Cheaper 3D glasses for Nvidia 3d vision !

Rayman

I'm on the bleeding edge here getting a 3D projector working with the NVidia solution...

One issue is that extra glasses are $120 or more...

Anyway, I just got some cheap wired glasses, 2 for $30, off Ebay.
Found the timing and command format for the IR emitter off the web...
I think it'll be pretty easy to wire up a photodetector to a Prop and drive the glasses. I've read the glasses want 25V to work the best, so that's one issue I'm looking for a solution to...

So, I'm thinking that for maybe $40 or so in parts I can make some extra glasses. May not be too pretty, but I'll have fun doing it anyway...

Tired2

Rayman,

That sounds like a fun project....

Not sure if you are asking for advice or not, but you might look into a Toshiba TD62783 series. You can hit them with 3.3 v and they will output whatever you feed in VCC, up to 50v. They source up to 500mA I believe, per channel on 8 channels. Should be enough to run some glasses.

Do you have a projector that does 60Hz? I'm behind the times.

Rayman

Thanks for the tip. That chip sounds great, but a little overkill... Just need 1 channel and a few mA (maybe 10 mA or so I believe). But, I'll definitely take a look...

I suppose the way to make this affordable is to make one receiver box that several glasses can plug into. They wouldn't be as wireless as the regular glasses, but much more cost effective...

BTW: The projector does 120 Hz...

Rayman

I looked at the TD62783, and I see it's an octal switch basically...

But, I think I can just switch 25V with a mosfet or transistor.

What I need to figure out is how to generate the 25V from 5 or 3.3V.
I have some LED drivers that may do it, but that might be a hack...

Rayman

I was just looking at this page:
http://www.epanorama.net/documents/pc/3dglass.html
that says you need to apply AC voltage to the glasses...

Now, I'm not so sure I know what I need to do...

PJAllen

What's the Propeller connection?

How is this related to the Propeller?

There is no mention of the Propeller.

Rayman

yes, see the first post...

You need a microcontroller to interpret the IR signal and control the voltage on the glasses accordingly...

Rayman

I've got more people coming for Thanksgiving that I have glasses, so I decided today to make this little project top priority.

It occurred to me that the easiest, although perhaps not cheapest, way to generate the ~25V AC signal from the Prop was to use a transformer. I happened to have one with about the right turns ratio and it actually works. I just toggle a Prop pin at about 4kHz and the 3.3V gets turned into a ~20 Vpp wave. It's kinda an ugly, drooping square wave, but it seems to work.

I looked in my stash for an IR photodiode, but I can't find one. But, I see RadioShack has some in stock, so I'll drive there tomorrow...

Here are some photos of my test rig:

Rayman

Got the hardware done last night. Using a little Propmodule.com proto board for the Prop Platform that Gadget Gangster gave me. Now have both transformers working and added in a transisitor to boost the glasses voltage up to a perfect ~20 Vpp. The IR receive circuit works well, although the range is only ~2 ft. But that's OK because my glasses have very long cords.

Here's a photo of the hardware that plugs into a Propeller Platform. Also, I'll show the voltage on the glasses and the two IR codes I get from the Nvidia transmitter.

The codes I see are different from what I found on the web...

Now, I've got about an hour to write some code...

Rayman

It works! I'm cheating by just waiting for the start of an IR signal and then checking the signal again 50us later to determine which side should be on.

It's useable now, but there's a hint of flicker I still need to get rid of before it's as good as the NVidia glasses...