Maximum PC DIY RSS Feed

How to Build Your Own 3D Camera Rig for Under $20

Eric Kurland — Wed, 18 Nov 2009 23:00:00 -0600

How Does Stereoscopic 3D Photography Work?

Stereoscopic 3-D photography has been around almost as long as photography itself. In the 1830s Sir Charles Wheatstone theorized that we see the world in three dimensions because our eyes are set about 2.5 inches apart, and see from two slightly different viewpoints. You can test this by holding your thumb at arms length. Close one eye and look at your thumb, then look with just the other eye, and you will see that there is a deviation, or parallax, between what your eyes see. Your brain fuses these two views together, interpreting the amounts of parallax as depth. This is called binocular stereopsis.

Wheatstone figured out that two cameras could be placed side-by-side and take simultaneous pictures, creating a pair of photographs from both left eye and right eye perspectives. When viewed through a stereoscope, the left eye only sees the left image, the right eye only sees the right image, and we perceive a single 3-D view.

The author's 3D photos from Comic-Con

Throughout the late 19th and early 20th centuries, stereo photos were all the rage, with many thousands of stereo cards produced. In fact, many Victorian era homes kept a stereoscope as the centerpiece of their living rooms - sort of the entertainment center of the day. Still, the process of making 3-D images was very complicated, as it was necessary to have two synchronized cameras to take the pictures, and quite a bit of skill to align and mount the finished prints or slides for viewing. Over the years, a number of film cameras have been made with dual optics and shutters, specifically for stereography, but these still require a great deal of meticulous work by the photographer in order to properly align pictures for display.

Do-It-Yourself 3D

The 21st century has seen a resurgence in the popularity of stereography, or 3D imagery, and thanks to the availability of inexpensive digital cameras and photo-processing software, do-it-yourself 3D imagery is now possible.

The simplest method for taking a 3D photo requires just a single camera, and a stationary subject. Place your feet firmly on the ground, with your weight on your left foot, and take a picture. Shift your weight to your right foot and take a second picture. You now have a stereo pair of images, one for the left eye and one for the right eye, which can be viewed in 3D. Obviously, this technique, called “sidestep” or “cha-cha” 3D, only works for subjects that are not in motion.

To take stereographs of dynamic subjects, we will need to take two photos at exactly the same time. Japanese camera manufacturer Fuji recently released the first digital camera equipped with two lenses for 3D. Of course, for the technologically savvy, you can make your own 3D camera rig using common building materials and two digital cameras.

For this project, we’ll use a pair of matching Canon PowerShot cameras and specialized synchronization software called StereoData Maker, or SDM, which is a nonvolatile firmware upgrade based on CHDK, the Canon Hack Development Kit. SDM adds a set of features to certain Canon cameras, specifically for the taking of 3D pictures.

What You Need

Two Canon PowerShot cameras compatible with SDM (Buy them here)
Two 4GB SD cards
Two right-angle metal brace clips
Two tripod screws or 1/4-inch thumbscrews
Cloth tape or sturdy electrical tape
Metal washers
Two USB cables
Altoids tin
Push-button switch (Buy them here)
Two female USB connectors
Battery holder
Three 1.5V AAA batteries
Hot-glue gun
A Dremel tool
Red/cyan 3D glasses (Buy them here)

Aside from the digital cameras and tools, the core components of the rig won't cost you more than $20! Now it's time to assemble the pieces.

Step 1: Load the SDM Firmware

First, you will need two Canon PowerShot cameras (they don’t need to be the exact same model) and the corresponding StereoData Maker firmware. While SDM isn’t available for all Canon PowerShot models, it does work on a wide variety. A full compatibility list can be found at the Stereomaker.net website. Scan the list for your cameras and download the specific firmware and common_files.zip for each. Unzip both archives to the same directory.

SDM comes with a simple installer program that will format your SD cards and install the SDM files. Run the sdminste.exe executable, insert one of your SD cards into a card reader on your PC and click “new install.” Select whether this flash card will be for the left or right camera and click OK, then follow the onscreen instructions for formatting. Do the same for the other card. Make sure to note which card is for the left camera and which is for the right.

Slide the physical write-protect tab down on the SD cards and insert each into the proper camera. The firmware only loads from the cards when they are in the “locked” position, but the cameras are still able to write photos to them normally.

Step 2: Build the Mounting Rig

The next step is to mount the cameras in a side-by-side orientation. Some hobbyists sell specialized 3D slidebars for two cameras online, but you can make your own. This can be as simple as drilling two holes in a wood ruler and bolting the cameras down with 1/4-inch thumbscrews.

Ideally, you want the lenses of your cameras as close together as possible—about the distance between two human eyes. The best way to do this is with one of the cameras turned upside down. To mount the cameras in this way, we will build something called a z-bar with two right-angle truss clips or braces, which you can buy at any hardware store.

Align the sides of these two bars and fasten them together using heavy cloth tape, leaving the holes along the base exposed. With 1/4-inch thumbscrews, mount a camera onto each clip, using metal washers on each side of the base to make sure you get a tight, level fit. Position the cameras so that the centers of the lenses are as evenly aligned as you can make them. Don’t worry if the alignment isn’t 100 percent perfect, as we can correct the images later in software.

Step 3:Build the USB Switch Remote

One of the functions added by StereoData Maker is synchronization of the cameras’ shutters via a 5-volt pulse sent through their USB ports. This requires that a battery-powered switch be attached to both cameras via USB cables. The Stereomaker.net website contains several varying schematics for this synch controller circuit.

The simplest to assemble uses a pair of USB connectors with both pins 1 wired to a button, and both pins 4 wired to a negative battery terminal. The batteries’ positive terminal connects to the other contact on the button, so that when it is pressed, it completes the circuit to both cameras. The cameras need to receive a 4.5- to 5-volt pulse, so you can use a combination of three 1.5V AAA batteries.

You can build this circuit into any small enclosure, such as an Altoids tin, which has a hinged lid for easy access. We found female USB connectors, battery holders, soldering supplies, and push-buttons online at Allelectronics.com.

Cut openings into the side of the Altoids tin to fit the two USB ports and glue the ports in place. Drill a hole in the face of the enclosure for the push-button as well. On the battery holder, connect the positive battery wire to one contact on the button switch, and carefully solder the negative battery wire to pin 4 on both USB ports. Solder a short wire from pin 1 on both USB ports to the other contact on the button. You can use the USB cables that are supplied with the cameras to connect them to your synch controller. Alternatively, you can hardwire USB cables to the controller in place of the connectors. If this step seems too daunting, there are links on the StereoData Maker website to sources that sell pre-assembled USB switches.

Step 4: Shoot Your Photos

Once you have the hardware assembled and the StereoData Maker firmware installed onto the SD cards, you are ready to start shooting 3D pictures. Power up both cameras and wait for the SDM splash screen to appear. You can access the SDM menus by briefly pressing the “direct print” button to put the camera into <alt> mode, followed by the menu button.

The SDM menus contain numerous options for both beginners and more advanced stereo photographers. For now, we will just check to ensure that the USB synchronization is turned on. Make sure that any settings you adjust on the left camera are also changed on the right camera. Press the “direct print” button again to exit the SDM menu.

The left photo

You can now set your cameras up as you normally would to take a photo, adjusting the ISO, shutter speed, and aperture identically on both cameras. Press and hold the button on your USB switch to auto-focus. When both cameras are ready, their blue LEDs will light up. Release the USB button and both cameras fire simultaneously, capturing your stereo pair.

A general rule of thumb for taking good 3D photos is that the distance between the rig and your subject should be at least 30 times the distance between your two lenses. In other words, if your lenses, measured from center to center, are 2.5 inches apart, you should be at least 75 inches, or about 6 feet, away from your subject.

The right photo

Step 5: Process Your Photos

Now that you have taken a pair of images, it’s time to look at them in 3D. To do this, the two images need to be aligned and put into a format suitable for 3D viewing. While this can be done with general image-processing programs such as Adobe Photoshop, most stereographers prefer a specialized freeware application called StereoPhoto Maker.

Begin by downloading and installing the StereoPhoto Maker program. Remove the SD cards from your cameras and copy the contents onto your PC. We recommend organizing your files into subdirectories for left and right images to make it easier to keep track of them. Run the StereoPhoto Maker program and under the File menu, select “open left/right images.” A dialog box will open, asking for the left image. Browse to the folder with the left photos, select a file, and click Open. Do the same for the right-side image, selecting the corresponding picture from the folder with the right-side images. The program will open both files and show you the two pictures side-by-side.

Under the Adjust menu, select “auto color adjustment” to match the tone of the two images. Next, select “auto alignment,” and StereoPhoto Maker runs an algorithm that corrects for misalignments between the cameras, and sets the stereo window based on the nearest point in the shot. Once the auto-alignment is finished processing, you can put on your red/cyan 3D glasses, select a color anaglyph mode from the Stereo menu (we prefer Dubois anaglyph, for its color correction), and marvel at the depth in your 3D photo.

If you would like to make more advanced alignments, you can select the easy adjustment mode, and do manual corrections as needed. StereoPhoto Maker will allow you to save your pictures as anaglyphs, parallel, or cross-view pairs, and will even print out a vintage-style stereo card for your Victorian stereoscope.

Additional Resources

Stereo Club of Southern California -- The Los Angeles–based 3D club offers 3D tutorials and information on 3D photography on its website.

3-DIY.com -- The author's website on do-it-yourself 3D.

Microsoft Acquires Interactive Supercomputing's Technologies for Faster, User-Friendly DIY Computing

Paul Lilly — Wed, 23 Sep 2009 08:38:53 -0500

In a blog post on Monday, Kyril Faenov, a general manager at Microsoft, announced that the software maker has acquired the technology assets of Interactive Supercomputing (ISC), a company whose bread and butter has been porting the power of parallel computing over to the desktop.

"This move represents our ongoing commitment to parallel computing and high performance computing (HPC) and will bring together complimentary technologies that will help simplify the complexity and difficulty of expressing problems that can be parallelized," Faenov wrote.

Faenov added that Bill Blake, the current CEO of ISC, will make the transition to Microsoft and work at the New England Research & Development Center in Cambridge, MA. Blake and others will put into motion Microsoft's plan of integrating ISC technologies into future versions of Microsoft products, although exactly what products have yet to be announced.

9 Kick-Ass DIY Projects to Get Your Hack On

Alex Castle, Norman Chan, and Florence Ion — Tue, 22 Sep 2009 10:00:00 -0500

These 9 amazing DIY projects will give new meaning to your old hardware

Techies are too often tempted by the lure of new technology, leaving perfectly good hardware drifting in the wake of compulsive upgrading. And while we love getting new gadgets as much as the next geek, we also like how a new purchase gives us the opportunity to take apart and tinker with our older gear in the Lab. Whether it’s by soldering circuit boards or loading open-source firmware, we pride ourselves on being able to stretch the lifespan of older electronics by performing undocumented (and sometimes warranty-breaking) hardware hacks.

The projects we’ve included here range from relatively safe software tweaks to more challenging technical exercises. You’ll learn how to bend USB connections to your will and imbue home routers and digital cameras with robust new features. We’ve also taken some inspiration from projects we’ve seen online, including building a blue laser gun and making a digital picture frame you can mount on the wall of your office. These hacks will help you showcase your craftiness and give you a better understanding of how your electronics work. And the best part is that your old hardware will be faster, cooler, and more awesome afterward.

So, let’s get hacking!

Power Everything with USB

A simple first modification for budding do-it-yourselfers is to alter a non-USB gadget so that it can be run off of USB power from your computer. This mod is fairly easy to perform and is an important part of many more-complicated DIY projects, such as the USB charger on the next page. Here, we show you how to use USB to power a desk fan and book-light lamp.

First, a quick primer on USB power. Any USB cable (2.0 or 1.0) is composed of four wires—two for data and two for electricity. The power is delivered across the outer two pins—a +5-volt wire and a ground. USB connectors are configured to provide 100 milliamps of current through these pins when in “low-power” mode or 500 milliamps in “high-power” mode. Although some USB connectors will provide maximum power without any questions asked, most won’t unless the USB device requests high power using the proper protocols. Most USB hacks aren’t that sophisticated, and are therefore limited to about 100-200 milliamps of current.

One last warning: An improper USB mod that results in a short circuit can fry your USB port or even your motherboard. So make absolutely sure that all wires are spliced correctly and that any exposed copper is covered with electrical tape or heat-shrink tubing.

Case-Fan Desk-Fan

Our first project is to turn a case fan into one we can use on our desk to keep us cool as we work. All that’s needed is a 5-volt case fan (preferably with grill) and an unused USB cable.

(image A)

First, you’ll have to expose the four internal wires in your old USB cable, so snip it near the end furthest from the connector for the PC, and use a razor blade or other sharp knife to cut back the outer, rubber coating. Pull back the foil insulation, and locate the four wires inside. You should see red, black, white, and green wires inside (image A). Using a knife or wire strippers, expose the ends of the red and black wires.

(image B)

Your case fan should have two wires—one red and one black—terminating in a Molex power connector. Snip and strip the wires (image B). Following convention, the red wire is positive, and the black is ground—just like in the USB cable.

(image C)

Simply twist the exposed ends of the red wires together, solder, and cover with electrical tape or heat-shrink tubing to prevent the wires from shorting (Image C). Do the same for the black wires. Just like that, you have a USB-powered fan for your desk. If you want to get fancy, make a fan stand out of a bent coat hanger.

Book-Light Case-Light

Using very much the same procedure as above, you can convert an old battery-powered reading light into a USB-powered lamp to illuminate the back of your case. All you need to do is find an LED reading lamp that uses around 5 volts (the equivalent of about three AAA batteries) and open it up with a screwdriver. Under the battery compartment, you should find a red and black wire (image D).

(image D)

Splice the two wires to the wires in a USB cable, just like with the fan, then put the battery cover back on the lamp, chipping out a hole big enough to feed the USB cable through. Slap a strip of poster tape on the bottom, plant it on the back of your case, and plug it in.

Create a Battery-Powered USB Charger

Nothing can ruin a nerd outing faster than a catastrophic battery failure in one of your vital gadgets. Fortunately, although you may not always have access to an outlet and a wall-wart to recharge, it’s possible to create an emergency backup battery that fits inside a common Altoids tin and can power your toys for at least a few extra minutes—all for just a couple of bucks.

Gather the Parts

First, you’ll need to find a suitable casing for your USB charger. A perennial favorite of amateur gadgeteers: Altoids-style tin boxes. They’re cheap, sturdy, and relatively attractive. The traditional tin, about as big as a deck of cards, provides ample room for the components we’ll be using, but if you’re ambitious, it’s also possible to cram them into the newer, small Altoids tins.

In addition to the tin, you’ll also need the following parts. The total cost of parts (sans tools) should be only a few dollars, but you’ll either have to do some scavenging or place an order online to get some of the components.

A 9V battery clip
A +5V voltage regulator
A female USB connector
A 9V battery
Insulated copper wire
Soldering equipment
A Dremel tool

Cut the Altoids Tin

To start, we need to make a hole in the side of the tin big enough to hold the female USB connector (image A). When done, this is where you’ll plug in your gadgets; it will be the only visible difference between your charger and a run-of-the-mill Altoids tin. Make the hole on one of the narrow ends of the tin, a little to the left or right of center. We used a Dremel to make our hole, though you can also do it with a drill or a hand file. Try to make the hole just big enough for the connector to fit into, and no bigger.

(image A)

Wire the Circuit

Next, we’ll need to put together the circuit that will allow us to charge USB devices (which need about 5 volts) with a 9-volt battery. If electrical engineering sends you into a cold sweat, don’t worry; this is about as simple as a circuit can get. We’ll be connecting the positive (red) wire from the battery clip to the Vin pin on the voltage regulator, and the Vout pin to the +5V pin on the USB connector. We’ll also connect the ground wire from the battery clip to the ground pin on the regulator and the USB connector. Confused? Just solder everything together according to the diagram (image B).

Complete the Package

After you’re done soldering, wrap the connections in electrical tape so they don’t short out as we install the circuit in
the tin casing. Since both the battery clip and voltage regulator are smaller than the USB connector, you should be able to feed them through the hole first, and then fit the USB connector into it so that the lip of the connector rests on the edge of the hole. Once you’ve got everything tucked neatly into the case, with the voltage regulator sitting beside the connector, use some hot glue or epoxy to hold the wires in place.

(image B)

Get Stereoscopic 3D with Your Existing Hardware

Stereoscopic 3D is the Next Big Thing™ for PC gaming, at least if you believe Nvidia’s marketing department. But not everyone has $200 to spend on Nvidia’s 3D Vision kit, let alone a new 120Hz LCD monitor required to display it. Thankfully, there’s a way for you to play your games in 3D without buying any expensive new hardware. Nvidia’s 3D Vision drivers actually include an anaglyph mode so you can experience 3D gaming with red/cyan 3D glasses. The one caveat: This method only works if you have an Nvidia GPU and are running Windows Vista or Windows 7. Here’s how to get anaglyph 3D up and running in less than 10 minutes.

Download the Drivers

First, you need to download Nvidia’s 3D Vision drivers. Head over to the download page (http://www.nvidia.com/Download/index.aspx?lang=en-us) and select 3D Vision as the product type, along with your operating system. If you aren’t running Nvidia’s latest GeForce videocard drivers (version 186.18 at press time), you’ll have to download and install those, as well.

Turn on 3D Vision

After you’ve installed the 3D Vision drivers, launch the Nvidia Control Panel from the Windows Control Panel menu. You should see a section labeled Stereoscopic 3D. Expand that menu and click “Enable Stereoscopic 3D.”

Enable Anaglyph Mode

In the following pop-up window, click “Enable 3D Vision Discover.” This is the option that switches Nvidia’s 3D Vision settings from 120Hz shutter-based 3D to anaglyph (red/cyan) that can run on any normal 60Hz monitor.

Rock the Retro 3D Glasses

The next time you launch a 3D Vision–compatible game, you’ll be able to play it in 3D with any pair of generic red/cyan glasses—the set Intel gave away for viewing this year’s 3D ads during Super Bowl works perfectly, for example. You can also purchase a pair for less than $2 online (http://www.3dstereo.com/viewmaster/gla.html). During gameplay, you can toggle anaglyph view with the Ctrl+T shortcut.

Since anaglyph 3D is based on color filters, games can lose a bit of their vibrancy when you’re playing in this 3D mode. Left 4 Dead, for example, works wonderfully, but games with lots of red and blue color tones (like Team Fortress 2) do not. We recommend adjusting the 3D depth with Ctrl+F3 and Ctrl+F4 to find the best level of comfort for you.

Control Your PC with a Wii Remote

While some of us who jumped on the Wii bandwagon have a great time with Super Mario Galaxy and Cooking Mama, there are undoubtedly a few regretful gamers who just can’t get the hang of Nintendo’s waggle-based gaming console. But there’s no need to chuck that Wii out the window yet—you can use the Wii Remote as a wireless pointer for your PC!

Find a Compatible Bluetooth Adapter

The Wii Remote uses Bluetooth to connect to the Wii, but Windows will also recognize it as a Human Interface Device. To connect the Wii Remote to your PC, you’ll need a compatible Bluetooth receiver. Most new laptops have integrated Bluetooth, but you can also purchase a USB Bluetooth receiver online for less than $25. Check the Wii Brew wiki (http://wiibrew.org/wiki/List_of_Working_Bluetooth_Devices) for a list of compatible adapters.

Pair the Wii Remote with Your PC

We paired the Wii Remote with our Dell laptop using the “Add Bluetooth Device” option in the Windows Control Panel. For the laptop to recognize the controller, we also had to press the red sync button in the Wii Remote’s battery compartment. Your PC should detect it as Nintendo RVL-CNT-01. No Bluetooth passkey should be required.

Run WiinRemote Software

Now, download and launch the latest version of WiinRemote (http://onakasuita.org/wii/index-e.html). If you successfully paired your Wii Remote, the program will let you calibrate the motion sensor and assign buttons. By default, the program uses the controller’s gyroscope to control your mouse cursor. The Wii Nunchuck peripheral’s analog stick will also control mouse movement. You can achieve more accurate control by activating the IR sensor, but you’ll need to mount two infrared light sources above your monitor for this to work. The Wii’s IR light bar is suitable, and we powered it by splicing its proprietary plug into a USB cable.

Add DSLR Features to Your Canon Point-and-Shoot Digicam

We love point-and-shoot pocket cameras for their small size and ease of use, but we lament their relatively paltry feature sets when compared to more expensive DSLR models. The good news, for owners of the popular Canon PowerShot cameras, is that your consumer-grade gadget can be upgraded with custom software to endow it with professional features like RAW image recording and live histogram feedback. CHDK (Canon Hack Development Kit, http://chdk.wikia.com/wiki/CHDK) is an easy-to-install software package created by a savvy group of programmers to supercharge the Canon PowerShot. We show you how to safely install and configure this free firmware add-on with no risk to your camera.

Find the Right Software

Download the version of CHDK software that’s appropriate for your Canon PowerShot. CHDK only works with a camera using Canon’s Digic II or newer image sensor—any PowerShot made after 2005 should work. To find the right download, you’ll have to first find your existing firmware version number. Using Notepad or any other text-editing tool, create and save an empty file named ver.req. You’ll have to disable the “Hide extensions for known file types” setting under Windows Explorer’s Folder Options in order to change the file extension to .req.

Using a USB card reader, drop this file into the root directory of your SD card (not while the card is in the camera). Put the card back in your camera, turn on the camera under playback mode, and press the “set” and “disp.” buttons together. If done properly, the camera should display the firmware version number, i.e., Firmware Ver GM1.00C.

Next, head over to the CHDK download site (http://mighty-hoernsche.de/) and find your camera model and firmware version. Download the corresponding Zip file under the column labeled Complete.

Load CHDK

With your SD card back in a card reader and connected to your PC, extract the entire contents of the software package into the root directory of the card. Now you’re ready to run the CHDK software. Put the card back in your camera again and turn on your camera under playback mode (the lens should be retracted). Hit the Menu button, and scroll down to the bottom of the first menu tab. You should see an option for “firm update.” Select this and choose Yes when prompted. This is an entirely safe process since CHDK installs additional software instead of replacing the existing firmware in your camera.

CHDK should automatically load in a few seconds and display its logo. You can now switch the camera to capture mode to begin using the new features. Keep in mind that since your core firmware hasn’t actually been modified, CHDK will be disabled every time you turn off your camera, and you’ll have to manually enable it with every boot. We’ll go over how to make CHDK automatically boot later.

Configure the New Features

The first thing you’ll notice with CHDK enabled is that the onscreen display (OSD) shows new information, including the remaining battery life as a percentage, focus distance in meters, and a digital clock.

To enter the special CHDK menu, you need to enter Alt mode by pressing the Shortcut button on your camera (this button is later configurable). When in Alt mode, you’ll see an <ALT> indicator at the bottom of the OSD. Pressing the Menu button will bring up the CHDK menu, where you can enable a live histogram, zebra stripes (to indicate overexposure), and turn on RAW recording mode. The available feature set depends on your PowerShot model, so check the official CHDK wiki (http://chdk.wikia.com/wiki/CHDK_firmware_usage) for more information.

Boot CHDK at Startup

If you don’t want to manually load CHDK every time you use your camera, you can set it to auto-load, as long as your SD card is smaller than 2GB and not formatted for FAT32 (most aren’t by default). From the same Zip file you downloaded earlier, copy the PS.fir and DISKBOOT.bin files to the root directory of your SD card. Enter the CHDK menu using Alt mode and navigate to Miscellaneous Stuff. Select “Make Card Bootable” and hit the set button. Take out the SD card and slide its physical locking mechanism into the “lock” position. The next time you turn on the camera, CHDK should automatically start up as well.

Make a Working Laser Phaser

As a kid, did you ever run around your back yard waving a plastic toy gun around and making “pew pew” noises? Did you ever wish that toy gun could shoot an actual laser beam? Well, you’re a grown up now, and it’s time to make your dreams come true. We’re going to show you how to implant a real, high-powered blue laser into a plastic Star Trek Phaser.

This is a long exposure shot in a dark room. Your results may vary.

But before we tell you how to make it, we need to stress that this how-to is showing you how to take a perfectly good toy and turn it into something that is absolutely, unequivocally NOT A TOY. The blue laser used in this guide can burn electrical tape and pop balloons, which means that it’s also strong enough to do some extreme eye damage to anyone unlucky enough to catch a stray reflection. Because of this, always wear proper eye protection while using the laser, and NEVER point the laser at another person.

Get a Laser

There are two ways you can get the blue laser you’ll need for your phaser—you can buy one on the Internet for about $30, or you can salvage one from an old Blu-ray or HD DVD player. If you opt for the scavenged laser, be forewarned: You’ll have to build your own driver circuit, a task that’s pretty easy by circuit-building standards, but not for someone who doesn’t know his way around a soldering iron.

Prepare the Phaser

You’ll need a plastic gun to put the laser in. We bought a retro Star Trek phaser on eBay for $30, but there’s no reason you couldn’t do basically the same thing to a different toy. To prepare the toy phaser, you’ll need to make a couple of easy modifications using pliers and a rotary tool, such as a Dremel. First, widen the battery compartment so it can fit a 9-volt battery, instead of two AAs. Do this by pulling out the battery contacts with your pliers, then using the rotary tool to grind away all of the plastic protrusions inside the battery case. Also drill a hole that you can feed the wires from the 9V battery clip through.

Replace the Internals

Next, remove the light bulb from its black plastic clip, and grind down the clip so that the side opposite the two prongs is totally flat. If you remove the metal cap that covers the acrylic laser lens, the laser will fit perfectly into the hole in the clip. Now hot glue the black plastic clip into the “barrel” of the phaser, and grind out anything in the front of the phaser that would keep the laser housing from fitting in behind it. Connect the laser to the battery so it turns on, align it so that it’s straight, and glue it into position.

Finally, fix your switch into the trigger hole of the phaser, and use wires to complete the circuit between the battery, the switch, and the driver circuit. Use a little hot glue to stick everything in place, and reconnect the two halves of the phaser. The laser will burn many dark-colored items, including electrical tape and some black plastic, and it can also pop balloons. Blue lasers are hard to see in the air, even at high power, so if you want to see the beam, use some sort of particles in the air, such as smoke or fog. Have fun, and remember to be safe.

Upgrade Your Router to Manage Home Network Traffic

Third-party router software has been around for a while, but we can’t help but keep recommending it to users who want to add undocumented features to their home network. Our favorite router firmware package is still Tomato (http://www.polarcloud.com/tomato), which we favor for its compatibility with a wide range of router brands and models, user-friendly interface, and powerful feature set. We’ll show you how to upgrade your router’s firmware to the newest version of Tomato and then configure the Quality of Service settings to manage your network traffic.

Install Tomato Firmware

First, you need to make sure your router is supported by Tomato. The Linksys WRT54G-series routers work best, but some Buffalo and Asus routers also work. Check the Tomato FAQ (http://www.polarcloud.com/tomatofaq#what_will_this_run_on) to see if your router model and version number is supported. Download the latest firmware package (version 1.25 at press time) and extract its files with 7-Zip (www.7-zip.org). Access your router’s administration page with its gateway address (default is 192.168.1.1) and find the Firmware Upgrade section. Choose the firmware .bin file that matches your router and begin the upgrade process. Tomato will automatically transfer your router settings over so you don’t have to reconfigure the basic settings (image A).

(image A)

Configure Quality of Service

Quality of Service lets you manage the different types of data packets as they are routed around your home network and to your service provider. Internet surfing, gaming, VoIP, and BitTorrent traffic can all be prioritized so you can run web services simultaneously without clogging your bandwidth. There’s no one set of settings that will work for everyone, but we’ll give you the basics for you to get started.

QoS works by classifying network traffic types and then ordering those classes for bandwidth prioritization. First, you have to determine your connection’s maximum uplink bandwidth (since upload traffic is the source of most connection clutter). We used Speedtest.net to find our upload cap, and put that bitrate number under Max Bandwidth (image B).

(image B)

Next, you’ll have to configure the upper and lower bandwidth bounds for each class of packet. By default, the “Highest” class has a range of 80 to 100 percent. This means that packets ranked in this class will always claim at least 80 percent of your bandwidth. The “Lowest” class, on the other hand, has a range of 2 to 95 percent. This means packets under this class will at most claim 95 percent of your bandwidth, if it’s available. Higher ranked classes should be reserved for services that require steady connections, like gaming and VoIP, while lower priority classes should be reserved for normal web surfing, downloads, and peer to peer networks like BitTorrent.

(image C)

Under the Classification menu, you’ll have to assign specific services to class rankings (image C). You can identify services based on their network protocol type, port, or packet size. You can even use MAC addresses and local IPs to relegate one user on your home network to a specific prioritization class. This is where trial and error will help, and we recommend that you utilize Tomato’s Graphs feature to show you what effect your configuration has on your current traffic. We also recommend referencing the Tomato wiki (http://en.wikibooks.org/wiki/Tomato_%28firmware%29) for further clarification on all of the firmware’s varied settings.

Turn Your iPod into a Mini-PDA

For most people, an MP3 player serves a pretty narrow purpose: It plays music, maybe a video here or there if you’ve got a newer model, and might have a handful of applications. All in all, though, MP3 players are rarely treated as anything more than tiny, portable jukeboxes, which is a shame, because as gadgets they’ve got the potential for so much more. That’s why we’re going to show you how to install custom Rockbox firmware—to add support for new codecs, gapless playback, and even Doom on your MP3 player.

Rockbox is open-source replacement firmware for MP3 players. It supports a wide range of players, including many (but not all) players from Apple, Archos, Cowon, iRiver, Olympus, SanDisk, and Toshiba. Before reading any further, check out the chart at the top of the Rockbox homepage (www.rockbox.org) to see whether your specific model is supported. If it’s not, you are sadly out of luck, for the time being.

Install Rockbox

First, you’ll need to go to the Rockbox website and download the Rockbox utility (http://www.rockbox.org/twiki/bin/view/Main/RockboxUtility#Download), which includes an automatic installer tool that works with any of the supported MP3 players.

Simply run the utility, and it will automatically detect that this is the first time it’s been run and ask if you want to install Rockbox on a new device. Plug your device into your computer, then select whichever drive letter has been assigned to it, and specify what model it is (image A). Click OK.

(image A)

The Rockbox utility will now allow you to customize your Rockbox installation. Generally, clicking Complete Installation is advisable, as it will also install the full set of extra plugins to allow you to get the most out of your hacked MP3 player.

Sit tight for a bit while the installation completes, then select whichever theme you want installed on your MP3 player (image B). You’ve now got a hacked MP3 player. You can change your theme whenever you want to, using the Rockbox utility. Read the Rockbox documentation for your player to find out how you can customize it using the extensive options menu.

(image B)

Rockbox's Notable Features

Advanced Media Playback

Rockbox allows you to expand the functionality of your MP3 player in several core ways. For instance, with Rockbox firmware, an old iPod Photo (the one before the iPod Video) is actually capable of playing .mpeg video files. Many players can play music and video in more formats and containers than are supported by default, such as FLAC and Matroska. Additionally, Rockbox can add voice to menus, and supports voice recognition, to make it easier for people with impaired vision to use an MP3 player.

Apps, Apps, Apps

With Rockbox, you get access to an enormous catalog of apps (most of them written by hobbyists) that you can load onto your player for added functionality or just to have some fun. The standard Rockbox install includes a bunch of apps and games, including classics like Minesweeper and Sudoku.

Doom

Did we mention that you can play Doom? On a funky, old-school iPod? Sure, trying to play Doom on a grayscale iPod screen is enough to make your eyes commit ritual seppuku, but the novelty factor alone is sure to keep you blasting demons with a click-wheel for a few minutes at least. Remember that nerd-cred thing? This is how you get it.

Build a Netbook Picture Frame

Considering that netbooks get outdated by model refreshes every few months, it’s quite likely you’ll find yourself with an old netbook lying around the house, catching dust. But there’s no need to let it go to waste. Instead, turn it into a Wi-Fi-enabled digital picture frame! We used an old Acer Aspire One for this project, but it should work with most netbooks.

Disassemble the Netbook

The disassembly process will be different for each netbook model, but generally, you need to remove all the screws on the netbook’s underside (which are sometimes hidden under rubber pads) to free the motherboard from its plastic shell. Be careful not to cut any wires, and make note of where you disconnect cables. The important components to extract intact are the motherboard, hard drive, Wi-Fi card, and LCD screen, of course. We also kept the small daughterboard, which houses two extra USB ports and the power button (image A).

(image A)

Choose a Frame

It took us quite a bit of time to decide on where to purchase a frame and how the LCD would be fitted inside. We unsuccessfully searched for a premade shadowbox frame that matched the dimensions of our netbook’s 8x4.5-inch LCD panel, an unorthodox size for picture frames. You may have more luck with your own netbook (check http://www.frameplace.com/xshdboxs.htm for cheap shadow box frames), but we had to have our frame custom made at a local shop for $100.

(image B)

After a week, we had a custom-made frame with the LCD in place. We ordered a glassless, simple black frame with about three inches of allowance in the back for whatever hardware tweaking was necessary. The frame specialists were kind enough to seal in the LCD panel with a piece of cardboard, while making sure the LCD ribbon was still accessible (image B).

Assemble the Frame

With a well-made, well-measured frame, the actual assembly of the photo frame shouldn’t be much of a challenge. First, make sure all of the motherboard cables are attached, including the LCD ribbon, the HDD SATA cable, the connection to the I/O board (if there is one), and the power cable. To mount the motherboard into the case, you’ll need to create some small spacers so that it doesn’t sit directly on the LCD screen’s backing. You can use whatever’s handy; we cut ours out of dense packing foam. With a netbook motherboard, heat shouldn’t be much of an issue, but just in case try to place the spacers under screw holes near the corners, away from the CPU. To fix everything in place permanently, glue the spacers to the frame and use pins through the screw holes to hold the motherboard down.

(image C)

The Wi-Fi card attached to your motherboard should have two wires attached to it. The card needs these antenna wires to function, so make sure they’re secured inside the frame, with the ends taped down at least six inches apart. You can use additional foam spacers on the corners of the motherboard to hold the I/O board and HDD in place, or you can screw them to the back edge of the frame (image C).

Set up the Slide Show Software

To configure your picture frame, plug a USB keyboard and mouse into the motherboard (alternately, you could do your entire software configuration on the netbook before you take it apart). Remove any unnecessary software, such as image editors, office suites, and antivirus applications, and sweep your hard drive. You’ll also need to download and install a slide show application to display photos you have stored on either your hard drive or USB thumb drive, or accessed via an RSS feed.

We used Flickr as our photo storing service; we chose this service because you can update your feed remotely, from almost any Internet-capable device that can send picture attachments. There are actually several programs that can run a Flickr slide show, though we picked Google Photo Screensaver (http://pack.google.com/screensaver.html).

Once you’ve downloaded and installed the screensaver, either run the application straight from the installer or right-click your Desktop and select Properties. Then, under the Screen Saver tab, choose Google Photos Screensaver and go into Settings. From here, you can configure whether to stream your photos from a list of RSS feeds, Picasa, or a specific folder on your computer.

To run the screensaver from Flickr, go to your photo stream (flickr.com/photos/yourusername), scroll down to the bottom of the page, and find the RSS icon. Copy the RSS address and paste it under the Configure option in your Google Photos Screensaver preferences. Click OK, and you’re all set up.

In addition to the slide show, you can set your frame up as a digital wall clock, have it stream daily headlines from a news RSS feed, or hook it up to a set of speakers and run an Internet radio portal. To control the frame, you can hook up a wireless keyboard and mouse. Our netbook had Bluetooth capabilities, so we used Bluetooth peripherals, including the Wii Remote!

How to Build a Kick-Ass MAME Arcade Cabinet from an Old PC

Alex Castle — Wed, 09 Sep 2009 11:00:00 -0500

If you were born in the 70s or 80s, chances are good that a big part of your childhood was spent wasting quarters at the local arcade, or in front of the Pac-Man machine at your local pizza place. Sure, games have become a lot more complex since then, but the old titles had a lot of charm, and in some cases a level of skill and patience-rewarding challenge that hasn’t been matched since.

Sadly, the arcade is rapidly becoming a thing of the past. Now that PCs and game consoles have become so powerful, the only way for arcades to compete has been to offer games with enormous, complicated controls, which end up costing a dollar or more per play. And besides, that’s only if you happen to live next to one of the very few remaining full-sized arcades. For most people, the closest thing they’ve got to an arcade is the worn-out Initial D machine at their local multiplex.

But you can bring the classic arcade experience back to life, in your own house. With a MAME arcade machine, you and your friends can play your favorite old games, on the authentic controls they were made for. In this article, we’re going to show you, step-by-step and with a lot of pictures, exactly how to build the custom arcade machine you’ve always dreamed about using old PC parts. We’re going to describe how we built our MAME cabinet, but we’re also going to describe all the choices we made along the way, including cabinet style, monitor and controls, so you can put together a machine that’s just right for you.

Part 1: The Cabinet

When you think about an arcade machine, what comes to mind? For most people, it’s the cabinet. From the classic standup cabinets like Centipede, with its loud sideart, to the behemoth six-player, two-screen X-Men machines, to the sit-down cocktail Galaga cabinets, every games was its own distinct experience. They were more than just video games, they were furniture.

With that in mind, picking what style of cabinet you want to build for your MAME machine is one of the toughest and most important decisions you’ll have to make. Although exactly what your cabinet will look like is totally up to you, there are three basic styles of cabinet: the upright, the cocktail, and the bartop. We’ll provide a description of each of these types, as well as a breakdown of that cabinet’s pros and cons.

The Upright Cabinet

A standup cabinet is what you probably think about when you think “arcade machine.” About six feet tall, fields of these wooden monoliths are what make an arcade an arcade.

Image Credit: BYOAC Wiki

Pros:

• Big size means lots of room for a big monitor
• Room for custom or replica sideart and marquee means you can make your machine as gaudy or nostalgic as you want it.

Cons:

• Because uprights are the most arcade-y looking of the cabinets, they’re also the most likely to make your living room look like an Aladdin’s Castle. This might sound OK to you, but you should definitely run it by any significant other you might have.
• The screen in an upright cabinet is generally fixed in place. This means you’ll have to choose between a vertical (think Pac-Man) or horizontal (think Street Fighter) orientation, and games of the other orientation will only be able to use a limited area of the screen.

The Cocktail Cabinet

“Cocktail”-style arcade machines are essentially a screen set into a table, with controls on one, two or three sides. Traditional cocktail cabinet games with two sets of controls are generally meant to be played by two players on opposite sides of the table taking turns, with the screen rotating 180 degrees between turns so that each player sees the screen as upright.

Pros:

• Less obtrusive looking, and doubles as a surface for drinks.
• With three control panels, can play both vertical and horizontal games at full screen size. Vertical games are played at the two facing control panels, while horizontal games are played at the longer side control panel.

Cons:

• Despite the more subtle profile, cocktail cabinets actually take up more floor space than uprights, especially with the third control panel. Remember, you need space for people to sit on all three sides of the cabinet.
• Without the third control panel, 2-player horizontal games, like Double Dragon are difficult to play. Not impossible, because MAME has a video option which allows you to mirror a horizontal game into two cloned screens, but you get significantly less screen space if you do this.

The Bartop

A Bartop-style cabinet is basically a standup cabinet, minus the bottom half. Like the name implies, these cabinets are meant to sit on a counter or table as they’re played. These are less common in actual arcades, though you may spot similar machines in bars running trivia or puzzle games.

Image Credit: BYOAC Wiki

Pros:

• Small size means greater portability, less intrusiveness, and cheaper materials.

Cons:

• Small size also means a smaller screen, and usually less room for controls.
• With much less room to build in, significantly more planning is needed to make sure you’ll be able to fit everything inside.

As for us? We decided to go with a cocktail cabinet. We really liked the fact that you can play both vertical and horizontal games using the entire screen, as well as the camaraderie that comes from the whole office huddling around a table, watching Will humiliate Norm at Galaga.

Cabinet Construction

So, you’ve figured out what style of cabinet you’d like to build? Great! Now you’ve just got to build it.

Again, there are three options. First, you can find an old arcade machine for sale somewhere and use its cabinet as a basis for your MAME machine. Second, you can build your own out of plywood or MDF. There are plans available online for this, but be warned: it’s real easy to make a shoddy looking cabinet if you don’t have a firm grasp on carpentry, or the right tools (a router is a must).

Finally, you can do what we did: order a kit online. Sure, it costs a bit more than you would pay for parts, but it dramatically simplifies the whole construction process, and it’s the only way for a wood-working newbie to ensure that they get a great-looking cabinet.

We bought our kit from Arcade Depot, and although we had initially been tempted to try to build our own cabinet from scratch, we quickly realized that we’d made the right choice in buying a kit. Not only did the cabinet turn out much nicer than anything we could have built, Scott over at Arcade Depot was a huge help, giving us a lot of useful advice throughout the whole project. The kit’s a little trickier to put together than, say, IKEA furniture, but still well within the capabilities of any fledgling MAMEsmith.

We thought you might be interested to know what goes into building a cabinet like this, so we asked Scott to describe what it is they do over at Arcade Depot. This is what he said:

“The Arcade Depot cocktail cabinet design is the result of carefully listening to customer feedback over the course of many years. The initial thrust of the cabinet was one of offering a high-quality replacement for factory original systems whose own cabinet faltered long before the electronics within it. It later became a natural choice for customers inspired to build their own home arcade systems with PC-based arcade emulation software. In order to directly address this growing desire for in-home systems we chose grade A-1 plywood complete with a hardwood finish to transform a classic cocktail cabinet into spouse-approved furniture!

“Cabinet construction begins with the shaping of each cabinet panel using high-precision, high-speed CNC (Computer Numerical Controlled) wood routers accurate to 0.001” for perfect parts and alignment features. All alignment features have been designed to make the cabinet assembly process simple and straightforward with virtually no possibility of error. Once machined, each cabinet is dry-assembled as part of our in-process quality inspection to ensure it meets our stringent standards. Our staff craftsmen complete the sanding, staining, surface sealing, and t-molding installation by hand so that active quality inspection continues throughout the entire process. Each step of the fabrication process has been optimized and refined over many years of operation to allow us to offer the highest quality, most cared for cabinet kits on the market at an unbeatable price!”

Next, we pick a monitor.

Part 2: The Monitor

The next major consideration that faces you on the path to retro gaming nirvana is a doozy: What monitor should you use in your MAME cabinet? As much as we’d like to be able to simply tell you what to go with, there’s just not one answer that works for everyone. So, as with the cabinet styles, we’ll list your options for you, along with the pros and cons of each. We ended up trying out both an arcade monitor and a new LCD screen for our cabinet; we’ll tell you how each one worked out.

Arcade Monitor

The first option, and the most straightforward, is to simply get an arcade monitor—a big ol’ CRT monitor built to display the low-resolution games. These monitors allow you to see games the way their creators saw them, with big, blurry pixels that create a softer image and allow colors to subtly blend together. For modern MAME systems, several multi-sync monitors are available, which can also display higher resolutions and refresh rates, and can accept VGA input.

Pros:

• The most authentic visuals you can get.
• Slightly curved screen gives your cabinet an “old school” look.

Cons:

•   Becoming very hard to find; many manufacturers no longer sell arcade monitors.
•   Takes up a lot of cabinet space, and requires additional cooling.
•   Weighs one billion pounds.
•   Can literally kill you.

Did we mention that an arcade monitor weighs more than my car and can actually kill you? The first of the two statements in that last sentence is an exaggeration, but the second definitely is not. Because the capacitors in a CRT can store more than 20,000 volts, you have to be very careful when handling them. We bought our Tri-Res arcade monitor from arcadeshop.com, though we’ve heard that it’s getting harder and harder to find good arcade monitors.

Installing the arcade monitor was the most difficult part of the entire construction process. The monitor had to be mounted to the side of the cabinet, because it’s too heavy to be mounted to the top. This meant creating a riser that held the monitor the correct distance from the side, so as to be centered in the middle of the table. As you can see from the picture, this involved quite a bit of wood, and a not unsubstantial amount of time gluing and screwing the platform together. Once the platform was solidly attached to the side of the cabinet, we used four big 2 ½” long screws to make sure that the monitor would stay fastened to the side of the cabinet and wouldn’t come crashing down on the delicate computer parts inside.

So, all in all, the CRT is a pain. Sure looks nice, though.

LCD Monitor

So, you’re willing to give up a little authenticity for the convenience of being able to find, install, and not get maybe-killed by a monitor? That’s ok, we don’t blame you, and in fact we think that LCD screens are a perfectly respectable alternative to CRT monitors.

Pros:

•   Lightweight and easy to install.
•   Cheaper than a CRT, and much easier to find.
•   You might have a spare one lying around.

Cons:

• Too-sharp picture means the games don’t exactly look like they did in 1986.

For our second cabinet top, we used a lovely 21.5” Asus LCD, which we chose because it fit the table nicely, and had a wide horizontal viewing angle (important for a monitor that you’ll be looking down at, from the side much of the time).

Our experience installing the LCD was a much easier one than with the CRT. Scott over at Arcade Depot routed us out a custom cabinet top, with a hole and bezel cut that were the exact right size for the monitor. We just dropped the display in, then fastened it down with a couple strips of metal strapping and some wood screws. After that, all we had to do was attach the top panel, with screen, to the rest of the cabinet.

The custom-cut cabinet top for the LCD monitor

Other

It’s also possible to use an old CRT television or monitor, which will give you a picture quality somewhere in between an arcade monitor and an LCD. They’re still heavy and bulky, but you should be able to find one for much cheaper than either of the other options. In other words, if you don’t mind a display that’s middle-of-the-road in pretty much every way, this might be the cost-effective solution for you.

No matter what you do, though, here’s one major tip: Use a bezel.

Image Credit: ArcadeShop

In arcade machines, the bezel specifically refers to the piece of plastic or cardstock used to hide the edges of the monitor. You can make your own by cutting black card to fit around your monitor, but more often than not this ends up looking pretty janky. Instead, we recommend picking up a molded plastic bezel. Most arcade suppliers sell them, sized for all common monitors, for less than $25. Considering how much better they make a project look, we definitely think this is a worthwhile expense.

Our 19"arcade monitor without a bezel

And with a bezel.

Part 3: Controllers

Finally, we get to the fun part. Fun for some, anyway, although if you’re not the type who gets a perverse glee from designing the perfect arcade control setup, this project just might not be for you. Like the other decisions so far, designing your controls is all about what kind of experience you want your MAME cabinet to provide. Below, we’ll discuss the pieces of control equipment you’ll need to consider.

But first, a word about microswitches. A microswitch is pretty much what it sounds like: a tiny little switch, designed to be both responsive and durable enough for extended arcade use. When you press an arcade button, you’re actually just pushing down on a plastic plunger which itself presses a microswitch. When you move a standard arcade joystick, you’re actually just using a little metal stick to press one of four microswitches.

Joysticks

Probably the most recognizable symbol of arcade gaming, the joystick is the primary method of input for most games. And although picking a joystick might seem simple at first, there are actually a lot of factors you have to consider.

First, you need to decide whether you want to go with a 4-way or 8-way joystick. Either joystick will have 4 microswitches located at the base of the stick, which are pressed when the joystick’s shaft moves in a certain direction. In an 8-way joystick, moving the stick diagonally presses two buttons at once. In a 4-way stick, this is prevented from happening, usually with some sort of restrictor plate. For most games, you want an 8-way joystick so you can do things like move diagonally. However, several classic older games such as Pac-Man, Donkey Kong and Dig-Dug can’t handle diagonal inputs, and therefore need a 4-way joystick.

Image Credit: Happ Controls

Some people choose to install a single, dedicated 4-way joystick somewhere on their control panel, since most 4-way only games are only played by one person at a time. You can also use a joystick that can switch between 4- and 8-way, which is what we chose for our machine. Some of these joysticks have a switch on the underside, which you can use to change them, but we ended up going with the Mag-Stik Plus, a 4-way/8-way switchable joystick that can be switched from the top of the panel. You just pull up on the stick and turn it to switch between the modes. The Mag-Stik Plus is sold by Ultimarc, who sell high-end parts for home-made arcade machines. Because they were kind enough to send over 4 Mag-Stick Plus joysticks, we went with them for all of our control panels.

In addition to 4-way or 8-way, you have to consider the “style” of the joystick. Japanese style joysticks tend to have a ball top, light action and more play. American style joysticks tend to have bat-shaped tops, and tighter action. You can also consider restrictor plates, which limit the area in which the joystick can move, for instance to an octagon or smooth circle shape.

Image Credit: Slagcoin

There are also joysticks with more specific functions, like 2-way, 49-way, analog, and rotary joysticks, but generally these are used by a very limited subset of games, so unless you’re dying to play a particular game that requires one of these unique joysticks, you’re probably better off investing in a high-quality 8-way or 8-way/4-way joystick.

Buttons

Fortunately, after the tricky world of joysticks, there’s really not that much to choose from with buttons. Your biggest decision will probably be whether you want the “classic” style of button, with a concave surface, or the “tournament” style button with a convex head. Most arcade games used the classic buttons, although modern Japanese fighting games frequently use the tournament buttons. To get the best of both worlds, we opted for classic buttons on the two facing control panels, and tournament buttons on the side-by-side panels.

If you’re up for, you can also get translucent buttons, which can have an LED mounted inside for a light-up control panel. Since we wanted a subtle, classic look for our cabinet, we opted for no lights, and a single primary color for each of the control panels.

Trackballs and Spinners

After joysticks and buttons, which you’ll find on pretty much every MAME cabinet, the most popular controller inclusions are trackballs and spinners (also called dials). Although these controls are supported by far, far fewer games than joysticks, some of the games that do use them are such classics that many people choose to make room for one or both on their console. Games that use trackballs include Centipede, Marble Madness and Missile Command. A spinner is used with games such as Arkanoid, Pong and Tempest.

For our machine, to keep the control panels uncluttered and clean looking, we chose to go with a standard Street Fighter-style setup for all control panels, with 6 play buttons, a joystick and a start button (except for the two facing panels, which had both start buttons on the player one controller). In retrospect, however, there’s little need for more than 4 buttons on each of the facing panels. Generally speaking, the only games which require six or more buttons are fighters, which are played by only two players, and always side-by-side. Given that, it might be possible to fit a trackball or spinner on the narrow panels without overcrowding them.

Considerations for Control Panel Design

How you build your control panel—what controls you include and where you put them—is entirely up to you. That said, here’s some tips for how to design the perfect controller for your cabinet.

• Consider the games you’ll be playing. If you absolutely love Centipede, but hate fighting games, then you’ll definitely want a trackball, and you can probably do with just 4 buttons.

• Don’t go overboard. It’s tempting to try and make a panel that can play every game under the sun , but before you try to shoehorn that second spinner onto your controller ask yourself “Am I really going to use both of these?”

Image Credit: Crapmame

• Similarly, you probably don’t need as many buttons as you think you do. If you try and fit 6 play buttons, a start and coin button for each player, as well as a pause, menu, and exit key, you’re controller is going to be way too crowded. MAME is highly configurable; which means that you don’t need to bind a specific button to add a coin for player 1, for instance. Instead, you can create a shift button, then tell MAME to add a coin when shift +button 1 is pressed.

Image Credit: Crapmame

• Consider how the controls are going to feel in your hand before you commit to them. After you design your panel, make a printout of it and see if the scale feels right. If possible, make a temporary panel out of cardboard and install the controls into that first, to make sure that everything feels comfortable.

• Need inspiration? Check out some of the awesome MAME cabinets people have built to see what works in controller design.

Image Credit: Jeff's Arcade

• Need to know what to avoid? Check out this site, which maintains a list of awful MAME cabinets. One look at some of these cabinets, and you’ll understand exactly why you should exercise restraint in designing your control panels.

Image Credit: Crapmame

Part 4: PC Hardware

At its heart, a MAME machine is really just a fancy enclosure for a computer that emulates old games. This means that everything will be for nothing if you don’t have a computer to put into your cabinet. Fortunately for you, the system requirements for MAME are pretty darn low. If you’ve got a spare computer or parts from the last 5 year, it’ll run MAME just fine. Here’s what we used in ours:

CPU: Core 2 Duo E6600
Motherboard: Nvidia 680i
Graphics: ArcadeVGA card
Memory: 1GB DDR2
HDD: 150GB

Right about now, you may be asking yourself “What the heck’s an ArcadeVGA card?” It’s one of two specialty bits of computer hardware you’ll need for a MAME cabinet—it’s a special video card which allows you to connect your computer directly to a 15Khz arcade monitor. This is necessary, because sending a stand 31Khz signal to an arcade monitor won’t work and can damage the monitor. Ultimarc makes the cards, which are available for around $100.

The other special piece of hardware you’ll need to order is a keyboard encoder. Remember that all your joysticks and buttons are actually just little microswitches, which complete electrical circuits when pressed. A keyboard encoder is wired to all of your microswitches, and to your computer through the USB or PS/2 interface, and it translates the microswitch signals into key presses for your computer to use with MAME.

There are several different keyboard encoders available. Among the most popular are Ultimarc’s I-PAC 2 and I-PAC 4 boards, which support up to 32 and 56 inputs, respectively. For our build we chose the I-PAC 4, so we could hook all of our controllers up to a single encoder. When calculating how many inputs you need, bear in mind that a joystick contains 4 individual microswitches.

Mounting

You can mount the computer in the case however you like, as long as there's room. In our cocktail cabinet, the large CRT monitor meant that there wasn't enough vertical space to mount the motherboard into a case. We could have mounted the mobo directly onto the wood floor of the MAME cabinet, but instead chose to build it into a plastic tray, and glue that tray to the bottom of the cabinet.

To make way for the speakers, we drilled a grid of holes through the case and hot glued in a couple of simple Logitech PC speakers, facing toward the holes.

To power everything, we glued a power strip to one corner of the inside of the case. We connected the PC, monitor and speakers to this power supply, and then ran the power supply cable out through a hole in the bottom of the case.

Hot Glue: The solution to all of your problems

To turn the PC on and off, we cut the ATX power button out of a spare case and connected it to the motherboard. We ran the wire through a hole in the floor of the cabinet, and glued it under the bottom panel, facing sideways so that it isn't visible from the outside, but is still easy to access.

Part 5: Construction

Once you’ve bought your parts and designed your control panel, it’s time to put it all together. There’s nothing overly difficult about building the control panels, but it can be very time consuming.

Installation

First, you’ll need an actual panel to install your controls into. If you’re building your own from scratch, we recommend 5/8” MDF or plywood, and you’ll definitely need a router to precisely cut the hole for each controller. To ensure accurate placement of holes, you can print out a diagram of your control panel, tape it to the panel, and cut through the paper.

Mounting buttons is easy—you just need a hole big enough for the button to fit through, and a plastic nut locks it into place.

However, joysticks are a bit more trouble. If you have enough clearance under the panel, you can cut a button-sized hole for the joystick, mount the joystick assembly under the board, and then feed a long joystick shaft [link to long joystick shaft] through the hole. Alternatively, if your router skills can pay the bills, so to speak, you can also cut out a relief in the top of the panel that’s the right shape to simply drop the joystick into. If you go with a wooden control panel, you’ll want some sort of overlay to make the panel look and feel nicer. MAMEMarquees.com is an excellent source for reproduction and custom artwork.

We had Scott from Arcade Depot make us a plywood panel for the two side-by-side controllers with a glossy black Lexan overlay. The joysticks drop in from the top, then the overlay conceals the sticks’ metal mounting plate. For the two short panels, we got custom-cut metal control panels, which are easier to mount into, and look and feel great even without an overlay, but are only suited for smaller panels, such as ours. For a full-sized control panel on a standup machine, wood is really your best option.

Wiring

Once you’ve got your controls mounted, it’s time to start wiring. Every single microswtich needs to have two wires connected to it: one running from the middle prong of the microswitch to an input slot on the keyboard encoder and one running from the prong on the bottom of the switch to the keyboard encoder’s GND input.

Since every switch connects to the ground, you can save a lot of wire and minimize clutter by daisy chaining your grounds. This means that instead of running a wire from every switch to a single ground hub somewhere, you simply wire the hub to the first button, then the first button to the second button, then the second button to the third button, and so on and so on.

We daisy chained each of our control panels in this way, so that we only had a single ground wire running from each set of 6 buttons, and each joystick. We joined all of these wires at a grounding strip bought at Radio Shack (err, The Shack), and connected the strip to the keyboard encoder.

You can attach wire by soldering it to the switch, if you want, but doing this is time consuming, and a pain if you need to go back and make any changes later. Instead, we used crimp-on female disconnects, which made attaching and detaching wires much easier. Ultimarc sells a wiring kit, which includes all the wire you’ll need, a wire cutter/stripper/crimper and 100 disconnects. Pretty handy if you don’t already have all those things already lying around.

Part 6: Software

Once you’ve gotten your cabinet built, you might be tempted to start celebrating, but hold your horses—there’s still a lot of software configuration to be done. In this part of the guide, we’ll explain the different software you’ll need to get your MAME cabinet running full-tilt.

Drivers

As with any new PC, the first thing you’re going to want to install is the drivers for your hardware. Motherboard drivers, if you need them, and video drivers. Assuming you went with the ArcadeVGA card, there are actually three drivers you’ll need to install. First, you need the video drivers. These come on a CD you get with the card. Next, because the ArcadeVGA card is a modified ATI card, you should install the ATI Control Center. This is also included on the Ultimarc CD, or it can be found on ATI’s website. The Control Center isn’t strictly, necessary, but it allows you to do some things like rotate Windows, if you’re using a vertical or upside-down monitor.

Finally, if you’re using a tri-sync monitor with your ArcadeVGA card, you need to download the Tri-Sync Utility here. This utility modifies the ArcadeVGA drivers to allow your system to make use of the tri-sync's ability to switch to 31 Khz mode, letting it display at higher resolutions without interlacing.

MAME and MaLa

Next we’ll cover how to install and configure MAME and MaLa, the two programs which will allow your cabinet to actually play old games. MAME, of course, is the Multiple Arcade Machine Emulator, and it emulates the software and hardware in thousands of old arcade games. To play a game on MAME, you need a ROM of that game, which is a file containing the data dumped from that arcade machine’s main board. There is a selection of obscure ROMs which have been made available for free by their copyright holders on the MAME homepage. You can also contact game companies directly about purchasing ROMs from them; although some companies are more receptive to this than others.

MaLa is a MAME Launcher, or a “frontend;” software which displays and organizes your ROMs. Although originally designed for MAME, MaLa can actually launch games with any emulator that runs from the command line, meaning that you can manage all your classic gaming from a single program.

Unfortunately, there’s more to getting MAME and MaLa working than just clicking on setup.exe. But don’t worry, we’re going to show you everything you need to get each program configured just the way you want it.

One tip before we begin: None of the software we’re installing right now makes any changes to your system registry. Because of that, it’s possible to get everything installed in a folder on one computer (say, your desktop rig at home) where you’re most comfortable, then just copy the whole folder over onto another computer (the computer in your MAME cabinet, for instance).

Installing MAME

You have to install MAME first, because MaLa configures itself based on a MAME installation. There are several different versions of MAME available, including ones with nice GUIs, or additional features like video filters which try to simulate the look of a CRT on an LCD, but for our purposes the basic command-line MAME is all we need.

To get MAME, head to the official MAME website and pick up the binaries for the latest version of MAME. If you’re running a 64-bit OS, make sure to grab the 64-bit MAME binaries. Simply run the self-extracting archive, and select a location to install MAME to.

You can install the program wherever you like, although we prefer to keep all of our emulation programs in one folder, such as C:/Emulation. MaLa will need to reference a several files and folders within the MAME installation, so it keeps everything more organized if you’ve got a single hub for all of your programs.

The default MAME installation is all you need to play any ROMs located in the roms subfolder of your MAME directory. However, the main goal of the MAME project is to preserve arcade history, and to that end there are other databases and files that you can download to give MAME more background info about the games you’re playing. Here’s a list of those files and what they do.

Artwork: MAME has in-game support for bezels, backdrops, and overlays, which can be enabled to give the game its original, arcade flavor. These artwork files can be found for individual games at this site, or you can search for the entire artwork.zip archive of ALL game art on Google or using whatever torrent search engine you prefer. Put the game art into the artwork folder in the MAME directory, leaving it zipped in individual game packages.

Samples: MAME strives for perfect emulation of old games, but it still has some flaws. Particularly, the sound circuits of some older games are too complicated to properly emulate, so MAME “cheats” a bit by using samples of the sounds used in the game. In order for the games that use samples to sound right, you’ll need to populate the samples folder in the MAME directory. Samples for individual games can be found here, or you can search for a complete archive.

History.dat: This file is an archive of information about games supported in MAME. Downloading this file and including it in your MAME directory will allow MAME and MaLa to provide detailed information about any game in your list. Download it here and put it in your MAME directory.

Catver.ini: This file contains genre and version information about every game supported by MAME. This will allow programs such as MaLa to sort or filter your games using this information. This file can be found here. Put it in your MAME directory.

Controls.ini: This file contains information about which controls are used by which game. This will allow MaLa or other programs to filter your games so that you only see games which you can play with your controls. The file can be found here. Put it in your MAME directory.

Additional Artwork: This data is not necessary, but frontends like MaLa can display additional artwork, including screenshots, photos of the cabinet, flyers and more. Most of this artwork can be found on the excellent MAMEWorld website in the Artwork section. If you would like to use any of these assets with your frontend, download them, then place them in their own subfolder in the MAME folder.

Configuring MAME

To configure MAME the way we want it, we’ll need to edit the mame.ini file. Unfortunately, this file should not yet exist; so we’ll create it. To do so, open a command prompt, navigate to the folder that contains mame.exe and enter the following command:

mame –cc

Now you should see a mame.ini file in the MAME directory. Use your favorite text editor to open the file. All of the settings in the file are pretty self-explanatory, but here’s a couple of useful one:

Under the Core Artwork Options heading, you may want to change the “bezel” setting to 0 to turn it off. Otherwise, MAME will automatically display a virtual bezel around any game for which it has artwork, reducing the screen space that game gets to use.

The Core Rotation Options allows you to make sure that the orientation of the screen is correct for your monitor. To rotate the screen ninety degrees to the right or left, enter a “1” for the “ror” or “rol” settings, respectively. To flip the screen 180 degrees, enter a “1”for both the “flipy” and “flipx” options.

If you’re using an arcade monitor, you should disable automatic screen stretching (necessary to actually get the benefit of an arcade monitor) by changing these options:

#
# WINDOWS VIDEO OPTIONS
#
video ddraw

#
# DIRECTDRAW-SPECIFIC OPTIONS
#
hwstretch 0

#
# FULL SCREEN OPTIONS
#
switchres 1

Configuring MaLa

Once MAME is properly installed, setting up MaLa is pretty easy. Just download the MaLa zip file here, and extract it to a folder in your emulation directory. Run mala.exe, and a dialogue box should pop up informing you that this is the first time MaLa has run, and that the configuration tool is going to open.

The configuration will open, with the MAME Config -> Basics tab front and center. In the field marked "MAME Executable" press the “…” button and select mame.exe from the MAME folder. MaLa should automatically find the catver.ini file and other information files. If it doesn’t, you can manually locate them in the Additional tab. You can also define the fields in the Pictures and Video tab for the location of any additional art resources you’ve downloaded, which will allow MaLa layouts to use this information in your gamelists.

In the Basics tab, tell MaLa where to find the folder with your ROMs in the field marked “Rom path.” Using the dropdown menu, you can define additional locations for MaLa to search for ROMs in, but for our purposes that shouldn’t be necessary. Hit OK. A box will pop up asking you to refresh your game list; click on ok, and when it’s done scanning your ROMs, MaLa will start.

Layouts

But what’s that? MaLa is ugly, you say? Well that’s just because you’re using the default layout, which is pretty lame. Instead, we’ll show you how to find and install a custom layout. First, you need to find a layout—a good source is here. When you download a layout file, it will have a .MLL file, and a set of art files, usually in a folder. Place the .MLL file into the MaLa/layouts directory, as well as the folder of art files. It’s important that the art files be in a folder in the layouts directory, with the exact same name as the .MLL file.

ROM Lists

Finally, we’ll examine how to set up ROMlists, which allow you to sort your games into various lists within MaLa. For instance, you might set up a list of top-down shooters, or a list of games that can be played in “cocktail mode,” with the screen flipping back and forth between two players. You can create and edit game lists within MaLa using the menu (by default, the “2” key), but if you want to quickly work with a lot of games it’s much quicker to use the MalaGamelist.exe program included with MaLa.

In Conclusion

That's it for our MAME guide. There's an almost-infinite number of ways you can continue to tweak and customize a MAME cabinet, but if you follow the steps in this article, you'll have designed and built a powerful, flexible all-in-one arcade machine. We hope you're tempted to try this project for yourself, and if you do build a MAME cabinet, we hope you enjoy it as much as we've been enjoying ours.

Make Your Own Blu-Ray Laser Keychain!

Paul Lilly — Fri, 26 Jun 2009 09:54:35 -0500

You probably have an old processor lying around that you ended up modding into a keychain, but to take your geek cred to a whole new level, try wielding a blu-ray laser like a light saber the next time you fumble around for your house key.

Not only can it be done, but "jayrob," a DIY lasers expert, has posted a worklog of how he built his own using a keychain light made from a solid piece of brass that he picked up from Lowe's. In short, Jay stuffed a laser diode and a larger battery inside, did a little drilling, and ended up with the coolest keychain we've ever seen.

Read all about it here.

Image Credit: hacknmod.com

Scanner and Old Lens Used in DIY 130-Megapixel Camera

Andy Salisbury — Tue, 09 Jun 2009 16:26:02 -0500

While the concept of a scanner being reworked into a camera isn’t entirely new, someone creating one that can take photos at 130-megapixels is.

A yet unnamed Japanese man with some tech know-how was able to create this beastly camera by fusing a 1200 dpi Epson GT-S620 scanner and old Cannon FD 50mm lens together. He says that he chose this scanner because it has a CCD sensor, uses a camera-like lens and has LED lighting.

If you want to see photos taken by the camera, you can check out his Flickr stream here.

Image Credit: Spyuge

Build Your Own Multitouch Surface Computer

Alex Castle — Tue, 07 Apr 2009 00:00:00 -0500

It all started while we were researching an article on future user interfaces. Touch interfaces are hardly futuristic at this point, but multi-touch hardware like the Microsoft Surface or the iPhone is just starting to become a big deal, and we decided to see what big things are going on in that field. What we found that surprised us the most wasn’t anything about the future of multitouch; it was about something that people are doing right now.

There is, it turns out, a whole community of very smart folks out there on the internet perfecting the art of building DIY multi-touch surfaces. The process isn’t exactly simple, but the results we saw were stunning: multitouch surfaces with responsiveness rivaling Microsoft’s $12,000 offering, built in a garage on a shoestring budget. “Future UI article be damned,” we thought, “we’ve gotta build one of these for ourselves.”

And so we did. We documented the whole process, from start to finish, so that you can try building one of your own, if you’re so inspired. We’re not going to claim to have done everything perfectly the first time, so think of this article as more of a build log than a definitive how-to. Still, we’re very pleased with how the table turned out. We’re so pleased, in fact, that we put together a video showing the table in motion. Check it out, and read on to find out how we did it!

First, some acknowledgments are in order. Virtually all the techniques used to create this table were discovered at the Natural User Interface Group website, which serves as a sort of repository for information in the multitouch hobbyist community. If you find the technology shown in this article interesting, you owe it to yourself to check out their forums, where you can participate in the development of multi-touch hardware and software.

The Theory

Before we can get into the actual, physical construction of the table, it’s important to understand just how it works.

There are several different ways to make a multi-touch surface, but we’ll focus on the one that we employed: the FTIR screen. An FTIR (short for Frustrated Total Internal Reflection) setup involves three vital components: a sheet of transparent acrylic, a chain of infrared LEDs, and a camera with an IR filter. The LEDs are arranged around the outside of the sheet of acrylic so that they shine directly into the thin side surfaces.

Once the IR light is inside the acrylic, it strikes the top and bottom surfaces of the acrylic at a near-parallel angle, and is subject to the effect known as total internal reflection. This causes it to be wholly maintained in the acrylic. This is a little tough to describe in words, so we’ve made a simple diagram:

The net effect of the setup described above is a sheet of acrylic full of internally reflecting infrared light. When a finger is pressed against the acrylic, it causes some of the light to be reflected down, through the acrylic and into the cabinet, where it is detected by the webcam. This effect, called frustrated total internal reflection is a little complicated, and involves something called an evanescent wave, but you don’t really need to understand why it happens, just that it does happen, as illustrated in this diagram:

The webcam, which has been modified to detect only infrared light, sees this reflected light as white spots on the screen; something like this:

From that picture, software running on a nearby computer extracts a map of where fingers have been pressed on the screen, and uses that data to control multi-touch applications.

The Screen

An FTIR multi-touch table’s screen is comprised of three basic components: The acrylic sheet, the LED lighting, and the projection surface. Each one requires a bit of work, so we’ll discuss them one by one.

The Acrylic

The foundation of the screen is the sheet of acrylic which serves as the medium for the infrared light. Why acrylic? Acrylic has several properties that make it a good fit for our project. First, it has the right optical properties, allowing for an excellent FTIR effect. Additionally, it’s lightweight, strong, and very clear (more so than glass).

We constructed our screen from a 24” X 30” X 3/8” acrylic sheet, which we bought at local plastics dealer TAP plastics. Acrylic can also be purchased on the web, although high shipping costs mean that it’s best to try and find a local plastics dealer. For a 24” X 30” sheet, 3/8” is thick enough to prevent any noticeable sagging in the sheet, even when firm pressure is applied to the middle of the screen. A larger screen would, of course, require thicker acrylic for stability.

Most acrylic comes with saw-cut edges, which are rougher and therefore more opaque. Because we wanted to shine infrared light into the acrylic from the sides, we needed to do something to guarantee a clear edge. We had two options:

1. Buy laser-cut acrylic. Most large plastics stores will have the capability to do this, though they generally charge extra. Because we here at Maximum PC always have our mind on our money and our money on our mind, we decided to go with option number 2:

2. Buy saw-cut acrylic, then polish the sides ourselves. To do this, we simply gave the edges a thorough sanding with 200-grit sand paper, then went back over each edge with Dremel rotary tool using the buffer attachment and a polishing agent. This certainly took a little while, and involved inhaling more acrylic dust than is probably healthy, but the result was a nice, clear edge.

Smoothing the edges with 200 grit sandpaper

Polishing to a sheen with a Dremel and buffer bit

Next Page: Soldering LEDs and spreading silicon

The Lights

The array of infrared LEDs is what floods the acrylic with light and creates the vital FTIR effect. The exact construction of the array can differ greatly from one table to the next: which LEDs to use, how far apart to space them, how many sides of the screen to wire were all variables we had to consider. For our table, we decided to cover all four sides with LEDs spaced just a little more than an inch apart.

Like with the acrylic, there is an easy way and a hard way to connect the LEDS. The easy way is to buy premade infrared LED ribbons. Right now, the only source for IR LED strips that we could find was a company called Environmental Lights. These strips can be installed around the edges of the acrylic using an aluminum channel such as this one. Both the Ribbon and the channels run on the pricey side.

The hard way is to buy LEDs in bulk and solder them yourself. Once again, because we were committed to putting this project together on as tight a budget as possible, we opted to go for the cheaper option. We bought 110 IR LEDs (850nm wavelength, not 940nm—it’s easier for the camera to pick up) from www.digi-key.com for about 40 bucks, and whipped out the old soldering iron.

Now, we won’t lie to you, readers; soldering and wiring the LEDs was a pain in the ass. Not only is soldering 96 LEDs together tedious to begin with, but the LEDs’ leads had an unpleasant tendency to break under even slight force, requiring quite a bit of LED repair work. Also, even though our table worked just fine in the end, we would probably try to use even more LEDs in a future build. Because the premade ribbons pack more LEDs per inch and are much easier to use, we would probably go with those the second time around.

Because the voltage drop across each LED is 1.5V, and we’re using a 12V rail from a PC power supply to run them, we soldered the LEDs in chains of 8 (for a total 12V drop), then wired 12 chains up in parallel (leaving us with a handful of spare LEDs, which is absolutely vital). To make it easier to solder, we drilled 8 holes in a line in a piece of scrap wood, just big enough to hold the LEDs in place as we soldered them together.

There are different ways the LEDs can be mounted around the acrylic. Some people choose to drill holes into an aluminum or wood strip in order to make a frame to hold the LEDs in place. Since we were committed to doing things on the cheap, and also on a very tight schedule, we simply used electrical tape to hold all the LED chains in place, three on each side, shining into the acrylic. Sure, it’s not the prettiest solution in the world, but it was effective, and because the outer two inches of the acrylic are covered by wood, the tape doesn’t show up on the finished screen.

The Surface

Now we’ve got our acrylic, and the LEDs are set up to shine into it, but our setup has still has two problems.

For one, acrylic is very clear. More so than glass, even. This is nice if you’re building a window out of Plexiglas, but it also means that if we tried to project onto the acrylic the light would pass right through. To solve this problem we’re going to use a sheet of drafting vellum, which is essentially a high-quality, durable tracing paper. This will act as a reasonable projection surface, and is fairly cheap. We got a 36” by 24” sheet for about 5 bucks at San Francisco art supply superstore FLAX. If you don’t live near a huge art store, you might have to do some calling around to find a sheet, or you can order them online, usually in somewhat larger quantities.

In our experience, the vellum worked very well as a projection surface, but gave the surface a distinctly "papery" look and sound, and it was sometimes difficult to make it lay flat. In a future revision of the build, we would like to experiment with having the vellum laminated before using it as a construction material.

The other problem with the acrylic surface isn’t really noticeable until you turn on the lights and camera and watch what happens when you actually touch the screen. On the bare acrylic, or the acrylic with the vellum, pressing your fingers down causes the FTIR effect to occur, reflecting light into the camera. However, if you try dragging your fingers on the screen, the effect gets much weaker, or disappears completely. To solve this problem, we need to create a “compliant surface” to enhance the FTIR effect. We made our compliant surface out of silicon sealant.

When it’s spread on with a foam roller, the silicon creates a thin coating of “microblobs,” with a very rough, rubbery texture. This is ideal because it allows the vellum to lie lightly on top of the acrylic, silicon side down. When you press down on the vellum sheet, the silicon squishes onto the acrylic, momentarily bonding with the surface, which alter the way light bounces around inside the screen and allows more to escape down into the camera.

To create the compliant surface, we first taped the vellum to a flat surface with painters tape, then applied silicon onto the sheet with a caulk gun in a loose grid. After that, we quickly used a dense foam paint roller to spread the silicon evenly across the vellum. We waited about an hour for the silicon to set, then repeated the process. We waited another hour, then applied a third and final layer. As an experiment, we also readied an additional sheet of vellum with only a single coat of silicon. During our testing we found that the 3-coat compliant surface created a dramatically more responsive surface.

Next Page: Performing open-camera surgery on a Playstation 3 Eye

The Camera

In order for our setup to work, we needed a camera that senses infrared light, but not visible light. It sounds expensive, but you’d be surprised. In this section, we’ll show you how we created an IR camera with excellent resolution and frame-rate for only $35—the price of one PlayStation 3 Eye camera. “But that’s not an IR camera,” you say? We’ll show you how to fix that.

As it turns out, most cameras are able to sense infrared light. If you want to see first-hand proof that this is the case, try this simple experiment: First, find a cheap digital camera. Most cell phone cameras are perfect for this. Next, point it at the front of your TV’s remote control. Then, while watching the camera’s display, press the buttons on the remote. You’ll see a bluish-white light that is invisible to the naked eye. That’s the infrared light used by the remote to control the TV.

However, for the sake of preserving an accurate color balance, most cameras have an IR filter applied, which causes the camera to detect only visible light. It’s possible (and in the PS3 Eye’s case, reasonably easy) to open up a camera, remove the IR filter, and replace it with a visible light filter, making an infrared-only camera.

But before we could get at the PS3 Eye’s sweet, sweet IR filter, we had to crack it out of its shell. To do this, we started by flipping it over and popping off the four little black disks glued over the screw wells. We had seen this done using an X-Acto knife in this excellent video, but when we tried to recreate the feat ourselves we didn’t manage to do anything except snap the tip off our X-Acto's blade. Instead, we found that using the corner of a regular rectangular razor blade to pry the disks off was more effective.

Once the covers are gone, the screws can be removed and the two halves of the shell pulled apart. This is a little easier said than done, though; the shell is glued together. To break it apart, we had to use a process that involved going around the seam that joins the two halves of the camera, inserting a flathead screwdriver and twisting every centimeter or so, until the halves separated.

With the back half of the shell removed, the circuit board is exposed. First, we removed the two screws at the bottom, labeled (a), allowing us to removed the camera’s base, then we unscrewed the five screws labeled (b) and separated the circuit board from the front casing. Finally, we removed the two smaller screws that had been hidden behind the camera's base, freeing the lens from the board and making sure not to damage the sensor beneath it.

The infrared sensor is the innermost piece of glass on the lens assembly. When it catches the light, it looks ruby red – a dead giveaway that this is the piece filtering out infrared light. In order to remove it we simply used a razor blade to gouge out the plastic in a circle around the filter, allowing us to easily pop it out.

That red circle is the infrared filter

The lens with IR filter carved out

So now the IR filter is gone, but we need a visible light filter to replace it with. You can buy fancy IR bandpass filters off the internet, which will give the best results, but it’s also possible to make a very passable (no pun intended) filter out of the magnetic tape inside of a floppy disk, or a couple of pieces of exposed film negatives. We went with the magnetic tape method, and (after a few false starts) were able to cut a square that fit nicely into the square space between the lens assembly and the image sensor. We reassembled the PS3 eye, now converted into an IR-only camera.

Magnetic tape after several attempt to cut a filter

PS3Eye lens enclosure with visible light filter added

The PS3 Eye camera has two focus settings, for a wide or narrow field of view, which can be selected by twisting the plastic ring around the lense. It’s worth noting that the removal of the IR filter messes up the focus of the PS3 Eye slightly, and we found out through trial and error that in order to get it to focus sharply, we had to twist the focus ring very slightly, so that it was “balanced” between the two settings that it normally snaps to.

Next Page: Building the cabinet and installing the computer and projector

The Computer

For the build we used a small form factor computer we had laying around. With a Core 2 Duo and 2 GB of memory, it's harrdly a beast of a system, but still this computer ran all the multitouch software we tried just fine, so most any computer from the last couple years probably would work as well.

Note that we also could have run the cables for the PS3 Eye and the projector out of the cabinet, which would have allowed us to run the system off of a laptop, eliminating the need for a dedicated PC, but making the Multitouch display into more of a peripheral than a standalone system.

Inside the cabinet, we connected the screen’s LEDs to a 12 volt rail from the computer. To do this, we cut off one end of a 4-pin Molex connector, and attached the (yellow) +12v wire and one of the (black) ground wires to the LED wires with electrical tape. Then, we ran a 12v rail from the computers power supply through an empty expansion slot and out of the case, plugging it in to the Molex connector.

Modifying the Molex connector

Connecting the power supply to the LEDs

The Projector

Like the computer, the projector we used for the build was something we scavenged up. The major concern for a projector to use in this kind of system is throw distance—the ratio between projection distance and image size. Short-throw projectors, which are sold by all the major projector brands, work the best for this kind of project, because they can be set up at the bottom of the cabinet and aimed directly at the surface. Unfortunately, they also tend to be more expensive.

Ever thrifty, we went with a projector we could use for free: an older home-theater projector borrowed from a friend. Because of the longer throw distance on this model, we had to mount the projector near the top of the cabinet, facing down, and use a mirror to reflect the image up onto the screen. For this we ordered a front-side mirror (a mirror with the reflective surface on the front of the glass, rather than behind it) to eliminate any potential “ghosting” problems, caused by dual reflections from the front and back of the glass in an ordinary mirror.

We also mounted a piece of heat absorbing glass in front of the projector. This piece of glass absorbs heat, which prevents the projector from warming up the acrylic, and also acts as a filter to remove infrared radiation that might otherwise be seen by the camera. We bought both the front side mirror and the heat-absorbing glass from Surplusshack.com for about $13 total.

The Cabinet

Finally, there’s the cabinet—the structure that holds everything else together. The cabinet really only needs to do one thing: support the screen (including the acrylic, the lights, and the vellum surface) in such a location that's accessible to both the projector and camera. In an FTIR setup, the cabinet doesn’t even need to be closed.

Our cabinet is—essentially—a wooden cube with a square hole in the top and a removable front panel. The screen sits over the hole, held in place by a lip. Then, a wooden frame is placed on top, covering the wiring and exposing only the part of the screen that’s meant to be touched. Our cabinet is constructed from 3/8” MDF, with a stained hardwood frame on top.

Next Page: Using open source software to run the rig

Software

So now we’ve completed the hardware section. The process of building a multi-touch computer is far from over, though, we need to get the software installed and configured so that we can actually use the thing.

The central software that powered our rig is Touchlib, an open source library which takes the visual data received by the camera and parses it into touch events, which can be used by other programs to provide multi-touch control. Some programs implement this library directly, allowing for standalone multi-touch apps, while others, such as those written in ActionScript, require an extra software layer to allow the program to receive touch input. In this section, we’ll explain how we got both up and running.

But, there’s something else we had to take care of first. The PS3 Eye, as we mentioned earlier, is a fantastic fit for this project because of its high resolution, impressive framerate, and ease of modification. There’s just one problem: it’s meant to be used on a PlayStation 3, not a computer.

Fortunately, PC users are famously unconcerned with what things are “meant to” do, and enterprising multi-toucher Alex Popovich has written a driver that allows the PS3 eye to be used with a computer. To get it working, we followed these steps:

1. Download the PS3EyeSetup file here. The download link is a ways down the page, in red, just above the comments section.

2. Make sure that the modified PS3 Eye isn’t plugged into the computer, and then run the executable. Plug the PS3 Eye back in. If the Windows found new hardware wizard pops up, tell it to search for drivers manually, and point it to the folder we installed the drivers in (C:/Program Files/AlexP/Drivers).

3. Now, we’ll want to test to make sure that the drivers are working and that our computer can see the PS3 Eye. To do this, run the PS3Eye Test App included with the driver. Because we’ve already modified the camera, you probably won’t see anything on the screen unless we point the camera at a source of infrared light, such as a light bulb or a sunny window.

4. Now that we know the camera works, we need to check to see that the DirectShow filter works, which will allow other programs to access the PS3 Eye. There’s another program called AmCap installed with the drivers. Run it, and if the preview view shows what the camera is seeing, we’re golden. If it doesn’t, try unplugging the PS3 Eye and plugging it back in, as well as rebooting your computer. For reasons unknown, the first time we tried, we got stuck at this stage. For us, running the uninstall program, then installing the drivers again fixed the problem.

Now we'd gotten our PS3Eye up and running. Next, we had to get Touchlib set up to handle our touch detection. Touchlib can be found here, and doesn’t need to be installed. We simply extracted the files to C:/Multitouch.

We had to replace certain Touchlib files with ones specifically designed to work well with the PS3 Eye. We downloaded these files here, then extracted them to C:/Multitouch/touchlib, overwriting when we were prompted to do so.

Now, at long last, we’ll get to see how our surface actually works. We ran ConfigApp.exe from C:/Multitouch/Touchlib. This program launches a total of eight windows, six of which are the video stream from the PS3 Eye, at different stages of processing. It’s a little over whelming the first time, but it’s actually not that hard to use these to get Touchlib properly configured to do touch recognition on our setup.

The most important window is the one in the bottom right, with the slider marked “Rectify” is the one that’s most significant. This window displays the “blobs” that will get passed as touch events. When the touch surface is working properly, this window will be entirely black until we touch the screen, at which point a white blob will appear, hopefully without flickering. Starting with the window in the bottom left, and moving right, we adjusted all the sliders so that we got the clearest blobs when you touch the screen. Generally, we accomplished this by playing with each slider until we started to get background noise on the Rectify window, then scaled it back slightly. Once you’re happy with the sensitivity of your screen, it’s time to calibrate.

Calibration is necessary to sync up the projected image and the touch surface. To calibrate, we first pressed the Enter key. This enables full screen mode, and displays a grid of green crosses. To begin calibration, we pressed the ‘c’ key. One of the crosses on the display turns red. By pressing on the dot, Touchlib is able to map that point in projector space to a point in camera space. The next cross will turn red, and this continues until all crosses have been pressed. We learned the hard way that when you’re done calibrating Touchlib, you must press the escape key. If you close the program any other way, it won’t update the config file with your changes.

Now our surface had been be properly configured (at least until we moved the camera or projector, or the lighting conditions changed significantly). To test it out, we ran the smoke.exe app in the Touchlib folder. With everything calibrated properly, colored “smoke” particle effects were displayed on our surface everywhere we touched.

However, we didn’t let ourselves celebrate for too long, because many apps written for the multi-touch surface are coded in the ActionScript language used by Adobe Flash. These programs are not set up to natively use multi-touch data, so we had to use a software layer to allow the flash-based apps to work properly. This is a three step process:

1. Change Flash’s global security settings to allow the flash apps access to the touch data. Go to this page and click the “Edit locations…” dropdown box, then select “Add Location,” then “Browse for folders.” Browse to the folder containing the flash programs you want to run, which by default is C:/Multitouch/Clients. This only has to be done once.

2. Run OSC.exe from the touchlib folder. This is an implementation of a protocol called OpenSound Control, which was originally designed to allow musical instruments to interface with computers, but can also be used to (among other things) allow programs to access multi-touch input data. This needs to be run any time you want to use a multi-touch flash app.

3. Run FlashOSCv2.jar (requires the Java runtime environment) from C:/Multitouch/Clients/flosc. And press the “start” button on the window that pops up. This program simply allows flash programs to access OSC data. This also has to be run every time you run multi-touch flash apps.

With that done, we were finally ready to try out the whole array of apps that have been written for DIY multi-touch tables. There aren’t a ton of apps available right, but we were able to find enough to have a good time with the table. Some apps come with Touchlib, in the C:/Multitouch/Clients folder, and we also recommend the AudioTouch apps, available at Seth Sandler's blog and the Multitouch Media App, by Laurence Muller.

Next Page: Conclusion and Bonus Gallery

Conclusion

We completed this project over the course of about two weeks’ work. All said and done, everything worked out pretty well. We ended up with a fully functional, highly responsive multi-touch surface. Just because we like to show off, we've included some extra pictures of the table in action below, and of course there's the full video that we mentioned at the start of the article.

Still, during the project we discovered a lot of ways that we could do better a second time around. We’ve tried to incorporate those into this article as we’ve gone, but it’s important to understand that this is the sort of thing that’s very difficult to get totally right the first time. Even with all the resources available on the internet, there’s a certain element of trial and error inherent in a DIY project of this magnitude. In other words, if you’re inspired to try a build like this yourself, don’t let the little setbacks get you down; perseverance is the most important part of any DIY project.

Microsoft Developer Shows You How to Make a DIY Surface

Paul Lilly — Thu, 29 Jan 2009 14:00:54 -0600

If you followed David Murphy's path to building a budget PC with a cardboard chassis, then why not compliment it with your own homebrewed Surface, also with a cardboard exterior?

Microsoft technology evangelist Paul Foster posted a YouTube video showing how you can build a functioning multi-touch surface using budget parts. Items you'll need are paper, scissors, picture frame with glass, tape, cardboard box, a webcam, and multi-touch software such as Touchlib.

From start to finish, it takes Foster less than four minutes to complete the project and run a short demonstration. Of course, that's with a cardboard box - skilled modders will want to invest a bit more time coming up with custom enclosure.

Watch the video here and tell us what you think.