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The Mechanics of Motion Sensing 119

Dr. Eggman writes, "The AP has a short technology piece on the mechanics that go into the motion-sensing capabilities of the Wii and PS3 controllers. It also details some of the past uses of the technology and gives a nice overview of just how far the technology has come from the earliest missile-guidance sensor equipment."
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The Mechanics of Motion Sensing

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  • Interesting. (Score:4, Interesting)

    by Mendak Jemuna ( 998832 ) on Monday November 20, 2006 @05:24PM (#16920986)
    Interesting, but I have one question. Do the silicon springs recalibrate every so often, or will they wear out and break? My old N64 controller did this.
  • by American AC in Paris ( 230456 ) on Monday November 20, 2006 @05:28PM (#16921042) Homepage
    It also details some of the past uses of the technology and gives a nice overview of just how far the technology has come from the earliest missile-guidance sensor equipment."

    See, I think we should re-incorporate early guidance systems into modern-day game controllers.

    I mean, think about it: game controllers with trained pigeons in 'em! That'd take force-feedback to a whole new level!

    • by krell ( 896769 ) on Monday November 20, 2006 @05:37PM (#16921194) Journal
      "I mean, think about it: game controllers with trained pigeons in 'em! That'd take force-feedback to a whole new level!"

      You'll need a speaker-hole so that the birds in the controllers could communicate with the miniature pterodactyl inside the console box that actually pulls the strings and sticks to make the game work.
    • by EmbeddedJanitor ( 597831 ) on Monday November 20, 2006 @07:56PM (#16923116)
      Sure, a guidance system will have accelerometers, but by far the more important part is the gyro. The Wii does not have a gyro. While silicon gyros do exist, they're still relatively large and expensive.
    • by rantingkitten ( 938138 ) <kitten@mirrorshades . o rg> on Tuesday November 21, 2006 @09:32PM (#16943506) Homepage
      The missile knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the missile from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't.
  • by Joe The Dragon ( 967727 ) on Monday November 20, 2006 @05:34PM (#16921146)
    Globalvr's new Ultrapin features Globalvr's Patent Pending U-Shock Board Which allows players to interact with the cabinet for a totally realistic pinball experience. You can BUMP and NUDGE the cabinet to affect the ball in play - just like real pinball
    http://www.globalvr.com/products_ultrapin_intro.ht ml [globalvr.com]
    • by Duggeek ( 1015705 ) on Monday November 20, 2006 @05:54PM (#16921454) Homepage Journal

      I know where you can BUMP and NUDGE to affect the gameplay... an actual PINBALL game!!!

      It's always irked me to see some hand-held P.O.S. that touts "realistic pinball action". (...action ...action ...ction ...tion)

      If I want to play pinball, I'll play pinball.

      However, if I want to ride a dragon... well I can't really do that now, can I?

      THAT is why the new controllers are so incredible; they give a new, visceral edge to creative gaming... rather than try to "come full circle" with a gaming platform that's already been around- and around- and around again.

      I'll grant you that someone will ultimately make a pinball-sized cabinet with two HD screens on it that uses the very implementation you describe. It will be neat, but it won't be real.

      You'll get a two-fold "wow factor" out of me when you can manufacture a true-physics pinball game that truly does something no other pinball game has done before. (Remember the face in "Fun House"? Now, that was some awesome innovation, back in its day.)

  • Other applications (Score:4, Interesting)

    by inKubus ( 199753 ) on Monday November 20, 2006 @05:36PM (#16921166) Homepage Journal
    It would be cool to incorporate this type of controller into a portable device. You could have portable laser-tag like games with real-time mapping, or incorporate some type of ball and it automatically keeps score and records the game. You could have "operations" players indoors that have some different role (view the maps, for instance, and direct the players)

    With networking and GIS in a portable device, it's almost necessary to have new interfaces to use all the new space it knows about. In gaming it's the most fun but these types of thing could be used in more professional ways also.

    • by LordPhantom ( 763327 ) on Monday November 20, 2006 @05:37PM (#16921196)
      Laser Tag with a doom-style map on the gun/on a wristband?
      Brilliant!
      Then again, it also makes a great set for a horror movie (big arena, psychopath with a real gun, etc, etc *groan*)
    • by MankyD ( 567984 ) on Monday November 20, 2006 @05:45PM (#16921322) Homepage
      It would be cool to incorporate this type of controller into a portable device. You could have portable laser-tag like games with real-time mapping
      While it would definitely be cool, you can't really use accelerometers as location devices. Accelerometers and, to a lesser degree, odometers both do a pretty terrible job of keeping track of where an object is located. That's why the Wii also includes a sensor bar.

      They'll generally give you pretty good readings for a single movement, like 'the object just moved 1 meter forwards', however as soon as you turn or travel a long distance, they suffer from drifting, skidding, and general measurement errors.

      A different sort of tech would be needed for mapping. You can do some research into Robotics, such Markov Localization, for some more information. GPS and related techs are better for real time location reporting.
      • by DerekLyons ( 302214 ) <fairwater.gmail@com> on Monday November 20, 2006 @09:13PM (#16923852) Homepage
        It would be cool to incorporate this type of controller into a portable device. You could have portable laser-tag like games with real-time mapping

        While it would definitely be cool, you can't really use accelerometers as location devices.

        I guess then all those inertial guidance and navigation systems the military has deployed don't really work then? (Or, IOW, you are incorrect. Considerably.) Accelerometers by themselves can't be used as location devices - but if you use a clock and a computer and integrate acceleration over time..., they work just dandy. (For real-world use, you need a stable platform (I.E. gyros) as well.)
         
         
        They'll generally give you pretty good readings for a single movement, like 'the object just moved 1 meter forwards', however as soon as you turn or travel a long distance, they suffer from drifting, skidding, and general measurement errors.

        That's true of odometers, but again with accelerometers it's just a matter of engineering your system properly. (The USAF equips its fighters with inertial navigation systems - and they remain accurate through a bloody dogfight!.)
         
         
        A different sort of tech would be needed for mapping. You can do some research into Robotics, such Markov Localization, for some more information. GPS and related techs are better for real time location reporting.

        I suggest that you do some research on inertial navigation and inertial guidance - because what you say is true at the level of the casual gamer, its not true (as you imply) of accelerometers in general.
        • by dcam ( 615646 ) <david@@@uberconcept...com> on Monday November 20, 2006 @09:33PM (#16924026) Homepage
          They'll generally give you pretty good readings for a single movement, like 'the object just moved 1 meter forwards', however as soon as you turn or travel a long distance, they suffer from drifting, skidding, and general measurement errors.


          That's true of odometers, but again with accelerometers it's just a matter of engineering your system properly. (The USAF equips its fighters with inertial navigation systems - and they remain accurate through a bloody dogfight!.)


          No the OP was right. It is also true of accelerometers. And the fact that they are measuring data during a dog fight it irrelevant, it is the amount of time/distance they are measuring data. They include a random walk error that is small for a short time/distance, but compounds over time.

          You will find that typically this is corrected with something that can give an absolute position (eg GPS). Your absolute positioning device typically also has a know error. The values from both of these are generally married using a Kalman Filter or Extented Kalmna Filter.

          I've written code to do this in the past.

          I suggest that you do some research on inertial navigation and inertial guidance - because what you say is true at the level of the casual gamer, its not true (as you imply) of accelerometers in general.


          I suggest that you also do some. 4 years of Mechatronic Engineering would be good start.
          • by big tex ( 15917 ) <torsionality.gmail@com> on Monday November 20, 2006 @10:08PM (#16924294)
            4 years of Mechatronic Engineering would be good start.

            OK, you made that up.
            It sounds like you design robotic enemies for Godzilla.

          • by Animats ( 122034 ) on Tuesday November 21, 2006 @02:39AM (#16926272) Homepage

            Low-end solid state accelerometers aren't that good. Accuracy is only 1% or so. You can't really get position by integrating them twice; you'll get huge amounts of drift as false velocity builds up. If you have some external reality check, even an odometer, you do much better.

            Low-end rate gyros aren't that good either. We did badly in the DARPA Grand Challenge because our heading measurements were about +-3 degrees off, which was enough to mess up the maps being built up from the laser rangefinder. We should have spent the $20,000 for a fibre optic rate gyro, like the more successful teams. (Today, they're down to around $2000-$3000).

            • by dcam ( 615646 ) <david@@@uberconcept...com> on Tuesday November 21, 2006 @05:02AM (#16927556) Homepage
              Cool. It looks like the ACFR, where I did my BE, has been involved [usyd.edu.au] in DARPA. I haven't been in contact with any of them since I left uni, so I don't know what the project is. It isn't surprising that UTS is involved, the guy who heads UTS's Mechatronics dept is a former ACFR man.

              The ACFR has for some time had a bit to do with vehicles. The've used a UTE as a testing platform for a while. Most of their work has been to do with industry, mining trucks and straddle carriers. They've done some solid work though.
          • by DerekLyons ( 302214 ) <fairwater.gmail@com> on Tuesday November 21, 2006 @05:22AM (#16927712) Homepage
            No the OP was right. It is also true of accelerometers. And the fact that they are measuring data during a dog fight it irrelevant, it is the amount of time/distance they are measuring data. They include a random walk error that is small for a short time/distance, but compounds over time. You will find that typically this is corrected with something that can give an absolute position (eg GPS). Your absolute positioning device typically also has a know error. The values from both of these are generally married using a Kalman Filter or Extented Kalmna Filter.

            Here's a free clue for you, since you seem to need one so badly. Try actually reading my message and think real hard on what the words means. (Hint: Concentrate on the terms "engineering your system properly". What do you think they means?)
             
             
            I suggest that you also do some. 4 years of Mechatronic Engineering would be good start.

            I've got more than sufficient education on inertial systems, when you get out of high school, look me up.
            • by dcam ( 615646 ) <david@@@uberconcept...com> on Tuesday November 21, 2006 @05:57AM (#16927938) Homepage
              Haha thanks for the lesson. Love the ad hominem attack.

              I've got more than sufficient education on inertial systems...

              Clearly not. ...when you get out of high school, look me up

              Gee, somehow I forgot to look up up 10 years ago, how remiss of me.

              Ok I'll make it simple for you, so that with some high school physics and some elementary logic you can understand.

              Lets being by assumimg you aren't an idiot and use SI units.

              All sensors have some error. So lets take an example. I have a accelerometer, with a 0.1 m/s/s error that isn't moving (to make life simpler). To get a speed you need to integrate (multiply by time), to get position you need to integrate twice.

              Lets also say you are taking measurements every second (slow I know, but this is an example and I want it to be simple).

              With that error after one measurement you know both speed and position with an accuracy of 0.1 m/s and 0.1m respectively (+/-), over 1000 measurements, you know your speed and position to within 100 m/s and 100 m respectively (+/-). That is pretty large.

              So say we introduce something that has a large error (like GPS), but is give absolute measurements like say GPS or an odomoter. GPS has an error (now that the noise is switched off) of +/-10m. Well gee over 1000 seconds that is pretty darn good when compared 100m over 1000 seconds. On the other hand over 1 second that is pretty bad. So you use a Kalmal Filter to combine the values. This corrects the error introduced by the Interial Navigation System (INS).

              No matter how well "engineered" your system is you cannot escape the fact that interial sensors (gyros are Inertial too BTW) contain error (like all sensors do), but in the case of INS, the error compounds. You may be able to engineer a system so that the compound error is acceptable, but you cannot escape the compound error. So in essence, you don't know what you are talking about. Why don't you just pull your head and admit that you were wrong?
          • by glindsey ( 73730 ) on Tuesday November 21, 2006 @10:38AM (#16930210)
            Dude, Mechatron was my favorite Transformer!

            Seriously, though, I had no idea "mechatronic engineering" was a discipline. Fascinating...
            • by dcam ( 615646 ) <david@@@uberconcept...com> on Tuesday November 21, 2006 @11:22AM (#16930958) Homepage
              When I started my undergraduate degree (1997) it was kind of new. It had been started only 4 years before. At that point you began doing Mechanical Engineering and after 1 year had the choice of transferring into to Mechatronics, ie there was no first year for mechatronics. For the second year, it was identical to Mech Eng, except you dropped Materials for a dedicated Mechatronics subject. After that it tended to diverge quite a bit.

              Now it is a completely separate degree from the first year. It also needs better marks to get into and tends to attract brighter students.

              Effectively it still has a lot in common with Mechanical Engineering, but you drop a lot of materials, fluid flow and thermodynamics in favour of more Electrical Engineering. You also tend to do far more programming. You could get through a Mech Eng degree while being uncomfortable with coding. Not so with Mechatronics.

              Perhaps the kind of degree it is is best illustrated by a couple of the final year subjects. We were given a 16 bit intel microprocessor on an evaluation board and given a number of tasks to program in assembler, stuff like generating light patterns, talking down the serial port etc. Then to redo the projects in C. All of this would involve handling interrupts and working with the hardware of the chip to handle signals in an out. As a final project we were required to bring this together and hook up:
              - a scale running into an amp
              - LCD screen
              - keypad
              And build an acual scale. This is harder than it sounds. Then we needed to build an interface in windows on C, talking to the "scale" over the serial port.

              For the other subject we had a motor with I think an rotary positioning sensor. This spoke to a PC over, you guessed it, a serial port. You were required to build a number of differnt control systems to control the rotation of the motor (closed loop, open loop etc). This included working with an interrupt library and a graphics library to generate graphs representing the state of the motor over time.

              It was a good degree, and the lecturers really knew their stuff. The place had some pretty strong links to industry, which is generally a good thing in engineering.
    • by justkarl ( 775856 ) * on Monday November 20, 2006 @06:04PM (#16921622)
      That makes sense. Dosen't Wii come with wireless networking built-in? Or am I confusing it with the PS3?
    • by AcidLacedPenguiN ( 835552 ) on Tuesday November 21, 2006 @08:53AM (#16929058)
      Most importantly, you could have real time weapon switching!!!
  • Very odd (Score:2, Interesting)

    by also-rr ( 980579 ) on Monday November 20, 2006 @05:39PM (#16921220) Homepage
    Given the 10+ year development and 20+ year use lifecycles of military equipment it's surprising to see consumer gear _behind_ military tech.

    The main reasons for this, of course, are obvious. It's not often that your games console needs the same provable failsafes as a weapon of mass destruction and equally it doesn't cost £10m a unit (launch day eBayed PS3 excepted) so replacing it within a short timeframe isn't going to give you a massive budget deficit.
    • Re:Very odd (Score:3, Insightful)

      by the.Ceph ( 863988 ) on Monday November 20, 2006 @06:14PM (#16921790)
      Consumer gear is often behind military tech. Perhaps you have heard of velcro, or GPS, or the internet.
    • Re:Very odd (Score:3, Interesting)

      by DerekLyons ( 302214 ) <fairwater.gmail@com> on Monday November 20, 2006 @06:26PM (#16921958) Homepage
      Given the 10+ year development and 20+ year use lifecycles of military equipment it's surprising to see consumer gear _behind_ military tech.

      It's hard to actually say who is ahead or behind, partly because tech in the real world isn't a linear scale (like it is in various games), partly because the military deploys such a wide variety of accelerometers. The ones used in, say the Trident-II's MK6 guidance, are certainly much larger than these (about the size of a film can) and are 'old style' (asymmetrical floats in fluid) - they are also much more robust and less sensitive to vibration. (The accelerometers in the MK6 Guidance System are also a neat illustration of the nonlinearity of tech in the real world. It uses an advanced form of the same type used in Polaris - because they are more sensitive and accurate than an advanced form of the (quite advanced in and of themselves) ones used in the MK5 guidance of the Trident-I.)
      • by Anonymous Coward on Monday November 20, 2006 @07:08PM (#16922508)
        As you say, it really does depend on what you are talking about. About ten year ago I first started working with an old gravity meter from a Navy sub. They had upgraded to a newer generation. This meter was small (about the size of a large coffee mug). If you moved it from the floor to your desk, the at-rest readings would drop, because it was further from the earth. You can't do stuff like that with these cheap accelerometers.
      • by grammar fascist ( 239789 ) on Monday November 20, 2006 @07:51PM (#16923046) Homepage
        The ones used in, say the Trident-II's MK6 guidance, are certainly much larger than these (about the size of a film can) and are 'old style' (asymmetrical floats in fluid) - they are also much more robust and less sensitive to vibration.

        Now that's interesting. Is it the fluid that makes them less sensitive to vibration? (It seems like it would be.) In effect, the fluid would be working as a low-pass filter, so only large movements would be detected.

        Does the Wii-mote get around the vibration issue by doing the same thing in software? It seems like a Kalman filter would work more or less perfectly, and those are very simple to implement.
        • by DerekLyons ( 302214 ) <fairwater.gmail@com> on Monday November 20, 2006 @08:58PM (#16923742) Homepage
          The ones used in, say the Trident-II's MK6 guidance, are certainly much larger than these (about the size of a film can) and are 'old style' (asymmetrical floats in fluid) - they are also much more robust and less sensitive to vibration.

          Now that's interesting. Is it the fluid that makes them less sensitive to vibration? (It seems like it would be.) In effect, the fluid would be working as a low-pass filter, so only large movements would be detected.

          It's partly the fluid, partly the suspension system (the float is partly suspended by it's bouyancy, partly by a magnetic field).
           
           
          Does the Wii-mote get around the vibration issue by doing the same thing in software? It seems like a Kalman filter would work more or less perfectly, and those are very simple to implement.

          I have no idea how (or even if) the Wii-mote isolates vibration. I'd say they want a certain amount of vibration to filter through - as that could determine if player 'x' hooks instead of slices. Tuneable vibration isolation can also be used to set the difficulty level - less isolation as the level increases.
  • by xxxJonBoyxxx ( 565205 ) on Monday November 20, 2006 @05:42PM (#16921274)
    I thought the "snare" was the first motion-activated weapon. Or was it the "covered pit"?
  • by Jawood ( 1024129 ) on Monday November 20, 2006 @05:44PM (#16921304) Journal
    game where I do the moves (gloves and boots that sense when I'm punching and kicking!), I would buy that in a heartbeat! It would be an awesome workout!!!

    Think about it. Or have something like Worf's workout from ST:NG! That be sooo cool!

    Yeah, I've used those exercise bikes with the screen - it shows you racing with others. It's ok.

  • MEMS (Score:5, Informative)

    by Mike1024 ( 184871 ) on Monday November 20, 2006 @05:52PM (#16921418)
    A good picture of a two-axis accelerometer can be seen here: http://users.wpi.edu/~cfurlong/me-593Mech.html [wpi.edu] (second picture down). Sensing is usually performed by capacitive combs, structures which act as capacitors, with their capacitance varying with displacement.

    MEMS accelerometers have dropped in price in recent years because there's a big market: the automotive sector. A typical new car needs two accelerometers, one for the traction control system measuring roughly plus-or-minus 2 to 4g, and one for airbag deployment measuring more like 50g.

    Two big manufacturers are Analog Devices [analog.com] and ST Microelectronics [st.com], though others exist.

    The high demand of the automotive sector has driven prices right down; sensors which would have cost hundreds of dollars in the past can now be purchased in bulk for less than $4. In fact, you could order one right now; component retailers [digikey.com] will sell you one for less than $15.
    • by Magnusite ( 526038 ) on Monday November 20, 2006 @07:07PM (#16922480)
      I thought nintendo was supposed to be using the Gyration miniature gyroscopes. Link here [gamecubicle.com]
      • by Mike1024 ( 184871 ) on Monday November 20, 2006 @08:01PM (#16923196)
        I thought nintendo was supposed to be using the Gyration miniature gyroscopes.

        Analog devices make MEMS gyroscopes [analog.com] too. Nintendo could have gone to any vendor, of course.

        There's not as much market for gyroscopes as for accelerometers, hence they're more expensive. Sometimes they can be found in car satellite navigation systems as a way of increasing resolution above what GPS can offer - ever heard of a roundabout [google.co.uk]? They're useful there - and there are other applications as well. Games consoles, for instance!

        If you read the article, it says:

        Analog Devices Inc. of Norwood, Massachusetts makes a similar chip, which goes into the main Wii controller, the stick-like Wii Remote. According to Analog Devices, ST's chip is used in the auxiliary Freestyle controller (popularly known as the "Nunchuck") that connects to the larger controller for some games. ST said it was not allowed to say where exactly its chip is used.

        Sony Corp.'s "Sixaxis" controller for the PS3 also has an accelerometer. The six axises the name refers to are the three dimensions of space, plus three axises of spin. The company hasn't revealed who makes the chip.
        • by Kadin2048 ( 468275 ) <slashdot,kadin&xoxy,net> on Tuesday November 21, 2006 @01:56AM (#16925874) Homepage Journal
          Not that it's a particularly big market or anything, but MEMS gyros are also used in R/C helicopters as a stabilization/pilot-assist device. They keep the tail of the helicopter pointed in basically the same direction, by adjusting the pitch of the tail rotor dynamically. Without a gyro, the pilot has to constantly make this adjustment in real-time, or risk putting the heli into a spin.

          For somewhere around $90-120, you can run out today and get yourself a single-axis "Silicon Micro Machine" gyro that's set up to output a signal to control a standard hobby position servo. The gain on most of them is adjustable, but I assume that you could set it up so that the magnitude of the signal was basically proportional to the deviation from a particular position. Might be a little easier for a hobbyist than going the total DIY route from raw parts.
  • by eno2001 ( 527078 ) on Monday November 20, 2006 @05:53PM (#16921440) Homepage Journal
    Typically it's in my pants while watching Pamela Anderson's sweater meat bounce around like a raver on extacy. Come on! Laugh! It's funny! You KNOW you WANT to.
  • Oh CNN (Score:4, Insightful)

    by bunions ( 970377 ) on Monday November 20, 2006 @05:56PM (#16921484)

    Sony Corp.'s "Sixaxis" controller for the PS3 also has an accelerometer. The six axises the name refers to are the three dimensions of space, plus three axises of spin. The company hasn't revealed who makes the chip.


    Axises?? How can you mispluralize one of the most entertaining plurals around? Axes, dammit.
  • Who was first? (Score:5, Interesting)

    by Glacial Wanderer ( 962045 ) on Monday November 20, 2006 @06:04PM (#16921618) Homepage
    The Nintendo Wii Remote one-ups the Sony controller by including an infrared camera.

    I think they meant to say: The Sony controller dumbed down the Wii Remote by excluding the infrared camera.
  • datasheet (Score:3, Informative)

    by tonigonenstein ( 912347 ) on Monday November 20, 2006 @06:13PM (#16921770)
    Right from the source: http://www.st.com/stonline/products/literature/ds/ 11115.pdf [st.com] These things are not exactly new. They are used in the automotive sector, or for "stabilizers" in camcorders.
  • by PhysSurfer ( 872187 ) on Monday November 20, 2006 @06:22PM (#16921890) Homepage
    So what happens if in a game if you point the camera away from the sensor bar? For example, in tennis when you swing the remote I would imagine the camera would lose track of the bar at some point during the swing. How does the system know if you're swinging the racket in the right plane? (Or does it even know?)
  • by abscr ( 645403 ) on Monday November 20, 2006 @06:27PM (#16921970)
    so I can finally keep Mario from falling down the bottomless pit by jerking the controller above my head?
  • by Jeff1946 ( 944062 ) on Monday November 20, 2006 @06:53PM (#16922322) Journal
    A few years ago I went to a talk on making a position sensor for fire fighters. Remember GPS works poorly inside buildings. The idea was to use microaccelorometers to track the position of the firefighter inside a building. The author mentioned they placed the device in the heel of the boot. This way they could sense when the motion was stopped so they could rezero the accelerometers. Eliminating zero drift has always been a problem with guidance systems.
  • by xenocide2 ( 231786 ) on Monday November 20, 2006 @06:54PM (#16922334) Homepage
    Who decided that things that measure tilt should be called "accelerometers"? They can be used to measure acceleration, but thats not what the sensor directly measures!
  • by Mushdot ( 943219 ) on Monday November 20, 2006 @07:05PM (#16922454) Homepage
    "Put me down Steve"
  • by skeldoy ( 831110 ) on Monday November 20, 2006 @10:23PM (#16924410) Homepage
    I think this is another ploy in the american plan to monitor the politically divergant opinions of europeans and other non-americans. :P
  • by bVork ( 772426 ) <{rpantella+slashdot} {at} {gmail.com}> on Tuesday November 21, 2006 @07:01AM (#16928320)
    I found this absolutely fascinating video that shows exactly how the sensor bar detects the Wiimote's position - and how you can possibly hack up your own "sensor bar": http://www.youtube.com/watch?v=JTGSkYRDpWY [youtube.com]
  • by asjk ( 569258 ) * on Tuesday November 21, 2006 @08:36AM (#16928936)
    The Nintendo Wii Remote one-ups the Sony controller by including an infrared camera. It picks up signals from a sensor bar the owner attaches to the television set. This enables the remote to "know" where it is in relation to the screen, so the player can use the controller to point to things on the screen -- a useful feature in shooting games (and a lot of games are shooting games).
    Here's another interesting piece of information. According to this source [wordpress.com], the sensor bar is not even communicating with the console! I guess it's just shooting out a reference point for the remote, to act like a virtual mousepad to the remote's mouse?

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