Your source for daily hacks

Published on: October 29, 2013 / Comments: 1

There’s still time for these Halloween hacks!

Halloween isn’t over yet, there is still time to make something cool for Halloween.  Here’s a few to inspire you.

First up is Halloween Prank.  While not a completed project, this is a good base for Arduino powered scare tactics!  The build uses an Arduino, an Ultrasonic distance sensor, and a servo.  By detecting ‘someone coming to your door’ possibly, the servo is triggered.  In Jacob’s build the plan is to drop a bunch of spiders on people walking up.  That sounds like fun.  You could also make it actuate something to jump out at your unsuspecting victims.

Source code for Halloween Prank is available here on GitHub.  There are more pictures and a test video on Jacob’s site.

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Published on: October 23, 2013 / Comments: None

Keerbot uses steppers and g-code to draw on walls

Although it’s not a new concept, you can’t deny that it is awesome.  The Keerbot is a wall drawing robot.  By hanging on 2 known-length strings, the Keerbot uses stepper motors to shift from left and right, and move up and down by  contracting and letting out string on either side.  While moving a pen/marker/drawing aid makes lines of art.

In some of the demos I see the guys working on getting a spray paint fixture to work.  That could be more interesting than just dragging a marker.  Currently the guys are using vector art, and known CNC utils to generate g-code.  Very similar to how one would do laser cutting/CNC/and 3D printing.

Check out a few more pics and video after the break.  Also make sure to check out the full lineup of videos and details on keerbot.com.

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Published on: October 14, 2013 / Comments: None

The Tricorder project is about making discoveries with sensors

When you hear the term Tricorder, you might think of Star Trek but I assure you, this is no toy prop.  Keeping with the same concept of the Tricorder used on the TV show the Tricorder is about reading data, _lots_ of data.  And that is what the Tricorder project aims to do, develop handheld devices that are fitted with lots of diverse sensors in order to observe them.

So far the project has produced a few different versions.  The Mark 1, the Mark 2, etc.  They are currently working on the Mark 5.  Each version is pretty different from the other, and they all contain a wide variety of sensors such as atmospheric temperature, humidity, pressure and electromagnetic field, color, infra-red.  And the obvious like GPS.  They’re even working on developing their own sensors like this 3d printable mini spectrometer.

The project is open, and there are tons of pictures, and schematics on the tricorderproject’s web site.

Published on: September 26, 2013 / Comments: None

Building a noise generator with transistors

Believe it or not, it’s actually quite difficult to generate random numbers on computers and microcontrollers.  I’m talking about true random.  A lot of the randomness computers use isn’t random at all, it’s predictive (or pseudo random).  Difficult, but still predictive.   It’s important when doing cryptographic functions to use a good random source.

So f4grx decided to build a random circuit and do some analysis on it.  The circuit design is built around the idea of using an open collector on a transistor.  What’s essentially going to happen is tiny electrical noise in the air is going to cause the circuit to produce 1′s and 0′s which then can be used to plot random.

Interesting read.  Check out f4grx’s experience.

Published on: September 22, 2013 / Comments: 2

Lazy Sunday Links – 9/22/2013

It’s Sunday again, time to take a break from watching your favorite NFL team lose and learn something somewhat productive.

First up, you should fire up your 3D Printer and make yourself a set of these cool 8bit video game coasters.

Not in the mood for some video game coasters? Well did you know there are more places to get 3D models to print for your 3D Printer other than Thingiverse ?  There’s Defcad which commonly has all those items that people are forced to take down other places, and Yeggi which seems to just scour the web hunting models.  If you are making industrial designs like PCB layout, there’s 3dcontentcentral.  That should get you going.

You’ve obviously heard of FFT or Fast Fourier Transform, you have it on your trusty O’Scope and when you look at it, you think you see valuable information.  But what exactly is a Fourier Transform?  Check out the interactive guide to Fourier Transform so you can learn something.

Looking for somewhere to host your software project, not a fan of GitHub?  Srchub is just starting out, but offers subversion, git, mercurial, wiki, issue tracker.  Lets you assign multiple collaborators and also make private repositories.  Not a bad gig for free.

You JavaScript/Node.js guys have probably seen the Espruino microcontroller.  A micro that can be developed using JavaScript.  But did you know there is another one ?  The Tessel.  This one’s got on-board wi-fi.

Published on: September 19, 2013 / Comments: None

Solar Swing-Set Install

Benjamin has created a series of videos showing how he converted a swing-set to serve a dual purpose. He beefed up the structure with some 3/4″ conduit which he flattened the ends on and used it for cross bracing. A couple of solar panels we mounted to the roof and the wires were safely routed through conduit to a remote location when he uses the energy to charge his electric motorcycle.

The charging rate varies significantly proportional to the amount of sun. He was seeing 2 Amps on a cloudy day  and has witnessed up to 7 Amps. Check out the videos  after the break.

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Published on: September 15, 2013 / Comments: None

Lazy Sunday Links – 9/15/2013

Sunday is a good lazy day. Time to learn stuff and bang out some easy hacks.

 

Chirp is a Javascript toolkit for creating chiptunes.  Only works in Google Chrome but sounds retro-tastic and actually sounds pretty good.

Voltage dividers are an essential skill to learn when building circuits. Go learn some voltage diviers.

Transmit data serially without a Microcontroller.  Uses a specialized IC by Holtek to transmit and receive, but really quite useful if you have some data you want to move and don’t feel like adding a Microcontroller to your project!

The gMax is a pretty large 3D Printer on kickstarter.  It boasts a 16″ x 16″ x 9″ print volume.  Wow that’s some large prints!

Don’t understand how hobbyist FDM 3D Printers work ?  Here’s a writeup on how they work.

The illustrated guide to crypto hashes.  Informative

Tuning an RTOS can be daunting to pick the right scheduling algorithm. How to select the right algorithm using system modeling.

If you’re not a VIM guru, you’re probably using the nano text editor.  Here’s some tips to make your nano experience a little more pleasurable.  Works on the Raspberry Pi too.