[Wear-Hard] Heavy MyVu Crystal Modifications

Sun Jun 14 15:54:48 EDT 2009

@ Tetsu: I'm a seasoned hardware hacker like yourself, and yes I agree
cautions are necessity, especially when working with expensive devices such
as these. I guess for those up in the mainland, always practice good static
discharging, test your supply/input voltages before and after load, ALWAYS
use regulated power supplies, as stated earlier pots can be used for current
and voltage control, and when working with signals of different voltage
levels make sure you're not driving your circuits with anything higher than
it's used too.

Also, when working with anything involving lithium polymer packs or lithium
cells in general(like the one in the MyVy controller), make sure to
familiarize yourself with the safety issues with those. I'm not saying
anyone's going to go around stabbing their li-po battery pack anytime soon,
but just in case something sharp falls on it, or it accidentally shorts out,
knowing what to do if the pack suddenly bursts into flames is good (such as
not throwing water on a lithium fire).

Hope everyone practices safe happy hacking! (and posts their experients,
failed or not here!)
-Brian

On Sun, Jun 14, 2009 at 9:21 AM, Brian Kuriyama <yosh.five7 at gmail.com>wrote:

> It's definitely the same chip, but the chip's package is BGA as described
> in diagram 12.2. While supporting dvi may not be an issue, wiring it up to
> the myvu board is impossible. You would have to transplant the chip, which
> would require very expensive equipment and someone with a lot of expertise
> in the art of doing so.
>
> Also, that "decoder" it mentions in the diagram probably refers to one of
> the philips decoders it mentions on page 5
>
>
> -Brian
>
>
> On Sun, Jun 14, 2009 at 9:11 AM, Olli Markkanen <olli.markkanen at gmail.com>wrote:
>
>> But you are sure it has that SSD1502 chip? That document you linked was
>> the same I was looking at.
>>
>> There is a picture that says where we should connect the wires on page 10.
>>
>> "The SSD1502 accepts digital video signals directly, or an external
>> decoder may be used for analog video inputs."
>> The picture also says "NTSC/PAL S-Video or CVBS" goes to decoder, so it
>> really does not take raw S-video, but it can be connected to the same place
>> and that specific chip can handle them.
>>
>> So, if you are sure it's the same chip, it should be possible to connect
>> dvi.
>>
>> Olli Markkanen
>>
>>
>> 2009/6/14 Brian Kuriyama <yosh.five7 at gmail.com>
>>
>> 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
>>>>>
>>>>>
>>>>
>>>> _______________________________________________
>>>> Wear-Hard mailing list
>>>> Wear-Hard at haven.org
>>>> http://www.haven.org/mailman/listinfo/wear-hard
>>>>
>>>>
>>>
>>> _______________________________________________
>>> Wear-Hard mailing list
>>> Wear-Hard at haven.org
>>> http://www.haven.org/mailman/listinfo/wear-hard
>>>
>>>
>>
>> _______________________________________________
>> Wear-Hard mailing list
>> Wear-Hard at haven.org
>> http://www.haven.org/mailman/listinfo/wear-hard
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.haven.org/pipermail/wear-hard/attachments/20090614/8dad9679/attachment-0001.html 