Apparently, there’s some sort of sporting event being televised this weekend that has been historically used as an excuse to buy a big-screen TV. [Joel] wanted a huge-screen TV on the cheap, so he converted an overhead projector to something he can use with his XBox.

Using a bare LCD panel with an overhead projector is a decades-old hack we’ve covered before. The basic idea is fairly simple, but we’ve never seen anything that could be considered a semi-permanent build. [Joel] started his project by picking up a surplus overhead projector for $25 and routing a cutting board to mount the LCD in. The bulb in the projector added a lot of heat, so three small fans are used to blow air between the projector glass and the LCD display.

[Joel] started off looking at the LumenLab DIY projector project, but considered that to be a terrible amount of work with a fairly high initial investment. If you don’t count the few LCDs [Joel] burned through while building his project, his projector was built for under $100. We’re loving the result and are sure it will be much appreciated at [Joel]‘s LAN parties.

In the interests of interface archaeology, [Martin] sent in the Tworse Key, a telegraph key that posts to Twitter using Morse code. It’s a fantastic build that nearly looks like something out of the 1900s.

We’ve seen a ton of Morse keyboards over the years, but never one so well-engineered for a single purpose. The guts and brains of the Tworse Key is an Arduino Ethernet that connect to Twitter over the API. The Tworse Key automagically posts all the Morse messages to Twitter. The Tworse Key may have fallen off the table a few times in the past 24 hours, but we do see a few purposeful messages like ‘sos’ and [Bell]‘s preferred telephone salutation.

We could say that nobody uses straight telegraph keys anymore, but outside a few hardcore CW HAM radio guys nobody uses Morse anymore. This isn’t meant to be used as an everyday input device, though. It’s more of an exercise in interface archaeology. That being said, an iambic key would be a far more ergonomic solution. Check out the video of the Tworse Key after the break.

[Martin] got bonus points for the cloth-covered Ethernet cable. Anyone have a source for this?

If you’ve been thinking of adding some tactile controls and readouts for your flight simulators this guide should give you the motivation to get started with the project. [Paul] explains how to build controls and connect them to the simulator data. He makes it look easy, and thanks the interface examples in his code it actually is.

Here he’s built the hardware using a Teensy controller board. The controller communicates via USB and the software is cross-platform. He’s controlling the heading information of the X-Plane simulator using the rotary encoder for fine adjustments and the buttons for increments of 100. But he doesn’t stop there. He’s working on an auto-throttle design that uses a servo motor to move the throttle lever. A potentiometer can be used to vary the throttle, with the servo mapped to the position of that knob. But it works both ways, dragging the virtual throttle on-screen will do the same.

This is one way to make flight simulators more interesting without devoting a whole room of your house to the cause. Don’t miss [Paul's] fantastic demo video after the break.

[Thanks Deadly Dad]

Part of the fun with old computers is playing some old school games, and while you could play them with a keyboard it is much more fun with a joystick. You can get old joysticks all day long on auction sites, but you have to watch out. Some are digital, which wont work for many games on many systems. Some were cheap to begin with and probably worn out, and many are flight sticks … ever play pac-man with a giant flight stick?

What I really wanted was a game pad like device for my 1986 Apple //c , using one of the modern thumbstick analog controllers. Using a thumbstick out of an old XBOX(1) controller, some generic parts from Radio Shack, and a little bit of effort , I ended up with exactly what I wanted.

Join us after the break and I will show you how to get there!

First some basics, most computers that have analog controllers implement it in a pretty simple method. In a nutshell there is a 555 timer wired up for single shot mode, the computer triggers the 555 and counts how many cycles pass before the 555′s output changes. One of the potentiometers inside the joystick is hooked up to this circuit and controls the rate that a capacitor charges. Once filled the 555 changes output. Swing the joystick one way, resistance increases and the capacitor takes longer to charge. Swing it the other way resistance lowers, cap charges faster. Simple right?

Now just multiply 555′s for how many axis you need and you have a simple analog joystick. Apple //s, and IBMs work like this, and use a 556 dual timer (one, two axis joystick) or a 558 quad timer (two, two axis joysticks). Below is an example circuit from the Apple //c Technical Reference Manual.

Other computers like the 8 bit Commodore’s and Atari’s used this setup for their paddle controllers which were often in joystick or flightstick format. About the only one I know of that does not handle analog joysticks in this manner is the Tandy TRS series, but I am sure there are others. Check with your computers nerd club before proceeding.

Next thing to consider is the values of the potentiometers inside of your joystick. the most standard value for old computers is 100K ohm. Apple used 150K ohm. Why? I don’t know but with Apple stuff, if its hard to source, they will use it. Thumbsticks themselves come in all varieties of resistance, from places like Digikey. If you don’t mind spending a couple bucks + postage, that might be the best way for you.

Since I am using scavenged thumbstick from an XBOX controller I don’t have a choice of what value it is. The thumbsticks that come stock with that controller is 10K ohm. In order to compensate for the difference in resistance,we just need to add more capacitance.

Before I go bothering myself with math, I need to find out exactly where my joystick “tops out” while its in its enclosure. I went out an purchased a 4x2x1 inch enclosure from Radio Shack, and while I was there I also picked up a couple panel mount normally open pushbutton switches.

With these radio shack project boxes, they give 2 choices of a lid, a nice molded plastic lid that sits on top of the box, and an aluminum panel that sits a bit recessed in the box. I just had to have that aluminium panel for looks, but it ended up causing a bunch of problems.

First I had to cut the lip of the box off where the panel would not be recessed anymore. That was accomplished using some 90 degree flush cut wire trimmers and a file. Because I lost about a quarter of an inch in height, the thumbstick would not fit anymore using the screw mounts inside the box. I had to snap off the screw mounts, then flatten the area where they broke off with a chisel. Then I surface mounted everything to a piece of pad-per-hole perfboard flipped upside down, since the only way the thumbstick would fit is if the board was flat against the bottom.

With all of that sorted out, I went to drill holes into the aluminum panel. I drew the outline of the panel on some paper, and I was measuring everything out. I didn’t like how the holes were sitting, so in the end I just simply eyeballed them on paper. Then I taped the paper to the aluminum plate and made divots for the hole centers with a hammer and nail.

The aluminum plate was then screwed to a scrap chunk of 2×4 wood, and drilled. I used a 1 inch hole saw for the joystick (which is a bit too large) and quarter inch holes for the switches. I used a jewelers file to quickly deburr the holes, but the large joystick hole was still a little rough. To give a more finished appearance I decided that it needed a grommet.

I went to the local hardware store, and when I asked for a grommet with about a 1 inch inside diameter, they looked at me like I just stabbed a baby. I ended up at Lowes where I found a grommet in one of the “hard to find” bins in the screw section with a 1&1/8th outside diameter, and a 23/32nds inch (18.25 ish mm) inside diameter, which is good enough. The grommet was much too tall to fit both inside and outside of the box, so I just simply chopped its top off and glued it down with some goop (super strong and thick glue).

Now that the box is in order I can see where my thumbstick tops out at. I bent the leads of the thumbstick out to a 90 degree angle so I could surface mount them to the perfboard. Then I soldered it down and added some test leads, ran the wires out of a hole I drilled in the back of the box for the joysticks cable, and popped on the lid.

Using a multimeter I found out that it the furthest I could push the thumbstick came out to about 8.5K ohm on both axis. My meter is overkill for most of what I do, so I could have used the 5 digits of accuracy, but its not needed. I will add some trimpots later for fine tuning.

Now that I know 8.5K is my max resistance, its time to figure out how much capacitance I need to add so that the circuit internal to the computer will behave the same with this 10K pot as it did with a 150K. The formula to calculate the capacitance is pretty simple:

((original_potentiometer_value * internal_timing_capacitor) / new_potentiometer_value) – internal_timing_capacitor

Most of the time the internal timing capacitor is 0.022 uf, though you might want to check before assuming for your machine. The original potentiometer value of the Apple // is 150K ohm so…

((150,000 * 0.022) / 8500) – 0.022 = 0.366235294

Therefore we need to add about 0.36uf in parallel to the joystick so that a 10K pot works the same as a 150K pot in the timing circuit. My capacitor selection pretty much stinks so I ended up using 3, 0.1uf capacitors in parallel and 2, 0.1uf in series per axis, giving me about 0.35uf. It does not have to be exact because I also added a 10K trimpot in series with the capacitors which will allow me to control how fast the extra caps charge, giving a fine tuning mechanism. Below you will see the schematic I ended up with for my Apple //c.

Now it is just a matter of wiring everything up, connecting buttons and a cable, and then using a test program to calibrate the thumbstick. The Apple //c has a nice diagnostic program which also test’s joysticks, but you could just as easily write one up in basic. For example, in Applesoft:

10 X=PDL(0): FOR I=1 TO 10: NEXT: Y=PDL(1)
20 PRINT X " " Y " " PEEK(49249) , PEEK (49250)
30 GOTO 10

To calibrate I just need to adjust the trimpots until its about center, the program above shows value from 0-255, and we can give ourselves about 5% in error, from there its just a matter of making sure the thumbstick maxes the readouts when in its most extreme up/down/left/right positions. Some error is ok, and a little jitteryness in center is fine as well.

Anyone who has programmed for analog controllers quickly figure out a little dead space for middle and a little room for error on the extremes is needed whether it be a 26+ year old computer, or a brand new Sony PSP, nothing is 100% perfect.

Once the thumbstick is calibrated to the computer its time to button it up and play some retro games. How well does it work? Pretty darn good, I may go back and drill a couple small holes so I can fiddle with the trimpots without having to take it apart, but other than that it plays good and looks nice (IMO) .

Thanks for reading!

(Reference: The Computer Controller Cookbook)

Let’s get this straight, [Alex] is going to show us how to make controllers like this one? Where do we sign up? Even without seeing it in action we want one, but the urge to build is even greater after he shows it off (check the clip after the break). He’s a design student who made an open source project aimed at making it easier to build hardware controllers that pair with just about any software application.

The need for external controllers is on the rise, starting with music-based applications like DJ tools, and Midi controllers for musicians (we’re thinking Monome clones). But anything that can take input from a USB HID can be controlled with something like this. That’s because [Alex] is using the Teensy controller board as an interface. Just select the input types you want – sliders, potentiometers, buttons, switches – then wire them up to the microcontroller pins. If you start to run out of inputs he also discusses some add-on chips to use as port expanders.

Of course there’s a lot to be said for the physical appearance as well. Even though he used point-to-point connections for all of the controls, that wiring is hidden behind the aesthetically pleasing laser-cut dashboard. Follow his advice for layout and find a friend with access to a sweet laser cutter and you’re in business.

As masters of technology, our desks are often cluttered with odds and ends. We have cables spewing out of every nook, and our computer ports full. The last thing we really want is more stuff getting in the way or buried under piles of technical documentation when adding something like a USB hub. That is where [Michael] comes in, shoving a small USB hub into his Logitech keyboard.

The keyboard is already USB, and the hub has 3 forward facing ports and a fourth single port in the rear. Taking the 2 devices apart he used the already there USB cord from the keyboard replacing the input cord of the hub. Then he removed the rear port and directly wired his keyboard onto the hub.

From there, its just a matter of figuring out where he wanted the hub, and cutting out the plastic. He used a knife, and had fond memories of some minor cuts, which leads us to recommend being (more) careful. A little application of fire to blade goes a long way.

Once the keyboard is back together he has a convenient 3 port hub on the back of his keyboard that looks factory and saves clutter.

[Shawn] wrote in to share his post outlining the addition of rapid fire to an Xbox 360 controller. He’s going all out with this mod by including a pretty beefy microcontroller. But you get a lot of functionality for that. You can just make out the trimpot below and to the right of the green A button. This tweaks the speed at which your right trigger repeats. Next to the trimmer is an amber LED which indicates whether the hack is enabled or not. The switch to the left of the D-pad simply patches the add-on circuit into the right trigger hardware.

Some might raise an eyebrow when we call the ATtiny85 used here beefy. But considering the job at hand, we’re sure a lot of the lower end of the ATtiny family will work just as well. [Shawn] soldered everything up on a piece of protoboard and removed one of the rumble motors to make room inside the controller. The video after the break is pretty shaky and out of focus, but you can clearly hear him explain how the hack works.

If you’re looking for a rapid fire mod that doesn’t require programming a chip, perhaps you could just repurpose the PWM from the LED.

As a life long lover of his venerable Commodore 64, [Frank] was looking for a way to speed up the development time when writing C64 demos. His solution is a universal C64 cartridge that will connect to a PC over a USB port.

The board is powered by a CLPD and a microcontroller loaded with code from [Frank]‘s previous C64 USB controller adapter. A 16 Mbit flash chip is able to store 31 classic games like Pitfall, Dig Dug, and Lode Runner.

On his Google+ announcement, [Frank] says this is a very early prototype. He plans on reducing the board size to fit inside a standard C64 cartridge, and the firmware for the micro and CLPD aren’t finished yet. That being said, [Frank] does have a board that does what he wants it to do: extremely rapid C64 development.

Check out [Frank]‘s demo after the break of him compiling and re-uploading a simple demo to his cherished computer in just a few seconds. That’s a lot faster than it would take with a 1541 Ultimate or other SD card reader.

All for the want of a 6551

If you’re looking for a custom controller for a MAME cabinet build, CNC machine, or just want to control a robot build, you’re going to need to wire up some buttons. You could wire up a bunch of buttons to a microcontroller, but if you use an old computer keyboard the work is already done for you.

[Rupert] sent in a great tutorial on repurposing old keyboards. The build is very, very simple: just take a multimeter to each contact and measure the rows and columns for continuity. Once [Rupert] had the matrix codes for every button on the keyboard, he wired up a length of ribbon cable to the keyboard PCB. From there, a small breakout board provides all the connections that a MAME cabinet would need.

Opposed to a custom keyboard encoder like an I-PAC or a homebrew solution, [Rupert]‘s build is very easy and can be built for only the dignity required to dumpster dive for a keyboard.

No matter how good the intentions or how strong your hack-fu may be, sometimes you just can’t cross the finish line with every project. Here’s one that we hate to see go unfinished, but it’s obvious that a ton of work already went into reclaiming these smart white-board projectors and it’s time to cut the losses.

The hardware is a Smartboard Unifi 35″ computer with a projector mounted on a telescoping rod. It was manufactured for use with a touch-sensitive white board which the guys at the Milwaukee Makerspace don’t have. The projector works, but all it will display is a message instructing the user to connect the computer to the white board. Since they’ve got a couple of these projectors, it would be nice to salvage the functionality.

The first attempt was to replace the video signal to the projector. A few test boards were etched to experiment with DVI input. This included several logic sniffing runs to see what the computer is pushing to get the warning message to display. Alas, the group was not able to get the device to respond. But this opens up a great opportunity for you to play Monday morning hacker. Take a look at the data they’ve posted in the link above and let us know how you would’ve done it in the comments.

Many companies today try to simplify life by over complicating the keyboard. Microsoft has been doing it since 2001. If you love your ergonomic keyboard, but hate that “function lock” key, there are plenty of options out there for you to try.

The least complicated way is to either modify some XML or just set macros up in the MS software, but who wants to do that every time they re-install Windows? Reader [Elco] didn’t so he added a simple little 555 circuit inside the keyboard, that automatically re-enables the Flock after three seconds if he happens to hit it during fast and furious typing.

Now no matter what system the keyboard is plugged into he does not have to worry that if he hits F7 whether the system is going to spell check his document, or reply to an email, or that F2 is actually going to rename something and not undo his work silently.

[Aaron's] arcade controller really makes us want to put in a button order. There aren’t any secrets hidden in his design or fabrication, but he did a remarkably clean job of putting it together.

The housing is a writing box he bought at the hardware store (but he also shows off an emtpy Xbox 360 case hosting the same control layout). It has a hinged cover which is perfect for getting at the components inside, and is also at a nice angle for your wrists during long gaming session.

An Xbox 360 controller provides the connectivity for the device. Obviously it will work with the Microsoft hardware, but all modern operating systems have methods available for interfacing with these controllers as well. In the video after the break you can see [Aaron] gut the controller, soldering wires to all of the button pads and connecting those to some terminal strips. This makes the wire organization inside quite clean. He uses crimp connectors to jumper the buttons and joy stick to the other side of the terminals. Add  a nice paint job and you’ve got a controller that will look right at home in your living room.

[David] sent in a nice project to demonstrate augmented reality with ARtoolkit and discuss the deep philosophical underpinnings of the meaning of nothingness. The good news is he was able to create a volume control button on a sheet of paper with a marker. The bad news is the philosophical treatment is a bit weak; [David] built something cool, so we’re able to let that slide for now.

This build was inspired by the Impromptu Sound Board made using a Kinect and a piece of paper. The idea behind the sound board is simple – draw some buttons on the paper, and use them to play short sound clips. [David] took this idea to make a small tutorial on augmented reality for Occam’s Razor.

The hardware is very simple – just a webcam, a piece of paper, and a marker. After [David] draws a large square on the paper, the code recognizes it as a volume control. Rotating the paper counterclockwise increases the volume, and clockwise turns the volume down. It’s a neat build to get into the foundations of augmented reality.

Check out the video demo of [David]‘s build after the break.

[Victor] likes to watch movies on his laptop, but the tiny speakers in his machine don’t do [John Williams] and other perfectly fine soundtracks justice. To pump up the jams a little bit, [Victor] got a pair of Trust Mila 2.0 speakers for Sinterklaas. Unfortunately, these speakers were terrible – noise everywhere, tinny output and a brighter-than-the-sun blue LED. These problems were fixed once [Victor] replaced the amplifier in both speakers.

After shopping around for a new power amp to go in each speaker, [Vic] hit upon the MAX9575 3.2 Watt amplifier. This little guy met all of [Victor]‘s requirements. The only problem is that the MAX9575 is only available in a TQFN package.

After a deep breath and much sweat of the brow, both amps found a new home in their respective speakers, deadbug style. It probably would have been easier to etch a PCB, but we’ll give a tip of the hat to [Victor]‘s fine motor skills anyway.

Because of the insane soldering skill demonstrated in the title pic, [Vic] now has a really nice pair of speakers. Check out the demo of the improved speakers after the break.

We all need an excuse to play Half-Life 2 sometimes. [Jeri Ellsworth] put together a My First Crowbar controller to throw a few headcrabs across the room. It’s pretty much Half-Life 2 for the Wii.

The build is very simple – just a tilt switch hot glued to the underside of a childs-size crowbar. Two leads go from the tilt switch to the contacts on a (PS3?) controller. All you need to do to attack is swing the crowbar wildly.

[Jeri] has us wondering what other awesome game controllers could be made. Of course we’ve been wanting a real-life Gravity Gun or Portal Gun for years now, but right now we’re thinking about a real Katamari. We might need more hot glue.

As far as building our own, we’re thinking about using one of the Cheap DIY tilt switches we saw the other day. It’s a simple build, and sure looks like a lot of fun.