smash the homebrewed touch PC to bits along with a whooping howler monkey sound before the video goes completely blank.
  • $350 huh? (Score:5, Informative)

    by Anonymous Coward on Wednesday April 08, 2009 @01:32AM (#27500231)

    Here's a $2 version [youtube.com]

    • Here's a $2 version [youtube.com]

      That's $2 only if you can find a web cam within the price range.

    • Wow. When I saw the $2 I thought it would be fingerpaint and paper.
  • I have been playing around on a surface for the past two months at school. At first I thought it was sweet. When the novelty wore off then I thought it was kind of lame. I had seen the fiducials but hadn't really thought about them. The table can read over 200 unique fiducials. That is cool, and can lead to much more interesting things then spinning pictures. Also, the table is visible and more importantly, operable in a well lit room. Most DIY surface projects require darkness.
  • by Anonymous Coward

    Given that the system uses frustrated total internal reflection, I imagine it would be quite sensitive to grease from the fingers and any other dirt that changes the refractive index at the surface of the acrylic?

    It's a nice idea though. I wonder if it could be retrofitted to a standard glass topped coffee table or desk?

    • I think yes (Score:5, Informative)

      by SuperKendall ( 25149 ) on Wednesday April 08, 2009 @02:01AM (#27500331)

      Given that the system uses frustrated total internal reflection, I imagine it would be quite sensitive to grease from the fingers and any other dirt that changes the refractive index at the surface of the acrylic?

      From playing with a real Surface in Vegas, I think the answer is yes - it appeared to have a few dead zones where presses were not registered very well.

    • Re: (Score:2, Interesting)

      by minsk ( 805035 )

      I imagine it would be quite sensitive to grease from the fingers and any other dirt that changes the refractive index at the surface of the acrylic?

      That would be one of the reasons they put material over the acrylic, rather than touching it directly.

      Will be interesting to see how that design ages. My group experimented with textured silicone rubber. However, after a few months of use it had flattened out and bonded to the acrylic. Painting a clear layer onto the acrylic seems to survive better, though it

  • So much investigation on how to multitouch the computer and so little about how to make the computer...

    Ok, Ok.

  • didn't Johnny Lee [youtube.com] already do this?
  • not really 350$... (Score:4, Insightful)

    by polle404 ( 727386 ) on Wednesday April 08, 2009 @02:23AM (#27500397)
    Reading TFA, it's not really 350$, as they already had the projector and the PC.
    It's an impressive build nonetheless.
    • Re: (Score:3, Insightful)

      by Aladrin ( 926209 )

      Whoa... They had to add $350 on -top- of the PC and Projector!? I assumed that at least included a crappy projector. Ouch.

      So really, instead of a $10,000 professional table with big support behind it, we're talking about a $1500-3000 homemade table that isn't going to be nearly as refined and awesome. For 1/3 of the price, it had better be pretty competitive with the big one. For 1/30 the price, it was allowed to be pretty hacky.

      • PC price can be quite variable, from my low-to-mid range $350 whitebox, to a everything-but-the-kitchen-sink Mac Pro (~$30,000). I wouldn't want to put a hard number on that, either.
  • What about 2 mice? (Score:5, Interesting)

    by Peeet ( 730301 ) on Wednesday April 08, 2009 @02:41AM (#27500467)
    I've seen a lot of multitouch demos and have always wanted to mess around with the applications side of it, has anyone seen any software that allows you to plug in 2 usb mice and use that as at least a 2 point "multitouch" system? Windows 7 beta seems like it might possibly have the capability to do so with some sort of "TouchVista" add on, but other than that I can't seem to find anything for Linux or XP.

    Any multitouch software I have found uses complicated algorithms to process an image from a webcam to try and deduce points from a blurry low rez low fps infrared image of fingertips. It seems like the first step (to just test out apps without complex hardware) would have been to make a driver for multiple mice, but I can't find that seemingly trivial interstitial step anywhere.
    • Re: (Score:2, Informative)

      by Anonymous Coward

      Multipointer X has been in the mainline development branch of the Xorg X server for a year but wasn't released with X server 1.6.

      http://www.phoronix.com/scan.php?page=article&item=xorg_server_16&num=1 [phoronix.com]

      It should be released in X server 1.7

      http://en.wikipedia.org/wiki/MPX [wikipedia.org]

    • Re: (Score:2, Interesting)

      by minsk ( 805035 )

      I would be hesitant to sink much work into multiple mice. You would be stuck with a very small number of touches, and probably wind up using buttons to emulate multi-finger gestures. Without good guidelines for designing applications on large touch-sensitive surfaces, you're going to have trust the 'feel' of the application. Not sure how that would play out with mice.

      The reacTIVision [sourceforge.net] folks have an input simulator that might be a good place to start. The TUIO protocol is common enough that you wouldn't be co

      • A friend of mine was trying to make a "multi-touch" digital audio workstation controller for me and two mice was one of the ideas he started with. It was limited, but there were a few cool things I could do with it.

        I know there are some people who have done some very lovely and expensive things with music controllers like this (I saw someone in Bjork's band using one), but I appreciate the diy aspect (and I don't want to lay out 10k)

        For now, my theremin is as good as gets.

        • by minsk ( 805035 )

          Given my complete lack of knowledge about that problem domain, it sounds like you hardly need the projector. In which case a DYI tabletop would run more like fifty bucks. :)

          Or, if you don't need a surface at all, there are lots of ways to (ab)use a Wiimote [johnnylee.net].

    • by Zerth ( 26112 )

      You can do multi-mouse in XP(you can trap events from different USB mouses), but MS didn't provide for multiple pointers so if you wanted more than one arrow, you'd have to code your own pointers as sprites.

      see http://www.jstookey.com/arcade/rawmouse/ [jstookey.com] for code and games that use multiple mice.

      The real problem using mice is that they don't provide positioning, only motion

  • by UnixUnix ( 1149659 ) on Wednesday April 08, 2009 @03:06AM (#27500617) Homepage
    "DO NOT TOUCH"
    • When I set up regular non-touch workstations for new employees at my workplace, I'm tempted to hang a sign that says "do not use."

      It's the only way I can guarantee the continued integrity of the system.

  • It looks like this is getting less than 80% of the multitouch navigation events correct - rotating when the user intent is to zoom, zooming in when the user intends to zoom out, things like that. I hear MS Surface has the same issues.

    Mebbe in a bit. But for now, it's something that looks cool.

    • Microsoft launched Surface, its tabletop computer system, in the UK yesterday [today.com].

      People will use the touchscreen computer "the same way they have interacted with everyday items their entire lives," said Philippa Snare of Microsoft UK, "with hands and with gestures." Instead of a keyboard or mouse, the techno-table uses a 30-inch touch-sensitive screen that also reacts to objects placed on it. Photos are automatically downloaded from cameras or phones. A spilt cup of coffee causes the "I'm a PC" guy to appear

    • Re: (Score:2, Interesting)

      by minsk ( 805035 )

      Considering we're not even agreed on what gestures a user *should* do to zoom and resize things, there is definitely work to be done :)

      However, building these digital tabletops with a few hundred dollars and a projector makes them accessible to the dozens of research groups and hundreds (or thousands) of varied hackers who might have good ideas. Gestures are chronically tricky things to make natural and detect reliably, so we're going to need both the bazaar and the cathedrals chewing on it.

    • by zwei2stein ( 782480 ) on Wednesday April 08, 2009 @06:04AM (#27501295) Homepage

      Even if it works perfectly, it will not cut it.

        * You have to move your hands, without resting support. Thought mouse carpal tunnel is bad? Wait for days work with this tech

        * I have yet to see demo which looks, well, usefull. It looks like it is all about eye candy. They do a lot, but they do "random stuff" ... have photo pile, pick one at random, zoom, drag it to another pile at random. Impressive, but only if you don't think about what they do.

      It is more like mouse gestures which have very low user penetration for reason. (Why draw glyph if you can just press button?). Or voice command. Voice reconginition was perfected, but noone wants to use it (its slow, using it looks kinda dumb, it has no added value if you do not have disability).

      • by minsk ( 805035 )

        You have to move your hands, without resting support.

        That is actually one of the advantages of FTIR over things like Microsoft Surface* or traditional touch technologies. Because FTIR winds up detecting pressure, an application can easily differentiate between a finger resting on the surface, and one pressing down. Shape sensitivity comes into play as well, since a lightly resting arm is very different from a pressing finger.

        I agree that there is work to be done before applications are useful. However, I'

      • by Inda ( 580031 )
        I used to spend all day, every day, paring wood with a chisel. The first couple of weeks into my apprenticeship I had calluses on my hands, my arms ached, my feet were sore and my back felt like I'd been standing all day. After that I never felt sore again from a good days graft.

        These days I sit at a screen all day. My back aches, shoulder hurts and the pain in my fingers never seems to go away.

        These touch screen tables sound fantastic to me.
      • <quote>
        * You have to move your hands, without resting support. Thought mouse carpal tunnel is bad? Wait for days work with this tech
        </quote>

        Amazing that for years secretarial pools had absolutely NO incidences of RSI or carpal tunnel, until keyboards stopped looking like typewriters and people started relying on "resting support".

        There's no need for resting support - going eight hours of typing without it is no trouble if you have any modicum of wrist and arm strength.

        But like all
    • If a couple guys with consumer hardware managed 80%, I can't imagine that a decent team of engineers couldn't manage 100% with a custom build that clocks in at under $3000.

  • Bad LED design (Score:3, Interesting)

    by S-100 ( 1295224 ) on Wednesday April 08, 2009 @07:13AM (#27501569)
    In TFA they connect 8 LEDs in series directly to a 12V rail with no bias resistor(s). This is a bogus design and they should have known better.
    • by 2short ( 466733 )
      A typical IR led forward voltage is 1.5 volts, times 8 LEDs in series is 12V... You could slap a 1 ohm resistor in there if you're picky, but realistically, the way they did it is going to be totally fine.
      • by S-100 ( 1295224 )
        As you say, typical. However, if the forward voltage of the string is less than 12V, you get excessive current, and if you have more than 12V, you get diminished current. And maybe not coincidentally, the designers weren't satisfied with the IR output of their LED array.

        Proper practice is to leave enough margin so that the variation in forward drop of the string doesn't drastically change the current. This design fails in that regard, and it's not "fine" as you imply.
    • They are connected in series, the natural diode voltage drop and internal resistance across to them all puts current well with in an acceptable range. Since 1.5 * 8 = 12v, you need almost no internal resistance to keep the current within an acceptable range.

      From the article:

      Because the voltage drop across each LED is 1.5V, and weâ(TM)re using a 12V rail from a PC power supply to run them, we soldered the LEDs in chains of 8 (for a total 12V drop), then wired 12 chains up in parallel (leaving us with a

  • $350 for components is right (according to what I spent). However, buying a digital projector may bite a $700+ (the cheapest kind) chunk out of your wallet. Total cost: $1,050+ (Computer not included)

    A couple friends and I built a multi-touch for about $500 total [veuti.com] (plus $50 for a computer that our campus was scrapping.) We used one of those old-fashioned overhead projectors to do our work (and to save money). Not the ideal solution, but still works!
  • wiimote smartboard (Score:4, Informative)

    by Locklin ( 1074657 ) on Wednesday April 08, 2009 @07:37AM (#27501749) Homepage

    My wife built one of these "smartboard" like projects with a wii remote and a single infrared LED as per here [johnnylee.net]. Not exactly multitouch, but it works pretty well; calibrates quickly and you can write on a projected image anywhere. It uses the IR camera over bluetooth on the wii remote to track the LED "pen", and emulates a mouse for windows XP.

    I'll be watching for a Linux version of the software. It would be pretty sweet to run presentations off my Linux netbook and be able to draw on a regular projected screen.

    • by Locutus ( 9039 )

      I think there are already Linux versions of the laser controlled mouse. I remember seeing something where they projected images on the sides of buildings, calibrated the laser colors and for the size of the active region and then put on cool graphic shows from afar.

      try searching for "projector" "laser" and "computer" and you might find it. Otherwise, http://freshmeat.net/projects/lasertraq/ [freshmeat.net] is what I have found so far.

      LoB

  • by six11 ( 579 ) <(johnsogg) (at) (cmu.edu)> on Wednesday April 08, 2009 @08:07AM (#27502069) Homepage

    It looks like this article is implementing the system that Jeff Han made about a few years ago [nyu.edu] and famously presented at TED [youtube.com]. I'm glad to see this DIY article out there since it is getting lots of people interested in physical hacking, but I wish it would have referenced what came before. Here's the UIST paper:

    Han, J. Y. 2005. Low-cost multi-touch sensing through frustrated total internal reflection. In Proceedings of the 18th Annual ACM Symposium on User interface Software and Technology (Seattle, WA, USA, October 23 - 26, 2005). UIST '05. ACM, New York, NY, 115-118. DOI= http://doi.acm.org/10.1145/1095034.1095054 [acm.org]

  • Finally! I can now have my MCP desk from Tron!

  • http://johnnylee.net/projects/wii/ [johnnylee.net] There are several similar projects using the Nintendo Wii controller and IR LEDs
  • Even students can build one [rit.edu]!
  • Let me know when I can drive my car with a LCARS interface...
  • Does it run Crysis?
  • The vellum + silicone idea seems to lack durability, badly. Putting the display panel beneath the acrylic is one solution. Using a sheet of matte finish Lexan polycarbonate was suggested on the nuigroup website. That seems to solve the physical durability problem, but I have an additional question.

    I played a touch screen game and noticed that it was quite difficult to play because my finger couldn't slide over the surface easily. It would stick, rather than slide. I suspect the surface material of that

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