if firecracker-crossbows are outlawed, only outlaws will have firecracker-crossbows!

The Firecracker Crossbow

February 12, 2013 by Jeremy Cook 40 Comments

If there are two things that we love at [HAD], giant German firecrackers, and medieval weapons would have to be close to the top of this list. This clever hack gives us both, with a toy crossbow capable of both lighting and launching firecrackers to a safe distance. We didn’t see a blooper reel, but being ready to run in case of a malfunction is probably a good idea as well.

The post has some pictures of the mechanism, but at its heart, this hack consists of ripping up a grill igniter, and placing the contacts into a shortened-stock toy crossbow. Safety is of course encouraged, as much as it can be with this type of device. It’s especially important here as apparently “firecracker” roughly translates in German to “small sticks of high-explosive,” or possibly “road flare.”

Be sure to check out this modded crossbow in action in the video after the break!

Continue reading “The Firecracker Crossbow” →

Reverse Engineering The Furby

January 28, 2013 by Brian Benchoff 17 Comments

Furby

Furby teardowns are a favorite of ours, and there’s nothing quite like flaying open a creepy talking deformed animatronic owl/hell beast. There’s a lot you can do with a set of screwdrivers and a pair of scissors, but it takes a real clever person to reverse engineer a Furby without any disassembly (Russian, here’s the translation).

The new Furby comes with an iOS and Android app that allows children to interact with the Furby by feeding it, giving it commands, and even translating the Furbish into English. These apps work by playing a WAV file encoded with commands that give the Furby something to eat, or tell it to dance a merry jig.

Commands are delivered with these WAV files by means of a 4-digit, 4-bit code, complete with checksums. There are ten bits the Furby actually responds on, meaning there are potentially 1024 different commands the Furby can accept.

[iafan] wrote a Perl script to listen in on the audio generated by the Android Furby app and correlated all the possible commands with actions taken by the Furby. Everything is up on a git, allowing anyone to play an audio file and control the Furby’s mood and actions.

With this it should be possible to remotely control a Furby, letting it dance whenever you receive an email, or making it angry whenever someone retweets you. It’s a lot more clever than just putting a Furby through a wood chipper, but considering how creepy these things are, we’re not going to say it’s better.

Replacement Controllers For Slot Car Racing

January 23, 2013 by Mike Szczys 11 Comments

replacement-controllers-for-slot-car-racing

That blur on the right is a car racing into the frame. But look around the rest of the image and you’ll see the area is littered with extra hardware. [Matthew], [Doug], and [Barry] have been hard at work adding extra functionality and replacing the original controllers on this Scalextric slot car setup. So far it looks like their build log has not caught up with all the work they’ve done. We’re hoping to learn more details as they have time to write about them (this is coursework at University so we’re sure there’s a lot on their plates). But for now there are several videos and a gallery of images to drool over.

The cars are controlled by the voltage level in the track. The team replaced the stock controllers with a Raspberry Pi. It manages that voltage using Pulse-Width Modulation via MOSFETs. This allows the races to be automated but also makes it simple for a human operator to use just about any input device imaginable to control the cars. For good measure they also added a lap counter that uses an IR LED and detector to sense when a car passes the finish line.

After viewing several of their videos we think the goal of the project is to log the fasts times without sending the cars flying off the tracks during the turns.

Faceless Child’s Engineer Father Builds Him A Breathtaking Ride

January 22, 2013 by Mike Szczys 56 Comments

amazing-kids-car

Okay, the kid does have a face, but it looks like Dad blurred it for his protection. The real story here is the killer ride built by his engineer father. It’s far nicer than the cars driven by the Hackaday team, but then again, since it cost more than a BMW 3 series that’s no surprise.

[Lingzi] lives in China and does custom car work for a living. So to take on this project for his son was more of a stretch of the pocketbook than of his skill set. The car features a custom frame with rack and pinion steering, disc brakes, a rear differential, and a reputable suspension system. The body of the vehicle is crafted from carbon fiber. The lights all work and there’s an electric motor and transmission mounted just behind the driver’s seat. Unfortunately there’s no video of this in action (China blocks YouTube). But do take a look at the album above for pictures of the final paint job. There is also a little bit more information to be found in [Lingzi’s] Reddit discussion.

Communication Protocol For An Indoor Helicopter

January 21, 2013 by Mike Szczys 6 Comments

propel-execuheli-ir-protocol-revealed

There’s a special type of satisfaction that comes from really understanding how something works at the end of a reverse engineering project. This grid above is the culmination of [Spencer’s] effort to reverse engineer the IR protocol of a Propel ExecuHeli indoor helicopter toy.

The first thing he looked at was the three different controller channels which can be selected to allow multiple helicopters to be used in the same area. [Spencer] was surprised that they all used the same carrier frequency. The secret must be in the coded packets so his next challenge was to figure out how the data was being transmitted via the Infrared signal. It turns out the packets are using pulse-length coding (we were unfamiliar with this protocol but you can read a bit more about it here). The last piece of the puzzle was to capture packets produced by each unique change of the control module. With each bit (except for bit 11) accounted for he can now format his own codes for a controller replacement. Perhaps he’s looking to make the helicopter autonomous?

Real Life Mario Karts React To Launchable Items

January 17, 2013 by Mike Szczys 24 Comments

real-life-mario-kart

The team over at Waterloo Labs reasserts their reputation for creativity with this real life Mario Kart project. One of the team members must work at Austin’s Park because they seem to have had free rein when it comes to modifying the go-karts and filming the delightful video presentation found after the break.

It’s one thing to put on some costumes and head off to the go-kart track. It’s another to modify the vehicles to react to items launched by another rider. You can see the painted PVC launcher hardware to the right of each driver. By stuffing a plush item (banana, star, mushroom, etc.) in the barrel the driver can use compressed air to launch it quite a distance. Inside of each item is an RFID tag. When the RFID reader on a kart detects the tag it can take control of the steering, brake pedal, or speed limiter to inflict the appropriate actions.

If you don’t have this kind of insider access to your local go-kart track don’t fret. You just need to build your own set of karts.

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A WiFi Controlled RC Car With An IP Camera

January 8, 2013 by Jeremy Cook 11 Comments

Controlling your car over WiFi is good, but mounting a webcam on it so you can actually see where you’re going is even better. [Michael] goes over how he made his wifi car with some great videos in the post about it.

The car used is a seemingly standard RC unit, which came with a speed controller that was recycled for network use. [Michael] removed the standard radio, but having this controller available kept him from having to engineer an H-bridge circuit. The radio was then replaced with a WiFi module from Sparkfun.

There were a few problems with the IP camera to begin with, as the lag was originally unbearable. After some tricks that would qualify as a good hack in itself, the camera was eventually able to perform on an acceptable level and output data to the FLTK app he used to control everything. Check out one of his videos below of this car in action. Continue reading “A WiFi Controlled RC Car With An IP Camera” →