motorized sleigh

Dogless Dog Sleigh Is Perfect For Your Winter Commute

February 26, 2015 by 16 Comments

It’s a wee bit cold in Finland right now. And while dog sledding is always an option (though mostly for tourists), one gentleman who goes by [Jibjorkl] on YouTube decided to try making his own motorized sleigh — and it’s freaking awesome.

Unfortunately our Finnish language skills aren’t exactly up to snuff so we’ll just have to describe the invention; perhaps one of our Finnish readers could add some insight if we miss anything?

It appears that [Jibjorkl] has taken a hub motor with a wheel from a standard e-bike and mounted on what looks like a store-bought sleigh. The wheel has something which looks kind of like duct tape wrapped around it to help give it extra traction in the snow. There are two lead-acid batteries sitting atop the motor assembly, but we can see an e-bike Li-on pack mounted on the side too (likely 48V 20+aH).

Regardless of how it works — it’ll take two passengers pretty damn fast through the snow. We want to build one asap.

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ATtiny85 Does Over The Air NTSC

February 26, 2015 by 37 Comments

[CNLohr] has made a habit of using ATtiny microcontrollers for everything, and one of his most popular projects is using an ATTiny85 to generate NTSC video. With a $2 microcontroller and eight pins, [CNLohr] can put text and simple graphics on any TV. He’s back at it again, only this time the microcontroller isn’t plugged into the TV.

The ATtiny in this project is overclocked to 30MHz or so using the on-chip PLL. That, plus a few wires of sufficient length means this chip can generate and broadcast NTSC video.

[CNLohr] mentions that it should be possible to use this board to transmit closed captioning directly to a TV. If you’re looking for the simplest way to display text on a monitor with an AVR, there ‘ya go: a microcontroller and two wires. He’s unable to actually test this, as he lost the remote for his tiny TV from the turn of the millennium. Because there’s no way for [CNLohr] to enable closed captioning on his TV, he can’t build the obvious application for this circuit – a closed caption Twitter bot. That doesn’t mean you can’t.

Video below.

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File Sharing In Your Pocket

February 26, 2015 by 43 Comments

The idea of a pirate box is pretty simple. All you need is a tiny Linux system with a WiFi adapter, a bit of storage space, and the software that will allow anyone to upload a few files to the server and an interface that will let anyone on the network download those files. In practice, though, a pirate box is a mess of wires and power adapters – not the pocketable device a WiFi file sharing box should be.

[Chris] came up with a much smaller file sharing beacon. It’s not based on a router; instead, [Chris]’ build uses an ez Share WiFi microSD adapter. It’s a device meant to push pics taken by a digital camera up to the Internet, but by configuring the software just so, up to five users can connect to the adapter and pull files down from a microSD card. The build only requires putting power to the correct pins. A LiPo battery and charge controller takes care of this problem.

There are a few shortcomings to this project – [Chris] doesn’t know how to upload files to the device. Maybe someone sufficiently clever can figure out how to make that work. Still, if you’re ever in a situation where you’d like to share some files with people in the same building, this is the device you need.

Thanks [Jake] for the tip.

Spark Goes Cellular With The Electron

February 25, 2015 by 53 Comments

A few years ago, small and cheap WiFi modules burst onto the scene and with that the Spark was born. It’s a tiny dev board with a TI CC3000 WiFi module, capable of turning any device into an Internet-connected device. It’s only the very beginning of the Internet of Things, yes, but an important step in the right direction. Now, Spark is unshackling itself from WiFi networks with the Spark Electron, a dev kit that comes with a cellular radio and data plan.

If you’ve ever tried to build a high altitude balloon, a project that will be out of range of WiFi, or anything else where cellular data would be a godsend, you’ll quickly realize Verizon, AT&T, Sprint, and all the other carriers out there don’t necessarily care about your project. As far as we can tell, Spark is the first company to fix this gaping hole in what cellular can do by offering their own service – 20,000 messages for $3/month and no contracts. Officially, that’s 1MB of data spread over 20k messages that are about 50 bytes in length.

There are a few dozen companies and organizations working on the next generation of The Internet Of Things, but these require completely new silicon and spectrum allocations or base stations. Right now, there’s exactly one way of getting a Thing on the Internet without WiFi, and that’s with cellular data. We have to hand it to Spark for this one, and can’t wait to see the projects that will be possible due to a trickle of Internet everywhere.

Double Pendulum

Powered Double Pendulum Is A Chaotic Display

February 25, 2015 by 25 Comments

If you’ve never seen a double pendulum before, it’s basically just a pendulum with another pendulum attached to the end. You might not think that’s anything special, but these devices can exhibit extremely chaotic behavior if enough energy is put into the system. The result is often a display that draws attention. [David] wanted to build his own double pendulum display, but he wanted to make it drive itself. The result is a powered double pendulum.

There aren’t many build details here, but the device is simple enough that we can deduce how it works from the demonstration video. It’s broken into two main pieces; the frame and the pendulum. The frame appears to be made mostly from wood. The front plate is made of three layers sandwiched together. A slot is cut out of the middle to allow a rail to slide up and down linearly. The rail is designed in such a way that it fits between the outer layers of the front plate like a track.

The pendulum is attached to the linear rail. The rail moves up and down and puts energy into the pendulum. This causes the pendulum to actually move and generate the chaotic behavior. The rail slides up and down thanks to an electric motor mounted to the base. The mechanics work similar to a piston on a crankshaft. The motor looks as though it is mounted to a wooden bracket that was cut with precision on a laser cutter. The final product works well, though it is a bit noisy. We also wonder if the system would be even more fun to watch if the rotation of the motor had an element of randomness added to it. Or he could always attach a paint sprayer to the end. Continue reading “Powered Double Pendulum Is A Chaotic Display” →

Synth Guitar

Arduino Synth Guitar Really Rocks

February 25, 2015 by 18 Comments

[Gr4yhound] has been rocking out on his recently completed synth guitar. The guitar was built mostly from scratch using an Arduino, some harvested drum pads, and some ribbon potentiometers. The video below shows that not only does it sound good, but [Gr4yhound] obviously knows how to play it.

The physical portion of the build consists of two main components. The body of the guitar is made from a chunk of pine that was routed out by [Gr4yhound’s] own home-made CNC. Three circles were routed out to make room for the harvested Yamaha drum pads, some wiring, and a joystick shield. The other main component is the guitar neck. This was actually a Squire Affinity Strat neck with the frets removed.

For the electronics, [Gr4yhound] has released a series of schematics on Imgur. Three SoftPot membrane potentiometers were added to the neck to simulate strings. This setup allows [Gr4yhound] to adjust the finger position after the note has already been started. This results in a sliding sound that you can’t easily emulate on a keyboard. The three drum pads act as touch sensors for each of the three strings. [Gr4yhound] is able to play each string simultaneously, forming harmonies.

The joystick shield allows [Gr4yhound] to add additional effects to the overall sound. In one of his demo videos you can see him using the joystick to add an effect. An Arduino Micro acts as the primary controller and transmits the musical notes as MIDI commands. [Gr4yhound] is using a commercial MIDI to USB converter in order to play the music on a computer. The converter also allows him to power the Arduino via USB, eliminating the need for batteries.

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Openhand Combines 3D Printing With Urethane Casting

February 25, 2015 by 8 Comments

Yale University brings us quite a treat with their Openhand Project.

If you’ve ever operated a robotic arm, you know that one of the most cumbersome parts is always the end effector. It will quickly make you realize what an amazing work of engineering the human hand really is, and what a poor intimation a simple open-close gripper ends up being.

[Yale] is working to bring tendon-driven robotic hands to the masses with an interesting technique of combining 3D printing and resin/urethane casting. Known as Hybrid Deposition Manufacturing (HDM), it allows the team to 3D print robotic fingers that also contain the mold for finger pads and joints, all built right into the 3D part.  The tendon-driven fingers allow for a very simple design that are not only easy to make, but have a low parts count as well. Because of the human-like tendons, the fingers naturally curl around the object, distributing it’s force much more evenly and naturally, much like a human hand would. In the videos after the break, you can see the building process, as well as the hand in action.

Best news is that it’s all open source. They also include some python libraries so you can customize the CAD files fit your needs.

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