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April 30, 2009

Ask MAKE: Voltage annotations

Kevin asks:

What do all those little subscript letters and numbers after V on circuit diagrams mean Vcc, Vee, Vss mean?

I have to admit, I didn't really know the full answer to this one, so I looked it up. I found a page on the solarbotics website explaining the whole shebang: Vcc and Vdd mean that that point in the circuit is directly connected the power source, and Vee and Vss mean that point it is connected to ground. It went on to say:

Apparently this terminology originated in some way from the terminals of each type of transistor, and their common connections in logic circuits (i.e., Vcc is often applied to BJT collectors, Vee to BJT emitters, Vdd to FET drains, and Vss to FET sources). This notation then carries across to integrated circuits -- TTL ICs were originally based on BJT technology, and so often use the Vcc / Vee terminology; CMOS ICs are based on FET technology, and so often use the Vdd / Vss terminology.

The absolute distinctions between these common supply terms has since been blurred by the interchangeable application of TTL and CMOS logic families. Most CMOS (74HC / AC, etc.) IC data sheets now use Vcc and Gnd to designate the positive and negative supply pins.

Image is a snippet of the schematic for SparkFun's Blue SMiRF.

Have you got additional information? Post it in the comments! Have a question for Ask MAKE? Shoot me an email at becky@makezine.com or drop us a tweet! We'd love to answer your questions on anything MAKE-y.

The Boiler Bar and Theater's May Day Party

The fine makers over at the Boiler Bar in Oakland, California, are hosting a May Day Party this Saturday, May 2nd, from 8 p.m. "till the flowers wilt." There will be snake charming, cancan girls, fire and may pole dancing, burlesques, lots of live music, handmade hooch from the Boiler Bar, flaming aerial spectacles, and a chance to see the Golden Mean up close and personal.

Pictured above are Jon Sarriugarte and Krysten Mate, makers of the Golden Mean and key members of the Boiler Bar crew. We've featured them in MAKE Volume 16, on Make: Online, and they've been a presence at every Maker Faire we've hosted. Come see the Boiler Bar extravaganza as well as the Golden Mean gorgeous snail at this year's Maker Faire Bay Area 2009 on May 30th and 31st.

Glue anything to anything

Ever get confused about what sort of glue to use on a project? I'm twice degreed in Chemistry, and I certainly do. A great resource is This to That,, a comprehensive "glue advice" database run by a theatrical prop-builder and some buddies. They say:

We aren't a front for any manufacturer or some National Glue Association (if such a thing even exists.) Our recommendations are totally impartial. We have advertisers but they don't influence our selections at all. And they never will. We promise.

The folks at This to That were kind enough to give MAKE permission to reprint their main glue chart in The Maker's Notebook, so it's available in the notebook's reference section in the back.

In the Maker Shed:

Pick up The Maker's Notebook ($19.99) for all your big ideas, diagrams, patterns, etc. Exclusive to the Maker Shed: Sticker sheets and a band closure to customize your book.

In the Maker Shed: PVC Rocket Engine Design & Construction book

Check out the K450 PVC Rocket Engine Design & Construction book form the Maker Shed. It details how in just a few hours anyone can build a powerful K450 engine that will send a rocket soaring over 5000 feet! Easy to follow step by step instructions and 137 color illustrations demonstrate the exceptionally simple construction process. Best of all, only common materials are used and no special tools are required.

Check out the K450 PVC Rocket Engine Design & Construction book

Hydrogen balloon camera project

What says "family get-together" more perfectly than volatile, asphyxiating gas? Every year, Professor Fzz and his family get together over the Easter holiday and issue an "Easter Challenge." Last year, they made an Egg Cannon. This year, they built a hydrogen balloon and suspended camera rig to take pictures of granddad's house. I guess because part of the challenge awarded extra points for the "use of mad science," they even produced their own hydrogen!

This summer, we're going to be doing some content programming here on Make: Online around the concept of the MAKEcation, doing fun, educational, and geeky tech, science, and craft projects together with your family, as an alternative to the family get-away. This idea of issuing a family challenge to make and use something is really cool -- altho the hydrogen production might be a little over the top for most. You might wanna think through that "use of mad science" clause in your challenge.

If you have fun ideas for family challenges and MAKEcation plans, we'd love to hear about them in the Comments.

Reconnaissance Balloon

Car Wars IRL

I knew it was only a matter of time before Car Wars, Mad Max, and dozens of video games featuring weaponized vehicles, came to television. On May 11th, the producers of Mythbusters will be bringing Weaponizers, a three-part series, to the little screen. Two teams will design, build, and send into remotely-controlled combat, lethally-outfitted vehicles. Sounds like my idea of a good time.

Weaponizers [via Gizmodo, and BotJunkie]

Share a ride to Maker Faire Bay Area 2009

Our Maker Faire Bay Area 2009 is only 4 weeks away on May 30th and 31st at the San Mateo County Fairgrounds! Maker Faire is the world's largest DIY festival, so you won't want to miss it. In a nutshell, it's a two-day, family-friendly event to MAKE, create, learn, invent, CRAFT, recycle, think, play, and be inspired by celebrating arts, crafts, engineering, food, music, science and technology.

Every year, we strive to green our festival more and more. Last year, about 65,000 people came out to play with us, and this year we're expecting even more. If you are planning on joining us (which we hope you are), it's not too early to plan how you'll be getting there. One great option is to share a ride. We've set up a Maker Faire page on PickupPal to make coordinating that ride share easier. Check it out, make some new friends, and we'll see you there!

Pssst, you can also still get discounted advanced purchase pricing on your Maker Faire tickets until May 20th!

Round-up of gear-making books

Automata artist Dug North has posted a round-up of books related to gear-making and is looking for suggestions for others.

After seeing the beautiful use of gears in Bill Durovchic's kinetic sculpture, I started looking for books on gears. The following books all look good and get great ratings from Amazon's vast customer base.

Additional suggestions are welcome!

Handbook of Practical Gear DesignHandbook of Practical Gear Design (Mechanical Engineering, CRC Press Hardcover)
by Darle W. Dudley

Product Description from Amazon: "For more than 30 years the book Practical Gear Design, later re-titled Handbook of Practical Gear Design, has been the leading engineering guide and reference on the subject. It is now available again in its most recent edition. The book is a detailed, practical guide and reference to gear technology. The design of all types of gears is covered, from those for small mechanisms to large industrial applications."

List of books on gear design and fabrication

More:

Contactless dynamo bike light

Instrucrables user vbnicolau made this how-to for making a dynamo-powered bike safety light from an old relay coil and a few hard drive magnets.

John Park's earbud owl

Check out this sweet little earbud owl our very own John Park made, using the Epilog Zing laser cutter he's been playing around with, and an "owl wrap" cord manager file from Thingiverse. He was probably going to post it here eventually, but I beat him to it [cue: childish taunting sounds].

Laser cut earbud owl

Electric angry cat

Liane sent me this demo of an awesome little electric cat she built from wire, a pager motor, and a coin cell battery - so simple and cool! The battery pressure switch is a very nice touch (npi!). This could be a big hit on Halloween with a little fake fur coat ;)

Volume 10, Page 119

Quick n' dirty no-sew iPhone cozy

The holster for my iPhone broke recently and I've been reduced to carrying the phone around in my pocket. I sort of like this as a change, especially not having to worry about the case getting in the way of the keyboard area or the camera lens. But the phone is getting dinged up inside the garbage scow that is my pocket.

So I could use one of Lenore's no-sew (can't sew) iPhone cozies. With little more than some iron-on adhesive tape, some lightweight fabric, and a few minutes, you can fashion yourself a sleeve that'll at least protect your phone from car keys, little Leathermen, loose change, and the other indignities of an over-crowded pocket.

Super quick no-sew iPhone cozy

Make: Talk #007 show notes & next episode (today, 12-noon PDT!)

Last week, we had Nathan Seidle on the show, from SparkFun, talking about the company, how it all got started, and about the recent Autonomous Vehicle Competition that was just held at SparkFun HQ. SparkFun will, of course, be at Maker Faire, so look for Nathan and company there.

Our Hosts Picks:
As always, we also talked at the top of the show about what's going on at Maker Media and in the world of DIY.

Mark:
Mark was on about his chickens and how they'd recently ended up on the business end of a coyote's K9s. One of the family's beloved birds, Ethel, required $200 worth of sutures n' surgery. Mark came home after a day at the vet's to a lovely chicken meal he'd loaded into the crock pot in the morning. No, NOT Ethel, or any of the other family birds. They don't eat them. The girls name them and get too attached. But they do enjoy the eggs. We all shook our silly human heads at how we can blow $200 on pampered family fowl while merrily wiping the grease from a grocery store bird from our lips. Ethel is now recovering nicely, BTW.

Goli:
Dale was in Madrid, Spain, so once again, the most-awesome Goli Mohammadi, associate managing editor of MAKE and CRAFT, joined us. She talked about how jazzed she was by the wooden turntable we'd posted about earlier in the week. She also talked about the re-posting of the "Unsafe at any amperage" piece, the debate over the infamous "anti-gravity lifter" project we pulled from MAKE a few years back which sparked (er... no pun intended) a heated debate all over again when Goli reposted it.

Gareth:
My pics were the announcement of the discovery of extra-solar planets in the "Goldilocks zone" of a red dwarf, Gliese 581, some 20 light years away, the first such find from the recently-launched Kepler telescope, and the posting I'd just done before going on the air of the Jansen Walker, an Arduino-driven, laser-cut walking mechanism, inspired by the Strandbeest, Dutch artist Theo Jansen's kinetic sculptures/mechanical beach creatures. Becky Stern chimed in via IM to inform me that I was mangling Jansen's name. It's pronounced Te-oh Yon-son. Good to know.

Make: Talk #008 w/ Erik Knutzen & Kelly Coyne, Friday, May 1, 12-noon PDT
This week on Make: Talk, Mark, Dale and I will be joined by Erik Knutzen and Kelly Coyne of Homegrown Evolution. We'll be talking to them about small-scale urban agriculture, and their book, Urban Homestead, from Process Media.

As always, we'll also be taking calls from listeners and talking about MAKE, the upcoming Maker Faire, and news from the world of DIY, so please join us

Make: Talk on BlogTalkRadio

Arduino-powered Braitenberg vehicle

For the next issue of MAKE, our second robot-themed issue, I'm doing a review of one of my favorite robot-related books, Valentino Braitenberg's Vehicles: Experiments in Synthetic Psychology. It is a seminal work in robotics, especially with behavior-based robotics, BEAM, and other forms of simple, bottom-up robot architectures. Alex at Tinkerlog decided to build a simple robotic platform to experiment with Braitenberg vehicles, but using Ardunio, so that inputs and outputs could be easily swapped around in code rather than analog rewiring. He writes:

Valentino Braitenberg developed a model of simple vehicles with sensors and actuators (motors) and interconnections between them. While the vehicles are extremely simple, the emerging behaviour is not. It is often interpreted as love, aggression, or caution.

The easiest one is a light seeking vehicle. That's like "hello world" in robotics. The sensors are affecting directly the motors. The right sensor affects the left motor and the left sensor affects the right motor. That means, if light shines on the right sensor, the left wheel turns. And if the light shines brighter on the right sensor, the left motor will turn faster than the left one and so the vehicle will turn towards the light source.

These kind of simple robots can be build with analog techniques alone, they don't need a microcontroller. Think of two sensors feeding into two amplifiers that control the motors. The big advantage a controller brings in, is the possibility to rewire the connections between inputs and outputs in software. Even more complex functions for the interconnections can be reprogrammed easily.

Arduino-powered Braitenberg vehicle

Spring cleaning sale in the Maker Shed ends today!

This is the last day of our Spring-cleaning sale in the Maker Shed. We still have a lot of fantastic deals, but hurry it's over tonight at midnight. That's midnight Pacific Time, so all you East-Coasters get a little 'extra' time to scoop up some great deals!

We are rolling back the prices on over a hundred of our existing products. Most around 50% off, but some of them discounted as much as 75% off! Once they're gone they're gone. This is a limited time spring-cleaning that ends at midnight (midnight on our San Francisco clocks).

Use code BLOWOUT at checkout for the FREE shipping on orders over $100. (Contiguous US)

Check out all the products that are on sale now!

April 29, 2009

Interview with soft circuit maven Hannah Perner-Wilson

Syuzi at the Fashioning Technology blog just did an interview with my one of my favorite soft circuit creators, Hannah Perner-Wilson. Very inspiring!

More:

Flashback: Resurrecting This Old Amp

Nothing sounds quite like a vintage amp for that old school flavor, and there are plenty of them online waiting to be employed. But when you get your hands on that oldie but goodie, you're most likely going to have to do some housecleaning and resurrecting. Enter this "vintage" MAKE article from Volume 02, back in 2005. Brothers Tom Anderson and Wendell Anderson show you how to get all Bob Villa on that amp in their how-to, "Resurrecting This Old Amp."

From the intro:

Musicians use vintage amplifiers for their uniquely satisfying tone. Old tube amps are expensive, but you can find solid-state models from the 1970s for less. Some audiophiles argue that transistor amps from this era have the best sound of all, because they don't burn out like tube amps and don't exhibit the crossover distortion found in many modern designs. We bought a few classic amplifiers on eBay, restored their vintage tone, and made them safer.

Tom and Wendell give you the know-how you need to diagnose, open, and repair that old amp and make it sound as good or better than the day it was made. Check out the project in full in our Digital Edition to get started. And if you don't already own a copy of Volume 02, you can still pick one up in the Maker Shed.

Cheap, efficient LED lighting in West Africa

Matt Berg, of BuildAfrica.org, put together a photo montage (PDF) on the increasing use of super-cheap Chinese LED lighting in Mali, in West Africa. The middle picture is of a street-corner cell phone charging station. It costs about .25 to get your phone charged.

That last picture is basically of a motorbike filling station (with the fuel inside of recycled bottles). The little 36-lamp LED light on the left is the station's nighttime lighting. The light costs around US$4.75 and can be powered for a week to a month of 4 D-cell batteries.

LED Lights and 12V Cell Phone Charging Mali [via AfriGadget]

Detailed iPhone themed interface on Google Android

Using a handful of apps available on Android Market, the folks over at hdblog.it have transformed the stock Android interface into a detailed rendition of the iPhone interface complete with slide lock, dock, SMS, and icon themes. It even has a handy interface to change the color of the LED alerts.

hdblog.it (Site is in Italian) [via thebestdigital]

Amazing military sci-fi modeling

I did a massive double take when I saw this jaw-dropping model on Dinosaurs and Robots. "Wait, that's a Leman Russ battle tank! From Warhammer 40K!," I squealed to myself. Warhammer 40,000 is the "dark gothic sci-fi" tabletop wargame that almost put me in the poorhouse a few years back. One of the coolest things about the tabletop wargaming hobby is that there are actually so many different hobbies involved (the gaming itself, the miniature painting, the scenery building, the model converting, the writing fiction and scenarios in the gameworld).

One of my favorite aspects of the hobby is seen above at its finest: diorama modeling. Go to a Games Day or other tabletop wargaming conference and you'll see miniatures and displays like this that will blow your mind. The quality of the painting, the level of depicted detail, the ingenuity of the "hacks" (e.g. the kitchen trash that's been turned into realistic-looking model components) is tremendously inspiring.

These images come from an article on IPMS Stockholm, an international plastic modeling webzine. You'll find over 500 articles on plastic modeling there.

Road to Hell: An Old-School Bridge Layer From the Future