MultiTouch

Improved LCD FTIR

Posted by Nasir Aziz under Uncategorized

Just improved upon my existing LCD FTIR setup. Fixed LEDs/resistors, replaced the camera from XBOX Live to PS3Eye with AlexP’s drivers. Demo here is from the same exact setup with the new improvements.

Also worth mentioning is that these results are through a NonCompliant surface - just bare Acrylic in a normal well lit room. Performance and response with PS3Eye camera and TBETA For PS3Eye is way better. Video might look a little choppy but in real life the results are super smooth. I’ll see if I can capture it without the chops again. In the meanwhile check it out.

• LCD Screen: 17”
• 8 LEDs on each side(8×4 = 32 LEDs total) - evenly spaced
• LED Wavelength: 880nm (SFH485: 5mm)
• 1 Ohm 1/4 W resistor per 8LEDs
• 12 VDC 1A Power to light up this array.
• Acrylic: 5mm thick (Got it from Home Depot. Its thinner than what others have been using here)
• PS3Eye Camera. Removed the IR Blocking Filter. Added an exposed photo negative 1 strip only as a filter.

Also had to grind the PS3Eye lens holder base a little for focus purposes. Once you remove the IR Blocking Filter from the lens, you’ll notice that the camera loses focus. You can either add a new similar thickness filter lens to get the focus back or if you want to go the cheap route like in my case, for that you’ll end up grinding the lens base a little (2mm roughly I guess) for focus.

My First LCD FTIR Project Completed

Posted by Nasir Aziz under MultiTouch

So finally I was able to complete my first LCD FTIR Multi Touch Screen project. Once I gathered all the materials listed in the previous post, the housing of it all became an issue quickly. Meaning I didn’t want to initially set this up as a table top. I kind of wanted to have this on my desk so that I can play with it like a regular desktop computer setup.

 Anyway, after some thought and an available resource, assembling and putting this whole setup together became clearer. I had an old Sony Trinitron 19″ CRT lying around at the house. Works but yeah who uses CRTs anymore? So I gut the whole thing out and left just the shell, meaning the body of this old and about to be recycled monitor.

Size and depth wise it turned out to be perfect for housing all of the LCD components. WebCam went all the way in the back. In front I attached Acrylic Sheet surrounded by IR LEDs in the inside followed by LCD, then LCD plexi type base, a diffuser that came with it plus original backlight tubes. The LCD power and other components were attached to the shell ceiling. Well it did take a little while to plan this out but was definitely faster than building the table for it.

After long hours of putting this together, it ended up looking like an actual regular monitor - except it ain’t.

Here are some pics with some descriptions and then the video in the end.

Sacrificial LCD has been identified:

Operation LCD begins:

Getting closer:

Hmmmm, more layers to peel off:

Aha, so this is what it really looks like. Seems like all the circuits can be folded, we are good to go:

Sony Trinitron 19″ CRT Monitor case, to be used as housing for this project. Camera was initially mounted with the tape just to test the depth and view. Final version has it mounted on ceiling in the same fashion but properly with base glued on a mount etc.

The end product, doesn’t it look like just another regular good old CRT Monitor?

Ok, enough with the pictures, lets see the results:

Already thinking about improvements and a new Projector based MT project.

Stay tuned…

LCD FTIR Project

Posted by Nasir Aziz under MultiTouch

Started my first LCD FTIR Project a week or so ago. I’ll start posting pictures and updates here as soon as things progress:

 So far I have gotten the Acrylic on top of LCD in place. Acrylic is lit by 4 arrays of IR LEDs (8 in each array). Getting very nice Blobs already even through the LCD.

Items acquired for the project:

1. Dell 17″ LCD Monitor
2. Acrylic Sheet from Home Depot
3. XBOX Live WebCam: Removed IR Filter from it
4. SFH485 IR LEDs from DigiKey website
5. Aluminim rails: For LED mountings around the Acrylic Sheet (Home Depot)

Already have:

1. Windows Vista Laptop
2. Old CRT Monitor
3. Power Adapter for IR LEDs
4. Tools
5. Soldering iron etc.
6. Misc workshop type items/tools

I’ll start posting pics and more detailed descrptions as soon as I get to it. Plus cost and the references to items I used.

Here is what the scheme looks like at this stage:

Microsoft Surface at Rio - Las Vegas

Posted by Nasir Aziz under MultiTouch

Here’s a good example of surface computing use in social setup:

Enjoy!