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Displays Hardware

Building a Cheap HUD for a Wearable Computer? 43

BJS asks: "I'm in the process of building a my first Wearable Computer. The last thing I have to do in it's construction is to make a heads up display system. I want to have something like an iScape2, a MicroOptical C3, or even this TekGear component, however I'm in collage so I can't afford to spend much. A friend of mine suggested that I find a broken camcorder online and mod the viewfinder. Dose anyone have any suggestions or experience in making their own HUDs? Does anyone know where I can find a broken camcorder or camcorder parts? And finally, what experiences have people had with making a wearable computer? Thank you, Slashdot!"
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Building a Cheap HUD for a Wearable Computer?

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  • by Anonymous Coward on Monday July 19, 2004 @08:48PM (#9743552)
    If that's what they're teaching you in "collage" you should get a refund of your tuition.
  • EyeTaps (Score:5, Informative)

    by QuantumG ( 50515 ) <> on Monday July 19, 2004 @08:53PM (#9743589) Homepage Journal

    Have a look at the book
    Intelligent Image Processing []. It describes how to make an EyeTap [] which is definitely what you want. To date these devices are not available for purchase :(
    • AAGGLL Re:EyeTaps (Score:2, Informative)

      by Anonymous Coward
      Have any of you mods even followed the link QuantumG posted? How is this informative. The original question was for an affordable, home-brew HUD for a wearable computer.

      How is ANYTHING on the EyeTap site "informative" on how to build such a display?

      I mean, yea, it's a cool concept, but none of it is pratical in helping joe-slashdot build his cheap HUD.

      Just cause some karma-whore has a link handy doesn't make it informative.
      • Re:AAGGLL Re:EyeTaps (Score:2, Informative)

        by Anonymous Coward
        OK, how about wearhow/node16.html? took me all of five (interesting and informative) minutes or so to get there. How long did you spend on the site before making your judgement?

        It's a good idea to do your homework before accusing others of not doing theirs...

      • No you need to READ THE BOOK.
  • Parts, and ideas... (Score:4, Informative)

    by rusty0101 ( 565565 ) on Monday July 19, 2004 @10:02PM (#9744162) Homepage Journal
    For the camcorder, go have a look around on e-bay. I would suggest looking for one of the old analog tape recorders, either full size vhs, or vhs-c. The reason for the full size vhs is that most of the connectors may be reasonably easy to work with. Also on the full size VHS models, it was not at all unusual to find them as 'sholder mount', with the 'viewer' movable from one side to the other, and thus more easily removed.

    As an alternative to e-bay, ask at a local camera store if they have some old analog tape camcorders that they are trying to get rid of. Let them know you are not concerned about the tape mechanism, or the lense for that matter.

    I have had a couple of camcorders like this that would have worked well. None available at the moment.

    The primary down side will be that most of these were black and white displays, so you will probably be limited to that as well.

    I do not know for sure, but most of these should work well as 'tv' monitors, if the wearable you are making has vhs out, it should feed directly, though you will probably need to find some sort of power source to feed it as well.

    As far as setting one up. I would recomend a system where you mount it to the side of a baseball cap, with the screen facing forward. Use a mirror to direct it 45 degrees across the front of your face, and a half mirror, or even a clear piece of plexiglass supported by the baseball cap to reflect a second time into your eye. The two 'mirrors' will reverse the video twice, so you will not need to find a way to reverse the video you are feeding to the screen.

    You may also want to try tinting the second mirror using some of the off the shelf sunglass tinting kits, till you find a good ballance between the screen and your surroundings.

    Yes, until you get a good setup, properly housed in a plastic case with a pair of headbands (over the top, and around the back) you are going to look like a geek playing around. Then again, it sounds like you are, so this should pose no shock to anyone.

  • by jabberjaw ( 683624 ) on Monday July 19, 2004 @10:07PM (#9744197)
    I suggest you start here. As far as displays are concerned, I cannot help you construct your own, however I have heard that the Private Eye which was produced by the now defunct Phoenix Group was a rather good monochrome display and relatively cheap as well.
  • by TheLink ( 130905 ) on Monday July 19, 2004 @10:09PM (#9744223) Journal
    I suggest you design the thing first, and build the software for such a computer as the first step. e.g. superPDA, wearable webapp server, instant messaging, etc. Don't worry about the hardware yet.

    I'm willing to bet that once wearable computers become affordable and decent looking enough to wear, at a few would be using a linux x86 platform - the folks in Taiwan will take care of that. So you can target linux on an x86 platform with 128MB RAM, 640x480, 400MHz CPU,2 to 4GB HDD, 10-20 concurrent users.

    Basically the specs of an old PC now, will be the spec of a wearable computer of today/tomorrow.

    The software is where you can make a difference to many people. I also suggest you consider the "wearable server" concept as well - that way your wearable computer can serve wearable computers.

    Building an actual custom wearable computer from scraps isn't going to be that great on a long term basis - it'll be like the Apple I days. A few ppl will think it's cool, but that's about it- and evolutionary dead end, and very "been there done that".

    The difference is software. I suggest including support for browsers, because webservers are almost everywhere. Then you'll be able to use your wearable to do things like turn lights on/off, set airconditioner temps etc, all wirelessly. And you'd be able to IM your friends wirelessly too.

    Virtual telepathy and telekinesis.

    You probably should leave the video/image/audio recognition stuff to others. But that'll be useful too.
    • You're right that software is the place to make a difference...

      but what good is software that you can't test, because you don't have a wearable device? The place software is going to make the biggest difference in wearable computing is in the user interface, and that absolutely must be tested without using a keyboard and mouse setup, otherwise you're writing desktop software.
      • Don't get your logic.

        Just restrict your UI to using fewer inputs with a layer of abstraction - e.g. a numeric keypad (or even just arrow keys and two other keys). Keys can be remapped. There are even reasonable analogues to mouse input available - there's stuff which detects the position of the eyes etc, you can cater for those without buying or building those.

        You just have to clear on what your objective is- if you want a computer you can wear, just strap on your cellphone or nokia ngage.

        If you want som
      • I know the HUD is cool and all, but given the limits of today's affordable technology, a forearm mounted display would be more practical. You could probably do that with an off the shelf PDA and network it to another wearble computer if you needed more CPU or storage. Hell, some PDAs are small and light enough to clip onto a hat. Get maybe something like a Sony UX40 for $500. It's a tiny clamshell PalmOS PDA, weighs 6 oz and has a 640x480 camera. Clip it onto some headgear and tada! instant HUD. If you need
    • by craXORjack ( 726120 ) on Tuesday July 20, 2004 @01:04AM (#9745532)
      When I built my wearable computer to impress people at the StarTrek convention I thought I would do the easy part first too, but oh what a mistake that was. I started out with the mobo sewn into the back of a nylon unitard. Have you ever thought what it would be like to have hundreds of solder joints scratching your back with every step you take? Imagine a gentle backrub from Freddie Krueger. Blood was running down my tailbone like sweat into the asscrack of a refridgerator repairman. Of course it had to go somewhere and soaked through the nylon material mixing with the stains caused by my friends feeding me chocolate exlax the night before under the guise that it was a Hershey's bar for diabetics.

      Input devices are important of course and what I ended up doing was to split a keyboard in two and sew each half into the front of my unitard just below nipple level and extending downwards toward my waist. The mouse had to be a trackball since it needed to be stationary, so I put it in the only place easily accessible to both hands but still out of the way of the keyboard which happened to make it appear much like a codpiece. The numeric keypad was situated just below my navel which worked well for Quake III because of the easy accessability between the keypad and the trackball/codpiece. An LCD screen is a must for the display due to the weight factor of regular CRT tubes. I used an NTSC output from my video card to go to a 5" LCD from an SUV's backseat television. Then I painted it to look like a Beijoran pleasure crystal.

      Now power wasn't as much of a problem as you might think. All I needed was a 5 and 12 volt DC source. No inverter, none of that AC bullhockey. Of course, using Kirchoff's laws I was able to use a single 12 volt car battery to cover both bases. The battery didn't work to well mounted on my back. It kept sliding down and really stretching out the material of my betazoid uniform, so I had to mount it in a sling hanging between my legs. While it was the best place for it, it was rather uncomfortable walking because it tended to swing wildly and bash me in either knee.

      I soon replaced the single 12 volt car battery with two 6 volt lantern batteries wired in series. They didn't last as long but were much lighter and didn't stretch out the crotch of my purple unitard nearly as much. They also didn't look quite so out of place, although unnaturally large. However, an auditorium full of Star Trekkers can become quite warm and perspiration generally contains electrolytes in the form of salt which then conducts electricity very well, as you know if you've ever put your tongue on the terminals of a 9 volt battery. Needless to say, I was unable to sit during the keynote speech and sometimes would jump around a bit for no apparent reason which would have looked very strange to the other convention goers if I had dressed as a vulcan like I originally planned.

      The hard drive was very loud until I dampened the vibrations by duct taping it against my left butt cheek. One improvement I would like to make just for the sake of balance is to add a second drive on the right side and mirror the two. And I should add some sort of heat sink to them because they get hot! Speaking of heat sinks, I had the one for the CPU sticking out of my back almost like a shark fin. I think it got extremely hot because while waiting for Capt. Kirk's autograph I backed up a little and heard a sizzle and a scream. When I turned around there was a klingon warrior in tears on the floor licking and blowing on his forearm.

      Anyway, it really is important to build your hardware first because a lot of people mistook me for a borg who used to be a betazoid.
  • Ebay, yard sales, used electronics shops, hamfests, dumpsters... That part shouldn't be even remotely difficult.
  • There were some crappy tiger handheld games that had a hud. It was limited to red on the transparent grey though. Dunno if it'd work at all.
    • I remember those. There wasn't a general purpose hud at all, but basically a little cartridge snapped into a headband. The cartridge had an LCD with predone graphics just like the normal tiger games.

      Maybe he could gut a virtual boy and get headaches?
  • Saving an LCD screen (Score:2, Informative)

    by Cyberop5 ( 520141 ) *
    There was an ask slashdot article about saving LCD screen. People ask all the time about how useful an old device, like a laptop or pda is, if the hardware fails, but the screen is still good.

    To summarize the results of the story, LCD screens are worthless without a proper controller chip specific to that display. And these controller chips arn't cheap or easy to find.

    Unfortunatly, I couldn't find it on google.
  • by howman ( 170527 ) on Tuesday July 20, 2004 @01:47AM (#9745731)
    Did you consider some form of projection instead of having to mount a heavy (relatively) screen from a boom in front of the eye, you can mount a fairly light relfective surface and bounce the image off it into the eye.
    In this form you can use a fiber optic setup to the side of the face and project the image through a lens off the 'mirror' to the eye. At least you will not be too limited by screen resolution as such. The screen can be something as big as a laptop as long as the lens that picks up the image and transfers it to one end of the fiber does a decent job. On the other end a nice bubble lens should spread the image out nicely for you.
    I messed about in my last year of design with a wearable system including a docking station for data transfer. It was purely a form study and had no working internals, but it was based on the reflection of image to the eye.
    You can take a look at it Here []
    please excuse the mess of the rest of my site. Haven't had time since graduation to rebuild it.
  • I have often thought of doing somethng similar to this myself and to be honest I have my eye on a full colour one of these [] for a while with similar intent.
  • Remember the trade-off: resolution vs. field-of-view (FOV) - you can max one or the other, but always at the expense of the other one (unless you have money to burn for Kaiser Electro-Optics stuff).

    Now, since you are doing a wearable, and not an immersive VR rig, you are going to want detail (resolution), and not immersion (so FOV is not as important). However, you aren't going to be able to get that detail cheaply. You are going to want a minimum of 800x600, 20-30 degree horizontal FOV (and it will suck ba

  • I would say that any form of a screen will always have problems with focusing and the end users eye. I would think the only way around this is to have a liquid crystal display maybe at eyebrow level with an LED projecting the image onto the users cornea. I'm surprised I haven't seen anything like this...but it could all be done from the brim of a baseball cap.
  • Hey I have a Sony Clie NZ90/U that failed the in the sink full of dishes test.

    I doubt you will find a better screen anywhere else. E-mail me and we'll set something up.

    Linux User Alliance - Washington
    (Just starting out)
  • it was wonderful, no patents either, fantastic!

If it's not in the computer, it doesn't exist.