creating your first multi touch table

8/12/2019 Creating Your First Multi Touch Table

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http://www.instructables.com/id/Creating-your-First-Multi-touch-Table/

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Creating your First Multi-touch Tableby Jamaal_7lna on November 25, 2013

Table of Contents

Creating your First Multi-touch Table ...............................................................................................

Intro: Creating your First Multi-touch Table ........................................................................................

Step 1: The Planning (Information) .............................................................................................

Step 2: LCDs, the FFC issue, and Before Ripping (Information) ........................................................................

Step 3: Steps in determining your LCD screen dimensions before-hand (optional math information) .............................................

Step 4: Making a Box . . . ! (Hardware) ..........................................................................................

Step 5: Ventilation concepts and laying the support (Hardware) ........................................................................

Step 6: Re-purposing your Television--a step by step guide (Hardware) ..................................................................

Step 7: Giving Life to your table (Hardware) ....................................................................................... 1

Step 8: LED Setup (Hardware/Circuits) .......................................................................................... 1

Step 9: Acrylic Setup/ IR setup (Hardware) ....................................................................................... 1

Step 10: Did I break it? Testing the TV (Hardware/Information) ........................................................................ 1

Step 11: Understanding the software (Information) .................................................................................. 1

File Downloads ........................................................................................................... 1

Step 12: Choosing an OS (Information) .......................................................................................... 1

Step 13: CCV, Touch Injector and the Cleye + CCV tests (Warez) ...................................................................... 2

Step 14: Calibration (Software) ................................................................................................ 2

Step 15: Test run (Software) .................................................................................................. 2

Step 16: Done!!! (Happiness) .................................................................................................. 2

Related Instructables ........................................................................................................ 2

Advertisements ............................................................................................................... 2
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Intro: Creating your First Multi-touch TableIt has been a long time since I've contributed to this website--going on to a year almost--I was trying to accomplish a personal goal that was in the making since my earlyhigh school years. This instructable has taken 2 years of independent research and setbacks, but it is finally here. I present to you the complete guide to building apersonal Multi-touch table at home with basic design and engineering skills ( I will attempt to fully explain every detail so that even a beginner can find success!). Mostmathematics have been performed so the only fear regarding this project is the fact that it will take some time to put together . . . and some money.

As with every project, here is a bit of back-story:

When I was in my freshman year of high school, I was invited to attend an engineering "field day" taking place in Alabama's Redstone Arsenal. Although most of what wewere shown during this trip were projects that I am not able to speak about, one of the more relaxed projects was the Multi-touch table. I am not allowed to say what thetable was being used for--I've forgotten either way--but I can speak about its features. The table shown to us was a 30" Microsoft Pixelsense (then known as the Surface,before the tablet took its name) and to me, it was glorious. As a connoisseur of Natural User Interfaces (NUI), I'd always been fascinated by 3D spatial projections ( whatmost people call holograms) and anything of the like. I had never seen of these before so it would be easy for anyone to imagine my excitement. I asked the Projectmanager about what it would take to work with one of these and how I could be involved. You could imagine my disappointment when he told me that although it wassimple, it wasn't anything that I could ever make by myself. This very conversation sparked a 5 year personal vendetta against that one employee that led to the creationof this instructable--as a hobbyist. I enrolled in optic courses and searched through every crevice of the Web until I had enough information to build my own table. I hadtwo very important personal objectives:

1) Educational: To gain experience in NUI technologies and help spread this knowledge to students willing to learn via independent projects. I planned to stimulateinterest with the introduction of a hobbyist-made Multi-touch table in order to engage myself deeper into NUI technologies2) To create a product that was better than the table I was shown in my early high school years: bigger, faster, cheaper, and more efficient.

Thus, I can now say that the goal has been met. Now I can share this knowledge with all of you.

Also, a great amount of credit shall go to these mentioned organizations as they facilitated my goal. Without them, this would have taken much longer!NUI group --this collective of hobbyists and professionals dealing with NUI technologies shall gain the bulk of my credit. They taught me everything I needed totheoretically build my project and assisted me through every setback I encountered. They are also responsible for teaching me--above all things--how to conductmy own research. I strongly advise anyone who reads this to visit their website and forums.Ideum -- who would have thought that an established company would be so eager to lend a hand to an enthusiastic student? I literally called the hardwarespecialist at the time and asked him a bunch of questions, and he replied to each with informative tips. This company also led me to discover the NUI group andpushed me toward making my project bigger. If you get a chance, check them out too. If anything, they are a great source for inspiration.

**Note: I advise you to finish reading the guide at least once before starting.

**Disclaimer: I am not to be held in any way responsible for the damage you may inflict upon your equipment nor to yourself.

Notes on reading this guide:

This project was conducted with 3 other f riends, and the table is currently housed in one of the member's college dorms. As I am writing this alone and since Iconducted all of the planning and designing, I will refer to myself when I speak of things that are design related. I may also refer to the group as a collective in thearticle, hence my using of "we" on the occasion.This will be a very long instructable. My aim is to make the most detailed instructable in order to increase interest in NUI tech, but above all, for you to understandall that you are doing as you are doing it.You may PM me for clarifications if needed.I may use the word "warez" if referencing to the collective software as a plural noun.Each section is pre-labeled in the tit le, allowing for your easy navigation. "Information" refers to my explaining theories, plans, mathematical or physical concepts,tools, etc. "Hardware" refers to sections where I outline the steps to take in actually building the hardware for the table. Finally, "software" or "warez" refers tosections where I explain how to set up software.

List of Contributors: As you may have noticed, this account is the property of a collective of currently enrolled college students. The list of contributors for this project are:

Kareem Garriga (UAHuntsville)- Project Leader, Designer, Planner, Writer, Researcher, Photographer.1.Joshua Deaton (UAHuntsville)- Software Guru, Hardware help/ construction engineer, room provider.2.Jarrett Turman (UAHuntsville)- Hardware engineer, co-designer, Web blog manager.3.
http://ideum.com/http://nuigroup.com/go/lite


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Step 1: The Planning (Information)This will be the longest step for you since there are many variables to consider. It all depends on what you aim to accomplish. My table cost me an approximate $2000:

1. Vizio E471VLE LCD TV................................................ ~$600Target Purchase

2. Wood, screws, tools, and brackets.............................. ~$150Home Depot Purchase

3. Extra screws from home depot.................................... $3.824. Sample 2-way mirror.................................................... $10.80 (not needed at all)

Wanted to experiment with skipping the use of a diffuser.5. LED power supplies..................................................... $134.80

They will come recommended once you choose your appropriate LED reel6. Acrylic.......................................................................... $492.98

i. Evonik Industries ACRYLITE LED (Endlighten), sheet, Colorless 0E012 XLii. Evonik Industries ACRYLITE Abrasion Resistant, sheet, Colorless 0A000 MR2iii. Evonik Industries ACRYLITE FF (extruded), sheet, Colorless 0A000 GT

7. LEDs............................................................................ $216.95LED Lights World Flexible IR Tri-Chip LED Strip (We purchased the 300 LEDs in a 5 meter reel)LED Lights World Flexible White (we got the reel with 150 LEDs)

8. Cameras...................................................................... $239.25(2) Peau Productions Developer Camera (m12) w/ 850 nm Bandpass Filter and 2.5 mm lens.USB extension cable

9. Computer..................................................................... $0.00 (used my friend's)

As you can see, the specifics (as in amount of screws or type of wood) have been omitted. This is done to encourage creativity. As my project was a prototype, thedesign was made very simple. As of now, I am working on reducing the height of the table from the initial 3 ft to 1-1.6 ft; thus, giving a specification on the amount of woodand screws would be useless as I would only lead you to spend an inappropriate amount of money. Had I done the project correctly the first time, we could have savednearly $75 on Wood and screws alone.

We are going to be building a 47" Planar Infrared-based Multi-touch table using the Diffused Surface Illumination (DSI) Technique. This technique is not recommended ifyou aim to read objects (that are not fingers)--also known as fiducials--unless you plan on not using the diffusive panel of the LCD. It is also not the best to implementwhen using an LCD, but it i s the most convenient due to requiring less materials and work. I chose this one because of the convenience.

Theory:

By Diffused Surface Illumination (DSI), we place Infrared (IR) Light-Emitting Diodes (LEDs) around the edges of a special type of acrylic known as Endlighten Acrylic.This acrylic is manufactured with special properties akin to having microscopic mirrors that evenly distribute the light across the surface of the acrylic. When your fingertouches the surface, it creates a "blob" on the surface--it interrupts the evenness of the light. This blob is then to be read by the specialized camera and recorded as a"touch event".
http://www.peauproductions.com/main.htmlhttp://www.ledlightsworld.com/http://corporate.evonik.com/en/Pages/default.aspx


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Comparison to PixelSense:

The first PixelSense used a different technique called Rear-Diffused Illumination ( Rear DI). By Rear DI, the maker is required to use IR illuminators on the underside ofthe screen. Because of this, it i s nearly impossible to create using LCDs due to the IR light reflecting from the back panel. Thus, people will usually use a short throwprojector (usually more expensive if you want HD quality). All in all, DSI allows for higher visual quality at a reduced price. Input detection remains the same.

Why make one of these when you have a smartphone?

Typically, smartphones and tablets use either capacitive, resistive, or surface acoustic wave screens in order to detect user touch points. Capacitive uses the electricalproperties of human bodies in order to detect user inputs at certain points (the skin of your fingertips). Thus, devices using this screen are highly sensitive and neglectpressure--meaning that users cannot use regular styluses or gloved hands. In addition to this, the cost for capacitive layering on a large scale project would betremendous.

Resistive screens simply rely on pressure as they are built by layering screens. For resistive, there is an inconvenience in that building this setup would require the userto create layering patterns with little promise of multi-input detection.

In Surface Acoustic Wave (SAW) screens, when a panel is touched, the ultrasonic waves exerted in the panels are absorbed at those points and this registers a positionfor touch events to the controller for processing. This would be burdensome if applied to larger screens.

However, infrared technology holds the advantage of being able to deliver superior images without an overlay while granting the ability to detect most objects. Also, theability to use fiducial markers (programmable blocks). Also, they tend to have the higher number of Maximum touch inputs.

What is the first thing to worry about after I have my design plan ready?

The first thing you should worry about is your LCD TV. You won't be able to use just any TV as there may be issues. I will explain this in more detail soon.

Step 2: LCDs, the FFC issue, and Before Ripping (Information)The LCD is perhaps the most annoying hardware component regarding the setup of an LCD DSI table due to the FFC Issue--I will get to this soon. But first, a bit ofinsight: It is mildly important to understand how LCDs work for the purpose of explaining how the table works. Also, since we are taking one apart, it is important that weunderstand what each component does.

I. LCD theory

LCDs are an amazing piece of technology that remind us of how amazing and progressed our technological prowess has come. At the core, they rely on Liquid Crystals(LC). LCs are materials that are literally in a state between liquid and solid states of matter--this means that their particles maintain their orientation, yet they are able tomove around to different positions akin to liquid state materials. Thus, they are highly sensitive to temperature changes ( they must be at an exact temperature tomaintain their odd state). For LCD screens, LC particles are usually arranged in a twisted nematic phase. This only means that they are affected by electric current(nematic) and are naturally twisted. When we apply current to the LC substrate, the LCs untwist varying degrees depending on the voltage--which allows them to reactpredictably in controlling the passage of light. The orientation of the particles in the natural state depend on either a magnetic field or microscopic grooves. The change inorientation (for most LCDs) is described as either smetic c or chiral nematic. The smetic c orientation holds that the particles are layered in such a way that they tiltslightly in angles with each layer while the chiral orientation sees the molecules untwist slightly from layer to layer.

II. LCD creationFor the LCD screen construction there are 4 factors that are fundamental:

Light can be PolarizedLCs can transmit and change polarized lightLC structure changes with currentThere are transparent substances that conduct electricity

There are many types of LCD screens such as Passive and Active Matrix LCDs, but since we are most likely only dealing with an Active Matr ix, I will only explain thisone. Active Matrix LCDs depend on Thin Film Transistors (TFT) which are essentially tiny switching t ransistors and capacitors. They are arranged in a matrix fashion on aglass substrate and to turn a pixel on, the row corresponding to that t ransistor is turned on and a charge is sent through that column. Since the other rows are off, only thecapacitor at that row is receiving a charge--theoretically knowing that Capacitors can change current instantaneously, this is explained and we also factor that the chargecan be held until the next refresh cycle. Controlling the voltage, one can untwist the LC enough to moderate the amount of light that passes. This allows for the creation ofa gray-scale.

So how do we get color?

Each Pixel has 3 sub-pixels (red-blue-green{RGB}) and they each have their own transistor. each sub-pixel allows for 256 shades within their own gray-scale for a grandtotal of 16.8 million possible colors on your screen. this is true unless you have a fancy yellow pixel LCD display as we get the possible colors from 255^3 for the 3 sub-pixels.

How many transistors are we talking about?


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Depends on the display. A 1024x768 TV has 1024 columns and 768 rows, so if we multiply that by 3 pixels, we get 2,359,296 TFTs etched onto the glass panel. If thatdoesn't impress you, wait until you see how thin the screen really is and what happens when you turn it on away from its casing!

Why should you care about all of this?

In building your table, you are going to have to make predictions and decisions. You won't always have a perfect display built. Sometimes, you're going to have to figurethings out from the fundamentals in order to make sure you didn't just waste $$$$. Also, depending on your setup, you may have to predict the display size of your LCDbased on the properties of the screen. More importantly, this is knowledge! so take it in!

III. Things I should worry about in regards to the TV I will use for the table:

The FFC Issue as defined on the NUI Group Forums is when the FFC cables are either too small or fragile to be manipulated into building a Multi touch setup.1.The Flat Flex Cable is the cable that you will find connecting the LCD matrix to the Control boards. This can become a problem as they are hard to replace and ifthe get in the way of the construction, they may cause accidental damage. Fortunately, there are links to databases with TVs that do not have this problem andare perfect for Multi touch setups:

Small LCDs: http://baseportal.com/cgi-bin/baseportal.pl?htx=/L...1.Large LCDs: http://wiki.nuigroup.com/Large_LCD_Monitors2.Alternatively, you could just stick with the Vizio as it is perfect3.

The Aspect Ratio: You need to know your aspect ratio so that you can approximate the size of your LCD in order to create your chassis, or box. Most LCDs2.nowadays are 16:9 since this is the HDTV Standard. That is, 16 units of height for 9 units of width. Use similar triangles (yes, math) in order to determine the sizeof your LCD screen. Of course, this is only necessary in the case you do not want to rip the TV apart until you have everything else (Acrylic, wood, etc).Contrast Ratio: This is the measure between the brightest possible image and the darkest possible image. White/Black = Contrast Ratio. Unfortunately, there is no3.actual metric to standardize this so companies just exaggerate things such as 1000000000:1 (who knows what that means?) This matters only in terms of vanity--say you wanted the clearest possible image to be displayed on your LCD. An LCD with a high dynamic ratio is better than an LCD with a native that gives thesame ratio; however, an LCD with a higher native ratio is superior. Native describes what the LCD is able to produce on its own and dynamic refers to usingcircuitry to assist the panel in accordance to ambient light.

What about glare when the LCD is laying down?

The LCD screen comes with a set viewing angle that ensures the best possible picture--most consumer don't know this and miss out on the full experience. A Bias angleis designed to offset this angle. Because of this, your angle of acceptable viewing is made much larger. There is still an area of unacceptable contrast, but you will mostlikely not reach it.

*You can learn a lot more about LCDs on HowStuffWorks.com:

Link: http://electronics.howstuffworks.com/lcd.htm

Step 3: Steps in determining your LCD screen dimensions before-hand (optional math information)The first thing to do in determining the LCD size is to find out what your aspect ratio is. The beautiful thing is that LCD retailers are required to release a specs1.sheet concerning the capabilities and basic information regarding the TV. In these, the most notable of specs is the aspect ratio--usually 5:4 or 16:9.Next, determine the size of your diagonal from these sheets. A display that is 47" isn't exactly 47" (it may actually be 46.85 or 46.96, which actually matters). Find2.this on your spec sheets and write it down.Next, use triangle-angle relationships to determine the angle opposite the horizontal and vertical measurement of your display using the aspect ratio.3.

For example, a 16:9 ratio LCD will have 16 units of measure for the horizontal component and 9 for the vertical. The angle opposite is the given by cos1.(16/proper diagonal measure). For a television of a 46.96" diagonal, Cos(16/46.96") = 60.64224646 degrees, which makes sense.

Next, setup a similar triangle diagram where the 16:9 is within the LCD. You are to find the X and Y components of the outer triangle. You use law of sines with4.the angle determined above to find this.

For example, following our calculations, [Sin(60.642)/9] = [(x/46.96")/x] given that y = 9x/16.1.This will give you an approximation of 40.92918722/23.02266781 which falls under 16:9 ratio when reduced. This however, is not exact but fairly close.2.
http://electronics.howstuffworks.com/lcd.htmhttp://wiki.nuigroup.com/Large_LCD_Monitorshttp://baseportal.com/cgi-bin/baseportal.pl?htx=/Lumenlab/main


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Step 4: Making a Box . . . ! (Hardware)The First step of the hardware process is to build a box that will hold all of your components together. This step will be where your design starts taking a new lifedepending on whether you want a coffee table, a display monitor, a station, etc. I am currently in the process of modifying my box and make a coffee table. Once that iscompleted, if anyone is interested, I can upload some pictures and describe the build process. The pictures above are very simplistic due to our table being built as aprototype that was ultimately going to be modified either way.

I. Things to take into consideration when building the box:

Is your box the right size to hold your LCD screen? This is where aspect ratio comes into play. You need to make sure your layers won't fall through and that the1.LCD cables/components won't get in the way. Also, make sure you can make it mobile (it can fit through doors)Where will your computer be? You may not want to put the computer or the LCD components inside the box unless you are willing to include compartments on the2.underside for them as they will interrupt the image on the LCD and the camera's ability to track your fingers.Ventilation: The Cameras won't get too hot, but if you do decide to conceal the computer and LCD components (which does make it look nicer), you may want to3.invest on some ventilation. You can use a couple of in/outtake fans for this if you want.Are you accommodating for cabling? Make sure you have a plan in mind for neatly placing the cables in your table. One cable over the camera makes a4.significant amount of interference.Is your structure strong enough to hold the Screen layers? you have about 32-45 lbs of screen to hold and the additional weight due to people putt ing their hands5.on your table.A door? It may be a convenience to add a door so that you work with the LEDs and Cameras without having to remove your layers.6.Is your box closed? You should enclose your setup so that the white LED light do not escape your box7.Remember that Home Depot will cut the wood for you: You can get the exact amount you need and pay less. You must do this before checkout though.8.

II. Things we should discuss:

Your LCD panel has a back plate that acts as a partially reflective mirror in a sense. On your TV, you will mostly likely f ind fluorescent tubes. These are known as1.the back-light and their sole purpose is to provide the base light that the LCD screen will use. The panel also contains the polarizers necessary for the LCs tocontrol the light. We are going to replace this entirely with the LEDs. Why? The tubes are too weak to provide the lighting necessary for the LCD to work once thedistance is increased--and you must increase the distance so that you may accommodate for your cameras. Also, the tubes are very fragile and risky. The whiteLEDs will be placed on the bottom of the box in order to make the screen show an image. Additionally, for this to work, they must be place around the cameras sothat they are not in the way. the cameras should also be elevated so that you don't get too much light interference.You may want to first sketch your design or create a model using a CAD program. You can get Google Sketch-up and it will work wonders for free. It also has a2.built-in tutorial and gallery. You can find the Ideum MT50 table CAD file there too if you want a bit of inspiration.

Link: http://google-sketchup.en.softonic.com/ 1.You MUST calculate the distance needed between your camera and screen in order to determine the size of your box. I used two cameras so that I could stitch3.the two feeds together and reduce my height by three times. Normally, this means having to calculate angles and ray diagrams. Thankfully, the NUI forums has athread where Peau Productions created a lens calculator that may help simplify this. Please use this before purchasing your cameras or buying the wood. Also,consider looking through the projects on this forum.

Link: http://nuigroup.com/forums/viewthread/12777/ 1.

Consider putting the table on wheels. It will increase mobility and give your design an edge.4.
http://nuigroup.com/forums/viewthread/12777/http://google-sketchup.en.softonic.com/


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Step 5: Ventilation concepts and laying the support (Hardware)As laid out in the previous step, you may want to start thinking about ventilation for your chassis. As pictured above, our simple setup opted for neglecting this step as itwas only a prototype. You may want to consider it depending on your component and screen positioning. Remember that IR is also heat, so you may need a system toremedy problems relating to this if they arise. As far as layering for now, consider adding various lips and edges to your table. Remember that you will need a place tohouse a mouse and keyboard for initial setup and t roubleshooting. Also, If you are considering to lay a shell over your box as a design choice (as we did), you'll need away to support the acrylic. We personally ordered our Acrylic to be larger than our LCD screen in order to have the effect of a floating LCD screen. If you aren't expectingany children or aggressive people to touch your screen--the Endligthen layer is very easily scratched--you may even replace the extruded FF with the abrasion resistantlayer. All in all, lay a piece of acrylic for support. If you are a careful person, use the abrasion resistant layer as a support. If you don't want to risk anything going wrong,use the extruded FF.


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Step 6: Re-purposing your Television--a step by step guide (Hardware)The following is a guide to r ipping your TV apart. Remember, proceed only after you have either:

a. Made sure your TV avoids the FFC issueb. Are comfortable enough to rip your TV apart.c. Understand that I am not to be held responsible for the damage you cause, nor the risks to your lives.d. Have read this section at least once.

Taking apart the TV:

Of course, the first thing to do is turn off the power and remove the AC cable and gently lay the television screen-down on a flat and stable surface.1. With a screwdriver, unscrew the screws holding the back-plate in place and remove the back-plate.2.The Main Board: This is the most obvious piece you'll find. It is a circuit board that contains the audio and video inputs for the TV. You'll see the HDMI, USB, and3.S-video ports. This houses the CPU (on some TVs) and is also referred to as the Motherboard or the Main Module.Power Board: This is the odd looking circuit board. 98% of the t ime, it will be a brownish-yellow color. This one is the bulkiest/heaviest of the boards and houses a4.couple of capacitors, inductors, and heat-sinks. This is most obviously the power supply board as this is where the AC cord will connect to. Fun fact: Many times,people will replace a TV they believe is damaged when the only actual problem may be that a single Capacitor has blown. Seeing as how one of these may cost acouple of cents, it's funny how we'd pay over $400 for a $1 fix.Inverter Board: Long thin board along the edge of the display. Contains several transformers and performs logic operations regarding back-light and the display.5.T-Con Board: the Smallest board and is a Logic Board. Mostly contains the CPU (on some TVs) and processing chips.6.Speakers: you can either keep them or replace them with better ones. Choice is yours.7.LED for TV symbol: a simple LED that lights up as an indicator that the TV is on. You may want to keep this around.8.Circuit board for buttons: This i s just a circuit board found on the side where the on/off, channel, volume, etc switches are. You may not need this.9.A set of long flat cables: these are the FFCs. The Vizio has 3 ft cables which is beyond perfect.10.Take a picture of everything. You have to remember each connection for each component so that it can reconnect.11.Safely remove all the components and unscrew the boards from the back. Remove the speakers and everything. The connectors are usually Zero Insertion Force12.(ZIF) connectors. Keep one end of both of the FFC cables connected to the Inverter Board.


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You will see a metal back-plate with holes. Through those holes, you will likely see white sheets. Those are the diffusers and we are trying to get to those.13.Unscrew the screws holding the plate together and remove the plate. To do this, we have to take the front plastic casing off so you'll have to flip the TV. Do thiscarefully as you do not want to risk damaging the LCD panel.Take the casing off and work your way unscrewing until you get to the LCD panel. Gently and safely remove the connectors to the panel. The green and brown14.connectors DO NOT come off. If it looks like it won't come off, it most likely won't. Be very careful here.Lay the LCD panel safely on a flat surface and wrap it with a blanket or something that will protect it. The panel is ~2 mm thick and thus, easily warped. Have a15.friend help you handle it so you distr ibute the weight evenly. Now think back to all that theory you read in the previous section and be amazed at how compact thepanel is.Right under the LCD are the white diffusers. Take care as they are likely to be statically charged. The diffusers serve to evenly distribute the white light under the16.panel from the back-light. You may not need all three though. We opted to use the thickest one as the others did nothing for us. The case may be different for you.For now, just keep them until the testing of the LCD display.Do what you will with the back-light. If you opt for a size < 25" diagonal, you may actually make the factory light work and circumvent the cost of white LEDs. If not,17.do what you will with it--for the purpose of this table, it is no longer needed.

**Need more Pictures? This gentleman over at the NUI Forums was the one responsible for t ipping us on the Vizio. He also did a tear down and included a couple ofpictures worth taking a look at. I lost most of my pictures in transferring them from my phone so I used his as my first image on this section. Credit goes to him on thatnote.
http://nuigroup.com/forums/viewthread/14486/


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Step 7: Giving Life to your table (Hardware)Recall the last section where I advised you to take pictures of each and every connection. This is where all will come in handy. In this section, we will be essentiallyrebuilding the LCD TV on your box. How you do this is going to depend solely on how you chose to design your box a couple of sections back. As for our team, wedecided to go with designing an inner box that would later be concealed within another outer box. We simply used wood screws to screw the boards onto the back side ofthe inner box. The important thing to consider is to be careful that you don't crack the boards while screwing them onto the wood. For now, disregard the LCD panel. Donot place it until the next section as we must discuss the layering for the table. However, you do have the option of placing your computer along with the boards of theLCD. There is a great amount of flexibility when choosing a computer. To be honest, as long as it has over 512 MB RAM and is HDMI compatible, the computer willperform nicely. Any recent/decent PC will do--even a laptop if you so wish. We'll talk operating systems later on. For now, just choose your favorite as we have to seteverything up.


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Step 8: LED Setup (Hardware/Circuits)Now we will set up the LED back-light and Cameras. This part is fairly simple and will only require minimal knowledge of soldering.

I. Camera setup

Assuming you calculated the height of your table based on your camera lens as I advised in the previous planning sections (or have prepared an appropriate1.platform for elevating the cameras to their needed height), place the cameras where they need to be. You need to perform the above calculations for centeringyour cameras as well.

****If you do not yet understand how to perform any of these equations, you can PM me and I will try to help. You simply use the FOV for the camera to1.determine a distance from the screen where the cameras can see portion desired from the screen. This should give you an idea of proper height andplacement for the cameras.

As pictured above, we used Duct Tape to keep the cameras steady. This is because we were still experimenting and making sure that our calculations were2. correct. The cameras I referenced you to from Peau Productions have certain sections for you to screw the in place when you are satisfied with their position. Ishould advise you not to do that until you have first configured all the software needed.Next, run the USB extensions to your computer. Make sure you keep the cables neatly pinned to the surface of the bottom so as to not have them interfere wi th3.the camera lens or the lights.

II. LED setup

We are concerned with the white LEDs here. Make sure you have the white LEDs on hand and not the IR.1.The reel is designed in a manner that you can cut the reel at certain points to make smaller sections. You can tell where these sections are because you can see2.a scissors symbol. Also, the symbols for positive (+) and GND (-) will meet their counterparts here.Determine your section size, cut, and paste to the bottom around the cameras as pictured above (the underside of the LEDs is a 3M adhesive).3.Solder the positive to the positive and the negative to the negative as trivial. The power adapter for the LEDs also needs to be connected to these in some way.4.You may solder it directly, buy a female jack, or just twist and tape.


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Step 9: Acrylic Setup/ IR setup (Hardware)Find your Endlighten layer. It's time to wrap it in IR LEDs. You may want to consider purchasing some U-bars to give the table a cleaner feel and look. As for us, since wewere still testing, we used Duct Tape again to hold the IR in place. All you have to do is simply cut the IR reel to size and wrap it around the edges of the Acrylic. Next,connect to a power supply and verify that they work. You may not be able to see the IR wavelength with your eye, but if you use your phone, you will see an orange-yellowish glow.

I. Layering:

Now we will talk layering. This step is very important because depending on how you do this, your setup will yield differences in input detection, ghosting, andtransparency. We must find a way to balance these three perfectly.

ghosting refers to the "naturalness" of your interaction with the table. We say there is too much ghosting when the Acrylic layers are too thick or ordered in a way

that your touch doesn't seem to feel right. If your touch layer is, for example, an inch from the projection layer, the effect of refraction will be heavier and you willfeel as if your touches are off . This is a problem in that you won't get the full touchscreen experience.As far as input detection goes, what we are concerned with now is the positioning to yield maximum camera detection. There is a threshold where the layering istoo off, prohibiting you from properly causing any photon collisions. When you press on the Acrylic, you force photons to collide and cause "explosions" in a way.Those explosions are termed and read as "blobs" by the software. If, for example, your resistant layer is too far from the camera or the IR layer, there will be nocollisions read by the software.Transparency refers to the user's ability to see through the LCD. This can be used either creatively or it can be bad. The line between right and wrong is mainlyblurred on this issue.

II. Example setups :

I will now share the setups we experimented with and allow you to pick the best choice:

* Protective refers to abrasion resistant acrylic*IR refers to Endlighten acrylic*Support refers to extruded FF acrylic

The original plan:1.


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-------Protective (3-5 mm)----------=======IR( 8-10 mm)========~~~~~~~LCD (2 mm)~~~~~~~~~**********Diffuse( 1-2 mm)**********_______Support (8 mm)________ .... ~3 ft..._________|--camera--|___________

**Report: Heavy ghosting occurred due to the support being so thick. Also, the collisions in the IR wouldn't escape the 10 mm piece through the diffuse layer. Barely gotblobs registered unless the the user increased pressure of touch (which could harm the integrity of the system) AND removed the protective layer. Also, the distancebetween the camera and layers was too great. Discovered that it works better if the camera distance was reduced, the thickness of the IR and support were reduced:

-------Protective (3 mm)----------=======IR( 8 or less mm)==~~~~~~~LCD (2 mm)~~~~~~~~~**********Diffuse( 1-2 mm)**********_______Support (


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A. The diffuser sheet we used was the thicker one that is packaged with the LCD as my teammate accidentally threw away the smaller ones. I am fairly certain that thethinner sheets would have worked best to reduce transparency in the case of the setups we built without diffuse layers.

B. I highly encourage the builder to read through other projects accomplished on the NUI group forums and formulate a design plan before starting the project.

C. I did not feel that I needed to thoroughly explain the re-assembly for the LCD panel onto the box. All that you have to do is place it down on top of your support layerand reconnect the appropriate FFC to the sockets on the T-con Board. It is important that you connect them to the sockets they correspond to. Also, make sure thesockets are clean and that the FFC are in correctly. If you place them backwards or incorrectly, you may see a column of dead pixels. This is nothing to be too alarmedabout as you only need to fix the connection.

Step 10: Did I break it? Testing the TV (Hardware/Information)Once you are content with a specific layering, turn on the TV and watch something (or use your computer). Make sure that you have a mouse and keyboard as you arenot yet able to receive responses for your inputs. Also, make sure that your white LEDs are on (doesn't matter if your IR LEDs are on for this step). If you can see as wedid in the picture above, then all is well and you should congratulate yourself on being one of the few people to re-purpose an LCD and have it work on the first try!

I. Common troubleshoots:

Twice-inverted letters and picture? Your LCD is backwards, simply flip the panel1.No picture? Check that the HDMI or video input of your choice is properly configured. Also, if you kept the LED indicator, check it to tell whether the TV should be2.on or not. you will notice that the range of the TV remote just increased by 7 times. You are welcome.Screen is black? Turn on white LEDs. If LEDs are on, make sure they are white and not IR. If still no picture, your Flat Flex Cables are connected in the wrong3.order.No sound? your speakers are connected on the wrong socket.4.

**For those wondering, the picture above is the system running Ubuntu 13.04 "Raring." This was the first OS we decided to run.


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Step 11: Understanding the software (Information)We will be running a variety of warez for this project to work. Luckily for us, the NUI community has already developed an open source version of the tracking software inorder for the controller to properly determine whether an instance is a touch event or not. This is mostly lucky in that there are many tracking suites out there that go for agood $3,000 or so. The program we will be using, CCV, runs equally as great and is much easier to troubleshoot. This, however, does not mean that it is an easyprocess. I will start by emphasizing that you will come across many problems while attempting to run CCV. Your system may require you to do different things in order toget it working. Also, if you are running Windows 8.1 (although it would be an appropriate OS for mult i-touch) , the documentation is very scarce. The reason you will rarelyfind any information regarding software setup is that many of us who get it to work have done so by some stroke of luck. Depending on your machine, you may also need

to install the different packages in a certain specific order.I. How the tracking software works:

The algorithm for tracking and maintaining touch events is a bit complex, yet very fascinating. Keep in mind that although Jeff Han pioneered the use of IR technology inhis Frustrated Total Internal Reflection (FTIR) multi-touch displays just recently, the software techniques have been used for a long time.

The process involves a set of equations:

The state equation X_k = X_(k-1) + VU_k +W_kWhere X_k describes the propagation of the state variable for position X, X_(k-1) is the true position at time = k-1 of the event, W_k is a noise term, andVU_k is a velocity term of constant velocity V.

The observation equation Y_k = X_k + n_kwhere n_k is the zero-mean Gaussian white noise.

Applying a Kalman filter will recursively iterate a prediction of the object's position based on the position given by the previous states. Here, Y_k becomes a noisyobservation of X_k. Given this information, the controller can determine whether an input is continuous and traceable, or whether it has died.

* You can learn more about this on the NUI group's publication Multitouch Technologies available for free on the NUI group's forums or above as a .pdf file. This is a shorttwo chapter book aimed to educate beginners before they risk it all in attempting to construct a multi-touch display. The full explanation of the above equation is includedin this book as well.

File Downloads

Multi-Touch_Technologies_v1.01.pdf (2 MB)[NOTE: When saving, if you see .tmp as the file ext, rename it to 'Multi-Touch_Technologies_v1.01.pdf']
http://www.instructables.com/files/orig/FT2/1R5K/HQ1E7ZME/FT21R5KHQ1E7ZME.pdf?utm_source=pdf&utm_campaign=fileshttp://www.instructables.com/files/orig/FT2/1R5K/HQ1E7ZME/FT21R5KHQ1E7ZME.pdf?utm_source=pdf&utm_campaign=fileshttp://www.instructables.com/files/orig/FT2/1R5K/HQ1E7ZME/FT21R5KHQ1E7ZME.pdf?utm_source=pdf&utm_campaign=fileshttp://www.instructables.com/files/orig/FT2/1R5K/HQ1E7ZME/FT21R5KHQ1E7ZME.pdf?utm_source=pdf&utm_campaign=files


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Step 12: Choosing an OS (Information)Your input is going to heavily depend on your operating system of choice. Each OS delivers a very different experience; thus, it is hard to say which is the best. For thissection, I can only give a breakdown of a couple of OS' that I know and let you make your choice from there. This step IS important in that your method of capture(software-wise) will depend on the OS you choose.

I. OS Breakdown:

Microsoft's Windows1.Windows 8/ Windows 8.1/RT: Windows 8, RT, and 8.1 were optimized for the touchscreen apparatus. The metro offers a rich experience that feels like it1.was created specifically for a multi-touch device. Also, the corner sliding and huge amount of touchscreen apps already available through the windowsstore offer this OS a great advantage. We personally chose this OS because it was the easiest to set up. The NUI group; however, does not have toomuch documentation on this OS as it is not the preferred Windows OS. Also, a couple of changes in the coding made two library files be missing in thisupdate--this only means that you'll find yourself downloading additional f iles an databases in order to compensate. Also, you must choose whether tooverlay or keep the built-in touch system. The NUI community will push for the use of Touch Injector as a service to give the inputs functions rather thanthe established MT Vista. Also, since the three versions were written differently, the setup may be different. There are blogs whose users have moddedthe appropriate software in order to be optimized for your version. You may encounter problems such as no input being shown, the touch-tracker notshowing up on start-up, and permission revocation. You must be the account's administrator and run the warez in this mode in order for things to workproperly. Lastly, since the warez is open-source for the most part, you may have conflicts with your anti-virus application. Simply t reat these as falsepositives and move on.Windows 7: It is smooth, fast, and perfect for multi-touch. Similar to the above version, you should try to build your setup in a way that the corners are free2.for touching as the start menu and the important apps for this are located on the task bar's corners by default. You will need to install a number of servicesin order to get your input recognized by the controller, but this has the most documentation to any other OS in the NUI forums. You should not have manyproblems dealing with this OS when it comes to multi-touch. Also, if you are a student, you may have access to the Microsoft Surface Developer Kit whichwill increase the functionality of you table. You can also experiment with building your own frameworks and graphical interfaces if you so desire--which isalways a great thing. If you are an avid windows fanatic, I would recommend this OS as it is a blessing.Windows Vista/ XP: I grouped Vista with XP since after the service packs released for these OS', XP and Vista simply become Windows pre-7.1. I do3.believe their service has been discontinued (don't quote me on that) so I would not recommend these if you are worried about a longer-term experiencewith your table--I've not yet attempted to upgrade or downgrade an OS with the multi-touch Warez already installed. Other than that, you'll be finding agood amount of support in the NUI forums due to the newer software simply being a modded version of software originally for XP and Vista. You shouldn'thave too many problems with these, but i recommend not to go here unless you are planning to run a virtual machine with a more updated OS--most apps

have been optimized for the more recent OS' and I'd recommend starting at 7 i f you want that old-fashioned Windows appeal.** Side Note: Consider installing a program named Rain-meter . Rain-meter takes the widgets introduced in vista to a new level by allowing you to set up yourcomputer exactly how you'd like it. You can create futuristic displays or even have sound output given for certain actions. This app is compatible with mostWindows OS versions as far as I am aware. I use it last on my personal Win 8 laptop setup. Ubuntu offers an applet for this named Conky. If you use Conky, Iadvise downloading Conky Manager .Linux OS:2.

Canonical's Ubuntu (any release from 12.04 LTS to 13.10): When it comes to Linux OS', people seem to think you must be a hacker, or an overly1.obsessed computer maniac in order to understand what is going on--the movies seem to portray Linux as a completely text-based OS, and who wantsthat? Well, let me be the first to tell you that they are wrong! Ubuntu is a FREE (although I'd recommend leaving a donation to the company whendownloading) OS distributed by Canonical that is beyond wonderful. It is classified under the "Debian-like" distributions as this is where it i s sourced from.Ubuntu is virtually updated daily and provides the highest sense of security for the average user. I t handles similarly to Windows, yet it has it's ownadvantages that a Windows OS could not provide you. A big pro is that you won't find your system being infected by viruses. Although you can stillcontract Trojans and such, your system will be unharmed as the viruses are written for Windows users--they won't open and execute on Ubuntu or anyLinux distro (unless you use WINE, a windows emulator for Linux). If you dual boot with Windows, you can even use Ubuntu to rid your Windows partitionof any infections it may have. Ubuntu 13.10 (dubbed "Saucy Salamander") was written with touchscreen devices in mind much like windows 8; however,the format of the graphical interface is non-intrusive, and the options are all equally optimized for the non-touch aficionado. Paired with a variety of appsthat you can find in their software center, you can make this desktop exactly what you want it to be, giving you the ultimate freedom and maneuverability.So what's the problem with it then? It is very hard to find any documentation on setting up an Ubuntu multi-touch setup on the NUI forums. This is due tomany of the programs that are needed for touch implementation being written with Windows users in mind. You'll have to find a replacement capturesoftware--I've heard Cheese or VLC Media Player work well with Ubuntu in place of the CLeye for the PS3 eye, but you WILL have to experiment and gothrough a lot of hard work in order to get this setup to work. The few that I've seen are gorgeous, so it IS worth the trouble. I am personally planning ongetting my table back soon in order to experiment with changing the OS back to Ubuntu. Also, while on Ubuntu, you'll find yourself dealing with theTerminal (Linux equivalent of the Command Prompt console or Powershell) more than anything else. Although everything gives you the option of graphicalinput, you may find the terminal to be more satisfying. If you want to learn about computers, processes and all that goes into providing a rich, safe, andefficient user experience, I'd say give any Linux distro a chance.****You should probably keep in mind that although you can find a Linux replacement for any Windows program, you're not going to be Gaming too muchon a Linux Machine. Most developers and gamers prefer the Windows setup for gaming.Mint, Tails , Kubuntu , Xubuntu , Debian , or any of the other hundreds of Linux distros: I know I grouped a lot of OS' into one category--which should be a2.cardinal sin as each one handles and behaves differently. The issue is that I've only merely dabbled in these other OS' and haven't given myself muchtime to get fully acquainted with any other distro. Kubuntu and Xubuntu offer a more simplistic experience to Ubuntu and Tails is optimized for anonymity.I've not really heard of any members in the NUI forums dealing with these specifically, but I know that it can be done. I'm not able to fully give an opinionon these as I have not been so involved with them, but I have heard that Mint OS is a pretty good choice for those wanting to experience the feel of Linux.

Apple OS '3.I've personally never dealt with an Apple OS. I hear that the are Unix-like and have been developed from Unix, but I've never owned an Apple machine.1.However, there is some documentation on the NUI Forums and on the internet regarding Apple's many cat-themed OS'. I hear that a setup with these OS'

runs similar to a desktop rather than an iPad, unless you can configure it in that manner. I am unfortunately uninformed as to the warez necessary oranything of the like regarding apple. It 's not that I don't like them, but I've never had one so I cannot formulate a fair opinion on any of them. I do, howeverrecognize the security of the software implemented in their devices though. Unlike Linux, you may still encounter some minor infections due to the codenot being updated as frequently, but I'd say that for the regular user (not trying to access anything dangerous), this is a great choice.

So there you have it. Now all you have to do is choose an OS and get what you need to work things out. If you are not too much into computers, I'd recommend that youstick with the Windows setup (maybe Win 7). If you want a challenge--and want everything to be worthwhile (and don't want to spend money on an OS)--go with a LinuxOS. If you are an Apple user, go with Apple!

**If you really want something interesting though, try investing some time into setting up an Android setup. Android is Unix-like so there have been some developers thathave succeeded. Also, the developer kit is free and there is a rich community of developers for Android. You may have a hard t ime at first, but it should pay off in the end.Just an interesting thought for you.
http://www.android.com/http://www.apple.com/osx/http://www.debian.org/http://xubuntu.org/http://www.kubuntu.org/https://tails.boum.org/http://www.linuxmint.com/http://www.ubuntu.com/desktophttp://www.teejeetech.in/p/conky-manager.htmlhttp://rainmeter.net/cms/http://windows.microsoft.com/en-us/windows/buy


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Step 13: CCV, Touch Injector and the Cleye + CCV tests (Warez)Now that we chose an OS, let's talk about what we need to get things working for us. Keep in mind that for our setup, we decided to go for a Windows 8 setup as it wasfreely available to us as a donation f rom our software guy and since it was also the easiest for him to develop for under the time we had set out for the project. This is thewarez you will need to make touch work:

I. CCV:

CCV stands for Community Core Vision, the open-source and NUI group-developed tracking software at the basis for any multi-touch table you will find to be built in theNUI group forums. It comes with its own handy interface that luckily does not change too much in between version revision. I believe the CCV distro we are currently in is1.5--this is the one we used since it has documentation and support for multi-camera setups. There is a mod in the NUI forums for 1.4 that allows it to accept multi-camera setups. The more cameras, the faster your table and the smaller you can build it. I've explained in a very layman's terms how this program works in theUnderstanding Software section. There are various replacements to this program, although I do not recommend going that route as the NUI forums specifically highlightCCV over all other programs.

The interface can be quite confusing to deal with. Seth Sandler, a contributor to the NUI group has posted a blog with a great description of the interface and how tonavigate it here . Try to read through his site and discover more on the warez needed. I believe his is optimized for a Windows 7-based MT Mini--but the practicality is still

essentially the same.Other useful links for you:

CCV source Code: http://nuicode.com/projects/tbeta/repositorySandler's blog also contains links to the downloads for Linux and Mac .CCV 1.5 download from NUI: http://nuigroup.com/forums/viewthread/13330/ How to configure CLeye to CCV 1.5: http://nuigroup.com/forums/viewthread/14464/ If you choose to go with 1.4, another user has made a blog detailing installation very clearly here .

Changing the resolution and FPS requires you to edit the XML files as administrator.

*Make sure that the Blobs are perfect and perform as desired before moving onto calibration.

II. CLeye:

The Code Laboratories SDK for the PS3 eye. It comes with a variety of drivers and tools to sync and configure the PS3 eye to your setup via the computer. If you are

working with CCV 1.5, I recommend downloading this first and making sure that your input can be read through this program. The graphical interface should display thecapture of your blobs as you touch the table. Once you've got this done, you can proceed to CCV capture. There is a problem with registration regarding the CLeyethough. The SDK requires that you buy a license for ~$35 in order to get the software to work. Luckily, there are a couple of ways to circumvent this; however, you will bemaking things harder for yourself as the process requires the handling and manipulation of DLL files. This could potentially mess up your software setup and force you tohave to re-install everything all over again many times. You can find the dr ivers for the CLeye to be detailed on the main CCV 1.5 forum post given in the CCV section orhere , and here is the CLeye site .

III. Touch Injector:

Since we're on Windows 8, we have to find a replacement for MT Vista that will work as a service for your inputs. For this, we use Touch Injector. This was alsodeveloped in the NUI group and handles very well. It also has quite a bit of documentation and there are tons of forum posts on debugging and troubleshooting.Useful links:

Touch Injector Download: http://nuigroup.com/forums/viewthread/14448/ Project done with useful info on CLeye dlls and Touch Injector config: http://nuigroup.com/forums/viewthread/14648/ links for a TUIO mouse driver that may replace Touch injector: http://nuigroup.com/forums/viewthread/14725/ --this will convert touch events into Windows touchevents.

Forum with valuable info regarding config: http://nuigroup.com/S=e0ec20a79ebf6558e095464ab473...Refer here for TUIO software

* A note of Clarity: TUIO is a protocol used for describing the position and such of the blobs. If you can remember my explanation of CCV in the past sections, you willrealize that CCV outputs TUIO messages regarding your inputs. TUIO stands for Tangible User Interface Protocol. Expanding on this, we need an application that willtake those messages as an input and convert them to touch. Touch Injector takes these messages and converts them to native touch. But what if you wanted to go theother way and take native touch and convert it to TUIO? Refer to this thread .
http://nuigroup.com/forums/viewthread/14656/http://www.tuio.org/?softwarehttp://nuigroup.com/S=e0ec20a79ebf6558e095464ab47332248597bb01/forums/viewthread/14648/http://nuigroup.com/forums/viewthread/14725/http://nuigroup.com/forums/viewthread/14648/http://nuigroup.com/forums/viewthread/14448/http://www.codelaboratories.com/products/eyehttp://nuigroup.com/forums/viewthread/14152/http://kuchenzeit.wordpress.com/2012/08/04/ccv-mtv-on-windows-8-release-preview/http://nuigroup.com/forums/viewthread/14464/http://nuigroup.com/forums/viewthread/13330/http://sethsandler.com/multitouch/community-core-vision-guide/http://nuicode.com/projects/tbeta/repositoryhttp://sethsandler.com/multitouch/community-core-vision-installation-configuration/


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Step 14: Calibration (Software)Assuming that your blobs are perfect, and that you are satisfied with the framerate and all other factors, the final thing to do is to calibrate CCV settings. Once again,Sandler has provided an amazingly detailed guide on the steps for proper calibration. I advise that you go read it here . Once you are done with this step--if successful--you have essentially finished the construction of your setup. Your efforts and money should have (hopefully) paid off, and you will be the proud owner of an LCD-basedDSI touch screen table that is fully functional and pleasing.
http://sethsandler.com/multitouch/community-core-vision-calibration/


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