Beginner Concepts: Electronic Jack-in-the-box

April 5, 2010 by Mike Szczys 7 Comments

Behold the electronic Jack-in-the-box. Open the lid or enter the wrong combination and you’ll set off an alarm. But if you get the right 6 combination code entered using the three buttons you’ll be rewarded with a little ditty and the appearance of the Jack (who lives in the box). [Jeremy Blum] designed this as part of his introduction to rapid prototyping class at Cornell University. See his description of the project after the break.

When he shared the link with us he mentioned that this might be a fun project for beginners and we couldn’t agree more. The design is easy to wrap your mind around using the provided schematic. The source code package includes PDF files that contain well commented code segments along with their descriptions. You can use this to get comfortable with driving a speaker and servo motor using an Arduino, as well as to read from two different types of inputs. We are especially interested in the hardware debounce implemented for the switch that detects if the lid is closed. Software debouncing is pretty much the standard these days but because an external interrupt is used to read the switch that method won’t work here.

If you’ve got an Arduino and few of these components why not give this a try?

Continue reading “Beginner Concepts: Electronic Jack-in-the-box” →

Home Fabricated Boards In Any Color

March 31, 2010 by Mike Szczys 28 Comments

Tired of every printed circuit board you etch coming out brown? Take a page out of [Dane’s] book and dye your PCB to just about any color you want. One hour submerged in a 200 degree bath of Rit dye turned his brown FR4 substrate to the desired dark green. We give him points for being dangerous enough to use a broken bottle as a vessel, yet wearing eye protection at the same time.

We never really thought of doing this, but it’s pretty interesting that it works. We’ve stained the substrate when removing etch resist so this should have been obvious, but wasn’t.

Didgeridoo, Now Does Real Time Video

March 23, 2010 by Jakob Griffith 8 Comments

Some of you may remember when we introduced you to [Kyle’s] Electronically Modified Didgeridoo. Those same members will have their hearts warmed knowing he’s still playing and advancing on his Didgeridoo, now including real time video processing. There isn’t too many details aside from it being controlled by an ATMega168 and an unknown analog switching chip, and in its infancy it just looks like a bunch of dancing white lines but we expect this to turn into one amazing display.

Oh, and those determined on making their own Electronically Modified Didgeridoo should keep an eye out for the April ’10 issue of Popular Science where the instrument will be featured.

Floppy Disk Augmented Reality Is A Head-scratcher

March 23, 2010 by Mike Szczys 23 Comments

[Iain Gildea] tipped us off about a drill-powered coffee grinder he made but it was the floppy-disc augmented reality display a few paragraphs down that caught our attention. He’s taken 36 white floppy discs, sprayed one side black, then mounted them each with a center pivot into a 6×6 grid. Through a convoluted system of pulleys and servo motors the display can be manipulated to produce augmented reality markers. After the break you can see the display itself, then the result of viewing it through a webcam.

We’re amused, but also scratching our heads. There must be an easier way, such as a light-up grid covered in dark plexi or something along those lines. But then again, it’s his hack and he can do what he wants… and he seems to have a thing for floppies.

Continue reading “Floppy Disk Augmented Reality Is A Head-scratcher” →

1-Wire LAN With An LCD

March 23, 2010 by Jakob Griffith 14 Comments

[Viktor], one of our favorite avid hackers, has been playing around with 1-wire systems all this month. What started out as a MicroLAN Fonera has turned into an iButton interface, to a 1-wire powered hub, and finally a 1-wire character driven LCD. Anyone looking at 1-wire systems or OWFS could surely benefit from his testing.

However, if you still haven’t gotten your fill of 1-wire goodness, let us remind you of the 1-wire HVAC and IPv6 to 1-wire protocol translator.

[Thanks Juan]

Flip-book Style Digitization

March 19, 2010 by Mike Szczys 15 Comments

[youtube=http://www.youtube.com/watch?v=tCOXC5PTJj8]

This method of book digitization allows you to scan an entire book by fanning through the pages. It uses a high-speed camera that captures 500 frames per second to get a good look at each page. Processing software isolates each pages, analyzes any curve in the paper due to the flipping, and smooths out the image for better optical character recognition results. The greatly reduces the time it takes to digitize a book, even compared to setups that automatically flip pages.

[Thanks Erico]

Ditch The LPs And Build Your Own 3D Scanner

March 18, 2010 by Mike Szczys 22 Comments

Find yourself an old record player, a laser level, and a digital scanner and you can build a 3D scanner. That’s what [Rob] did. The camera and laser level are mounted on the turntable for steady rotation. The camera captures the vertical laser line traveling around the room by recording 30 fps at a resolution of 640×480. This data is then translated into a Blender 3D file via a Python script and the Python Image Library. You can scan a whole room or just a small object. The face above is the result of this image capture after a bit of processing. [Rob] found this worked best in the dark and when scanning surfaces that are not reflective.

Make sure you also check out the camera-and-projector scanning method.