Peer network using graphing calculators

These calculators are networked together, able to pass information and play games on a multi-screen playing field. All of this is thanks to [Christopher Mitchell's] work on a package called CalcNet. This networking software takes advantage of [Christopher's] shell and GUI for TI calculators called Doors CS. To demonstrate the high reliability and throughput of his network he wrote NetPong, a multi-calculator version of the popular game that you can watch in a clip after the break.
This is definitely an instance where asking ‘why?’ is the wrong question. We’re more interested in the how, a question you can answer for yourself by reading the whitepapers he provided in both of the links above. [Christopher] knows what he’s doing, he proved that with his face-recognizing augmented reality.

DIY Breathalyzer may be the hit of the party

Okay, this may not be saving any lives, but it makes for a fun novelty at your next rager. Most Breathalyzers aim to keep you from driving when you’ve had too many. The Squidalyzer encourages party-goers to drink more and more by treating a high blood-alcohol-content with great fanfare. An Arduino, a gas sensor, and Processing all come together for this hack. A television interface tells you when to blow into a cup which houses the sensor, and gives a reading of what it measures. Blow higher than the last guy and you’ll break the record. Watch the demo after the break to see the fun [Geoff] had with it. And remember, friends don’t let friends solder drunk.

External RAM for an ATmega128

Those who are familiar with Atmel’s line of 8-bit AVR microcontrollers should already know that some of them have support for external RAM. But have you ever actually used this feature? We haven’t. Now you can learn how it’s done by reading through this guide. It touches on all of the hardware, but doesn’t dwell on it. Instead, you’ll get the background you need on how to write to, read from, and test an external module like the one sticking up in the image above. The test routine shows how to make sure everything’s working correctly with your memory mapping before you begin developing firmware around this increased capacity.
[Thanks Spman]

SD activity indicator for Wii

[DeadlyFoez] wanted to know when the SD card in his Nintendo Wii was in use. He built and indicator LED using a PICAXE 08M and added it next to the SD slot. He uses one pin of the microcontroller to monitor the voltage on one pin of the SD card slot. That pin has a specific value when the card is idle, which rises when it’s in use. He didn’t share the details of which pin he’s sampling, or what the magic number from his source code actually represents. But the concept should be enough of a start if you want to do this one yourself. Watch it go blink-ity-blink in the clip after the break.

Home built knitting machine

Wow, we knew it wouldn’t be too long before we would see a fully automated home built knitting machine show up. We recently posted a hack where people were emulating the keyboard input of a commercial knitting machine, and that was pretty awesome, but we knew we would be seeing some hacked together machines soon. [corex37] hasn’t let us down with this beast. It is mainly composed of old printer parts, a couple servos, and a Picaxe 18-x microcontroller. It seems to do a good job right now, but lets hope he keeps going. It would be cool to see it able to change colors like the other one.
[via Make]

The Heinz Automato

[Bill Fienup] and [Barry Kudrowitz]‘s robots, The Automatos, have been leaving a sticky path of destruction all over the internet. Their sole purpose: to crap ketchup. They accomplish this feat by dumping a CO2 cartridge into a ketchup bottle at the push of a button, leading to some pretty awesome results.  While the details are a little sparse it appears that they are using RC cars for the base and a small air gun CO2 cartridge to push the ketchup. The latest version aka the Atuomato 4 appears to be multi-actuated and can shoot more than once for maximum ketchup proliferation. See some videos of it in action after the break.

Rich Decibel’s Kequencer

It’s totally excellent when a simple concept results in something inspiring and fun. [Rich Decibel]‘s Kequencer is a good example, starting off as many projects do: “I had an idea the other day and I couldn’t decide if it was good or not so I just built it to find out.” Be still our hackable hearts!
[Rich] built this sleek little sequencer from scratch and while the design may not seem very novel to begin with–eight square wave oscillators with on/off switches and pitch knobs, played in sequence–but the beauty of it is in the nuances of interaction and the potential for further hacking. From watching the video you can see how the controls can be used in very interesting ways to create and mutate adorable chippy tone patterns. Check it out after the crossfade.

Haptic feedback for the blind

[polymythic] Is helping the blind see with his haptic feedback device called HALO. At the heart of the device is an Arduino Mega 2560 which senses objects with a few ultrasonic range finders and then relays the information back to the user using some vibration motors from old cell phones. The user can feel the distance by the frequency at which the motor pulses. The faster the motors pulse the closer an object is.
This kind of sensing is something that it can be applied to pretty much any sensor allowing the user to feel something that might be otherwise invisible. While haptic feedback is nothing new its good to see continuing work with new sensors and different setups.

DIY clamp helps with surface mount soldering

Hackaday writer [Gerrit Coetzee] built a simple clamp to aid in surface mount component soldering. This cheap, easily made device uses gravity to hold tiny components in place. The tip of the bolt is pointed, but gently like a ballpoint pen so as not to harm the components with a sharp tip. Roughly position your component, rest the tip of the clamp on its center, then nudge for final positioning. [Gerrit] also points out that this acts as a heat sink, helping to prevent damage to the component if you’re too lethargic with the soldering iron.
It seems like this device has been around in one form or another for quite a long time. But the best ideas do keep on popping up. Another nice tip to go along with this one is the use of a dowel when ironing during toner transfer for your PCBs.

Putting too many horses in a golf cart

Want to put 100 horses into your golf cart and then take it to the Dragstrip? Why not? [Mac McAlpine] did just that by dropping a 2007 GSXR 600 EFI into a 1987 gas-powered Yamaha golf cart. After the break you can see a video of the test run, as well as an overview of the modifications made when swapping engines. [Mac] mentions that the setup still uses the stock bike chain and jackshift even with the upgrade in power. He has, however, upgraded both the front and rear axles with caliper and drum brakes respectively. There’s also a NASCAR Car of Tomorrow wing on the roof to help keep the wheels on the pavement.
Good thing he’s wearing that helmet. Without a seatbelt it’ll make smashing through the windshield a little more comfortable. Drive carefully [Mac]!

Game Boy VGA using an FPGA

[ViDAR] was looking for a project to keep him occupied and settled on creating a VGA converter for his Game Boy. He had some difficulty finding pinouts for the LCD and CPU but working with what was known, and an oscilloscope, he found the necessary signal. Tap into just a few lines using those thin blue wires; Vsync, Hsync, clock, and two data pins. From there a development board with an Altera Cyclone II field-programmable gate array takes care of the heavy lifting. The board already has hardware for a VGA connection so it was just a matter of processing the incoming signals into the VGA standard. His demo video is embedded after the page break.
Want a dedicated solution? Check out this Game Boy video adapter inside a VHS cassette.

Make your own cookie cutters this year

In case you needed another reason to build, borrow, or buy a 3D printer, here’s one way to design and print your own cookie cutters. [Nikolaus Gradwohl] put together a processing app that aims to make the design process a bit easier. So if you’ve never designed a printable object before, but can get your hands on a MakerBot or similar device through a friend or your local hackerspace, this is for you. Check out the video after the break to see the process of making a cutter in the shape of a mushroom, or just download the app and give it a go.

Nook color rooted: Hands on

Nookdevs have released information on how to root your nook color. So naturally, I had to run out and get one.  Who doesn’t want a multitouch android tablet for $250?  The instructions for rooting are extremely simple. You really only need microSD card and a Linux/Windows/Mac computer to connect to.  After rooting, your nook will work exactly as it did before, but you can now install android applications on it.  Many applications are built for a phone that has more physical buttons, so I have run into some issues, but over all, the applications that work tend to work well.
Join me after the break for more thoughts, a video of it in action, and a few pictures.

Jacob’s Ladder using EL wire

For Halloween [Paul] wanted to build a Jacob’s Ladder without the peril that working with high voltage might bring. He was inspired by a sequencer board for electroluminescent wire and decided to build a Jacob’s Ladder simulator using the glowing material. What he ended up with is quite convincing. Eight segments of EL wire have been mounted between two diverging towers. When a PIR sensor detects motion in the room, an Arduino switches on the simulation, playing a recording of the classic sizzling voltage sound while using the sequencer board to flicker the wires from bottom to top. See for yourself in the video after the break. We give [Paul] bonus points for constructing the base out of Lego.
But if you’re not one for being cautions, there’s always this real Jacob’s Ladder build. Or maybe you just want to make something glow with the EL wire.

Kids type with their eyes, robot arm prints their words

F.A.T. took it to the next level, combining a couple of their projects for the Cinekid festival. This contraption lets kids write their names with their eyes for printing by a robot arm. The first part is a glasses-free version of the EyeWriter, originally developed as an assistive technology. The system uses some IR LEDs to generate a reflection on your eye that a PS3 camera can pick up and use to precisely track your gaze. Just look at each key on a virtual keyboard to spell out your message. From there, a robot arm used previously in the Robotagger project prints out the name on a big sheet of paper the kids can take home. This is cool, but more importantly it’s a great way to inspire the next generation of hackers and engineers. Check out the video after the break.

RC plane built using pieces of an RC car

This hack’s old as dirt to be sure, but new to us and a great accomplishment. The plane above, which is meant to fly without an operator, has been given RC control thanks to parts from that little car. The transmitter and receiver pair are the obvious transplant, but how do you add steering to a $7 plane that wasn’t manufactured to have that feature? The tail was cut and reconnected with mylar hinges to turn it into a rudder. A rare earth magnet and a coil are also thrown into the mix to provide movement. Basically this is a simple solenoid where the coil pushes against the magnet when energized, actuating the rudder. This in combination with an upgraded motor allows for both speed control and yaw. It doesn’t look like you can control roll and pitch but what more can you really expect?
This would be a nice first step on that path to building an epic flying camera rig.
[Thanks Rob]

Using analog voltage references with Arduino

Little Bird Electronics posted an article about using an analog voltage reference with Arduino. This is a tool available when using an analog-to-digital converter. By setting up either an internal or external AREF, you can better use the ADC considering its resolution limitations. For instance, if you are measuring a signal that you know will always be below 2V, an external circuit, such as a voltage divider or an adjustable regulator, can give you a reference voltage just above that upper limit; say 2.5V. This way the 1024 divisions of resolution will be spread across your signal’s range, rather than just the lower half of the ADC readings.
Analog references are common to microcontrollers that have ADCs. Even if you’re not working with an Arduino, read through the article and use what you learn with your uC of choice.

ATX psu turned into an adjustable voltage bench supply

Here’s a fancy way to convert an ATX powers supply into a bench supply. [TG] didn’t just cut off the motherboard connector and add banana plugs, but improved the functionality. Right off the bat you’ll notice that he’s added a control panel. There is an Ammeter and Ohmmeter to let you know what the unit is putting out. He added an MIC29152WT adjustable voltage regulator so that he’s not limited to the fixed voltages of the psu. As a final touch he added an external voltage probe which can be used with the flick of a switch. It’s no replacement for a proper bench supply, especially since it doesn’t have adjustable current limiting, but it’s a nice improvement upon previous psu hacks.

Skillet reflow controller

Using an electric skillet to reflow surface mount circuit boards is a popular alternate use for those kitchen appliances. The real trick is monitoring and controlling the temperature. [Mechatronics Guy] built his own skillet temperature controller using a thermistor, a solid state relay, and an Arduino.
He was inspired by [Ladyada's] work which used a servo to adjust the temperature dial on the skillet’s power supply. This started by attaching the thermistor to the bottom of the skillet using JB weld. since this area will be heating up he also attached a terminal block for connecting the feed wires as the heat would melt any solder joints. Those wires travel back to a control box housing the Arduino and solid state relay. To gain finer control over the heating element the relay is switched on and off, resulting in low-frequency Pulse Width Modulation, which should help maintain a consistent temperature better than just turning the temperature dial on the cord.
Pair this up with the vacuum tweezers hack and you’re on your way to a surface mount assembly line. If you want to see this process in action check out this post. It goes from stenciling, to populating, to reflowing in a toaster oven.
[Thanks Rob]

Lego machine predicts future eclipses

Hidden behind the white face plates of this machine are racks of gears that make up a replica of one of the oldest known mechanical computers. This is a working model of the Antikythera mechanism made from Lego pieces. In the video, which you absolutely can’t miss after the break, The machine is disassembled into its various components. Each mechanical unit takes advantage of gear ratio combinations to perform numerous levels of mathematical functions in order to display the date and time that future celestial events will occur.
The background information on the original device reads like the script for a sequel to The Goonies. Believed to date back to 100-150 BC, the stone bronze mechanism was recovered from a shipwreck around the turn of the twentieth century. The use of x-ray analysis helped to unlock the functions and confirm the theories of its operation.
Part of what makes this so interesting is the historical connection. But the production quality of the video (which to be fair, seems to be an advertisement) really brings home how complicated this process is. Now it’s time for us to watch the video a few more times, sketching out the gearing to see that this works as they say it does.
Want more of the Antikythera mechanism? Check out the model built by [Tatyana van Vark].

EEG the Locomotion

The use of brainwaves as control parameters for electronic systems is becoming quite widespread. The types of signals that we have access to are still quite primitive compared to what we might aspire to in our cyberpunk fantasies, but they’re a step in the right direction.

A very tempting aspect of accessing brain signals is that it can be used to circumvent physical limitations. [Jerkey] demonstrates this with his DIY brain-controlled electric wheelchair that can move people who wouldn’t otherwise have the capacity to operate joystick controls. The approach is direct, using a laptop to marshall EEG data which is passed to an arduino that simulates joystick operations for the control board of the wheelchair. From experience we know that it can be difficult to control EEGs off-the-bat, and [Jerky]‘s warnings at the beginning of the instructable about having a spotter with their finger on the “off” switch should well be followed. Maybe some automated collision avoidance would be useful to include.

We’ve covered voice-operated wheelchairs before, and we’d like to know how the two types of control would stack up against one another. EEGs are more immediate than speech, but we imagine that they’re harder to control.
It would be interesting albeit somewhat trivial to see an extension of [Jerkey]‘s technique as a way to control an ROV like Oberon, although depending on the faculties of the operator the speech control could be difficult (would that make it more convincing as an alien robot diplomat?).

Segfault: balancing transport using a dozen op-amps

The Segfault is a balancing transport similar to a Segway, but it uses analog comparators instead of digital circuitry. On board you’ll find no less than twelve LMC6484 op amps. They take signals from the gyroscope and the accelerometer, balance and filter them, then drive the motor h-bridges accordingly.
[Charles], the guy behind the Segfault, is also the one responsible for DeathBlades. As with that project he does just as well at documenting as he does at fabrication. Take some time to enjoy his posts associated with this two-wheeled-wonder (especially the build process) and then watch in the video after the break.

Bluetooth temperature module

Wanting to know the outside temperature, [Jamie Maloway] built his own temperature sensor that can be read with a Bluetooth device. Let’s take a tour of the hardware above from right to left. There’s a linear voltage regulator with two filtering caps and a terminal block to attach a 9V battery or other power source. Next there’s an 8 MHz crystal and it’s capacitors, followed by a programming header on top and a 1-wire temperature IC, the DS18B20 we’re all familiar with hanging off the bottom. These both connect to the 8-pin PIC 12F675 that drives the system, and transmits using a Bluetooth module from Sure Electronics. Since this is using a serial protocol and transmitting ASCII data, it can be read using an automated script, or simply by using a terminal program.
Now, who’s going to be the first to get rid of the battery and leech off of the mains through inductance?

Kindle terminal with secret key-press activation

[Luigi Rizzo] has been working on some hacks for his 3rd generation Kindle. There is already a Python based terminal emulator called AjaxTerm but he wanted a lightweight standalone so he reimplemented the program in C. The 100k binary monitors the keyboard, launching the terminal emulator when it detects a Shift-T sequence. It also uses alternative key mapping to fill in for some of the keys the Kindle’s keyboard is missing.
We haven’t seen a whole lot of Kindle hacking since it was hacked to run Ubuntu. Seems like this terminal emulator is a useful and unobtrusive hack to try out on the beloved reader.

Using a chicken as a steadicam

This has been circulating around the net for a bit. For those that haven’t seen it, let me just give you a quick rundown of what is happening. This guy strapped a camera to a chicken’s head. No really, that’s it. There’s some interesting science behind it though. He’s taking advantage of the Vestibulo-Ocular Reflex in the chicken.  It is basically the reflex that we use to keep our eyes firmly focused on something while our head is moving. In a chicken however, they move their entire head. This means that he can strap a camera to the chicken’s head and have an instant steadicam. At least that is the theory. As you can see in the video after the break, the harder part is getting the chicken to look at what you want it to look at. We also found a conversation about it with the creator,[MrPennywhistle] in some reddit comments.

The Twelve Days of… self-replicating

Okay, it’s more like the 23 days but who’s counting? [Kliment] is giving the gift of self-replication this holiday season by uploading one new printable part a day. If you follow along and print each one you’ll have a Prusa Mendel by Christmas (this started on 12/2 so you’ll need to catch up). The Prusa is a variation on the Mendel that uses bushings wherever possible, reducing the need for bearings down to just two.
So yeah, you need to have access to a 3D printer in order to make the parts for this 3D printer, but that’s how it always works. [Kliment] has gone the distance to make this little exercise enjoyable. The parts that take longer to print are reserved for the weekends, some have been altered to include a holiday theme, and all of them have been optimized to fit on a Makerbot build platform.
[Thanks Christopher]

Copper-clad enclosures

Building a great looking box for your projects can be a challenge. [Ken] boils down his process of building enclosures out of copper clad (PDF) circuit board material into an illustrated guide in case you want to try this for yourself. Why would you want to use PC board? The fiberglass substrate makes for a strong and lightweight material. Also, [Ken] is a ham radio operator and the copper coating acts as an electrical shield for delicate components inside.
As you can see above he uses solder to tack the pieces together. There’s some important considerations that go along with this method. First, he cuts the pieces just a bit oversized and then sands them flat and square before assembly. Next, he uses some 20 gauge wire as a shim between a ninety-degree joint and a right angle jig. This shim compensates for the shrinking that occurs as the solder cools, making sure the joint gets pulled to a right angle. He even solders nuts in place so that screws can be used to attach the case cover to the chassis.
Yesterday we saw toner transfer used to make labels on an ABS case. If you make your enclosure out of copper clad, using toner transfer for panel labels will be a snap!

Cassette case cameraphone tripod

We see a lot of comments on shaky video asking why that person didn’t use a tripod. [Aatif Sumar] wants to use one when taking pictures and video with his phone but the threaded mounting hole you’d find in most cameras doesn’t come as a feature on smart phones. That didn’t deter him, he used an old cassette case for this phone tripod. The build started with a cheap flexible camera tripod. [Aatif] used a soldering iron to melt a hole in a plastic cassette case. We’re apprehensive about relying on the plastic’s ability to hold threads so we’re recommend epoxy to reinforce the joint. A bit more melting with the iron and he had a cradle on legs with a hole for the camera lens. It’s nothing fancy, but it also cost him next-to-nothing.

Home Brew Coffee Machine

There are already a lot of different ways to brew up a decent coffee at home, from the humble saucepan to the elegant vacuum flask. In an office environment the choice of coffee-making technique can have a major impact on workplace harmony—how can people be expected to work happily when the kitchen is filthy with grounds and the coffee is always stale? “Someone have mercy,” [Christian Finger] lamented, “and boil a pot of fresh.”
In the end he took extreme measures, building a machine that grinds whole beans, measures out a dose, brews a cup and self-cleans. He used all sorts of odds and ends to put the thing together, detailed in his long and hilarious build log (english translation—and check out the dude’s sweet ride). Refer to his shockwave animation for a summary of the intended operation.
The end result is an extremely impressive Goldbergian contraption—download the video from the build log. It is pretty noisy and probably energy- and water-hungry, but that wouldn’t stop us from using it every day, if given the chance. Hell, this here could form a major part of your next breakfast machine.
We’re sure that there is further potential in this, because to get the really freshest possible cup of coffee you’d want to roast the coffee beans just before grinding them. Then you’d be well on your way towards something else entirely: a delicious breakfast machine.

Ice Tube Clock, meet the ChronoDot

[Alex] ramped up the precision of his timepiece by adding a ChronoDot to the Ice Tube Clock. These two items are among our favorites; the Ice Tube Clock for its old-style multi-digit display, and the ChronoDot for combining a DS3231, battery, and components into a nice small package.
There is a schematic link at the very bottom left of [Alex's] writeup. He mentions that he depopulated the clock crystal and its capacitor pair from the board and patched into the clock input on the AVR. A 100K pull-up resistor is included in the wiring as called for in the DS3231 datasheet. Although not specifically referenced, we assume that [Alex] reprogrammed the ATmega168 clock select fuses to use an external clock signal.
Now he can sit back knowing that the clock will be within 10 seconds per year accuracy.

Part 2: Help me reverse engineer an LED light bulb

Almost a month ago I started trying to reverse engineer an inexpensive LED color changing light bulb. With your help I’ve mapped out the circuit, and taken control of the bulb. But there’s still a few mysteries in this little blinker. Join me after the break to see what I’ve done so far, peruse the schematic and source code, and to help solve the two remaining mysteries.

Designing an RF transceiver

[William Dillon] is finishing up his degree. His final project as a student was to design an RF transceiver. He decided to work with the Microchip MRF49XA, which runs around $3 but will cost you $20 if you want it in a ready-to-use module. He didn’t find a lot of info on the Internet about communicating with these chips so he’s shared his design, code, and board files. If you’re ever wanted to delve into RF design this is a good primer. [William] talks about building around the example circuit from the datasheet but also includes a discussion of the calculations he made in working with the 434 MHz band, and an AVR-based library for using his module.

Quick, cheap, and simple vacuum tweezers

[Ken] found that using traditional tweezers is a good way to lose tiny surface mount parts and so set out to make his own vacuum tweezers (PDF). He already had a small aquarium pump that he used as a bubbler for etching circuit boards. After opening up the case he found it was possible to connect tubing to the input of the pump to use as the source for the vacuum. The business end of the device is a syringe which he already had for applying oil in tight spaces. A file took off the sharp tip, and a small hole lined with a bit of soft tubing serves as a valve. Put the needle tip in place and plug the hole with your finger to pick it up. Works like a charm and will go well with our next feature, building your own reflow skillet.
We like [Ken's] work. We just looked in on his copper clad enclosures yesterday.

Original shell houses a Game Boy Advance SP

[Jackson] decided he wanted to give his original Game Boy a bit more power so he replace the internals with those from a Game Boy Advance SP. This keeps the case work to a minimum, as the original was larger than the SP. He kept the buttons, speaker, headphone jack, and power switch but modified the enclosure to use the volume, charger, and battery from the newer hardware. The cartridge connector was relocated to match the slot in the back half of the case, with the color screen being the biggest giveaway that someone’s monkeyed with the device. Not a bad use for a dead Game Boy, as least you’ll be playing this one instead of dedicating it to virtual storage.

Tuesday Two-Fer: Battery Cases and ABS Lettering

These are both interesting, unrelated, and can’t quite stand on their own so we threw them into one post.
On the left you see the product of using toner transfer on ABS plastic. [Bogdan] tried this out as a way to make front panels for his enclosures. It really shouldn’t work very well because ABS has a lower melting point than toner does. But it seems that it takes a while for the ABS to heat up. If you’re quick, ironing for about 10 seconds, you can get the toner to stick to the plastic and then soak the paper off, leaving your printed design looking nice and clean.
To the right you see a printed battery case. [Nikolaus Gradwohl] ran across the same problem we’ve face many times: how to attach batteries to your projects? We’ve duct-taped them together, used the blister packs they’re sold in, Dremeled them out of thrift-store toys and just about every other thing you can imagine. He decided to make them easy to manufacture with a 3D-printer. This is accomplished with an OpenSCAD file he wrote. Plug in the size and number of batteries and a printable package will be automatically generated.

Project hosting, a common question

Ok, you’ve finished your project, you’ve taken great notes along the way and photographed every step. Now you want to share. Where will you post it? There are a lot of options out there, private hosting, Hackaday,  instructables, and tons of others. How can you decide? Here are some handy break downs to help you figure it out at a glance.
Each has its own pros and cons. Take a peek at our list after the break and share your own as well.

Radio controlled hard drive security

[Samimy] has put together this really neat video tutorial on building a Radio Controlled secure hard drive. How can a hard drive be radio controlled? That’s the first thing we thought too. He has torn apart a remote-controlled car and is using the guts to remotely switch on power to the drive. This means that the drive is only active if you boot the computer after you put the fob in the hidden security system. It looks like it would be fairly effective. We’re curious though, if he is putting the entire drive assembly inside his PC, why rely on batteries for the circuit? Why not pull from the PC power supply? Another neat upgrade might be connecting to an internal USB connection on the motherboard so a reboot isn’t necessary.
Check out the entire video after the break.

Nails and some blacksmithing

Here’s a blacksmith turning 4 inch framing nails into buckles. In the clip after the break he starts by heating and bending the nail around a square form. Next the excess gets cut off and both sides of the square frame are ground flat while in a vise. A smaller nail serves as the prong and a flat piece of metal is shaped so that this can be connected to a leather strap. This ends up as part of the support system for a full suit of armor.
We’ve seen a lot of great welding projects over the years, but today’s blacksmithing video leaves us wanting. If you’ve got a favorite project that involved this kind of work tip us off about it and we’ll see if we can get some more hacks for the Smithies out there.

How to work with EL wire

As you can see, [Phillip Torrone] has a nice start on his Tron costume for the movie premiere. Electroluminescent wire is what makes these costumes glow and if you’ve never worked with the stuff before you’re in for a treat. Adafruit posted a tutorial explaining how to work with EL wire. The process isn’t hard, but they’ve got a few nice tips, like using copper tape as a platform for soldering the corona wires. There is also a discussion of the math involved with properly powering your setup.
In this case, Adafruit is using ready-made power inverter units. If you’ve interested in hacking together your own inverter take a look at the background information from [Jeri Ellsworth].

Christmas tree low-water monitor

The end of the year is rapidly approaching and there’s a good chance you have a slowly dying tree in your living room. Help it hold on a little longer by using [Eric Ayars'] Christmas Tree water monitor. He’s built a sensor out of a piece of strip board. Three bus strips on the board allow for a variety of alerts. When all three are submerged everything is ok. When the two longer traces are still under water but the third is not an LED will blink to let you know it’s time. If you don’t pay attention and there’s no water left, a piezo buzzer makes noise until you add water (or the coin cell runs out of juice).
This project centers around an ATtiny85 that [Eric] programmed using an Arduino, one of the methods we covered in our AVR Programming Tutorial. But if this simple circuit isn’t high-tech enough for you, we saw a similar method last year that will send an alert to your iPhone.

Vintage car audio gets MP3 input

[Nali] is fixing up a 1966 Rambler Ambassador and decided to give the audio a bit of an upgrade. Instead of replacing the head unit he added a connector for audio input. The method he used is simple, inexpensive, and allows the original unit to continue functioning as a radio. He cut the feed wires going to the volume knob and patched in a headphone jack. The jack he used has an internal switch that is meant to switch off a pair of speakers when headphones are plugged in. The jack will allow the original signal from the radio tuner to pass through whenever there isn’t a connector plugged in. It seems like this is easier on older hardware than it is on modern equipment.
This isn’t where his entertainment enhancements stop. [Nali's] working on a 7″ in-dash Linux machine so keep your eye on his thread to see what he comes up with.
[Thanks Joel383]

Composite video with MSP430 chip

[NatureTM] used part of the Thanksgiving holiday to get composite video output working with an MSP430 microcontroller. He’s using one of the chips that came with the TI Launchpad, which is a big hardware limitation because of the relatively small code memory and RAM. The chip displays one still image at a resolution of 192×40 pixels. Still, this is a great way to learn about composite video signals, as a lot of other projects use a TVout library to save you the headaches. All you’ll need is a TI Launchpad, a 16 MHz crystal oscillator, two resistors, and an RCA jack. Dig through the code and see what a great job [NatureTM] did of offloading as much work onto the chip’s peripherals as possible.

Sluggy Wind Speed Sensor

Sometimes when we look at a hack, its to see how someone chose those parts for the project. In this case, it would have been hard to see it coming. [Janne Jansson] decided to combine a set of measuring cups, a hacked Linksys NSLU2 NAS, and a PS/2 Mouse together to make a self-contained Wind Speed Sensor for his roof. The measuring cups act as wind catchers, which in turns drives the rotation of one of the mouse ball sensors. This data is then logged and transmitted by the NSLU2. The NSLU2 is running a custom Linux based firmware, similar to how OpenWRT works for wireless routers.
To calibrate the device, he also made the best logical choice: to duct tape it to the hood of his car along with a much more expensive wind sensor and use that data to make his own device as accurate as possible. When placed atop his house with a 1500VA 220V UPS, the device managed 250 days of uptime before meeting its demise. Those 250 days also included 5 days of being frozen solid, yet still transmitting (somewhat meaningless) data. All of the relevant code and build instructions are available, for those of you with similar parts to spare.

Classical VCR head jog wheel

[Osgeld] takes on the classic VCR head jog wheel in this instructable. He has done a fantastic job not only in his build quality, but in the quality of the writeup. As he points out, the idea of using the head as a jog wheel isn’t new. His construction and build quality however have yielded a fantastic looking reliable device that we would be proud to have sitting on our desk.
As usual, the most interesting bits of the writeup are how he solved problems he encountered. For example, he’s using an optical mouse to detect the motion of the wheel. This requires that he print out a pattern to mount opposite the optical sensor. This sounds straight forward enough, but he found the results to be less than stellar. He documented his fix, basically reworking it in GIMP, so others can save some time. That is how tutorials should be. Great job [Osgeld].

Breathing motion powered USB charger

When your batteries run low you can use your body to recharge them. This contraption generates power from chest expansion while breathing. [Jmengel] used some gears from old optical drives to boost the RPM generated by a belt around your torso that he calls a thorax expansion coupler. When you breath in, that belt pulls on a plate that spins the gears, ultimately rotating a small motor. The AC current generated by that motor is run through a rectifier and a boost converter, then fed to a charging circuit.
Does it work? Not really, as this only outputs around 50 mW. But we like the twinge of Dune nostalgia we get looking at it. Wouldn’t this be a perfect addition to a stillsuit?

Hot resistors used for color-changing clock face

[Sprite_TM] built a full clock display using thermochromic paint. This picks up where he left off with his paint-based 7-segment display prototype. He never really saw that design through to a finished project, but he recently came across the leftover paint and decided to do something with it. Instead of making thin traces on a PCB he’s heating up resistors mounted on protoboard. Each resistor has been coated with the black/light grey paint after getting a rough sanding on the tops of the packages. Run around 500mW through a segment and they heat up enough to change the paint to light grey. Once shut off, the segments gradually fade over the next 60 seconds.

Star Trek inspired pocket doors

Do you have enough confidence in your hacking abilities to build a project into the walls of your home? [Marc] used his skills to build an air-powered sliding door for his bedroom. It is similar to the sliding door you’d find on the Enterprise, two sections that slide nicely into the wall to let you pass. Although the picture above shows the internals, he followed through and ended up with a fully finished room that looks fantastic. A compressor in the attic provides the pressure necessary to move the door sections. It is automated, but uses a button press or keypad combination to run instead of detecting motion. Of course, since he’s using a PIC microcontroller to drive the system there’s always room for future changes. Check out how great the finished look is in the video after the break.

Knitting machine hack by keypad emulation

[Travis Goodspeed] and Hackaday alum [Fabienne Serriere] joined forces to develop an alternative interface for a knitting machine. They’re working with the Brother KH-930E machine. We saw [Becky Stern] use the same model by manipulating data on an emulated floppy drive for the device. [Travis] and [Fabienne] went a different route, and are emulating the keypad using an Arduino and a set of transistors.
They started by reverse engineering the keypad matrix using a continuity tester. Once they worked out the column and row layout they connected each to an NPN transistor. The Arduino sketch simulates button presses to set knitting bits for each row, with just one reset button for user input. This can be used to send data from a PC, or as a standalone system. Either way, it’s not only a great way to add functionality to the kitting machine, but a good example of how to interface with the keypad on just about any device.

Meter clock with pleasing design considerations

[AndyO] embraced his inner geek by building this meter clock. It exhibits a lot of features that you’d want to see in a home-built timepiece, include over-complexity, abundant features, and RGB LEDs. We’re fascinated by the design he put into this. For instance, the two indicator LEDs on the clock face are not poking through the surface, but use brass tubes as light pipes. Also, the three buttons on the top are almost indistinguishable, and have an RGB back light that places a halo around each. The case itself was built by first making a form, then laminating thin sheets of wood (a difficult task due to the tight curves). The needles themselves are not actually meters, like the clock the inspired the build, but are attached to servo motors. This all comes together into a fascinating build, and a great writeup.
[Thanks Graham]

Make your own solenoids, then play the xylophone

Learn to manufacture your own solenoids and then use them to play the xylophone by watching the tutorial video after the break. [Humberto Evans] and the team at Nerd Kits do a great job of not only manufacturing the coils, but the xylophone itself. The bars are machined from some aluminum stock and they take you down the rabbit hole with they why’s and how’s of engineering the keys.
We’re unlikely to replicate this machining process but the solenoids are another story all together. Starting at about 3:30 you can learn about designing, building, and using these little marvels. They’re basically an electromagnetic cuff with a metal slug in the middle. The solenoid seen above uses a body milled from HDPE and wrapped with magnet wire. The slug in the center is steel, with a few rare-earth magnets at the top. When you run current through the coil it repulses the magnets on the slug, witch then strikes the xylophone key. Using a MOSFET and a protection diode, actuating them is as simple as sending a digital high from your microcontroller of choice.
We’ve seen solenoids used to play a vibrophone before, but those were commercial units. Making your own hardware is far more hardcore.