Baseball cap head-up display

For a while now I’ve been interested in augmented reality. Working in the field of geospatial science, I’m always looking for better ways to present location-based information, and augmented reality shows a lot of potential. Plus I’m a big fan of science fiction, and AR interfaces have featured in some of my favourite movies – The Terminator (1984) and Robocop (1987) – as well as some of my favourite books – Neuromancer (1984) and Virtual Light (1993).

But although the idea has been a part of popular culture for nearly three decades, the reality has been disappointing. Head-up displays have long been used by military pilots, and are starting to be deployed in luxury cars, but personal units have been gimmicks at best. There have been augmented reality motorcycle helmets and ski goggles, and Google is rumoured to be releasing Google Glasses by the end of the year, but none of them provide a full field-of-view display. This limits their ability to provide fully immersive graphics or even to play movies.

So I decided to build my own. How hard could it be? Not very, it turns out.

I put one together using a smartphone (an HTC Desire Z), a baseball cap, a couple of fresnel lenses, a plastic mirror, some mirrored film from an iPhone screen protector, and assorted office supplies. The smartphone is held in place with a rubber band, and whatever appears on the screen is displayed in the wearer’s field of view. The fresnel lenses are there to push the screen’s perceived distance out to about 50cm, otherwise you’d get serious eye strain.

It works pretty well. Lining up the reflective screens is fiddly, so future designs should lock them in place. They also don’t work too well in direct sunlight, since the mirrored film isn’t very reflective, so the reflected light from the screen is pretty dim. Ideally you’d want some sort of mirror that automatically adjusts to the ambient light, and you’d want the smartphone screen to dim at night, but these work fairly well indoors.

The image quality from fresnel lenses is mediocre at the best of times, but I was forced to use a pair of these in series to get the focal length short enough. As you’d expect, that creates a fair bit of distortion at the periphery, especially since the mounting isn’t very rigid. It would be better to use a single, rigid lens, with just the right focal length – preferably a bit shorter than my current setup, since the 50cm screen distance is a bit too close to be comfortable. I suspect that the best solution would be to do away the fresnel lenses altogether and use curved mirror-tinted surfaces to display the image, but that’s beyond my design and manufacturing ability.

My HTC is fairly heavy with its slide-out keyboard, and with all that weight on the end of the bill you need to put the cap on nice and tight to keep it in place. Something a bit lighter, like an iPhone, would probably be more comfortable.

But it works as a proof-of-concept. It’s pretty cool to run Wikitude with some duct tape over the camera lens, and see all the points of interest rotate around as you turn your head. Now all it needs is some custom software so I can see where I’m going while I read my e-mail.

Taking pictures of an inside view of the display was tricky. In the end, I turned the cap upside-down, stuffed a t-shirt in it, and rested a manual-focus camera on top. The resulting pictures were taken through an upside-down display, but you get the idea.

77 Comments on “Baseball cap head-up display”

  1. Nightweave says:

    Nice, I found your website on Slashdot. Glad you did this, keep up the project and the good work.

  2. vernes says:

    You are allowed to photoshop the rendered view with photo’s to recreate the view you saw.
    That way, we as the readers can have a better picture of how it looks like when used.

  3. sedeer says:

    That’s a great DIY project! I guess the only major drawback is that you can’t control the phone while using it as a HUD. Is there any kind of voice control app for Android? Maybe you could use that with a microphone and earpiece…? At the very least that might let you launch and quit apps or answer calls — I can imagine this working quite nicely with a VOIP/video app, too.

  4. Rob says:

    Factastic. Made my day reading this. I now want to build one myself. Where did I put that baseball cap.

    Got here via slashdot.


  5. twittech says:

    So it turns out email is the killer app for a HUD. Priceless.

  6. Philipp says:

    Very cool stuff!!

    Greetings from Austria!
    Your Wikitude Team

  7. Harland says:

    Ugh! Redneck to the max. Leave it to the hillbillies to “invent” a useless item and duct tape it to a gimme cap. Shouldn’t there be a welder and American piss-beer involved?

  8. […] way to get that Terminator-like augmented reality experience, you’ll want to check out this hacked up HMD baseball cap from Melbourne area maker Matt […]

  9. […] easy way to get that Terminator-like augmented reality experience, you’ll want to check out this hacked up HMD baseball cap from Melbourne area maker Matt […]

  10. Igor says:

    And I would like to repeat this project (dont want to waste $$ on precious Vuzix’s equipment which is by any way incompatible with Android phones). Any hints?

  11. simoncpu says:

    Combine this with your ASCII cam project, and you can perceive the Matrix that underpins the very fabric of reality. Hehehe…

  12. […] return for cheap augmented reality? A DIY option has been cooked up by Matt Kwan, running Android just like Google’s tech-specs are expected to, but with an altogether […]

  13. […] from my20percent decided he wanted to make his own augmented reality heads up display, and to do so he used a […]

  14. Robert B says:

    Can you add a drawing / diagram of how the thing works? Draw it on paper, take a pic, post it, and let the rest of us play!

  15. […] are many modern day Franklins.  Like this guy, who didn’t like the fact that nobody had a wearable immersion experience display.  So, he […]

  16. Amazing! An example of how a simple idea can make a huge impact. Kudos for not patenting it~!

    I’m almost sure someone is gonna want to manufacture these kind of baseball caps for a variety of smart phones.

  17. Nada says:

    Awesome initiative, you just got slashdotted

  18. jujuju it´s amazing, How much it cost?jaja

  19. Jehova says:

    Excellent work!
    Got here via Slashdot as well.

  20. […] easy way to get that Terminator-like augmented reality experience, you’ll want to check out this hacked up HMD baseball cap from Melbourne area maker Matt […]

  21. […] to get our hands on a pair of augmented reality glasses?! The same thing went through the mind of Matt Kwan when he created this DIY version of an augmented reality […]

  22. Napa says:

    So, is it over 9000?

  23. […] from my20percent decided he wanted to make his own augmented reality heads up display, and to do so he used a […]

  24. June says:

    Why not just buy a Vuzix Wrap for $149 (£99) and plug it into the phone and use the phone’s camera and video see-through?

    • mattkwan says:

      1. The Vuzix Wrap is a virtual reality headset, so you can’t see where you’re going when you’re wearing it. Using a video feed to see is possible, but you lose a lot of quality.
      2. You can’t plug external displays into Android smartphones.
      3. My rig cost a lot less than $149.

      • June says:

        Fair comment, but with screen mirroring, you can hang the phone around the neck or mount on hat with camera pointing out and the camera and AR App show all including the scene and augmentation in the glasses. Granted this doesn’t work with all phones, but I think will work with Android and latest iPhones.
        You can also use the Vuzix glasses to watch movies, even 3D and play games 🙂

      • like matt said, the quality is not good enough. Try walking around using the iphone camera as your only view of the world, it’s tough.

  25. […] when we see it.  Therefor, you can imagine our excitement when we first heard of Matt Kwan’s Do It Yourself Heads Up Display made from relatively simple components, all strapped to an everyday baseball […]

  26. […] required to push to perceived distance of the screen to about 50 cm, to avoid serious eye-strain.Courtesy of Matt KwanAccording to his notes, this setup worked quite well, with some design changes recommended to make […]

  27. MattIdeas says:

    it looks great, you need to register this idea, this could be very useful in the near future, think about a doctor working in the distance….

  28. […] Kwan] says that coming up with a personal heads-up display wasn’t that hard. Well that’s because he made design choices that make all the […]

  29. Doktor Jeep says:

    Here is a tip for those “curved tinted lenses”.

    Go out and get some very cheap red-dot “holographic” (as they call them) gun sites.
    You can probably get them even cheaper than this

    These contain a lense that has the curved shape and the semi-reflective coating (usually reddish). You can salvage the lenses from them.

  30. […] des lunettes Android que Google serait en train de préparer et qui sont attendues pour fin 2012. Matt Kwan n’a pas pu attendre, et s’est fabriqué sa propre […]

  31. You can think about use camera. You can reflect camera image into piece of plastic and you have amazing capabilities to make an Argumented Reality.

    P.s. Sorry for my English 🙂

    • Hmmm… I think you can use one mirror less than that. If you put phone on the peak of this cap propably you can use only two mirrors (plastic pieces) for oculars… I think so…

  32. […] from my20percent decided he wanted to make his own augmented reality heads up display, and to do so he used a […]

  33. Ren says:

    Interesting but I wouldn’t want a mobile phone so close to my head like that 😛 I rarely stay on the phone for longer than 5mins as they give me a headache.

  34. Nils Davis says:

    Really cool! Amazing that it works when built with rubber bands and binder clips. Looking forward to seeing a sketch of how it works, and then what the next guys/gals do with the ideas.

  35. […] enough because it didn’t have “a full field-of-view display.” So in response, “I decided to build my own. How hard could it […]

  36. luke says:

    This is a great idea and I’m sure will be put through many design changes and edits from many people. It kinda reminds me of the “eyewriter” ( ) an opensource diy style computer controller (for paralised people). If the two were intergrated you may still be able to control the phone in a way. Good luck with future developments.

    • mattkwan says:

      Thanks for the link to the eyewriter. I wasn’t aware of that project. I’ve been developing an eye tracker of my own, using the Android camera and an infrared filter, and it’s always interesting to see what others are doing. I’ll post an article about my own efforts in a week or so.

  37. […] a lot of science fiction movies and literature we find head-up displays as part of the action. It is definitely one of the emerging […]

  38. […] Here, Matt Kwan, a PhD Candidate in Geospatial Science, shows how he turned a baseball cap into an Augmented Reality headset. […]

  39. […] a cool DIY augmented reality monitor baseball cap… thing. I’m tempted to see if I can put one of these together […]

  40. […] developed, and at least one person has published instructions on building a heads-up display into a baseball cap, but the VISOR-like device Google recently announced is much better […]

  41. wasap says:

    I think this is the future of mobiles

  42. […] to get our hands on a pair of augmented reality glasses?! The same thing went through the mind of Matt Kwan when he created this DIY version of an augmented reality […]

  43. […] Alltag arbeitet Matthew Kwan im Rahmen eines 20-Prozent-Projekts, das er auf Forschung verwendet. Im Februar 2012 hatte er dazu das erste Mal etwas geschrieben – zu dem Zeitpunkt waren „Google […]

  44. Bobby Austin says:

    what would be needed for 3d stereoscopic displays that would output a clear Hd picture?

    • mattkwan says:

      You’d need two screens with a very high pixel density, one for each eye. The visor would have to be redesigned so that each screen was only visible to one eye, so it would have to come fairly close to the face if you want a wide viewing angle.

      • Meower68 says:

        Or, you could put some kind of opaque separation between the two halves of the screen, with one half being directed to each eye, and write an app that displays 3D in field-sequential fashion.

        But, as mentioned, that would need a custom app.

  45. […] DIY Augmented Reality Heads-up Baseball Cap […]

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