Quick and easy Arduino-powered theremin

April 5, 2012 By Leave a Comment

[Martin] sent in a great guide to a simple Arduino based theremin. It’s a very small build – just a single common IC and some passive components – and easy enough to build in an afternoon.

The theremin is based on a simple LC oscillator built around a 7400 quad NAND gate IC, a wire antenna, and a few caps and resistors. When a hand moves closer to the antenna, the frequency of the oscillator increases; when a hand moves away, the frequency decreases. On the software side, the oscillator is connected to the internal hardware counter of the Arduino. Every time there’s a change in the voltage output by the oscillator (all the time, varying slightly with the distance from a hand to the antenna), the counter increases by one. This counter is tallied up over 1/10th of a second, and the distance from the instrumentalist to the theremin can be determined. From there, it’s just outputting a frequency to a speaker.

All the code, schematics, and board layouts are available on [Martin]’s guide, and most of our readers probably have the parts to build this lying around their workbench. You can check out a video of [Martin]’s theremin in action on his guide.

Filed Under: arduino hacks, musical hacks Tagged With: , , ,

Hackaday Links April 5, 2012

April 5, 2012 By Leave a Comment

A Remote Sphero-Control Trackball

sphero drives car

Sphero is a cool little ball that can roll around under the control of a smartphone.  Although super-cool by itself, in this application it’s been hacked into a sort of trackball to drive a remote control car!

Arduino Voice Control

Arduino voice control

[Sebastian] Wrote in to tell us about this article about using the Arduino EasyVR shield to add voice control to your project. Worth a look if it your application calls for voice-control.

OpenBeam Tiny 80/20-Like Extrusion

openbeam extrusion

Openbeam is a Kickstarter project designed to produce an aluminium extrusion for building stuff.  Although we’ve seen lots of this kind of thing, the small 15mm profile is quite interesting, and it’s designed to use off-the-shelf hardware, which should save on costs!

Hexapod + iPad = Fun for All

hexapod-ipad

There’s not a lot of information on this hack, and the price or this hexapod device isn’t even listed, so we’ll assume it’s quite expensive.  On the other hand, it’s got a cool video of it being controlled by an iPad, so maybe it will give you some hacking inspiration!

USB Sound Card Write-Up

usb sound card

[George] wrote in to tell us about his USB sound card write-up. Before you think that this is a dupe of this post, he freely admits to building it nearly identically to the one previously posted. Imitation may be the sincerest form of flattery, but [George] is also requesting some feedback on his blog and the aforementioned post. feel free to let him know what you think in the comments.  Please be polite!

Filed Under: Hackaday links Tagged With: , , , , , ,

Make your RC car drive itself with this simple brain swap

April 4, 2012 By Leave a Comment

arduino-rc-conversion

If the kids have lost interest in that RC car or truck you bought them over the holidays, [Randy Sarafan] from Instructables has a few ideas that might help make the toys fun again, while teaching your kids a bit about electronics in the process. In his writeup, he shows how to swap out the brains of your run of the mill RC truck, enabling it to do far more than was originally intended. The procedure is pretty simple, and something that you can easily involve your kids in, if you’d like.

He uses an Arduino and a motor shield to keep the conversion simple, but this can be done with just about any capable microcontroller you might have on hand. [Randy] added a Parallax Ping sensor to the front of the truck enabling it to avoid objects as it drives itself, but since he cut out the truck’s original control board we’re assuming that there’s no way to override the truck’s actions at present.

[Randy] calls the conversion a “robot” though it seems like more of a semi-autonomous rover if you ask us. Regardless, revamping an old RC car is certainly far better than letting it collect dust on a shelf, or worse, tossing it out during spring cleaning.

Continue reading to see a short video of [Randy’s] RC truck in action.

[via HackedGadgets]

[Read more…]

Filed Under: arduino hacks, toy hacks Tagged With: , , ,

Board games over IP means telepresence chess

April 4, 2012 By Leave a Comment

Correspondence chess, or playing a game of chess via email or snail mail, is well-known in the chess community. [FunGowRightNow] thought he could bring correspondence chess into the 21st century, so he built two robotic chess boards that communicate over the Internet. The end result makes for an awesome senior project for school.

Instead of a simple monitor displaying the other player’s moves (and having to manually move both black and white pieces), the positions of all the pieces are controlled via a laptop an Arduino underneath each board. An electromagnet mounted on an xy frame moves one piece at a time. To detect the positions of the pieces, an 8×8 grid of reed switches open and close with magnets put in the base of each piece. The end result is a nearly seamless chess game that can be played by two people separated by hundreds of miles.

Right now, all we have are a few videos and the descriptions of the inner machinations of the chessbots. [FunGow] promised the Internet design specs after he turns this in as his senior project on April 10th. Until then, you can enjoy a few of the videos he’s posted after the break.

via reddit

[Read more…]

Filed Under: toy hacks Tagged With: , ,

Auto-locking pet door ensures that your outdoor kitty obeys its curfew

April 4, 2012 By Leave a Comment

auto-locking-pet-door

If you’ve got a pet that roams freely in and out of your house, you may find yourself wanting to more closely regulate how they come and go. [tareker] was looking to keep his cat indoors at night when dangerous animals might be lurking in the neighborhood, but he didn’t want it to become a hassle.

He already had locking pet door on hand, which he hacked to regulate the egress and ingress of his cat automatically. He installed a pair of reed switches to determine if the door had been opened outwards (cat leaving) or inwards (cat returning), keeping track of the state using an Arduino Nano. A servo motor attached to the door’s frame locks the door whenever it detects the cat is safely inside after nightfall.

While he also added an RGB LED to reflect the status of the door, he’s considering connecting it to the Internet so that he can control and check the door from wherever he might be at the moment.

Filed Under: arduino hacks, home hacks, news Tagged With: , , , ,

Recorder controlled Snake game played on a Nokia 6110

April 3, 2012 By Leave a Comment

Dig out an old cell phone, hit the dollar store for some plastic recorders, and build this sound controlled snake game for your next party. The project will be a snap for those comfortable working with microcontrollers, and a great learning experience if you’re looking to try your first Arduino project.

[László] and his friend call the project the Snake Charmer. As shown in the clip after the jump it uses music notes to direct the path of the solid line in the classic cellphone game of snake. But this isn’t just some PC-based rip-off. They’re playing on the actual cellphone. A camera points at the screen to project it for the enjoyment of spectators. The control scheme uses relays soldered to the pads of the four directional buttons. The pitches are being detected by a Max/MSP program, with the corresponding commands pushed to the Arduino via USB. Yep, it’s overkill but the point was to get this up and running quickly and with a minimum of work. We’d say they succeeded.

Actually, now that we think of it, this isn’t a two player game. Perhaps the recorder control concept needs to be applied to a more modern version of the game.

[Read more…]

Filed Under: cellphones hacks, musical hacks Tagged With: , , , , ,
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