If you needed a reason to dress up for your next Dungeons & Dragons adventure this is surely it. Not only will this attractive wrist adornment go right along with your medieval theme, but the gauntlet doubles as a multi-sided digital die.

Sparkfun whipped up this tutorial which details the build. Yep, they’re hawking their own goods but we must say this is one of the few projects using sewable electronics which we thoroughly enjoy. It calls for several Lilypad modules, including an Arduino board, accelerometer, and slide switches. The switches let you select the number of sides for the die you are about to roll. The accelerometer starts the fun when you shake your wrist back and forth (that’s what she said). The project is powered by a rechargeable battery, which we always like to see, and uses a four-digit seven segment display located where the face of a wristwatch is normally found.

Of course, you could get the shaking action and use no batteries at all if you wish.

[Iron Jungle] just finished building this gear indicator for his motorcycle. It uses a red 7-segment display to show the rider what gear is currently engaged. This hack is pretty common and makes us wonder why all motorcycles don’t come standard with the feature? But then again, if they did you wouldn’t have a reason to hack them.

The motorcycle does have a gear sensor; apparently it only lacks a way to display this data. The sensor outputs a signal between 0 and 5V which [Iron Jungle] reads using a PICAXE 18M2 microcontroller. Patching into that signal wasn’t hard at all. Once he found the correct wire he simply removed a portion of the insulation and soldered a lead to the conductor. This should stand up to the vibrations encountered in an automotive application like this one. Since the computing power is already there, he also included a DS18B20 to take ambient air temperature readings. Check out the quick demo after the break.

This is not the first time we’ve seen the V-Storm get a custom gear indicator. But if you really want to go all out, perhaps you need to build an interface for your tablet or smart phone.

The V-USB library is a pretty handy piece of code that lets you add USB connectivity to ATtiny microcontrollers (it was previously named tinyUSB). But if you’ve ever looked into adding the library to your own projects you may have been stymied by the complexity of the code. There are many examples, but there’s a lack of a concise quick-start for the uninitiated. [Joonas Pihlajamaa] has been working to correct that shortfall with his four-part V-USB tutorial series. It’s not for the absolute newbie; you should already be comfortable working with AVR chips but that’s the only real prerequisite we can see.

He starts the series with a look into the hardware considerations. USB provides a 5V power rail but the data lines expect 3.3V logic so this must be accounted for. With the test rig built on a breadboard he moves on to pick apart the code, covering various user-defined variables that you’ll need to set based on your project’s needs. We’re going to keep this on the back burner and hopefully the Troll Sniffing Rat will get a makeover (although we must say comments have been a lot nicer as of late… keep it up!).

We’ve embedded links to all four tutorial parts after the break.

• http://codeandlife.com/2012/01/22/avr-attiny-usb-tutorial-part-1/ (primer)
• http://codeandlife.com/2012/01/25/avr-attiny-usb-tutorial-part-2/ (hardware)
• http://codeandlife.com/2012/01/29/avr-attiny-usb-tutorial-part-3/ (software)
• http://codeandlife.com/2012/02/04/avr-attiny-usb-tutorial-part-4/ (wrapping up)

[Navic] added a slew of abilities to his RFID reader. It’s now a full-featured RFID reader and smart card writer with extras. When we looked at it last time the unit was just an RFID and smart card reader in a project enclosure. You could see the RFID code of a tag displayed on the LCD screen, but there wasn’t a lot more to it than that.

The upgrade uses the same project enclosure but he’s added four buttons below the display. These allow him to access the different features that he’s implemented. The first one, which is shown in the video after the break, allows him to store up to six tags in the EEPROM of the Basic Stamp which drives the unit. He can dump these tag codes to a smart card (pictured above), but also has the option of interfacing with a PC to read from and write to that card.

We don’t think you can directly write RFID tags with the device, but we could be wrong.

We love ‘em, and we hope you do too. Here’s [Phase2plus'] take on the most useless machine.

Scratching like it’s 1989

[Nick] spent three bucks at the thrift store and ended up buying days worth of fun with this cassette player. He hacked it to scratch like vinyl.

3D printed jawbone

This lady now has her own 3D-printed jawbone. We’re not talking about the Bluetooth headset… it’s an actual bone replacement! And yes, the skeleton for the Terminator was 3D printed… we’re that much closer now. [Thanks Steve]

Hexbug superbowl

Why not let robots decide our sports gambling choices? [Eric] let this slew of HexBugs battle it out as an early indicator for who would win the Super Bowl. Seems he has no shortage of the little toys, all of which received an MSP430 upgrade. The firmware actually implements obstacle avoidance, but he makes a poke at the Chicago Bears who seem to have the same mission.

Foil fix for worn out remotes

[Viktor] found an interesting repair tip. If you’ve got remote controlers whose buttons are not working so well anymore you may be able to fix them with tin foil. He uses a single-hole punch to clip out circles which are attached to the underside of the misbehaving button. Worth a try!

To us it makes a lot of sense to hold the tablet in one hand and type with the other. That’s exactly how [Adam Kumpf] has implemented this one-handed typing interface which was originally conceived by [Doug Engelbart].

As you can see, there’s a large contextual area for each finger on your right hand. Letters and navigational keystrokes are input through this interface based on single touches, or combinations up to and including all five digits. This offers up 32 possible combinations (including all on and all off) which is enough to cover the modern English alphabet.

[Adam's] demo page works for most tablets so give it a whirl. Yes, it works with iDevices too which is a surprise as we would have thought this was using Flash. If you’re not near a touch-sensitive device you can get the gist of the operation from the demo video embedded after the break.

Now, who’s going to be the first to make this into a replacement keyboard on iOS 5?

[Abhimanyu Kumar] has been hard at work building and posting about his quadcopter. So far he’s published ten installments for this build, letting us relive the adventure vicariously. But it’s number 11 that we’re really excited about as he plans to share the first free-flight footage in that one.

The bug was planted in his brain after hearing that a quadcopter was used to shoot some of the footage in Spiderman 2. He wanted one to call his very own but the cost of a ready-made unit was out of his league. So he decided to build one instead. The first version uses aluminum bracket for the cross making up the motor mounts. He added LEDs to liven things up and even made a demo video of the thing tied to a table (no IMU yet so free flight would be fatal). After this stepping stone he decided to go with a Wii Motion Plus and Wii Nunchuck as the positioning feedback sensors. There is also a body redesign with helps lighten the load.

It’s a fun project, and we can’t wait to see where he goes from here!

Add some fruit to your indoor bounty with this hydroponic strawberry farm. [Dino] whipped this up as his 45th hack a week episode (getting pretty close to his year-long goal). He used parts you probably already have sitting around the house somewhere. But even if you bought everything and used it once you still wouldn’t be out much.

A plastic storage container serves as the base. [Dino] also grabbed four identical plastic containers (large yogurt containers would work here) to host the plants. He cut off the bottom half and inserted some netting to keep the plant from falling through. After tracing the size of the container on the enclosure’s lid he cut out holes which will host each plant. This provides a way to dangle the roots into the nutrient solution which is kept oxygen rich with an aquarium pump and two air stones. It certainly deserves a place next to that salad farm you threw together. Don’t miss [Dino's] build video after the break.

It used to be that the contents of your pocket protector directly mirrored your geek level. But that just doesn’t cut it in our fast-paced digital age. We think [Jonathan] is headed down the right track though, by creating a scrolling LED name badge which he takes to conventions with him. With the right enclosure this could reach the same geek level as Woz’s watch. There’s a lot packed into the little device, but readability at close range doesn’t look like one the features so make sure you glance at the tag before you approach him for a conversation.

As you can see, the PCB for the project is the same form factor as a landscape ID card. It hosts an 8×5 LED matrix, which meshes nicely with the registers of the MSP430 chip which runs it. He admits that the hardware may not last very long as the chip is multiplexing the display directly, with no resistors or LED drivers for current protection. But there is potential in the design. It uses a rechargeable battery (which we like) and he included a QR code in the board artwork for easy exchange of contact information. We’ve embedded his description of the project after the break.

[Quinn Dunki] got some free stuff from Element14 to evaluate, including this Mircrochip WiFi module. It’s been used as the centerpiece of an Arduino shield in the past, and she grabbed a copy of that library to see if it would play nicely with an ATtiny chip. What follows is a struggle to de-Arduino the code so that it’s portable for all AVR controllers.

This module is one of the least expensive ways to add WiFi to a project, coming in at around $23. But it’s not really an all-in-one solution as there’s still a huge software hurdle to cross. The hardware provides access to to radio functions needed to communicate with the network, but you need to supply the TCP/IP stack and everything that supports it. Hence the re-use of the Arduino library.

Battling adversity [Quinn] fought the good fight with this one. Switching from an ATtiny to the ATmega168, compiling more code, and troubleshooting the process. She used a single LED as feedback, and can get some connectivity with her hotspot. But to this point she hasn’t gotten everything up and running.

We’re hot for an AVR WiFi solution that is cheap and easy to use. But as we see here, the software is complex and perhaps best left up to beefier hardware like the ARM controllers. What do you think?

If you’re just getting into hobby electronics chances are there are lots of tools you’d like to get you hands on but can’t yet justify the purchases. Why not build some of the simpler ones? Here’s a great example of a 4-channel logic analyzer that can be your next project and will add to your arsenal for future endeavors.

As you can see, [Vassilis'] creation uses a cellphone-sized LCD screen as the output. It is powered by four rechargeable batteries and driven by an ATmega8 microcontroller. He’s designed the tool without power regulation, relying on the ATmega’s rather wide range of operating voltages, and a few diodes to step down that voltage for the LCD screen.

As you can see in the clip after the break, alligator leads can be used to connect the test circuit to the inputs (don’t forget the ground reference!). Thee buttons at the bottom let you navigate the captured data by panning and zooming. Perhaps the best design feature is the single-sided circuit board which should be quite easy to reproduce at home.

[via Dangerous Prototypes]

We find the programming challenge of game-playing bots to be fascinating. Take a look at this Python bot which plays Burrito Bison all the way through (video after the break). This is a totally pedantic exercise which has no purpose, other than to hone your mastery of a certain programming problem. And to that we say Bravo!

We looked in on a similar project which used some C# code to dominate the game Bejeweled Blitz. We’re not fantastic at C# and that code was never made public. But [Audionatics] has released this code through Github, and it’s written in Python which is a language in which we’re well versed.

The script monitors pixel locations to use as an input, which [Audionautics] admits is very error-prone. But if everything is setup just right it works like a charm. He’s also using the PyWin package which we believe is what lets the script move the cursor and register button clicks. We think this is really fun, but it make us wonder about the black-hat possibilities. What are the chances this could be turned into a gambling bot? Scary thought, huh?

[via Reddit]

Members from the London Hackerspace recently got a little on-air time with a ping pong ball launcher. They were invited to build something for the Click show on BBC. The launcher that they built responds to hash tags on Twitter by barraging the audience with balls.

The hardware was built in two parts. The first is a dispenser that responds to incoming Tweets by releasing one ball onto a set of staging ramps. The other portion is the launcher itself. Building it like this makes it a rapid fire device, as the spinning wheels of the launcher make quick work of several dozen balls just waiting to be let loose. Check out some footage from the show after the jump.

We like this one just as much as that remote controlled launcher. We’re glad to have seen these both because we happen to have a surplus of the balls lying around since we built that clock and we’re not about to undertake some of the more dangerous ping pong based projects we’ve seen.

[Darrell] made his own cyclonic dust separator which connects to a shop vac. We’re amused by his poke at Dyson’s marketing machine where he mentions that the ads say it took years to perfect those vacuum cleaners and he managed to put his together in a few hours…. from trash/recyclables no less!

Two mini-kegs are used as the separating vessel. The only other parts are some PVC plumbing fittings which help to direct the air and give him a way to attach the collector to the shop vac. The top keg is where all of the magic happens. Air and debris is sucked in through the hose coming in the side wall. A 45 degree elbow directs it downward and to the side, which starts the cyclonic action. The shop vac is attached to the tube in the top, with a cylinder extending into the keg. The spinning air must make a sharp turn to get into that cylinder; it’s at this point the debris drops out into the lower keg. See for yourself in the clip after the break.

This isn’t the first time we’ve seen dust collectors that use this concept. [Darrell] pointed out this one made out of plastic cups, and this other made from a 5-gallon bucket.

[William] developed this temperature candle as a tool to help keep babies safe as they sleep. It seems that ambient temperature has an effect on Sudden Infant Death Syndrome (SIDS). This device is meant to alert you when room temperature is outside of the recommended envelope.

The board hosts an eight-pin PIC microcontroller (12F683P), a temperature sensor, RGB LED, and a push button. The round PCB is the same size as a votive candle, which is nice except that you’re going to have to drill a hole in your candle holder to accommodate that barrel jack.

The temperature sensor is read by the microcontroller and used to determine the color of the LED. Red is hot, blue is cold, and just right is somewhere in between. But if you’d rather know the exact current temperature you can press the button and it’ll blink out the Celsius reading using blue for 10 degree increments (three blinks is 30 degrees, etc.) and red for single degrees. Don’t miss the demo of the candle in the video after the break.