[DIY] shutterglass parallax-inverters / eye-sync-swappers

[iondrive]

Hi all,

Well, I think it's time I start a topic on hardware solutions to the wrong-eye-sync problem that many will have when using DLP projectors or for any other reason. I think there's room in one thread for multiple designs so if you have your own design for one of these things, then go ahead and add it in here. Of course, improvements on my designs are also welcome. My designs were made for use with E-Dim dongles but they might be easily adapted for other kinds of systems too. Just be careful if you decide to try something else.

I've got three designs to share with you (two wired and one wireless) so let's take them one at a time - easiest first.


EDIT: (2nd edit: noticed that this approach causes irregular flickering. I recommend not using it but it might work better on your hardware than mine so try it if you want)

If you're using an old-school nvidia setup, you should try a hotkey/registry tweak solution first:

RUN the REGEDIT program and go to:

[HKEY_LOCAL_MACHINE\SOFTWARE\NVIDIA Corporation\Global\Stereo3D]

Find an entry called "GlassesSwitchDelay".
Set it to decimal 27.
Start a 3d test.

Eye-sync should now be reversed compared to previous condition.

Hotkeys: Hit Alt-minus to go back to previous sync and hit Alt-equals to undo that. You may need to hit them multiple times.

That's it. Please report problems if you use this. thanx.

--- iondrive ---

[iondrive]

Wired parallax inverter using 3.5mm stereo plug to RCA cables:

version 1 is the easiest one I've got for you and all you have to do is connect some cables (after you get/buy
the parts of course). If you just want an inverter with no switch for one or two wired viewers, this might be good enough for you, especially if you want an easy project where you don't have to solder anything. You need:

2 cables - 3.5mm (1/8th inch) stereo plug to double RCA plugs (all plugs male). These are the same as for standard stereo audio connections, nice and convenient.

1 pair of RCA male-to-female converters (double-ended female)

1 male-to-female 3.5mm stereo adapter (double-ended female)

optional 3.5mm stereo Y-cable adapter for two viewers using two pairs of glasses.

Of course, feel free to modify the parts list and design as you like. Just use this post to get the idea of how to do this kind of thing.


Picture 1: cable-inverter.jpg
cable-inverter.jpg shows you how to start laying out the parts. The three plugs on the top right are from one cable and the three plugs on the bottom left are from the other cable. The bottom right plug is from the wired glasses. You should realize that if you connect them this way, the signals go straight through with no change. To make this thing an inverter, choose either cable and swap the locations of the RCA plugs from it. Connect everything and it should be clear to you that this should work. It works with E-Dimensionals and X-Force dongles/glasses except that the X-Force needs additional adapters since it uses smaller plugs/jacks, not 3.5mm. There is a chance that some other system might not work if they have an odd signal setup so be careful. Note that in the case for E-Dims, there is no ground. None of the three signals on the stereo plug is ground and if you ground the sleeve on the stereo plug or the RCA shield, you may get a black display or your computer and it might even reboot itself. Look for a Topic on Shutterglass Signals that I will start if you want more details on these sigs. You should also realize that you could use this setup to swap stereo audio signals.

Picture 2: cable-inverter-y.jpg
cable-inverter-y.jpg shows everything connected except for plugs from two pairs of glasses and a Y-cable adapter. That's what you need if you want to have two viewers with wired glasses. Self explanitory.

That's it. Easy, huh? And it's easy to switch back and forth but not as easy as with a built-in switch like the next version. Also, the next version has outputs for 5 wired viewers.

[iondrive]

hi again, ready for more?

wired parallax inverter plus 5-viewer junction box:

Version 2 of my inverters includes a junction box for 5 wired viewers. It's a little flimsy since it's made from a thin cardboard box but it's good enough for me. If you want a nicer one, it shouldn't be too hard to find a good little plastic box for it. I suggest you keep the same general design because it's right or left handed depending on how you set it down and you can have it with the wires facing you or going away from you. The way you use it is you put your hand on top of it to hold it down (since it's so light-weight) and use your thumb to toggle the switch. I managed to make this with no soldering but I recommend that you solder. The box was nice and thin and I was able to use the stereo plug to poke holes in it for the jacks so you don't even need a drill if you do it like I did. You can use a pencil for the switch-hole since it's bigger. Using panel-mount parts allows you to not use any circuit board. Here's the parts list:

1 box in a size and thickness that you like
6 panel-mount 3.5mm (1/8th inch) stereo jacks (make sure you don't accidently get mono jacks)
1 dual-pole dual-throw switch, it can be 2-position or 3-position (center position will be "off")
and 1 stereo extension cable (1/8 inch double-ended male) to connect the box to the dongle.

Note that when "off", one glass may stay partly dark for some time. I don't think this does any damage but if it worries you, don't use it that way.

Pictures are outside, inside, wiring, and schematic. The 6 stereo jacks are the same but one will be for input and the other 5 will be for output. For my box, the one with the black circle is the input jack. Note that for easier wire routing, the bottom 3 jacks are mounted upside-down compared to the top 3 jacks, and that's true for both the schematic and the actual box. Also note that the "ground/common" signal doesn't need to go through the switch and the warning about it in the previous post applies here too. FYI: the signal on the tip of the plug is for the left-eye, the signal on the ring of the plug is for the right-eye, and the signal on the sleeve of the plug goes to both eyes. Audio signals are the same and you could use this box for audio "ear-swapping" and sharing although it might be bad to split the signal so much with 5 people. As for shutterglass signals, I've read that you can use this method for at least 10 wired viewers. I think that's all I need to say for this. The pictures say the rest. Next project: a wireless IR parallax inverter cable adapter box thingy.

[iondrive]

OK, we finally get to everyone's favorite glasses, wireless.

wireless parallax inversion thing:
OK, I prefer wired but anyway, this version takes advantage of 5V and ground on the 3-pin mini-DIN to power a chip with an inverter on it. That inverter inverts the shutterglass square wave signal so that it's effectively the same as changing the phase by 180 degrees. This project is for you to complete since I don't currently need this although I have tested it and it works great. I suggest getting the plugs first and then the wiring because the plugs use really small wires and this way you'll know the size wiring you need. You can probably solder the wires right to the pins on the chip and avoid using a circuit board and then just heat shrink or tape everything over so that it's more like a cable than a cable with a box attached. Also, if you decide to include a switch, then you might decide to make the wires extra long so that you can use the switch from far away. Speaking of which, I would love it if someone could design a new version of this that lets you switch parallax with an IR remote. That would be cool. Another redesign would be to just use a single transistor and some resistors to do the signal inversion but I prefer the chip. The chip is a hex inverter which means it has 6 inverters on it and we just use one. I used a HD74LS04P but you should be able to use any chip with an inverter on it that works with 5V and ground.

Not using the dongle:
If anyone skipped the first post, this is for the E-Dimensional dongle but it also may work with the 3-pin mini-DIN on some newer TVs that have their own 3-pin mini-DIN built-in. If the E-Dim wireless emitter is compatible with the TV, then this should also be compatible although you probably won't need it for those TVs but you never know. Anyway, if you don't have a dongle and want to use old-school nvidia drivers and don't mind hacking into a VGA cable, then you don't need the dongle after all. You need 5V, ground, and the shutterglass signal and you can get those from your analog VGA cable. Pin 9 should have 5V, pin 5 should have ground, and pin 12 (DDC) should have your shutterglass signal. I say "should" because sometimes a card's output might be missing something. However, if you do this without a dongle, then know that ED-Activator will not work for you.

The pics include some plugs that you can find cheap on ebay. It shows how the plugs come apart so you can solder the wires to them. Well, that's all for today. I hope something works for you if you need something like this. Please post your comments and especially if you decide to use these ideas.

--- iondrive ---

[THEDRUMMER]

thanks Iondrive for your work and observations. I will try to get it to work on my system when I get it. I'm getting the Optoma HD20 1080p DLP projector in a week and I'm hoping it will work with shutterglasses at 85hz (it's max refresh rate). I have an old set of Asus shutterglasses that I'll try before buying the Nvidia3dVision kit so I'll probably run into messing with the right/left sync issue. Thanks so much for your input!
Eric
Do you think it's possible to sync shutterglasses to the vga/dvi output without a vga pass through dongle? by setting computer to 85hz and getting the shutterglasses to run at85hz by connecting them to some other device? Even using an old computer with Asus v3800 video card on it to drive the shutterglasses? Maybe I could plug and unplug the glasses until I chance to get them in sync?

[iondrive]

Hey drummer,

Thanks for posting your interest. It's easy to think that noone cares about these posts and it's a waste of time for me to post them. But then I think that I wish someone else had posted this info for me to find and I think the info could be here for a year or more before someone finds it and so it's still worthwhile in the end. Anyway, regarding your question, no, I don't think that syncing from another source will work. From my experience with CRTs getting signals from the same dual-output video card, it still takes some effort to get them in sync. Often times, freq will be the same but phase will be different. If you use completely different sources, I wouldn't expect one 85 Hz to equal another 85 Hz. I did have good luck with my 7800GTX card though. Just set them to the same freq with the same "Display Mode Timing" (general timing formula, fixed aspect ratio, coordinated video standard, etc,) and I expect you to be lucky. It doesn't matter which standard you choose, just as long as they're the same. You really need CRTs and shutterglasses to confirm same freq and phase. Then you would need a VGA splitter and you could take the DDC signal but you still need a dongle to supply the right voltages to the glasses so sorry to make you read all this. I just hope you found it interesting. It is related to my other project where I take a dual output stereo signal and switch them into a single shutterglass signal.

By now.

[Likay]

Cool Iondrive! I had a nice reading. Shutters aren't really catching my concern anymore but thansk for the detailed sharing!
Btw: I didn't know the e-d dongle uses blue line coding. True? In that case i should be able to dig out my old crt and e-d glasses + iz3d driver for a retrotrip with newer games. If the e-d works anymore though. They were wireless and in the last the transmitter only reached about 2-3 decimetres...

[iondrive]

hi Likay,

BLC:
Yes I tested it with X-blades but I have to try a different game because her blue electric blades would keep triggering a sync reset. I think it should be OK with iZ3D's BLC driver and a game that uses not much blue but I still need to test that idea along with so many other ideas. Your dongle should have the E-Dim logo on it. I mention this because I have 3 identical-looking dongles except for the logos and only the E-Dim works with BLC. The others say H3D or 3D-world (X3D) and they don't respond so obviously the electronics is different inside. I bought the E-Dim one because I wanted to try the LCD setting in ED-Activator and what it does is delay the shutterglass signal by 3/4 of one refresh if I remember correctly. I doesn't really help with the LCD monitor I tested with but at least I got my answer. The other dongles don't have that delay so again, the electronics inside are different. For those interested, I will post this info for others to read elsewhere eventually.

Changing X-blades resolution:
By the way, X-blades can be a little stubborn about which resolution it runs at and I can tell you how to change it if you want. I think it just tests your system during install and then sets the res based on that. I wanted to lower mine to match my projector 800x600 so I had to figure out how. So, yeah, I wound up playing that game through and liked it more than I thought I would. It's better than it seems at first. I like the level with the various elementals and you have to keep using different powers for each kind. I used iZ3D's driver at the time but now I think Tridef's is better because it has good autoconvergence although sometimes, like you, I prefer a fixed setting.

More for Likay:
Oh yeah, I read some other thread where you kept explaining something to someone and it just went on and on. Man, you deserve a metal or something. Wow, you really spent alot of time helping that guy. Anyway, good for you. I forgot which thread that was. Anyway...

l8r all.

PS: tried the dongle with White Line Coding and it didn't respond.

[Okta]

Ion have you built a shutter timing adjuster? Im considering one for my samsung plasma to maybe reduce the gohsting, wondering what teh cheapest and simplest form would be?

[iondrive]

Hi Okta,

the short answer is "not really". Here's the long answer:

Well, I started to, then got distracted for a long time. In its current form, it uses 4 555 timer chips (actually one chip is a 556 that has 2 555 timers on it). One pair is used for each of the leading and trailing edges of the square wave if I remember right. I did it that way because I didn't like the results from a 2-timer design. That was a little flaky/unstable/touchy. It needs more work to be usable and I don't know when I'll get back to it. I have alot of posts I want to make about various games and other issues. I don't know any links to give you off the top of my head.

Hmmm, you've been here a long time now so you know that you might still have some ghosting from light leaking through dark LCD glass and timing won't fix that.

Hmmm, a samsung plasma display...
Is the ghosting only on the top or bottom of the screen, or can you tell that the timing is way off because the 3d is so bad? I wanted to make a circuit that has a very short clear-time for use with some LCD monitors but that would just be for an experiment to see how bad it is. Is there another thread where you describe the ghosting in detail? I'm thinking that the plasma paints the image from top to bottom like a CRT but I don't really know if that's true. Also, what refresh rate would you like to run at? I was designing it for myself with a range around 60 to 85 Hz.

PM me next time because I just happened to check this thread by coincidence.

OK, I searched 555 timer and ragedemon and found this. It's a good place to start if you've got the inclination but I think you should have an oscilloscope so that you can actually see what the signal is doing because otherwise it can be bad and it's hard to know what's going on with it.

http://www.mtbs3d.com/phpBB/viewtopic.php?f=26&t=25" onclick="window.open(this.href);return false;

How bad is the ghosting? I get almost none with my projector but it lacks some range of brightness/contrast/color because of the shutterglasses and I guess because I spread the image out to 8 feet wide.

Point me to the other thread where you talk about this. I thought I saw that somewhere but was not really in a position to help just then.

--- iondrive ---

[The_Nephilim]

OK this is COOL. I need and inverter for my nVidia 3D Vision glasses. I have Parralex inversion and just use glasses upside down for now.

I do have an older Converter I bought from 3DFlightsim.com could I use that somehow??

http://www.3dflightsim.com/product/product_01.htm" onclick="window.open(this.href);return false;

I also have the 3D Dongle from ED but I would prefer using the Glasses from the 3D Vision kit??

here are my specs:
1. 3 Sharp XR10XL DLP Projectors

2. PNY 470GTX Vid Card

3. nVidia 3D Vision kit

4. Matrox TripleHead 2 go


Please help me get an inverter as wearing the Glasses upside down is a PITA..I tried using the ED Dongle but then my Matrox TH2Go unit did NOT work, it would not recognise it and I only had a single screen working.. Any other solutions for making an inverter??

[atariguy]

This is great stuff.

BTW, the X3D controllers have different initialisation methods to the edim controllers.
They flash two lines of pixels at the top of screen to set them into different modes (e.g. over/under, page-flip or interlaced)

I have managed to capture those lines of pixels and save them out as an image.

All you then have to do to activate the X3D dongle is display the relevant bitmap full screen for a second (using any image viewer program).

This means you can use the X3D controller on any card and any Operating System. It will even work with Bluray players, DVD players, consoles etc. as all you have to do is display the initialisation image once and then the hardware takes over, which is kind of neat.

[iondrive]

hi guys,

The_Nephilim:
I hate to post a lame "can't help you" post but I think your system is too dissimilar to mine. I have no nvidia 3d-vision or else I could play around with it. Did you try the registry hotkey hack at the top of this page. There's a chance it might work.

RUN the REGEDIT program and go to:

[HKEY_LOCAL_MACHINE\SOFTWARE\NVIDIA Corporation\Global\Stereo3D]

Find an entry called "GlassesSwitchDelay".
Set it to decimal 27.
Start a 3d test.

Eye-sync should now be reversed compared to previous condition.

Hotkeys: Hit Alt-minus to go back to previous sync and hit Alt-equals to undo that. You may need to hit them multiple times.

Neat device/converter you've got there. It's nice to know it exists but I don't see how you would use it here with the nvidia glasses. Too bad your Triple-head goes away when you try to use the old dongle. That might have been a way to use your setup if it worked but I guess you tried it enough already. Hmmm, maybe you could block the IR signal from the pyramid and make a re-transmitter with an adjustable delay. I guess that would work but I can't really make it for you or help you much there. Sorry. nvidia really should include an inverting option. It's just common sense that some people will need it in some odd setup. Hmmm, maybe you could use a VGA splitter like a Y-cable. Send one branch to your projector so that it can be ID'd by the computer correctly and the other branch to the E-Dim dongle and use the glasses triggered from that after using the ED-Activator. Sounds round-about but it might work. I know you'd rather use the nvidia glasses but it might be OK with the E-Dims. Well, good luck anyway.

Hey atariguy,
could you post the color-code info for your X3D controller to the Activator thread. It would be a welcome addition to the data. I'll have to re-test my X3D dongle to see if it responds to the ED-Activator colors because I thought that it did for sure.

http://www.mtbs3d.com/phpBB/viewtopic.p ... 505#p59505" onclick="window.open(this.href);return false;


Later all,

--- iondrive ---

[iondrive]

inverter plus junction box v2.5

Hi all,

My box got old so I finally upgraded it. It's now made with a small project box from Radio Shack. I considered using a different box like a soapdish box or candy container but it turns out it's hard to find a perfectly-sized box sometimes. Anyway, I finally soldered the connections, drilled some holes just by eyeballing the locations and I think it turned out well. Wiring is all the same as in post 3 in this thread. Daisy-chaining another box like this should be no problem so maybe I'll make another someday if need be and then that will enable 4 more viewers for a total of 9. In the following pictures, you can see the switch is labelled with an X and ||, and the input jack is labeled with a simple dot. Once again, panel-mounted jacks make it all pretty simple with no circuit board required. I think this will be the final version for me.

IJ-Box-outside.JPG

IJ-Box-inside.JPG

C'ya.

--- iondrive ---

[cybereality]

Looking good.

[iondrive]

3-pin DIN signal inverter for wireless emitter parallax inversion toggling

Hi all,

This is a continuation of post number 4 above ("wireless parallax inversion thing"). I finally built this thing but the design is slightly modified. Differences are that the two DINs are both female and the chip uses pins 3 and 4 instead of 1 and 2. Otherwise it's the same. Let's start with the parts list and picture and then I'll describe it.

parts list:
2 female 3-pin DIN panel-mount connectors, mounting screws and maybe nuts too.
1 SPDT switch (use any style you want. Mine is a push toggle on/off (not momentary) RadioShack part # 275-1555)
1 project box to jam all these guts into
7 segments of 2-inch long wire, 3 of those should be 30 gauge for the connectors. I used Shack's wrapping wire. Adjust length for the size of your box.
1 inverter chip - HD74LS04P
1 socket for the chip. Insert the chip after soldering wires to the socket to avoid overheating the chip. The chip has 14 pins but my socket has 20 pins. That still works fine and you may choose not to use a socket at all if you feel confident about not overheating the chip during soldering. You can bend the used pins out flat for easier soldering.

IR-inverter-guts.JPG

Key things to know:
- the input is on the left, output is on the right.
- the chip is on its back for easy pin-access for soldering.
- Basically there are 4 contacts here: 5V, ground, signal and inverted signal.
- blue wires are crimped onto DINs, other wires are soldered.
- the two DINs are upside-down from each other for easier wire routing. Normally if you put connectors back-to-back you get a 123-321 alignment but if you flip one upside-down, then the wires can go straight across as in this case.
- left DIN has alignment square on top, right DIN has square on bottom. Refer to the schematic in post 4 above for the pin-numbering just to be sure. Ignore the male DIN in that image.

Wiring:
5V - upper blue wire goes straight across to output and orange wire goes to power chip's pin 14.
ground - lower blue wire goes straight across and green wire goes to ground chip on pin 7.
input signal - middle blue wire from left goes up to left terminal of switch, then down to input on chip's pin 3.
inverted signal - comes from chip's pin 4 and goes up to the right-side terminal of the switch.
output signal - blue wire comes from center terminal of switch and goes to output's middle pin.

other things needed:
2 male 3-pin DIN plugs - not pictured. Use these to make a male-male extension cable of a length of your choice. This connects your dongle to this box.
Wiring for above.
wire-strippers or razor for stripping insulation. RadioShack has a wire-wrapping tool with a very useful 30-guage wire-stripping tool hidden in it's handle. Just pull off the top.
pliers to crimp down on pins of DINs after inserting wire. Don't let it slip out or you'll have to solder it.
Drill and bits to put holes in box.
screwdriver, soldering iron, solder, wicking to undo mistakes.
electricity, eyes, arms, hands, torso.

dang, seems like alot for a such a small project.

boxing
This has been tested and it works but I still have to jam it into the box. Hopefully I won't break any of those thin 30 gauge wires when I do that. I'll post another image here later. The box is 3x2x1 inches and is kind of small. You might not like it that small. It's part number 270-1801 from RadioShack. It has some ribs on the inside that interfere a little with the mounting of the DINs but it's awkwardly manageable. Some boxes come with a circuit board inside but this one doesn't. If you want easier construction, you might want to mount everything on a circuit board, you just need a board-mountable switch. The DIN pins will fit into the holes but it's very tight since they are in a triangular arrangement. I think that's it. Ill add more if I think of anything.

--- iondrive ---

[cybereality]

Wow! That thing looks serious.

[iondrive]

Hey, you forgot a smiley to show you were kidding. It's only 7 wires after all. It's in the shape of a cross so you can also use it to ward off vampires.

I got the bigger drill bits I needed and made the holes and jammed it all in the box. The switch sticks out a bit since it's so tall and the box isn't so tall but it all works so that's good. I still have to make the extension cable but that can wait. I tested it with some jumper wires since that's easy with female connectors and now I'm posting the final pics. It works fine as a footswitch as long as you're gentle. The button was placed off-center so that I can use the box upside-down if I choose so that the whole box is like a foot-pedal switch. It turns out that doesn't really work so well since it's a little wobbly. I could fix that with a stabilizer but I'm happy using it right-side up. As I mentioned elsewhere, this switch does not indicate if you are inverting or not inverting the signal since it looks the same either way but that's OK with me. I'm calling this box a switchable-inverter or swinverter. I thought it was a good swapportunity.

swinverter-inside.JPG

swinverter-outside.JPG

Finally, if you have a special situation like The_Nephilim, you can read through his thread. Page 5 has a nice diagram for a bypass switch in case you have cables with a non-switchable inverter in the middle:
http://www.mtbs3d.com/phpBB/viewtopic.p ... 635#p71635

bye now.

--- iondrive ---