Introduction To The H-bridge Motor Controller

May 20, 2011 by Caleb Kraft 22 Comments

[Chris] sent us this fantastic tutorial, introducing beginners to H-bridge motor drivers. While many of you will consider this stuff basic, those who are trying to expand from building only things the arduino board can handle to bigger more expansive (and powerful) projects will find this quite helpful. [Chris’s] tutorial is very in depth, not only going through the construction of the basic circuit but also showing you how to make your own PCB. Pop on over there and learn some theory and some practice. Then you can build that battle bot you’ve always been dreaming of!

Chemical Wood Burning

May 16, 2011 by Caleb Kraft 25 Comments

Make: Projects has posted an interesting way to burn designs into wood. Instead of doing the traditional method of using a hot iron to hand draw or trace patterns on the wood, they show us how to use a chemical process to make things easier. They are using a solution of Ammonium Chloride, applied with a foam stamp, then heated. When it is heated it breaks down to ammonia gas and hydrochloric acid, burning the surface. The advantage here is that you can easily use a stamp to create patterns whereas doing it by hand might be difficult. They do point out that improvements could be made, such as adding something to keep it from soaking into the wood and blurring the edges.

Papercraft Flowers Teach Kids About Batteries

May 12, 2011 by Mike Nathan 6 Comments

saltwater_papercraft_batteries

[Emily Daniels] has been teaching interactive electronics workshops geared towards children for some time now, recently holding a session that demonstrated how batteries work in a pretty novel fashion.

She wanted to keep things safe and simple due to the class size, so she didn’t want to rely on using soldering irons for the demonstration. Instead, she showed the children how batteries function by building simple voltaic cells with paper flowers, salt water, and LEDs. The paper flowers’ absorbency was used to act as a salt bridge between the wire pairs that adorned each petal. After salt water was applied to each of the flower’s petals, the center-mounted LED came to life, much to the amazement of her class.

The concept is quite simple, and the LED flowers are pretty easy to build, as you can see in her Instructables tutorial.

We think it’s a great way to demonstrate these sorts of simple concepts to kids, and hope to see more like it.

[via Adafruit blog]

I2C 101

May 11, 2011 by Kevin Dady 15 Comments

Embedded Labs has come out with a very detailed I2C 101 tutorial, that you should check out if you have any questions on the system. I2C is a short distance serial interface that only requires 2 bus lines. Keep in mind that as wires go down complexity goes up. While there are more than a few I2C devices out there in the wild, and the 2 wire system does make wiring a breeze sometimes, the information required to make use of it often seems confusing to someone who is just starting with it.

The tutorial covers basic theory, stop / start conditions, addressing, data transfer, and acknowledgment plus illustrations. A couple of specific examples are given in the form of a 24LC512 serial eeprom, and a DS1631 digital thermometer complete with code.

Machining Replacement Parts With Hand Tools

May 11, 2011 by Kevin Dady 18 Comments

Jeff is a huge music fan, and like many of us likes old technology, so it seemed a bit silly (to him) that he did not have a turn table. His dad had a spare in the basement. A neat old Braun model from the 1970’s that was broken.

Opening the unit up he found that part of the arm mechanism was broken, and thanks to the age of the turntable and the wonders of mass production chances of finding a replacement were slim to none. Not being discouraged he busted out the hand tools and fabricated the replacement out of some aluminum. The end result is a perfectly functioning turntable that will serve many more hours pushing out warm jams.

Check out the fourm post above to get details and pictures, and we just wanted to tell [Jeff], awesome job!

DIY Portal Turret Is… Looking Pretty Good.

May 10, 2011 by Jesse Congdon 19 Comments

[Ryan Palser] wrote in to tell us about his Portal Turret. [Ryan] set about making this Portal 1 style turret by first carving a Styrofoam form, bondo and waxing then casting molds of the various components. Anyone interested in mold making (like us) should check out all the pictures and comments in the stream. The turret’s camera lens style eye has some excellent detail including a laser cut aperture with text inlay. A couple LEDs behind the eye assembly provide the signature red glow and evidently [Ryan] also fitted the little guy with a red laser. An internal Arduino (Incident Resolution Chip?) takes ques from a PIR sensor mounted in one of the turret’s arms to play one of 17 sound clips through a sparkfun MP3 player shield. In order to fight repetition the sound module runs through a playlist of the 17 tracks then shuffles it before playing through again. Theme music can also be spammed by pressing a button in the back of the motion sensing arm. The turret can be battery powered or plugged into a wall socket for constant operation. All that’s missing are the Aperture-Brand Resolution Pellets. We would love to see this integrated with some similar turret projects previously featured here.

Are you still there? We have more Aperture Science stuff including a Sentry Turret, Weighted Companion Cube, and even a portal shirt. If you are interested in more model making check out the spectacular Daft Punk helmet build from a little while back.

Learning Electronics Concepts Step By Step

May 8, 2011 by Mike Nathan 38 Comments

arduino

We realize that not everyone out there holds a degree in electrical engineering or has the ability to tell NPN transistors apart from PNP transistors by taste alone, so we occasionally like to mention things that appeal to the beginners in the crowd. While there is a clear division between Arduino supporters and detractors, it is hard to deny that the devices have their place, and can be quite useful when exploring certain electronics concepts.

For the supporters out there, [John Boxall] has put together a site jam-packed with Arduino tutorials covering a wide array of concepts and techniques. We have covered his work before in relation to specific topics, but we felt that his site deserved mention as a whole. His tutorials cover some of the most basic concepts such as lighting LEDs with the Arduino, and work their way to more advanced subjects, lesson by lesson.

He is not satisfied with simply introducing a concept and handing out a sketch that does the work. He takes the time to expand on the concepts, giving the reader enough detail to use their new-found knowledge in later projects. If you were to follow his tutorials from beginning to end, you would be exposed to LCD screen control, shift registers, real-time clocks, I2C bus communications, and more. These skills and concepts can be carried on to future projects as well as other micro controllers, making his tutorials a very valuable learning tool worth checking out.