Soda Can Theremin Made In Minutes

June 1, 2014 by 18 Comments

Looking for a fun weekend project? How about building your very own sci-fi Theremin using just a soda can and a few simple components you probably already have.

Not familiar with Theremins? It’s an electronic instrument that can be played without any physical contact. Essentially, the antenna (soda can) acts as half of a capacitor — your hand acts as the other. By varying the distance of your hand to the soda can, you change the capacitance, which can then be used to modulate a sound. It was invented in 1928 by the Russian inventor [Leon Theremin], and you can actually see a video of him playing it on YouTube — we’ve never seen this before, but we must say it’s actually quite impressive!

Anyway, back to the hack. All you need are some op-amps, a few capacitors, some resistors, a diode, a breadboard, and of course — a speaker. [Will’s] gone into great detail in how each circuit works with both schematics and diagrams of the breadboard configuration — it’s a great little project even kids can follow along.

Take a listen after the break.

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NES RetroPi

Original NES Guts Upgraded With RetroPie

June 1, 2014 by 21 Comments

If you have an old broken NES lying around and have no idea what to do with it, you may want to check out [snoius’s] latest project. He replaced the guts of his old NES with a Raspberry Pi. [snoius] started out by removing most of the electronics from his original NES to make room for the Pi. He left the original control panel board so he would be able to use the original power button and power LED. The NES power switch is an on/off toggle switch. [snoius] decided to just route the 5V USB power input directly through this switch. The result is a hard power switch for the tiny computer. The original power LED is wired up to the Pi’s 3.3V GPIO header through a 330 ohm resistor. Now when the Pi has power, the LED lights up.

The next step was controllers. It looks like [snoius] is using some USB SNES controller clones. He wanted to use the original NES controller ports but obviously the NES did not utilize USB. [snoius] used a saw to cut the backs off of the controller ports, leaving a flat surface. He then used a utility knife to carve out a hole in the shape of a female USB port. He mounted some ports in place and then wired the inside up to some short USB cables with male ends. These were plugged into a USB hub that is hidden inside of the NES case.

The Pi is also hooked up to a short HDMI cable and a short power cable. The loose ends of the cables are mounted to a small block of wood. Notches are cut out of the wood to better fit the cable ends. The rear of the NES has two holes cut out where the original connectors used to be in order to accommodate the new connectors.

With all of the hardware taken care of, [snoius] still needed a way to actually play his games. That’s where RetroPie saved the day. RetroPie is a Linux distribution for the Raspberry Pi that is specifically created to make it easy to play old video games. It includes emulators for many old systems including NES, SNES, SEGA Genesis, Gameboy, etc. [snoius] installed RetroPie onto an 8GB SD card and copied over all of the ROMs he could find. The end result is what appears to be an original NES at a glance, but is in fact multiple retro gaming systems in one. It also contains hundreds of video games in on board memory instead of requiring a large library of physical cartridges.

[via reddit]

Poor Man’s 3D Printer Looks Rough, Prints Great!

May 31, 2014 by 39 Comments

In this Instructable, [Gelstronic] proves anyone can afford a 3D printer. Why? Because you can literally build one out of computer e-waste — specifically, DVD/CD drives.

His goal was to build a printer for less than a hundred euros. And he darn well did it. The most expensive part was the hot-end coming in at 20 euros. He managed to find a Chinese Arduino MEGA 2560 for only 10 euros, and everything else was basically pocket change.

The hot end features a geared NEMA 17 look-a-like stepper motor he found in a printer, and the XYZ axis all make use of the DVD drive trays. The only downside to this massive reusing of e-waste is the bed size. Due to the limited range of motion on the DVD trays, his build area is only 40 x 40 x 40 mm, which in the world of 3D printing is pretty tiny. On the plus side, he’s even thrown in a heated bed making use of two 7W resistors which can get it all the way up to 110°C!

After a bit of tweaking he was able to get some surprisingly good prints, with a 10mm cube coming out at 10.06mm! He must have a pretty good caliper Anyway, check out the following demo!

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Wiimote Controlled Extermination: Dalek-Style

May 31, 2014 by 11 Comments

Dalek Build

Convention-goers have likely strolled past a number of Daleks: the aliens drive around the event space, spouting threats of extermination and occasionally slapping folks with a rotating eyestalk. [James Bruton] has been hard at work building this Wii-remote-controlled Dalek with his fellow hackers at the SoMakeIt Hackerspace (you may remember our write-up from earlier this year).

Most Dalek builds seat a driver inside the body at the helm of a salvaged electric wheelchair, where they plunk around using a joystick control and simmer in an increasingly potent aroma. This version started like most, with a wooden structure from plans sourced at Project Dalek. Inside, however, [James] and his crew have tapped into the wheelchair’s motor controller to feed it a PWM signal from an Arduino Shrimp, which is linked to a Raspi. The Pi receives a Bluetooth signal from a Wiimote, and, through their custom Python script, directs the Dalek with ease.

They’re still working on finishing the Dalek’s body, but they’re using some clever tactics to push onward: using a 3D-printer to solve some of the nuanced styling choices. They’ve uploaded a gallery with additional photos on Facebook, and you can watch them goofing around with their creation (losing their balance and nearly exterminating themselves) in a video after the break.

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HAL Is Duct Tape For Home Automation

May 31, 2014 by 17 Comments

HAL Home Automation

When it comes to home automation, there are a lot of different products out there that all do different things. Many of them are made by different companies, and they don’t often play very well together. This frustration ultimately led [Daniel] to develop his own Python based middleware solution to get these various components to work as a single cohesive system. What exactly did [Daniel] want to control?

First up was the door lock. [Daniel] lives in an apartment building, so there are actually two locks. First, a visitor must be allowed into the building by pressing a button on the intercom system in the apartment. Second, the apartment door has its own dead bolt lock that needs to be opened and closed. [Daniel] was able to control the building’s front door using just a transistor hooked up to an Arduino to simulate the press of the physical button. The original button remains in tact so [Daniel] can still easily “buzz” in a visitor.

The apartment’s dead bolt was a bit trickier. There are off-the-shelf solutions to control a dead bolt, but they are often expensive. [Daniel] built his own solution using a simple servo motor bolted to the door. The servo is controlled by the Arduino which is in turn controlled via two broken intercom buttons that already existed within the apartment. The buttons were originally used to either speak to or listen to a visitor before buzzing them into the building. They had never worked for [Daniel] so he re-purposed them for his own project. The whole DIY door locker is enclosed in a custom-made laser cut wooden box.

Click past the break for the rest of [Daniel’s] story.

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The $50 DMX Tester

May 31, 2014 by 7 Comments

DMX

Despite being around for about as long as MIDI, DMX, the industry standard for controlling stage lighting and smoke machines, is still an astonishing expensive protocol to work with. Where MIDI can be banged out with a simple microcontroller – with odd bit rate requirements, no less, DMX testers cost hundreds of dollars. Of course this means the market is wide open for a DIY DMX tester, and over on the projects site [Tony] has just the thing.

For the hardware, [Tony] is using few 4×4 matrix keypads for user input, and a character LCD for the display. With this, he can set any of the 512 lighting channels in a DMX setup to any one of the 256 intensity values. Setting a range of channels to any intensity is a snap, with an extremely cut down command protocol. All the processing is handled by an Arduino, which seems more than capable of handling the DMX protocol thanks to the Conceptionetics DMX library.

While it’s not a full-blown lighting console you’d find in the back of a theatre, it’s more than sufficient to test a lighting rig. It also seems pretty simple to use, just the thing if you’re trying to wrap your brain around some theatrical lighting.

Four strings drag an aluminum slug through a sandbox

CNC Zen Garden

May 31, 2014 by 31 Comments

[youtube=https://www.youtube.com/watch?v=Ge4H4Uw630o&w=580]

 

Meet the second version of [David’s] sand manicuring CNC machine. We saw version one about six months ago which he built for a science museum in Canada. This offering is much the same, except for the controller. The initial version demanded a full-blow computer to drive it but now that has been swapped out in favor of a Beaglebone Black.

The software has no feedback on the position of the plotter, which is an aluminum slug that [David] machined at Calgary Protospace. It needs to be in a specific position when the machine starts out, and from there patterns are traced by calculating how much spooling or unspooling of the four strings will move the slug.

There’s a bunch of other really neat art installations and projects on [David’s] webpage, it’s worth clicking through!