[Wear-Hard] Heavy MyVu Crystal Modifications

Sun Jun 14 15:17:47 EDT 2009

On hardware hacking,

I had a lot of fun a few years ago buying cheap camcorders from thrift
shops (usually $30 a piece) and pulling the minicrt's out to rewire up
to my own video signals. However, I easily destroyed three Cool Things
by overloading them with weird signals. I bought a $40 IR NTSC
'security camera' from Sams Club and, after testing with my voltmeter
(no oscilloscopes for me) and finding it's voltage to be significantly
higher than the inputs it's used to, quickly blew the things out and
now have nightmares about that horrible burnt-silicon smell.

I urge you to take A LOT of caution when hacking these expensive
devices. Set up some potentiometers to limit voltage and I don't
really know any other good safety precautions to reduce current or
anything. Advice would be appreciated.

Olli,
Glad to see you posting on the list! If you're really that close to
building a wearable, come here for support and cheering!

I'd also love a wearable IRC channel, but never found one. It seems
the folks into wearables like mailing lists and asynchronous
communication. I've been told that freenode#linuxice has some wearable
folks who come in frequently (source: Wirelessdreamer of joy2chord).
If you'd like to start a channel on Freenode or any other server I
will be a frequent user.

On Sun, Jun 14, 2009 at 5:22 AM, Brian Kuriyama<yosh.five7 at gmail.com> wrote:
> Sorry to break it to you, but the Myvu board definitely seems like their own
> original creation. They're using the specific chip who's datasheet I linked
> too, but the driver board is extremely packed and looks incredibly hard to
> modify for dvi input. You would have to remount the package onto your own
> custom board if you decided to go that route im afraid. Also, I don't
> believe the driver chip is capabale of taking a raw S-Video signal. It would
> need to be re-combined back into composite sadly.
>
> -Brian
>
> On Sat, Jun 13, 2009 at 9:46 PM, Olli Markkanen <olli.markkanen at gmail.com>
> wrote:
>>
>> Hi,
>>
>> I'm a lurker on this list and I am building my own wearable. Currently I'm
>> ordering the parts, BeagleBoard, Myvu Crystal and things for the
>> Spiffchorder.
>>
>> I also, just this friday, was digging the datasheet which I got from Kopin
>> webpage, the display is from Kopin and I hope the Driver board is their too
>> and not some Myvu original thing.
>> So I noticed it takes either that S-video/Composite signal, or bare
>> digital signal if rewired. It should not be too hard to hack. BeagleBoard
>> gives dvi-d signal, so that's what I hope to be able to feed the Crystal. If
>> we just could confirm this and get a how-to on the web, it would be nice.
>>
>> Man, this list thingy is weird. Is there/why is there not something like
>> irc-channel for wearables? There is a newish wiki on wearcomp.wikia.com, but
>> it still does not have too much content.
>>
>> Olli Markkanen
>>
>>
>> 2009/6/13 Brian Kuriyama <yosh.five7 at gmail.com>
>>>
>>> Crap, Accidentally hit the send button, my last email wasn't finished,
>>> here's the complete one:
>>> -------------------------------------------
>>> So, I was wondering how ballzy people here are. If they rip apart several
>>> hundred (if not potentially thousands) of dollars worth of displays to build
>>> their equipment, whats another $300 right?
>>>
>>> So, my UX's retarded Intel GMA950 chipset will not output to "TV out" and
>>> VGA output at the same time, if I wanted to add my HMD as a 4th screen to
>>> the setup without disabling my 22inch, I would need to use a USB to VGA
>>> adapter of sorts. Problem is, my display controller only takes composite
>>> video natively! And that's where a little digging began. I remember working
>>> with Kopin's display drivers before and I know they don't skimp on
>>> functionality. Especially for a display as useful as a full color VGA one!
>>>
>>> While looking up the driver chip found in my MyVy Crystal headset, I came
>>> across the datasheet for it!!!
>>> http://www.kopin.com/data/SSD1502.pdf
>>>
>>> What's awesome is that it notes under 'Features":
>>>
>>> Digital input formats:
>>> -  NTSC and PAL video (support rectangle and square pixel variants)
>>> -  BT656, with sync information in SAV/EAV blocks (8-bit words @ 27MHz)
>>> -  4:2:2 YCbCr (8-bit words @ 27MHz or 16-bit words @ 13.5MHz)
>>> -  16-bit RGB (5,6,5) @ 13.5 MHz
>>> - VESA VGA video
>>> -  480p RGB/YCbCr with separate sync signals which Hsync, Vsync and Pixel
>>> clock (Pclk) (24-
>>> bit words @ 25-36MHz).
>>> -  Serial wire interface for YCbCr video input source
>>>
>>> While I haven't gone too much into the specifics for it yet, it appears
>>> that it shouldn't be too difficult to rewire the controller, or make a
>>> separate board for the chip to take a VGA signal. Even if the driver doesn't
>>> take VGA natively, I'm sure one of the Philips video decoders do!
>>>
>>> The problem with this approach is that not only is reballing and
>>> remounting BGA packages like the one found in the MyVu controller extremely
>>> difficult, but there is no application circuit to copy and figure out how
>>> exactly this chip will respond to our/my intended setup. This looks like an
>>> extremely useful driver for a display, and despite the somewhat difficult
>>> documentation, If we were able to source these, we could possbily have very
>>> interesing display controllers produced, specifically tailored to wearable
>>> applications!
>>>
>>>
>>> Just an idea~
>>> -Brian
>>>
>>> _______________________________________________
>>> Wear-Hard mailing list
>>> Wear-Hard at haven.org
>>> http://www.haven.org/mailman/listinfo/wear-hard
>>>
>>
>>
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