Listening To Electromagnetic Interference With A RTLSDR Dongle

March 18, 2014 by 19 Comments

Being curious by nature, [Marios] decided to see what kind of radio-frequency emissions may be generated by an Arduino connected to a simple breadboard wire, and more importantly try to pick them up using a RTLSDR dongle. Electromagnetic interferences are disturbances that affect electrical circuits due to either electromagnetic induction or electromagnetic radiation. Before going into the market, all electrical devices are thoroughly checked for unwanted electromagnetic emissions so they usually aren’t obvious suspects when such problems arise.

Using the Arduino embedded PWM controller in fast PWM mode and by manipulating the duty cycle, he actually managed to create a primitive form of amplitude modulation and was able to transfer a very simple audible signal at several frequencies up to 1.75GHz. Embedded after the break here is video of the system at work.

As a side note, did you know that during the solar storm of 1859 the EMI were so strong that the telegraph operators received several shocks? Pipelines maintenance systems also have to be aware of such events, that can lead sensors to provide inaccurate results.

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Handheld Tetris Is Retro And We Love It

March 18, 2014 by 6 Comments

handheld tetris

[Eduardo Zola] has been playing around with Arduinos, and ever since he started, he wanted to try making a game. Having fond memories of playing Tetris back on Windows 3.1, he decided to try giving a handheld version of it a shot.

He started with two 8×8 Neopixel Matrices due to their simplicity — not to mention the massive library of code available! To make it truly portable, he’s also included a 3.7v 4400mAh lithium ion battery which will keep him gaming for hours. He found a 5-way navigation switch on eBay which makes up the joystick. A small LED bar display tells you what level you’re on, and he’s even included a smaller speaker for music, and a vibrating motor for successfully completed lines in the game!

He borrowed the Tetris algorithm (and added some improvements) from the source code by [Valentin Ivanov], who completed a similar project last fall. Stick around to see a demonstration video of it in action.

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Cute Tilt Beam Flashlight Adds Some Fun Interaction To Your Patio Table

March 17, 2014 by 26 Comments

Tilt-Beam-assembly

Here’s a cute little LED hack for your next soiree, it’s a solar charged piece of wood… with a motion controlled light in it!

[Zach DeBord] decided to try building his own version of this after seeing a commercial offering. He took a piece of oak and sliced off the top edge, and then laser cut the exact profile of the solar panel out of that slice. This allowed him to drill a nice big sloppy hole in the middle of it to fit the circuitry.

He’s using a nice big 8mm LED with a small 0.09V-5V DC boost circuit, a mercury tilt switch, a 4.5V solar cell, and a 2.7V 10MF super capacitor — plus a diode and 100ohm resistor. He’s glued the top slice of wood back in place, and sealed the entire thing with resin — you can hardly see the cut mark!

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MRRF: Repables, The Nonprofit 3D Object Repository

March 17, 2014 by 40 Comments

Repables

There’s a problem with online repositories of 3D printable objects: The largest repo, Thingiverse, is generally looked down upon by the 3D printing community. Thingiverse, owned by Makerbot, has seen protests, and calls for a an alternative repository. A few people have stepped up to provide a better Thingiverse, but these alternatives are either connected to specific 3D printer manufacturers like Ultimaker’s YouMagine, or have done some shady things with open source licenses; Defense Distributed’s DEFCAD, for example.

Repables, launched at the Midwest RepRap Festival this last weekend, hopes to change that. They are the only repository of printable objects and design files out there that’s backed by its own nonprofit LLC. It’s free for anyone to upload their parts and share, without the baggage that comes with an ‘official [company name] .STL repo’.

Just about everything can be hosted on Repables – .STL files for printable objects, .DXF files for laser cutter files, and even PCB files and Gerbers for circuit boards. Now, .STL files are able to be rendered in the browser, with support for viewing other formats coming soon.

It’s a really great idea that solves the problem of printer manufactures building their own hosting sites and the segmentation that ensues. It’s also headed up by a Hackaday alumnus, []. We’re everywhere, it seems.

Good Vibrations: Giving The HC-SR04 A Brain Transplant

March 17, 2014 by 23 Comments

[Emil] got his hands on a dozen HC-SR04 ultrasonic sensors, but wasn’t too happy with their performance. Rather than give up, he reverse engineered the sensor and built an improved version. Hackers, Makers, and robotics enthusiasts have had easy access to standard sonar platforms since the early 1980’s, when Polaroid began selling their 6500 sonar modules. A number of companies have released sonar boards since then, notably The Parallax Ping))) module. The HC-SR04 appeared on the market a few years back as a low-cost alternative of the Ping.

[Emil] found that the HC-SR04 would work reliably on hard surfaces as far as 4 meters away from the sensor. However, he got a lot of bad data back when using soft sided targets, or when no target was present at all.  [Emil] reverse engineered the schematic of the HC-SR04 and found some interesting design decisions. A Max232 RS-232 converter chip is used for its +-12V +-10V charge pumps. The charge pumps are connected to create 24V 20V at the ultrasonic transmitter. A mask programmed microcontroller manages the entire unit, commanding the ultrasonic transmitter to send 40Khz pulses, and listening for returns on the receive side of the system. [Emil] believes the micro is running in polled mode, due to the fact that it sometimes misses pulses. Even worse, the micro runs on an unmarked 27MHz crystal which had quite a bit of drift.

[Emil] solved these problems by creating his own PCB with an ATtiny24 and a 12MHz crystal. He increased the pin count from 4 to 6, allowing the ATtiny to be programmed in circuit, as well as opening the door to I2C and SPI operation. To build the boards up, [Emil] first solders his micro and crystal. He then uses a hot air gun to move all the components from the HC-SR04 board to his own. The new boards are still being tested, but [Emil] has posted his PCB and BOM data. He’s also promised to post his AVR code when it is available.

MRRF: Stuff From Lulzbot

March 17, 2014 by 8 Comments

A lot of the big names in 3D printers were at the Midwest RepRap festival showing off their wares, and one of the biggest was Lulzbot with their fabulous Taz 3 printer. This year, they were showing off a new filament, a new extruder, and tipping us off to a very cool project they’re working on.

The new products Lulzbot is carrying are Ninjaflex filament and the extruder to go with it. Ninjaflex is the stretchiest filament we’ve ever seen, with the feel of a slightly hard silicone rubber. Straight off the spool, the filament will stretch to a little less than twice its original length, and in solid, printed form its a hard yet squishy material that would be perfect for remote control tank treads, toys, and 3D printed resin molds. With all the abuse the sample parts received over the weekend, we’re going to call Ninjaflex effectively indestructible, so long as you don’t try to pull the layers apart.

Also from Lulzbot is word on the new 3D scanner they’re working on. The hardware isn’t finalized yet, but the future device will use a webcam, laser, and turntable to scan an object and turn it directly into an .STL file. Yes, that means there won’t be any point clouds or messing about with Meshlab. Lulzperson [Aeva] is working on the software that subtracts an object from its background and turns it into voxels. The scanner will be low-cost and open source, meaning no matter what the volume of the scanner will be, someone will eventually build a person-sized 3D scanner with the same software.

Videos of [Aeva] below showing off the new stuff and talking about the scanner.

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Hacking The Sci-Fi Contest Team Requirement

March 17, 2014 by 7 Comments

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We saw that some readers were not entirely happy with the team requirement for our Sci-Fi contest, which is running right now. We figured that those who do not work well with others might commit a bit of fraud to get around the requirement. But we’re delighted that someone found a much more creative solution. Why not enlist an AI to collaborate on your project?

[Colabot] is a hacker profile over on hackaday.io which is driven by ELIZA, a computer program that achieves limited interaction through natural language. Supposedly you add [Colabot] to your project and as it questions. We asked one on the profile page and are still awaiting the response. We think this itself could be a qualifying entry for the Sci-Fi contest if someone can find the right thematic spin to put on it.

As far as contest entries go there are only seven so far. Since everyone who submits an entry gets a T-shirt, and there are 15 total prize packages, we encourage you to post your entry as soon as possible. We want to see teams from hackerspaces and we can cryptically tell you that good things come to teams who post their project with the “sci-fi-contest” tag early!