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 DIY Oculus Rift - schematics, instructions and build pics! 
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Cross Eyed!
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So how do we drive a MIPI panel off a HDMI source?

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Thu Jun 13, 2013 12:04 pm
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Cross Eyed!

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well that TI TFP401A can receive DVI/HDMI. it's used on the Chalk-Elec HDMI-LVDS bridge. Check out their site you can find a open source schematic. It uses a 2 chip solution, the other chip is a SN75LVDS83B but it's for LVDS. if we can find a chip that can take the TFP401A's output and change it to MIPI maybe we'll just about have a solution to this. Does anyone know someone who designs display controller circuits? Vitrolight?


Thu Jun 13, 2013 12:36 pm
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Binocular Vision CONFIRMED!

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rfurlan wrote:
So how do we drive a MIPI panel off a HDMI source?



maybe do hdmi->rgb and then one of those boards I linked 2 posts up?

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Thu Jun 13, 2013 1:18 pm
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Cross Eyed!

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How much does the VX5AxB cost? Is it easily to get a hold of those chips?

The Toshiba TC358768XBG is a parallel RGB to MIPI(DSI?) chip. Supports 4-data lanes. they're listed at $3.25 in lots of 1000 but I don't know if we could have someone build a HDMI-MIPI bridge with these. The TFP401A costs around $9.

Can someone get the datasheet for the 5" Sharp LCD? I don't know anything about MIPI.... there's CSI-1, CSI-2, CSI-3, DSI? what would the panel use?


Last edited by Inscothen on Thu Jun 13, 2013 4:50 pm, edited 1 time in total.



Thu Jun 13, 2013 1:32 pm
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Diamond Eyed Freakazoid!

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On the Oculus forums"Wookiee" is talking about using this board with a ipad 3 screen .
http://dp2retina.rozsnyo.com/


Thu Jun 13, 2013 2:21 pm
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Binocular Vision CONFIRMED!

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3dvison wrote:
On the Oculus forums"Wookiee" is talking about using this board with a ipad 3 screen .
http://dp2retina.rozsnyo.com/


We have a thread on this on here as well btw.

10" is a bit very big. Maybe this rumor will pan out and it will be eDP connector as well: http://appleinsider.com/articles/13/06/ ... -this-year

2048x1536 on 7.9 inches

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Fri Jun 14, 2013 2:05 am
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Binocular Vision CONFIRMED!

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Panel list and gains over DK1:

Code:
DK1 Factor  Pixels       Resolution      Size         Phones/Tablets                 Connector
1           1024000      1280x800       7"             OR DK1
2.025       2073600      1920x1080      ~5"        HTC /Galaxy S4/ Xperia...          ???
2.025       2073600      1920x1080       6"        Asus Fonepad,Pantech Vega          ??? 
2.25        2304000      1920x1200      7"         rumored Nexus 7 2013               ???
3.068       3141632      2048x1534      7.9"       rumored Ipad mini 2013             ???
3.068       3141632      2048x1534     10.1"       IPad 2,3,4                         eDP
4           4096000      2560x1600     10"       Asus Infinity Pad,Toshiba Excite     ???
4.05        4147200      3840x1080     2x5"        as 2nd line. one per eye           ???



wanted to do this list for a while for myself anyway. thought maybe somebody else finds it useful...

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Fri Jun 14, 2013 2:26 am
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Cross Eyed!

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With these displays it would be good to figure out pixel fill per lens.

Using the DevKit's A cups not squashing your eyes:

The original prototype gets well over 320,000 pixels visible per eye but doesn't fill the possible FOV through the lenses.
The DevKit get about 230,000 but does fill the possible FOV.
The new prototype gets about 720,000 per eye if it's the 5.5" and more if it's the 5" but at reduced FOV.
If we found a LCD panel that was 5.5" with same ppi as the 5", the pixel fill would be something like 915,000.

Compared to Common resolutions pixel amounts
NTSC SD 486i 349,920
PAL SD 576i 414,720
HD 720p 921,600
FHD 1080p 2,073,600
QHD 1440p 3,686,400
UHD (4k) 2160p 8,294,400
UHD (8k) 4320p 33,177,600

The a 7" 1920x1200 panel would be wasted on the Rifts lenses in my opinion. LG 5.5" panel would be a great choice for FOV and the 5" for pixels visible if using standard Rift lenses.


Fri Jun 14, 2013 5:16 am
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Petrif-Eyed
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remosito wrote:
wanted to do this list for a while for myself anyway. thought maybe somebody else finds it useful...
Here is another one :
http://vr.wikinet.org/wiki/Displays


Fri Jun 14, 2013 10:56 am
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Cross Eyed!

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:o rozsnyo, the ipad retina display controller hack maker, said on the oculus dev forum that they might be able to get a HDMI-MIPI controller made if we can decide on a specific 1080p LCD panel like the 5" or the 5.5".

The 5" is available, maybe we could get them to source, test and bundle the LCD with the controller if rozsnyo is willing to do it. That might save on costs.

With the A cups you wouldn't see all the horizontal FOV but you would with the C cups I think. Way less pixels visible but same FOV as the DevKit.

All we would need then is a new 3d print housing for the new screen. We could still have the original LCD and use it as a display on our desktop machines and extend our screens.

The post was on the retina display hack thread

https://developer.oculusvr.com/forums/viewtopic.php?f=26&t=618&start=80#p20458


Sat Jun 15, 2013 12:22 pm
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Diamond Eyed Freakazoid!

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Inscothen wrote:
:o rozsnyo, the ipad retina display controller hack maker, said on the oculus dev forum that they might be able to get a HDMI-MIPI controller made if we can decide on a specific 1080p LCD panel like the 5" or the 5.5".

The 5" is available, maybe we could get them to source, test and bundle the LCD with the controller if rozsnyo is willing to do it. That might save on costs.

With the A cups you wouldn't see all the horizontal FOV but you would with the C cups I think. Way less pixels visible but same FOV as the DevKit.

All we would need then is a new 3d print housing for the new screen. We could still have the original LCD and use it as a display on our desktop machines and extend our screens.

The post was on the retina display hack thread

https://developer.oculusvr.com/forums/viewtopic.php?f=26&t=618&start=80#p20458


Dam this would be so cool. We need to decide on a screen and do a group buy.
Palmer said in that thread that the 5inch would be too small, I think you need a 5.5 minimum.
But you know what, I want more resolution so bad, I think even I would take the hit in Hoz.FOV to get more resolution and be very happy.I did not think I would want more resolution this bad, but after some time with the dev. Kit, I want more resolution very badly and would give up a bit of FOV for it..


Sat Jun 15, 2013 7:58 pm
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Cross Eyed!

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Yeah Palmer said it's too small for a wide FOV and that's true for the A cups, but all those PIXELS :D

If you use the C cups on the 5" Rift Hack, it would fill in most if not all of the possible FOV through the lenses at the cost of losing the amount of pixels visible. I'll do a test with my 5.6" and the C cups to see how much FOV is there with the 5" 16x9 panel. Edit: I just tested my 5.6" with the C cups(at the same distance from the Rift's LCD), and an image with the screen dimensions of the 5" 16x9 display. It appears that with the C cups you would see the almost same FOV on the 5" as you would with the DevKit. The very outer most edges would barely be cut off when looking straight ahead.

...and I must clarify for anyone who doesn't know about the C lens cups on the DevKit. They're only suitable for nearsighted people.(I neglected to mention it before because I just assumed DevKit owners would know it already but Palmer brought it up on their forums and I think I should mention it here too)


Last edited by Inscothen on Sun Jun 16, 2013 2:29 am, edited 1 time in total.



Sun Jun 16, 2013 1:40 am
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Cross Eyed!
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Nice thing this interface, it is possible to buy this new Hd panels or only in thosands? Definitively i want to go to this group of buyers.


Sun Jun 16, 2013 2:21 am
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One Eyed Hopeful
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Does anyone know where i can buy a EU-power supply for the Rozznyo iPad Board? I am very unfamiliar/new to this :)

http://dp2retina.rozsnyo.com/

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Sun Jun 16, 2013 9:12 am
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Binocular Vision CONFIRMED!

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I am probably the odd guy out with this.

But I am not terribly interested in doing a diy hmd that replicates what Oculus will release in a few months anyway as DK2. So a simple HD display upgrade is not intruiging enough. The only way to top what OR will be likely to release seems to me a dual display hmd. For such a one, smaller display are advantageous. So my vote would either go to the 4.7" htc one screen. Or the 5" amoled screen of the galaxy S4. Those 0.3 inches larger size detriment would be far out-weighted by potentially much higher refresh rates of AMOLED.

Math excercise of why 5" is to small and 7" is to big for single display circular lenses centered over your eyes:
Take the average IPD, multiply by 2, and then calculate resulting diagonal of 16:9 rectangle.

Basically if screen is bigger than that. You either start having overlap in the center or waste pixels on the sides.
If screen is smaller you either waste pixels in the middle or you start seeing screenborder on the outside.

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Sun Jun 16, 2013 2:06 pm
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Cross Eyed!

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A 5.5" 16:9 panel is what would work great with the DevKit's A cups. If you're near sighted and need the C cups you'd lose pixels but still fill the FOV. It appears that the DevKit's lens setup was made for the 16:10 5.6" panel. The 5.5 is wider and shorter.

The 5" 16:9 with A cups you lose horizontal FOV but tons of pixels :D ....and with C ups, almost gain all the possible FOV back.

Using larger panels would just add more to the tops and sides but wouldn't be able to see anyways unless you change the lenses, or get uncomfortably close. That's why the DevKit wastes soooooo much of the screen.

If you used two of the 4.7" side by side(32:9) in a Rift style setup(but with two panels obviously), you'd see the top and bottom of the screens if you use 38 mm 7x aspheric lenses setup(A cups) like on the DevKit the Rift. You would also waste lots of pixels on the outer edges.

If you did it side by side(18:16), you would waste pixels on the top and bottom, and the see the sides.

Using the two displays might cause sync issues and alignment issues. You could work with different optics, there are other threads where it's been done.


Mon Jun 17, 2013 6:02 am
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Sharp Eyed Eagle!

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I think it's safe to say that a MIPI converter would need to be used between the normal Realtek type controller board (scaler) and the panel.
It's very unlikely that the MIPI boards do any kind of scaling at all, so the controller would need to match the panel res first.

It may be possible to just output from the PC at the panel res, but you'd still need an HDMI / DVI to RGB conversion first.

So, it would go something like this...

HDMI -> Controller -> RGB 24-bit -> MIPI converter -> Panel

It doesn't look like the SSD2828 can take an LVDS input (only SPI or RGB), so we'd need the controller to output RGB.

The boards are finally a decent price on aliexpress now, so I might get one depending on my experience with the Rift (not arrived yet, but I did order very late)...
http://www.aliexpress.com/item/Ssd2828- ... 92255.html

Also, $79 !! Yes please. :D...

https://www.verical.com/part/722582-LH5 ... earchName=
http://octopart.com/lh550wf1-sd01-lg+el ... s-29506871

As I say, I want to test drive the Rift first, but I'm still intent on trying the MIPI thing.

I'll contact some of the sellers of the MIPI boards to see if they also supply any source code with it (necessary for configuring the chip, probably).

OzOnE.


Tue Jun 18, 2013 6:24 am
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Sharp Eyed Eagle!

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Just contacted one of the MIPI board sellers to ask about the source code.

In the mean time...

"God bless the Internet."....
https://mega.co.nz/#!j4wTgAwI!cpdskD22P ... zXptIAcCS8

:D :lol:


Tue Jun 18, 2013 6:44 am
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Cross Eyed!

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OzOnE2k10 wrote:
I think it's safe to say that a MIPI converter would need to be used between the normal Realtek type controller board (scaler) and the panel.
It's very unlikely that the MIPI boards do any kind of scaling at all, so the controller would need to match the panel res first.

It may be possible to just output from the PC at the panel res, but you'd still need an HDMI / DVI to RGB conversion first.

So, it would go something like this...

HDMI -> Controller -> RGB 24-bit -> MIPI converter -> Panel

OzOnE.


The HDMI-MIPI circuit would only take the native resolution of the panel as a input. I don't think it really needs a scaler when your computer's GPU can scale it for you. Just make sure everyone knows how to operate it and we'll be fine. Adding a scaler would increase cost, make the circuit larger, and take longer to design.

computer scales in GPU and outputs @ 1080p, HDMI to circuit(HDMI.to.RGB >>> RGB.to.MIPI >>> panelinterface) to panel connector


Wed Jun 19, 2013 12:48 am
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One Eyed Hopeful

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Awesome OzOnE !! a DIY 1080p rift is almost here, Can't wait to see your progress! :) :D


Wed Jun 19, 2013 2:43 am
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Sharp Eyed Eagle!

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Inscothen wrote:
I don't think it really needs a scaler when your computer's GPU can scale it for you.

Yeah, that's true. I guess the PC is already outputting at the DK1 native res anyway (since that's what the EDID recommends).

Actually, we can force it to 1080p only, and with the proper timings via the EDID too.
I hope the panel doesn't expect any weird timings that most graphics drivers won't like?

Hmmm, may get away with just an HDMI receiver chip and the MIPI chip then.
I do have a couple of HDMI to VGA adapters with the digital signals available between the chips, but IIRC, it uses the bt.656 protocol instead.
(I can convert that with an FPGA, but would cost more than the Realtek scaler).

To make it as simple and cheap as possible, it would just need an HDMI receiver IC with parallel RGB output, the MIPI chip, and a simple AVR chip to config the MIPI / panel.

The seller replied btw, he only said "We will provide a source.Please do not take papal."

I was about to buy the board, but it was late last night and I didn't want to go through the hassle of setting up Western Union or whatever they use.
I'll try to sort it out today though. At least if I have the MIPI board it will give me the incentive to buy a 1080p panel too.

I need to be sure I can get the ribbon adapter / pinout for the chosen panel, as well as make sure I'm buying the most suitable panel available atm.

That LG one looks good (LH550WF1-SD01), but I'm not an expert on the different panels. Does anyone think that's a fairly good choice as a tester?

I'll have a hunt for the pinout info / datasheet, but I'm imagining it being quite difficult to get hold of that info. :(

OzOnE.


Wed Jun 19, 2013 7:31 am
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Sharp Eyed Eagle!

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@Inscothen - you may have the answer...

The TI TFP401A chip on that Chalk-elec board does output 24-bit RGB and doesn't need any extra config stuff.
They're using a standard RGB-to-LVDS transmitter for the panel.

I'll get in contact them to see if they will make a MIPI version with the SSD2828.
I'd much rather that somebody experienced with board design will make the new version (making sure the track impedances and other stuff work OK is tricky).

They should also be able to handle the config stuff for the MIPI chip using the PIC. :)

Also, it would allow the future 1080p (and higher) panels to be used with the Rasp Pi as well, so will ofc be quite useful to them.

OK, I'll send them a message now and see what they say.

EDIT: Rather large message sent to Chalk Elec with all the links and info + SSD2828 datasheet.
I tried to keep it relatively to-the-point though, so..... Fingers crossed! 8-)

OzOnE.


Wed Jun 19, 2013 8:35 am
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Cross Eyed!
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This is so exciting! :D

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Wed Jun 19, 2013 8:59 am
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Sharp Eyed Eagle!

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I know, but what I don't want to do is let anyone down by promising anything.

Far too many times I've said things can be done, but got sidetracked with another busy project (hence the Vitrolight still sat on the shelf).

I think it's safe to say that we'd all love a 1080p Rift this early though.
It will absolutely blow people away when they try it. :woot

Next problem is - we need to find the pinouts for the actual panel.
You can download the datasheet on Panelook, but need to upload some datasheets first (the $800 "VIP" account is WAY too expensive).

The thing is, it looks like they've already got pretty much every LCD datasheet available already, which makes it almost impossible to find a new one.

I'll use my Google powers to track down the LG panel datasheet and / or pinouts. :twisted:

OzOnE.


Wed Jun 19, 2013 9:10 am
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Binocular Vision CONFIRMED!

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Press event tomorrow in London by samsung. possible reveal of galaxy note with 5.9" amoled HD display!

:woot

panelook info on older samsung amoled displays give refresh of sub 2ms. But operating freq of 60Hz.
Palmer is said to have liked the new galaxy S4 hd panel. Might indicate they got it to run inhouse.
Anybody got a good connection to PL? Would be very useful to know if the display can be pushed beyond 60Hz.

If I understood some intense article about blur. Simple superfast refresh rate aint gonna help if you cant push new pixel info at it faster than 60 Hz. Killing the main advantage of AMOLED...

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Wed Jun 19, 2013 10:10 am
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Binocular Vision CONFIRMED!

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Ozone:

while you are googling. could you look around for pinout and similar info about this panel?

http://www.etradesupply.com/oem-samsung ... embly.html

can that mipi chip you selected push more than 60Hz in HD? Just checked ssd2828 only goes to 60Hz :-(
Neither can your other chip. Only thing that I could find that can push Hd@120hz is this one:
http://www.chrontel.com/media/Datasheet ... 20V0.5.pdf
But that outputs LVDS. and I couldn't find any lvds-mipi capable of 120hz.

I guess time to bury AMOLED. No use paying triple for the screen If you cant make use of its main advantage :-(

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Wed Jun 19, 2013 11:02 am
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Sharp Eyed Eagle!

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Yeah, I just saw the SSD2828 specs too. It supports slightly higher than 1080p, but max 60Hz.

I think it will take a while before higher refresh rates are adopted for AMOLED driver chips? (again, I'm no expert).
Consumers are mainly going to want AM panels for their other advantages before higher refresh becomes a factor.

The other thing is whether or not we can even order these panels in low quantities.
I like the idea of the LG panel 'cos the price is right ("come on down"), they're available in low quantities, and seem to be a popular choice atm.

I noticed the Arrow / Verical sites have a min order quantity of 3 though, so that'll be a pain.

No word back from Chalk Elec yet.
I'm also waiting for Panelook to verify an LCD datasheet I uploaded...

The trick is that although they have tons of datasheets, there are some slight variations which they might not have.
I simply found one already on the Web and uploaded that to them. ;)

It would be amazing to have both the SSD2828 and the panel datasheet.
Then, if Chalk Elec don't get back to us (or can't do it), I can plod on with a simple PCB design (I will try my best to complete this project. hehe).

OzOnE.


Wed Jun 19, 2013 1:35 pm
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Cross Eyed!

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I really like the idea of using the LG 5.5" 1080p panel to make a HiRes Rift hack or DIY with the same lenses as the DevKit. That is if we can get it at all.

The Rift DevKit's lens setup was done for the 5.6" 1280x800 panel. Since the 5.5" 1080p panel is 16x9, the display is a bit wider and shorter than the 5.6", which is fine because the 5.6" with the Rift's A cups don't see the top or bottom of the 5.6" anyways(unless you mash your eyes against it). As long as you don't get too close to the lenses, you wouldn't see the edges of the 5.5" panel.

If we are able to get a company like Elec-chalk or rozsnyo to design/build the circuit, maybe they might consider bundling the screen(or attach the new HDMI-MIPI circuit behind the panel). That would make this so much better and easier.


Thu Jun 20, 2013 12:20 am
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Sharp Eyed Eagle!

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OK, I spent some time this morning adding the TFP401A and SSD2828 to a board design (under Cadsoft Eagle)...
It's just a rough start atm, and needs quite a lot added to it.

Also, I managed to get hold of the FULL datasheet for the LG LH550WF1-SD01 1080p 5.5" panel. :mrgreen:
https://mega.co.nz/#!a1RxyDIJ!OffkGAjNb ... AzjxeWGlHU

I don't know if those datasheets are meant to be public, but frankly I don't really care.
There shouldn't be so much secrecy with datasheets, I'm sure many companies will make many Billions of dollars before the datasheets are public anyway.

To start the board design, I actually "borrowed" the DVI2PAR project files, so I thought I'd mention it...
http://www.harbaum.org/till/dvi2par/index.shtml

The TF401A is pin compatible with the TF101A used in the DVI2PAR project, but the TF401A has a thermal pad added to the package / layout.

(The TF101A only works up 86MHz, or XGA resolutions, so we need the TF401A for doing 165MHz / 1080p).

As usual, the autorouter on Eagle SUCKS (or I just don't know how to use it), so if anyone can help with the board layout, please feel free. lol
Another issue is, I don't know how to stop the vias and tracks from being placed inside the thermal pads (on both the TF401A and SSD2828)??

I've tried adding keepout and restrict polys to the TFP401A, but the autorouter still puts vias in there?

We also need to add this stuf...

    The socket for LG panel. (not sure if this is the correct "polarity"?)...
    http://www.dzsc.com/product/infomation/ ... 21920.html

    LED backlight driver (3V per LED, 6 LED's per string, two strings, so 18V @ 20mA).

    Small PIC or AVR chip for the SSD2828 / panel config (may not even need that by the looks of it. I need to read the datasheet).

    1.2V reg for the SSD2828 MVDD supply.
    24MHz crystal.

    Change that huge 3V3 regulator for a smaller SMD one.

    USB socket and pass-through for Rift headtracker.
    (need to see if USB can also supply enough current for the MIPI board / backlight / panel).

    Source the SSD2828 chips (TFP401A should be OK, can even get samples).

    Source the LG panels (may be minimum order of 3 panels).

    Sort out the PCB layout, and how it will fit inside the Rift. (MIPI signals likely aren't designed for long cable transmission?).

    Get PCB made, solder parts (will need laser template for paste etc.).

Throw it all together, add sugar, mix well. :roll:

Can anyone help with the Eagle layout, or possibly using software they're comfortable with?
I'll have to find that guy who made that very nice DIY Rift and his own adapter PCB's, can't remember his name atm?

OzOnE.


Thu Jun 20, 2013 6:00 am
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Sharp Eyed Eagle!

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I've made the connector package for the LG now...

The connector datasheet says "GB042-30P" for both the plug and the socket. I'm pretty sure the socket is supposed to say "GB042-30S"?

I still can't stop the autorouter from putting vias under the chips though. :evil:

I've also added the 1V8 reg for the LCD IOVCC.
The LG LCD also needs a +5V and -5V supply, so will need a negative voltage gen.

This is very much a work-in-progress, but it's getting there...
https://mega.co.nz/#!vlARRbrS!VAXVnhCLy ... eAoY4DDv9c

tbh, I'm hoping somebody else will take this project on.
If we can finalize the board though, I don't mind paying to get some PCB's made. I might be able to solder those chips too.

OzOnE.


Thu Jun 20, 2013 12:13 pm
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Cross Eyed!
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I want to help however this stuff is way out of my league, at least I can help with the bill - let me know! :)

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Thu Jun 20, 2013 12:18 pm
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Sharp Eyed Eagle!

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Oh, trust me, this is out of my league too. lol

The most complex board I managed to design was a 240-pin FPGA board, but that took me around 6 months to figure out.
Even then, I made quite a few mistakes (like not adding a proper JTAG port).

I've never made a board for HDMI and MIPI stuff, so don't know how fussy the chips are to noise and placement.

I just wish the Eagle autorouter was better, it would be a great piece of software otherwise.
I'll see if I can route it better using Electra.

Oh, forgot to mention the other-other problem...
As far as I can tell, the LG panel only scans in portrait mode (1080x1920), so not sure if this will screw up the software side of things?

I also don't know which backlight LED driver to use?
I've built high-current LED drivers before, but not sure which is best suited to the LG?

btw, I noticed that the Oculus 1080p proto seems to use two fairly thick cables to the Rift...
This hints that it's probably a MIPI panel, and they're just using a separate HDMI cable instead of the normal LVDS pairs.
This could also mean that their MIPI converter is inside the Rift too?

The original DK1 cable doesn't have enough pairs for MIPI anyway.
The LG requires all four lanes, so 4 pairs plus a fifth pair for the Clock (ten wires).
The old Vitrolight panels only need 3 pairs plus a clock pair (8 wires).

That may be why they just went with an HDMI cable on the proto? (still only 8 wires, so MIPI converter must be in the HMD?)

OzOnE.


Thu Jun 20, 2013 12:37 pm
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Cross Eyed!

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OzOnE2k10 wrote:
Also, I managed to get hold of the FULL datasheet for the LG LH550WF1-SD01 1080p 5.5" panel. :mrgreen:
https://mega.co.nz/#!a1RxyDIJ!OffkGAjNb ... AzjxeWGlHU

Another issue is, I don't know how to stop the vias and tracks from being placed inside the thermal pads (on both the TF401A and SSD2828)??

I've tried adding keepout and restrict polys to the TFP401A, but the autorouter still puts vias in there?

USB socket and pass-through for Rift headtracker.
(need to see if USB can also supply enough current for the MIPI board / backlight / panel).

Sort out the PCB layout, and how it will fit inside the Rift. (MIPI signals likely aren't designed for long cable transmission?).

Oh, forgot to mention the other-other problem...
As far as I can tell, the LG panel only scans in portrait mode (1080x1920), so not sure if this will screw up the software side of things?

btw, I noticed that the Oculus 1080p proto seems to use two fairly thick cables to the Rift...
This hints that it's probably a MIPI panel, and they're just using a separate HDMI cable instead of the normal LVDS pairs.
This could also mean that their MIPI converter is inside the Rift too?

OzOnE.


You got the panel's Datasheet? :shock: :D

I'm not a circuit designer, but which vias and tracks run under the thermal pad? how many layers are the board? I would imagine some tracks wouldn't be a problem for under chip/pad routing like maybe ground vias.

If we replace(design/3d print) the display housing portion of the DevKit we can keep the DK intact(after removing the headtracker) and design to accommodate the new panel, circuit, head tracker placement and cable routing.

Yes, I thought they did put the HDMI-MIPI circuit behind the screen in the new prototype too.

and the panel orientation wouldn't matter because we could rotate in the GPU like we would do with scaling.


Thu Jun 20, 2013 12:55 pm
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Sharp Eyed Eagle!

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Yep, datasheet is in that first zip file on Mega.

Eagle is basically trying to put vias on the thermal pads even though I've set restrict polys on them for both sides.
The datasheets don't seem to mention if the thermal pads are connected to anything, so I'm just counting them as no-connects.

I'm only routing it as double-sided atm. 4-layer boards can be quite a bit more expensive, and I'm hoping 2-layer will work OK as a tester?

You're right though, a multilayer board would make routing much neater and wouldn't matter too much if it had a few internal vias under the pads.
I'm showing my lack of experience in that area though, I've only ever done 2-layer boards with Ground planes on both sides.

I'm really hoping we don't need to build a new front part for the DK1. The PCB will be challenging enough. lol
I don't have access to 3D printers or anything like that. :(

Does anyone remember who built that 3d printed Rift with the proper LVDS adapters?
I think I was even in e-mail contact with him, but my memory is shot to pieces. It was Andrew or Andy wasn't it?

EDIT: Ahh, found him!...
viewtopic.php?f=140&t=15247&start=520&hilit=windows#p83258

Andy uses Altium Designer as well, so I'll PM him later about the MIPI thingy.


OzOnE.


Last edited by OzOnE2k10 on Thu Jun 20, 2013 1:30 pm, edited 1 time in total.



Thu Jun 20, 2013 1:14 pm
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Sharp Eyed Eagle!

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Inscothen wrote:
and the panel orientation wouldn't matter because we could rotate in the GPU like we would do with scaling.

Would a portrait panel mess up the way some software renders the images though?
If the LG only scans in portrait, then the PC would have to see a portrait aspect as well?


Thu Jun 20, 2013 1:22 pm
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Texas Instruments do some wonderful SDK kits - and LG has a fair developer network it would seem.

What I am on the hunt for is in Google translate land is a lead on a 7" LG hardware SDK complete with driver board to allow for a straight dk1 swap . I think in the next 6 weeks or so the ground will change and we can look at such things - indeed I reckon a nexus2 7 tear down may happen within a month....

(Sorry Ozone - I know you like your challenges! but I like my simples !! ;) )

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Thu Jun 20, 2013 1:39 pm
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Sharp Eyed Eagle!

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I've thought about that too.
Maybe it's worth waiting a while longer for more boards to become available?

These HD MIPI panels haven't had a chance to mature yet, so controllers / SDK's for them are scarce.

I'd like it to be simple as well (trust me), but I want my MTV! (sorry, HD Rift) NOW damn it!! lol :lol:

I bet my DK1 arrives when I'm at Glastonbury. :(


Thu Jun 20, 2013 1:54 pm
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I wonder if these guys would consider making a MIPI board? Probably not? (originally posted by @3dvision)...
http://dp2retina.rozsnyo.com/


Thu Jun 20, 2013 2:01 pm
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Cross Eyed!

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OzOnE2k10 wrote:
Eagle is basically trying to put vias on the thermal pads even though I've set restrict polys on them for both sides.
The datasheets don't seem to mention if the thermal pads are connected to anything, so I'm just counting them as no-connects.

You're right though, a multilayer board would make routing much neater and wouldn't matter too much if it had a few internal vias under the pads.
I'm showing my lack of experience in that area though, I've only ever done 2-layer boards with Ground planes on both sides.

I'm really hoping we don't need to build a new front part for the DK1. The PCB will be challenging enough. lol
I don't have access to 3D printers or anything like that. :(

Does anyone remember who built that 3d printed Rift with the proper LVDS adapters?
I think I was even in e-mail contact with him, but my memory is shot to pieces. It was Andrew or Andy wasn't it?

EDIT: Ahh, found him!...
viewtopic.php?f=140&t=15247&start=520&hilit=windows#p83258

Andy uses Altium Designer as well, so I'll PM him later about the MIPI thingy.


OzOnE.


Some circuits would require under pad routing. I read some say not to do it ever, but then I read that sometimes it's the only way, just watch for which tracks would go under.

I think a 3d printed part would be the easiest and safest(not breaking the Rift) way to do this, whether making a DIY with the Rift's tracker and lens cups, or using the lens mount/headstrap portion of the DevKit. I saw the display housing on the DevKit is just attached by some screws. we would just need to design so the panel and lenses align properly and the housing fits with the kit.

If we design the housing correctly then we could just get 3D parts made and shipped to us from shapeways or someone.

OzOnE2k10 wrote:
Would a portrait panel mess up the way some software renders the images though?
If the LG only scans in portrait, then the PC would have to see a portrait aspect as well?


I don't know about others but with NVIDIA you just select the displays orientation and the panel would act like that kinda screen. the 1080p prototype is said to use a 1080x1920 panel so Oculus is probably just doing it this way. Maybe the EDID has something that identifies orientation.

zacherynuk wrote:
What I am on the hunt for is in Google translate land is a lead on a 7" LG hardware SDK complete with driver board to allow for a straight dk1 swap . I think in the next 6 weeks or so the ground will change and we can look at such things - indeed I reckon a nexus2 7 tear down may happen within a month....


I seriously doubt there would be any panel(even 7") that we could just allow just a straight swap. If a panel is MIPI, there wouldn't be room for the LVDS-MIPI circuit or

if we go the HDMI-MIPI route then no room for that circuit(unless using a small display) and we'd have to cut up the devkit's housing. If the 7" is LVDS then we'd still need to reroute and maybe replace the Rift's cable. Any way we do this would require some real work. If 3D printing a new housing it might be the easiest way without modding the Rift's current housing.

OzOnE2K10 wrote:
I wonder if these guys would consider making a MIPI board? Probably not? (originally posted by @3dvision)...
http://dp2retina.rozsnyo.com/


they said if we select panel we might make a HDMI-MIPI circuit, that they were planning on making something like that.

this is their post on the retina hack thread on the oculus dev forum

rozsnyo wrote:
Hi Guys, I am glad that you try to use my adapter that way. Actually we will be working on integrating a phone LCD into our UHD camera, so as a by-product, we could make HDMI to MIPI interface, to drive a 5 - 5.5" LCD in native resolution.

Would that 5" HTC DNA be okay? I assume that every display will have a different plug, so we have to use a very common one to have them for lower price.. if you decide which one to use, drop me an email to daniel@rozsnyo.com, thanks.


Thu Jun 20, 2013 2:10 pm
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Binocular Vision CONFIRMED!
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OzOnE2k10 wrote:
I wonder if these guys would consider making a MIPI board? Probably not? (originally posted by @3dvision)...
http://dp2retina.rozsnyo.com/


As you and I both know .. the cables are the hardest part!! ;)

When the ipad mini2 comes our ~ 2 months - again very viable I think...

Mean while... 2 X vitrolight displays spanned .. in portrait with 5 X lenses... aint too bad ;) You can appreciate the higher resolution but can't enjoy the experience as much as with the real kit...

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Thu Jun 20, 2013 2:22 pm
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