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Hardware hacking how-tos

The Ins And Outs Of Lithium-based Battery Packs

May 25, 2011 by 10 Comments

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So, you’ve got your awesome project built and are ready to take it on the go, but how are you going to power it? You could use a couple alkaline cells or perhaps swipe a Litihium battery pack from some infrequently used portable device – however before you do that, why not check out what [Lady Ada] has to say on the subject?

The detailed tutorial on her site discusses the different types of Lithium-based batteries and their form factors, as well as the strengths and weaknesses of each type. Voltage ratings are covered, as well as why it is important to choose a Lithium battery pack that fits the task at hand. The dangers of improperly handling batteries are clearly noted, highlighting the importance of selecting a proper charger and resisting the urge to ever wire Lithium batteries together to increase capacity.

While the bulk of the information presented is nothing new to most of our readers, it’s definitely a worthwhile read for those just starting to use Lithium battery technology in their projects.

We Know “Mario’s Early Years” Was A Let Down, But This Takes It A Bit Too Far.

May 22, 2011 by 27 Comments

[JJ Hendricks] wrote in to tell us about his SNES cartridge urinal. The fully functional urinal is constructed with 40 SNES cartridges and sealed up with polyurethane. The base of the whole operation is actually not a puddle of festering urine, but instead poured polyurethane that ensures proper flow through the drain. You heard right, this urinal actually flushes! As a bit of consolation [Hendricks] plainly states in the directions: “No good games were damaged in the making of this video. All the video games used in this urinal were already broken or worthless sports games”. We have featured some SNES cartridge readers before, so now you have something to do with all the leftover hardware! Gross.

Continue reading “We Know “Mario’s Early Years” Was A Let Down, But This Takes It A Bit Too Far.” →

Introduction To The H-bridge Motor Controller

May 20, 2011 by 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 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 6 Comments

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[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 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 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!