Sonar Built From Piezo And Microphone

January 26, 2015 by 22 Comments

[Jason] has continued to plug along with his sonar build and recently showed up a monostatic active sonar using a piezo element and microphone. Regular readers will remember [Jason’s] experiments from a Fail of the Week post which focused on his water-proofing woes from a much earlier prototype.

We find this offering far more engaging. He has ditched the ultrasonic module seen in those experiments. The new rig drives the piezo element using a 27V source. After each ping is sent out, the microphone input is immediately captured to detect the return of the audible sound. [Jason] mentions that the TI Launchpad he’s using for the project is fast enough for these experiments but he may switch to a Teensy 3.1 in order to double the RAM and thereby increase the sample size he is able to record.

Of course this is intended for underwater ROVs so his next iteration will involve a DIY hydrophone. We can’t wait to see that one as the process of converting this test rig into one that works underwater evades us. If you have some tips on that topic please let us know in the comments.

Continue reading “Sonar Built From Piezo And Microphone” →

Rendering Fractals With Just HTML And CSS

January 26, 2015 by 18 Comments
What’s better than spending hours and hours with CSS
trying to get images and text to center properly? Not [Jim], but he did notice that
CSS3 was a very powerful language. He wondered about building Tetris, a Turing Machine, or rendering fractals purely in CSS and HTML. The jury is still out if a Turing machine is possible, but he did manage to generate some simple fractals using just CSS and HTML, no JavaScript required.

Most fractals are recursive, and CSS rules can be applied to HTML objects that have already have rules applied to them. It’s not quite recursion, because there’s no way to dynamically generate HTML with CSS. However, with just a few tags, [Jim] can generate one level of a Pythagoras Tree. This method requires placing tags in the HTML for every level of the tree, greatly limiting the cool factor. That’s easily remedied by a few CTRL+Cs and CTRL+Vs.

The same technique can be used to render a Koch snowflake – seen on this page. Yes, it’s all HTML and CSS, without JavaScript. Why? Because he can, and that’s good enough for us.

Using RC Transmitters With Flight Simulators

January 26, 2015 by 21 Comments

It’s winter, and that means terrible weather and very few days where flying RC planes and helicopters is tolerable. [sjtrny] has been spending the season with RC flight simulators for some practice time. He had been using an old Xbox 360 controller, but that was really unsuitable for proper RC simulation – a much better solution would be to use his normal RC transmitter as a computer peripheral.

The usual way of using an RC transmitter with a computer is to buy a USB simulator adapter that emulates a USB game pad through a port on the transmitter. Buying one of these adapters would mean a week of waiting for shipping, so [sjtrny] did the logical thing and made his own.

Normally, a USB simulator adapter plugs in to a 3.5mm jack on the transmitter used for a ‘buddy box’, but [sjtrny] had an extra receiver sitting around. Since a receiver simply outputs signals to servos, this provides a vastly simpler interface for an Arduino to listen in on. After connecting the rudder, elevator, aileron, and throttle signals on the receiver to an Arduino, a simple bit of code and the UnoJoy library allows any Arduino and RC receiver to become a USB joystick.

[sjtrny] went through a second iteration of hardware for this project with a Teensy 3.1. This version has higher resolution on the joystick axes, and the layout of the code isn’t slightly terrible. It’s a great project for all the RC pilots out there that can’t get a break in the weather, and is also a great use for a spare receiver you might have sitting around.

The Proper Use For A Gameboy Advance Carrying Case

January 26, 2015 by 14 Comments

About a decade ago, Nintendo released a Game Boy Advance carrying case in the shape of a Game Boy Advance. It was the obvious answer to the original brick Game Boy carrying case every eight year old had in 1990. This jumbo-sized Game Boy Advance case also makes a really good platform for a console mod, which is exactly what [frostefires] got when he put an N64 in one.

This isn’t the first time we’ve seen this bit of old Nintendo paraphernalia used to house an N64. A few years ago, [Hailrazer] used the same GBA carrying case as the body of an N64 build. There were a few shortcomings in that build, most importantly the removal of the D pad.  [frostedfires]’ build fixes this oversight.

Inside the GBA enclosure is a 4.3 inch screen, a replacement Gamecube joystick, an SNES D pad, and of course the entire N64 circuit board with a few modifications.

[frostedfires] entered this into a ‘Shark Tank’-ish  competition at school, and this build was so impressive he won first place. Link to the full build thread here.

ANUBIS, A Natural User Bot Interface System

January 26, 2015 by 14 Comments

[Matt], [Andrew], [Noah], and [Tim] have a pretty interesting build for their capstone project at Ohio Northern University. They’re using a Microsoft Kinect, and a Leap Motion to create a natural user interface for controlling humanoid robots.

The robot the team is using for this project is a tracked humanoid robot they’ve affectionately come to call Johnny Five.  Johnny takes commands from a computer, Kinect, and Leap motion to move the chassis, arm, and gripper around in a way that’s somewhat natural, and surely a lot easier than controlling a humanoid robot with a keyboard.

The team has also released all their software onto Github under an open source license. You can grab that over on the Gits, or take a look at some of the pics and videos from the Columbus Mini Maker Faire.

First CNC Project Results In Coffee Table Of Catan

January 25, 2015 by 16 Comments

[Christian Finklea] was inspired by a glow in the dark table, and decided to try his hand at making his own… and it’s absolutely fantastic.

He designed the table using SketchUp Make, and overlaid the continents of our planet on a grid of hexagons — Though it looks like he left Antarctica out of the mix — poor Antarctica! Why hexagons you might ask? Well, his CNC machine isn’t that big, so he had to choose a smaller work piece size in order to make the table. Kind of gives off a Settlers of Catan vibe too…

Once he had all the intricate hexagons milled out, he began assembling the table. Lots of wood glue later the table started looking like a table. Now here’s the fun part — making it glow.

Using what looks like a kind of glow-in-the-dark epoxy, [Christian] filled in all of the country cutouts and waited for it to cure. Bit of sanding later, some more lacquer, and boom — he has an awesome coffee table.

Now if only he had stuck some LEDs in there too like one of these RGB coffee tables we’ve seen — Then you could also play Risk anytime!