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But, but... the ATmega644P costs 9.28$USD!

And you can keep your half-sunflower seed ATtiny10, I'd rather use a DIP-8 ATtiny85!

And your ATtiny10 is actually 1.19$USD, so don't crap on my 2.44$USD ATtiny85. ;)

* This message was not approved nor endorsed by Digi-Key.

Nice, you've discovered the best way to make a link unclickable in Slashdot. I can't even highlight and select "Go To URL", because it's already a link (to your comment, which doesn't have any content).

http://www.digikey.com/

...this equipment can run $500 or more...

The scientific equipment is more expensive because laboratories are willing to pay more, and have the money. Gamers aren't willing to pay $500 for a controller.

Look here: Digikey has 18000 pressure sensors available. I picked one at random, and it can measure pressure up to 115 psi, which is about 60 meters deep in water. It only costs $12. I could make you the serial port/USB interface for like 20 bucks.

Scientists only pay that much because they are willing to pay that much.

...this equipment can run $500 or more...

The scientific equipment is more expensive because laboratories are willing to pay more, and have the money. Gamers aren't willing to pay $500 for a controller.

Look here: Digikey has 18000 pressure sensors available. I picked one at random, and it can measure pressure up to 115 psi, which is about 60 meters deep in water. It only costs $12. I could make you the serial port/USB interface for like 20 bucks.

Scientists only pay that much because they are willing to pay that much.

anyone here know where I could get one (or at least, a 30x30x7 (mm))?

Don't know about x7, but here is 30mm L x 30mm H x 6mm W fan. This is a 5V part without tachometer. There is also 259-1327-ND which produces higher airflow (and is noisier, I'd guess.)

I have to disagree that DIY is dying; if anything, people have more ideas because of watching other projects on the Internet. For instance, over the past couple of years I have been working on a DIY electronic drum set. I really doubt that I could have done this even 5 years ago; things like the Arduino (easily programmable microcontroller platform) reduce the learning curve and give you a place to start, electronics tutorials help with theory, and other similar projects provide inspiration. While the informational aspects were around previously, it was much harder to find (you need to go to a library and look through a bunch of books), and short of finding a robotics club nearby, finding inspiration was almost impossible.

As for electronic components being hard to find - you just haven't been looking! While I agree that finding a selection of resistors, diodes, and ICs at your local Radio Shack is not as likely as 20 years ago, places like Digikey allow me to browse much more than Radio Shack ever did, and will ship it to my home overnight, for much less than even the gas to drive to various small shops trying to find a given component. (Not to mention that the prices online are much cheaper...)

While I'm sure that most people don't bother with DIY, there is still a thriving community of DIYers both online and off.

Cheers

I would suggest a project that is simple enough to understand, yet has a demonstrable practical circuit that they may choose to use after the class is over. One idea that quickly comes to mind is a simple (2-3-transistor or 2-3-per-channel (stereo)) audio amplifier, suitable to powering a small speaker, with a jack to connect to MP3 player.

It demonstrates one of two basic modes of operation for transistors, one of the most important semiconductor devices (diodes and ICs are others) that is a building block for analog (and digital) electronics. The other mode is when the transistor acts as a switch BTW.

You can cover electron and conventional current flow, waves (sound), and feedback as physics topics.

For the parts, using a mail-order suppler like Digi-Key, Mouser, or Jameco (US / Canada) you should be able to buy the parts for about $5 including the connector and a small speaker.

See Simple 3 Transistor Audio Amp (50 milliwatt) from Bill Bowden's hobby circuits web site.

I hit "submit" just as I realized that 556s are a better bet: two 555s on one chip, and Digikey has them for 55 cents per unit, or 50 pieces for $22.

There are so many things you can do with an 555 IC that it's not even funny. Digikey has them for 44 cents per unit here. With a handful of descrete components you can create everything from flip flops (with 2 555 ICs) to oscillators to time delay circuits. (some example circuits.)
I suspect with a handful of 555 ICs, descrete circuits, ICs and switches (or just touch wires together), you can easily create a whole host of illustrative experiments that show the idea behind modern gate circuits. And I'm sure you can easily do it all for a few dollars worth of components, though unfortunately breadboards can be quite expensive. (Around $8 for a small breadboard through Digikey, though you may be able to find cheaper.)

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=122-1573-ND

http://dkc1.digikey.com/us/mkt/pico.html

Another one. :) And this one is available now.

But not very many lumens! I wonder how the quality is.

Sad thing here, 20yrs ago I could pick up just about anything I needed for my electronics needs.

But now we have Digi-Key. Parts ordering is better than ever. Did you ever order from Allied Radio? It took weeks, and about 5-10% of the parts would be out of stock. Hamilton/Avnet wouldn't even take orders from individuals. Don't complain.

There's so much more information available on line. Online PCB design and fab works very well and isn't that expensive. Free CAD tools are available. Even SPICE simulation is available for free, and it works quite well. The big headache with do-it-yourself electronics today is that surface mount assembly is beyond the ability of most hobbyists, and the newer parts are surface mount only.

The real problem is that it's tough for a kid to build anything cool out of parts. Forty years ago, it was cool to build an intercom, or a touch lamp. Today, not. Consumer electronics is way ahead of DIY electronics.

As usual, Digikey has them as well -- and a vastly superior web site. You can search on USB cables and select connector to raw cable, or I'm guessing you're looking for part number Q363-ND. (If you're actually looking for PC-mount sockets or something, they have those too...)

I'll give the LED as light sensor some thought, but I imagine you'd just wire it as a photodiode (it should act like any other photodiode, though less efficiently) with an op amp, possibly log scale it to get good response across ambient light conditions, and AC couple it. If you were willing to use a phototransistor you'd get a simpler circuit, I think. Blinking stuff is then done with either a 555 (or similar) or a microcontroller.

When I was 13 I would have loved to get one of these.

I thought about buying it for my cousin, but she is still way too young.

The Atmel AVR Butterfly is a $20 microcontroller on a board intended to be an introduction to AVR microcontrollers or microcontrollers in general. Low cost of entry, plenty of real world I/O (temp sensor, LCD, speaker, light sensor, ADC) and easy to program (free tool-chain, including gcc C compiler). Available from Digi-Key or Mouser online.

Illustrated Guide to Home Chemistry Experiments from O'Reilly and Make-zine. Check out the author's associate website, HomeChemLab including their small but friendly and supportive forum.

Finally, for free, teach the lessons that freedom comes with the price of responsibility, and that knowledge and understanding are powerful (physics jokes aside) tools. Also honesty and integrity, include admitting to making mistakes and being unsure are valuable currency for building a reputation that can lead to being trusted (and respected). And that it is okay to be curiosity (though sometimes some tact is also needed). -- My parent's tolerance and patience were important factors in developing my good "geekiness" qualities, so I encourage an environment that is supportive not punitive about failure (mistakes).

"Anyone who has never made a mistake has never tried anything new." - Albert Einstein

As much as I like ThinkGeek, their selection is limited to gadgets. I found that assembling and -- to my parents dismay -- disassembling things are what really grabbed my interest.

I would take a look at the various kits from American Science & Surplus. There are a number of other sites (e.g., Carl's Electronics) which have even more kits, but I haven't ordered from them so I can't say whether they're worthwhile or not. (These days, most of my toys come from DigiKey, and not in kit form.)

An even cheaper version will be available from Digikey in Jan. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=296-23836-ND

hi, it's phill from MAKE - we cover and celebrate what *makers* are doing, over 50,000 sales of arduinos means a lot of people are doing projects and sharing them.

that said, we do feature articles on basic stamp and we had a huge article on the parallax propeller chip, picaxe, you name it. it's more about what folks are making more than a chip.

if you don't like arduino because it's simple and there's "nothing to it" that's likely the reason it's so popular and it's good to see so many people from all walks of life and skill sets getting in to electronics.

Actually, for $99 (or less, depending on which micro you want to use) you can get a Silicon Labs kit. And that kit comes with a JTAG dongle for program download and in-circuit debug.

One might argue whether the ATMega is better or worse than the SiLabs 8051 variants.

But please tell me why the Arduino developer did NOT bring the debugWire out to a header. The chip has fine in-circuit debug capability but if you can't attach your debug adapter to it, it's of no use. Well, I suppose a Maker could hack the board and glue a header to it.

Then again, the Atmel JTAGICE costs another $299 while the SiLabs JTAG interface is included with the kit, or you can buy it for $35.

So, really, I'm glad a lot of folks are getting into microcontrollers, but Arduino isn't the only game in town, and I think that the SiLabs kits, with the debug interface, make it easier to actually learn.

Digikey sells them. They're pretty cheap:

http://dkc3.digikey.com/PDF/T083/P2246.pdf

I know you're trying to be cleverly ironic here, but you can buy ultracaps today. The higher power capability, swifter charging, longer life, wider thermal operation range, more flexible packaging, and lower maintenance are already there and have been for years along with the superior environmental characteristics. However, "lighter" isn't true yet, since the energy density of an ultracap is an order of magnitude lower than that for a dry cell. That's why a breakthrough such as in this article is such a big deal.

If grapheme could reliably be utilized to create the sort of energy density posited here, any application requiring large amount of batteries (such as electric cars) would benefit greatly. Unfortunately, since capacitors are more prone than dry cells to losing energy over time due to internal resistance, this won't eliminate the need for dry cells entirely.

The http://www.arrickrobotics.com/ A-Robot is an excellent beginner's bot. It is rugged (can survive 10 years in a drawer and still function) gets you up and running quickly, and is expandable. A 12V, 2A power output, 3 spare RC servos, and a 40 pin I/O header (that takes an IDE cable) will let you play with electronics. Roger Arrick wrote "Robots for Dummies" that shows one project at a time how to breadboard a peripheral and code for it. Buy everything that's in the T1 kit, but don't get the BS2 - get the BS2e. $400.

The closest second for a beginner's bot is the BOE bot fromParallax. It's based on the same processor. The problem with the BOE bot is that when it breaks, it's dead. It's not really expandable like the A-Robot is. you would have to see the A-Robot (1 ft x 1ft) next to the BOE Bot (6in x 6in) to understand.

For less beginning, and more electronics, check out http://www.ere.co.th./ You are trading BASIC for assembly, and no longer have a beginner's book to guide you. You do have http://www.avrfreaks.net./ The really cool thing is all the peripherals on 16 pin headers, so you don't have to spend 3 days to get a stepper motor to spin. You will be able to bread-board parts too, with 16-pin headers on the boards.

A close second in this field would be the boards that accept Atmel STK-style headers. That's what I use when I'm not building a custom board. I'm too entrenched in 10 pin headers to go to 16 pin headers, though I made some 10-to-16-pin-adapter-boards.

Finally, you could get an AVR board like I use for my projects from http://www.geocities.com/mengjinsu. Meng's boards are great if you know how to stuff PCBs and solder them. I order them by the dozen. Get the ABR chips from http://www.digikey.com/ and the rest of your stuff from there or http://www.mouser.com./ Also, take a look at http://www.sparkfun.com/

Andy Out!

I've ordered a number of "Velleman" kits http://www.vellemanusa.com/ for various projects. They're quite similar to heathkits and others mentioned. The problem with kits like those is that they don't really teach you about electronics so much as they're just good soldering practice. A bit more professional and adult in execution than the wire+spring kits sold by rat-shack but just as empty in the theory it teaches.

If you're really interested in leaning about electronics the first thing you need to do is pick a project, pick something that someone else has already done and posted the schematics and other information about. Then head over to to this website Its the home page for a highschool electronics club but IMO it's some of the best info on the web on the basic theory about how electronics work as well as how to read diagrams, understand components and solder them together, everything you need to get started.

now you've got a project and some basic knowledge head over to a site like SparkFun loads of useful parts and kits to get you started on nearly any project. I order 99% of my parts from Digikey if they don't have it there you'd be hard pressed to find it elsewhere, it's not very beginner friendly though... Mouser Electronics is much more suited for beginners but their pricing is also a little higher and their selection not as good.

I didn't get into electronics until I was in college and I didn't study electronics in college at all. I basically just picked a project and then just did as much research and self teaching as I needed to get it done, then picked a harder project then a harder project until I am where I am today. I've actually had a couple of my custom electronics projects published in magazines and I only started learning this stuff about 6 or so years ago, not even knowing how to solder or what a resistor is. The resources above were invaluable though

Having good equipment is important too. Go to the rat-shack and buy their 15Watt iron, a spring stand with a sponge, some .22mm silver bearing solder, a de-soldering iron, a nice set of helping hands, a nice set of miniature pliers, a nice set of cutters/strippers/crimps, and some 22ga stranded hookup wire. You'll spend about $50 and have pretty much everything you need to tackle any DIY electronics project. You should also consider spending a bit of cash on a good multimeter, which isn't necessary but HIGHLY recommended for troubleshooting or reverse engineering.

Good Luck and have fun :)

I agree completely with parent. A few additional thoughts:

Although I second the suggestion to get a book, I'd also suggest the following website: All About Circuits. It's basically a short textbook, online. It has some nice intuitive explanations.

As for books... My top choice would be Hambley's Electronics. It's a complete, correct, and accessible introduction to the subject. It's a great book. The Art of Electronics is also very good.

I also completely agree with the suggestion to get a solderless breadboard. That's the way to have fun with this stuff. You can always build a soldered, "final" circuit later (which is fun in its own way), but I have to admit that that's more of an exercise in fabrication than it is a good way to explore electronics.

For me, the crucial central component of a lab bench is an oscilloscope, and that will be the hardest thing to get inexpensively. Digital scopes are wonderful! I haven't investigated this thoroughly, but you might go with a USB "oscilloscope" that uses a laptop/PC for its interface, as these tend to be cheaper.

Finally, there's the question of "what circuits should I build?" Personally, I always found op-amp circuits to be a lot of fun, and I think audio circuits are often a good choice as they are interesting and practical, give a good way to experiment with filters and many other analog signal processing circuits, and yet are low-enough frequency that the parasitics are negligible (i.e., the schematic is an accurate representation of what you've built).

As a side note, although the 741 is an armored tank and as cheap as dirt, my personal favorite op-amp is the LM6132. They're more expensive, but man are they beautiful! :-) (Seriously though, just buy 741s unless you're running off batteries or really need something faster.)

Oh! And while we're on the subject of buying things: The place to look is Digikey. You need to lump together orders to save on shipping, but it is almost always the best choice for buying chips.

When I wanted to get into robotics, I just dove right in. Bought some books on electronics and started buying tools and components.

For components, there are a lot of options. Check out E-bay and any of the many electronics surplus suppliers on the internet. For specific components, Mouser and Digi-Key tend to be excellent.

I'd recommend buying some of the mix packs of things like resistors, capacitors, ICs, etc. You can usually get variety packs of them pretty cheap.

As for books, Horowitz' The Art of Electronics is generally considered the bible, and for good reason. Any other basic book on electronics (Idiot's Guide type stuff is good) help as a second point of view, particularly if one description doesn't make sense to you, perhaps the way another author phrases it will.

As for projects, the if you don't have any ideas of your own, there are plenty of internet sites with ideas and schematics. There are several volumes of The Encyclopedia of Electronic Circuits, as well, which tend to have a variety of cool little projects. Buy a few breadboards or wirewrap boards and start building... I find breadboards to be pretty good for doing small projects.

If you want to learn, use the manufacturer's application notes and start from there. Usually they have sample circuits with equations. Buy your parts from Digikey.

Well, is it helpful to know that the amount of energy needed to run this in sleep mode or thirty years is sufficient to raise a one pound weight by about 2 1/4 inches, or roughly 5.6cm?

It may make you happy that the math doesn't seem to right in any case , based on a CR2032 battery, which is rated at 3V, 220mah. 263 years sounds more like what you'd get running off a large electrolytic capacitor, but that is an even more annoying notion.

Having recently started playing with electronics more myself, I can tell you that it is a very fun hobby. My recommendation is to find a project which you want to do, and work towards that, rather than just studying theory and doing tutorials. While it will cost you more (at least, I tend to make mistakes when doing things for myself, rather than just following instructions), the sense of accomplishment can be very worthwhile. My largest project to date is an electronic drum brain which I designed, prototyped, and soldered myself. In addition to learning the electronics side of it, I also taught myself Python (using that as the slave software to actually play the samples). See http://drummaster.thecave.homeunix.org/ if you are interested.

As for where to get equipment from, I would highly recommend Digikey. They have a good selection, decent prices, and low shipping costs ($8 to Canada for everything I have bought - that, and it is generally arrives the next day!)

Finally, as a software guy myself, I would also recommend the Arduino to start with (this is what was used in the article). It is a very nice bridge between computers and microcontrollers, as it uses a simple C-based language with a good IDE to simplify uploading and compiling. It is powerful enough to do some nice projects with, and yet is simple enough that you can get some simple projects going after just a few minutes / hours. It costs about $35 (less for various non-official versions), and is available from a number of places.

Another great help is to get a circuit simulator, and try playing with simple circuits in software before you buy components. I found a nice Applet based one at http://www.falstad.com/circuit/directions.html

Hope this helps, and best of luck with your soon-to-be new hobby!

Cheers

At least that's what Caltech's director of admissions told me when I asked why there weren't as many kids who followed in C.L. Stong's footprints in the frosh class.

So get them the $150 Altera FPGA starter kit
Still software, but at least they'll learn about hardware.

Make is okay, but it's much more oriented towards 'artistic' than 'rocket science'.

Check out the Society for Amateur Scientists

I always found Master Handbook of 1001 Practical Electronic Circuits to come in handy when I build projects. There are designs for all kinds of basic electronic circuits that you can chain together to come up with some usefull designs. The nice part about a book like this is that it gives you all the common chip numbers that many other manuals gloss over.

That and a Digikey catalog are all you need.

Go to the library and get a bunch of books on electronics. Then go to Radio Shack and buy a bread board. A bread board is a board where you test circuit designs out. You don't need to do any soldering on it. A strip board is for a more permanent circuit that you don't plan on changing. One thing I recommend if you're going to be soldering on a strip board is FLUX. It makes soldering a hell of a lot easier. Components to buy from Radio Shack: A soldering iron, solder, flux, a breadboard or two. Also get a few 9 volt plugs to plug into the bread board or strip board and 9 volt batteries. Radio Shack also has a few cases you can put your circuit in, although there isn't much selection. You're going to need wire of course.

Now the question is - what do you want to build? The library books will have some circuits. So will bookstores. You can find them on the net as well. This girl from MIT has a lot of cool circuits and kits. Once you decide what to put together you will also probably be getting some other components like capacitors, resistors and chips like 555 timers. You can find 555 timers and chips like that from Radio Shack, but for more obscure chips you might want to look to see if there are electronics components stores in your area that sell this stuff. If not, go to Mouser.com or Digikey where you can usually buy whatever you need, unless it is a specialized chip that they don't have. This should get you a start on putting boards together.

I agree with almost everything you said. First, let me toss out a few part numbers. I know it can be annoying to try to figure out which silicon component to buy when they all look the same but are obviously slightly different.

Digikey is your friend. If they don't stock it, find a replacement they do stock. Buy a hundred each 2N3904 and 2N3906 for your bipolar transistors. At a couple cents each, you don't need to worry about letting the magic smoke out occasionally. 2N2222 makes a great slightly higher current NPN switch. At $0.36 each, the venerable 741 makes an excellent op amp to experiment with; by the time you can figure out what to do with a better op amp, you'll know what to look for. Buy a big assortment pack of 1/4W carbon film resistors; they're cheap, and not having the right value is annoying. For caps, you'll want a big stack of cheap 0.1uF ceramics for local power supply decoupling, some modest size (10-33uF) electrolytics, and some larger electrolytics (100-330uF) (I suggest the Panasonic FM series as inexpensive high quality caps, but there are lots of choices). Grab a few poly film caps in the 1nF - 0.1uF range; that should cover most other uses of caps for experimenting. You'll want some 1N4148 signal diodes, along with some 1N4004 rectifier diodes. Might as well add a few 1N5818 schottky diodes for power supply work. And, of course, the 555 timer you suggested. I don't happen to have part numbers to recommend for CMOS discretes. Add some random indicator LEDs and buttons, and a couple variable resistors. 7805 / 7812 make good fixed voltage regulators, and the LM317 should handle your adjustable needs. Anyway, if you can't build it with those parts, it's probably not a good early project. Eventually you'll get around to the 7400 / 4000 series logic chips.

If you're doing real analog work, get a real power supply. Failing that (they're expensive; no, the one from that old computer is not an acceptable substitute) get a cheap wall wart that just has a transformer and a bridge rectifier and a cap in it, and add a regulator. If you're doing it that way, get several -- you'll want multiple voltages around.

I have to disagree about making your own PCBs. It's educational, but it's also a pain. When you need an actual PCB, buy it from ExpressPCB. If you only need to work with surface mount parts, Digikey sells a number of handy prototyping boards that will convert surface mount things into through-hole things, and optionally have space for a couple surface mount passives to go next to them.

Don't forget Agway (farm supplies), Digikey (far better electronics and gadgets than Radio shack), MCM Electronics (Ditto), RC Warehouse (Radio Control stuff), etc...

All sorts of places to get off-the-shelf technology and/or parts to build your own. Just about any tool or technology can be used for good or evil. I'd be concerned if someone was asking questions about weapons delivery or other issues where the intent was fairly clear, but even then, do you respond by clamming up, thus indirectly telling them of your suspicions, (and greatly increasing the chances that they will work to avoid attention), or do you maybe notify the authorities so they can use the situation to their advantage?

So what's the DigiKey part number? So I can buy a few (or a thousand, or whatever). I just entered "SPARC" in their database, and got "No records match your search criteria."

If I can't buy it from major distributors, it's not "commodity" silicon.

As an EE who started off with one of those 50-in-one kits when I was 8, I have a few recommendations. I had a 200-in-one, but the more impressive projects on it required so many wires it was nigh-impossible to get things to stay working. Put one in and two fall out.

You can start with one of those kits, but once you get to the point where you'll really learn what you're doing, go look for books and kits separately. Look for books by Forrest Mims III and Don Lancaster (TTL Cookbook and CMOS Cookbook are classics). Check their sites out as well.

As for parts sources, for online shopping, I'd recommend Digi-Key. Jameco is a little pricey, but they have some really interesting parts, including a lot of older stuff. All Electronics is a place I used to buy from a lot; they have a lot of manufacturer surplus parts, so it's kind of like shopping in a flea market or surplus auction. Another surplus shop is MPJA. Newark and Mouser are good places to look when you want some specific part that Digi-Key doesn't have.

For starters, you'll want to buy a modular breadboard, and one of the pre-cut wire kits for them. Or, if you want to blow some more dough, you might want to get one of the Analog Design Lab or Digital Design Lab things that has a bunch of things like power supplies, LEDs, and switches integrated into it already. Also look for parts assortments, like resistor and capacitor assortments (e.g. Digi-Key items RS125-ND and PHD1-KIT-ND). If you're going to be doing digital work, you'll probably want to get lots (20 or so) of 10K resistors (for pullups) and 0.1 uF capacitors (for decoupling).

Radio Shack is where you go as a last resort. Their selection is lousy and prices are worse.

At this point it's the easiest thing to do (do nothing.) But I can foresee that MS will come up with .NET 4.0 or something that requires Vista... in any case, there are always possibilities, but XP is the second MS OS that really works (after Win2K, which generally worked, after huge number of service packs,) and there were complains about EOL of Win2K still.

The difference here is huge, though. MS forked the OS in a big way. XP was a totally painless upgrade from Win2k; you lost nothing, you changed none of the GUIs, and you got to keep your classic (or corporate) theme etc. Most people wouldn't even realize that they got upgraded over the weekend. But who can claim the same with Vista? It's so much different (I played with one of RCs and drove it into the ground in 30 minutes, easily) that *I* can't say I can use it, despite my considerable experience with anything at or above SN74HC00 level. I was seriously confused about where the Control Panel is, how to do this, how to do that... and regular folks would likely need a lifetime of retraining to get barely OK with it. And all that pain for what reason?

I'll say it again: this is the time to break free from the MS O/S monopoly.

Yes, time - but where to go? Autodesk invested billions into AutoCAD and other products; their Inventor suite is married to the most inner guts of Windows, using DirectX and OLE and COM/COM+ and every other Windows "technology" that there is. Do you think, wearing Autodesk's hat, it is practical and likely to just dump the 10M LOC codebase that they built up and switch to something else? They can ship their own Linux with each Inventor package, for all I care, and a computer to run that too, so expensive the software is ($5K for the starter version.) But they *don't have* Linux version, and with all these Windows hooks into vital body parts, how long will it take to rewrite?

Nevertheless your question is very valid because MS just demonstrated, very publicly, that it will do whatever it wants, customers be damned. You see, until now Windows was seen as an "always there" platform that everyone has and everyone uses and everyone can afford. This is changing fast, and MS made itself a huge disservice by making Vista such a beast and at the same time by threatening to pull XP from the market within a year. For people like CAD makers a year is a terribly short time; they write *today* what they will sell in a year. I don't know how they are going to take this, but from what people report AutoCAD 2007 does not work under Vista, and that's the most lightweight package they have. If I were on Autodesk's board I would seriously ask where we plan to be in 10 years, when MS, for example, decides to only sell home entertainment consoles that explode if you try to change a fuse.

So again, the industry is only now seeing how the Windows monoculture can fold within only few years. MS came up with a product that is not suitable to businesses, and at the same time it pulls sales and support of the previous, well working software. I can see serious harm to US and other businesses. If I were the Congress I would forbid MS to drop sales and support of XP - and that could be the best outcome for MS as well. Otherwise businesses may be forced into Linux's embrace, kicking and screaming probably, but with no other choice nevertheless; insanity of "renting the OS" that is programmed to die on you as soon as it suspects something (or when MS wants more money) is unacceptable from every business POV. Businesses need assurance that the s/w that they build the business upon won't explode on its own, and Vista guarantees just the opposite. Maybe it's time to borrow Hugo Chavez and nationalize MS? Seriously, it is not a private company any more, it is a national and international resource. What if MS decides to close the shop, for example? That would be unacceptable, but they can do it.

With the smallest Spartan3 starting at 1.4 million.

• Teach Yourself Electricity and Electronics (4th ed.) by Stan Gibilisco
• Guide to Understanding Electricity and Electronics by G. Randy Slone
• Getting Started in Electronics by Forrest M. Mims III
• The Art of Electronics by Horowitz and Hill - IMHO an excellent reference, not as useful for the newbie
• Basic Electronics by Bernard Grob
• Understanding Basic Electronics by Larry D. Wolfgang
• Practical Electronics for Inventors (2nd ed.) by Paul Scherz

If you can't find it in a DIL (or DIP) then digkeyhttp://www.digikey.com/scripts/DkSearch/dksu s.dll?Criteria?Ref=33490&Site=US&Cat=34079261 sells adapters. Many manufactures will also send you a few samples of chips for development work, they generally send you ~5 of any sub $15 chip for free (including shipping). Maximhttp://www.maxim-ic.com/ is one of the best for sending out free samples quickly, but analog deviceshttp://www.analog.com/, and just about any of the others send out freebees as well.

While Z80s are cool, some people prefer microcomputers with RAM, ROM and I/O integrated on the IC. For example:

Microchip or
Atmel

or a small board level device like:

The Basic Stamp

A very cool supplier of microcontrollers and accessories is:

Sparkfun

And the usual suppliers:

Digikey
Newark
Arrow
Mouser

Don't get me wrong, I love the AVR microcontrollers - but we're talking a few K of RAM, 8 to 128K of Flash for the program, a smattering of EEPROM and a top speed of 16MHz. I would be impressed if you could run the Linux kernel on that.

You can get the starter kit from Digi-Key here. I only knew about this because I bought the AVR starter kit (not AVR32) which was dramatically cheaper - $100 rather than $550. Not sure if this even comes with an AVR32 chip, probably not, but they have that too (133MHz for $37.63.) Not sure how hard these are to program, but the normal AVR has support for serial in-system programming and if you know your way around an AVR you might be able to use an AVR to make an ISP chip for an AVR32. :)

You can get the starter kit from Digi-Key here. I only knew about this because I bought the AVR starter kit (not AVR32) which was dramatically cheaper - $100 rather than $550. Not sure if this even comes with an AVR32 chip, probably not, but they have that too (133MHz for $37.63.) Not sure how hard these are to program, but the normal AVR has support for serial in-system programming and if you know your way around an AVR you might be able to use an AVR to make an ISP chip for an AVR32. :)

There are a few more:

1. Books, all of them
2. Pr0n
3. Music
4. Digi-Key

But outside of that I guess you are right. I don't cook, so I can't say much about your recipe theory. I would only add news to the list, but that's hardly necessary, and all that matters will eventually propagate through traditional means anyway.

A good picture of a two-axis accelerometer can be seen here: http://users.wpi.edu/~cfurlong/me-593Mech.html (second picture down). Sensing is usually performed by capacitive combs, structures which act as capacitors, with their capacitance varying with displacement.

MEMS accelerometers have dropped in price in recent years because there's a big market: the automotive sector. A typical new car needs two accelerometers, one for the traction control system measuring roughly plus-or-minus 2 to 4g, and one for airbag deployment measuring more like 50g.

Two big manufacturers are Analog Devices and ST Microelectronics, though others exist.

The high demand of the automotive sector has driven prices right down; sensors which would have cost hundreds of dollars in the past can now be purchased in bulk for less than $4. In fact, you could order one right now; component retailers will sell you one for less than $15.

Even if they do have what I need, it's usually hideously overpriced. I've given up on Radio Shack (or The Source or whatever it's called now) for my parts. As nice as it is to be able to get things from a brick-and-mortar (since I'm very impatient), I've found that using http://www.digikey.com/ is just better all-around.

If anyone talks about the "long tail", ask them if they know how to integrate the area under the curve. The simplest number for evaluation purposes is the value for which half the area under the curve is before that point, and half is after. What's that number for movies? For books? For audio CDs? For iPod downloads?

Netflix says that 30% of rentals are from the top 50 films, so the halfway point is probably below 100.

This is a killer issue for companies that have huge hardware inventories. Consider Digi-Key. They have the broadest inventory of electronic parts in the industry, with over 70,000 parts. Which is a big win for them, because you can usually use them as your only supplier. So there's an Internet-based company that really does profit from the "long tail".

Digi-Key doesn't get much attention as an Internet company, but they're one of the most successful ones. They had online ordering early, and it works really well. Not just the web front end, which looks boring but has what users need, like the ability to search by component parameters. They have a near-complete collection of online data sheets. When a part you've ordered previously is about to be discontinued, you get an e-mail, so you can order a final supply before it goes away. And they have an incredibly effective order fulfillment operation. Orders entered before 7 PM (yes, PM) Central time ship the same day by FedEx. They actually do that, consistently. When you order from DigiKey, you get a confirmation e-mail when the order goes in, and another when it ships, with the FedEx tracking info. The shipping confirmation often comes in within fifteen minutes of placing the order. Now that's operating on Internet time. And that's for orders which might contain twenty different electronics parts in small quantities.

That's a real "long tail" company.

Yaright. Let's work that one out, shall we?

Design for a 100 W (max) light bulb and 120 V line input. First off, you'll need to put the diodes in series so their voltage drops knock off 12 V (10%). Then you'll have to put an identical string of diodes, reversed, in parallel with the first stack, because you want current to flow both ways. If you don't, you'll knock the brightness down by over 50%, since it will conduct only half the time.

An incandescent bulb is pretty much a resistor (more like a thermistor, but let's say it hit steady state already). Thus the equation P = VI holds, so I = P/V = 100/120 W/V = 5/6 A, thus we need diodes rated for at least 1.0 A. As a first approximation, diode forward voltage drops in this current range are in the ballpark of 1 V. So 1 V * 1 A = 1 W for the DC case. To figure AC power, you have to integrate over a cycle, but to simplify it, let's say the AC waveform is a square wave, so each diode conducts full power half the time, thus dissipating 1/2 W.

Now that we have our specs, we'll head over to Diodes Inc. and get the data sheet for the 1N4003. It has Vf = 1.0 V, Io = 1.0 A, and Vr = 200 V. Worst case, assume that the ambient temperature in the area is 40 deg. C. Thermal resistance, junction to ambient, is 100 Kelvins/W. So our 1/2 W, with a 40 deg. C ambient, gives us a 90 deg. C junction temperature, which is below the 150 deg. C maximum temperature, so it won't burn up, but it will get quite hot. Touch it and you could burn yourself, so you'll need to enclose it, and you'll need air vent slots or the diode's ambient temperature will likely rise well over 40 deg. C.

So far, so good. But since each diode only drops 1 V, we'll need a chain of 12 diodes each way to drop the voltage 10%. Each way. 24 1N4003 diodes can be had from Digi-Key for a total of $3.26.

You could try it instead with a pair of 11V Zener diodes connected back-to-back (11V reverse voltage on one diode + 1V forward voltage on the other = 12 V total drop). Unfortunately, the best I can find is the 1N5348, but it's only rated to 5 W, so you'll need a heat sink. You're dissipating almost 7 W per diode, so you'll need a thermal resistance less than (50 K / 7 W = ) 7 Kelvins/W. Looking at Figure 1 (on page 2) on the data sheet, we see that we'll need to attach the heat sink (a rather big one, since a small one will add more thermal resistance) right where the lead enters the package. Maybe we'll have to put a fan on it? At this point, I'd say this was unworkable. And don't say you can put more diodes in parallel to spread out the power; because of production tolerances in Vr and Vf, it is very unlikely that the current will be shared evenly; a 90%/10% current split wouldn't surprise me.

Conclusion: It would be far easier, and cheaper, to buy a 90 W light bulb.

And, while it may seem obvious, I have to say for safety's sake: Don't try this with fluorescents or other non-incandescent bulbs.

Actually, they make very efficient DC to DC converters that can take a variable input voltage and produce a steady output voltage. For example, this baby takes 1.8V to 5.5V input (I picked that one out at random, there are TONS of these things). So you could use 65% of the stored energy on the capacitor with one of these things, and there are probably better ones out there.

The first thing to realise there are plenty of technology related hobbyists around the world, although most are not high profile and some may be different very different demographics than yourself.

Some (hobby) groups to consider looking towards for ideas and help include: woodworkers, metalworkers (hobbyists using micromills and mini-lathes from TaigTools and Sherline, etc.), model railroads, model aircrafts (static and RC), robotics, amateur radio (ham), 2600, LUGs, and Artist Run Centres/Communities

Random list of some I use or know of:
  Make magazine http://www.makezine.com/
  Instructables http://www.instructables.com/
  ARRL http://www.arrl.org/
  http://www.sparkfun.com/ (check out their tutorials)
  http://www.fpga4fun.com/ / http://www.knjn.com/
  QRP-L http://mailman.qth.net/mailman/listinfo/qrp-l/>
  GQRP http://www.gqrp.com/
  http://www.pololu.com/ (cheap stencils laser cut, e.g. 3x4 for $32)
  http://www.diyaudio.com/
  http://www.digikey.com/ (if you're still buying electronics from Radio Shack, get these 3 catalogs now!)
  http://www.mouser.com/
  http://www.jameco.com/
  the ton of various surplus/NOS dealers online
  http://www.frontpanelexpress.com/
  http://www.seattlerobotics.org/
  http://www.chibots.org/index.php
  DorkBot
  http://eyebeam.org/production/production.php?page= tools
  MIT CBA FAB http://fab.cba.mit.edu/
  http://www.leevalley.com/
  http://www.smallparts.com/
  http://www.danssmallpartsandkits.net/
  http://www.wmberg.com/
  http://www.acklandsgrainger.com/
  http://www.grainger.com/
  http://www.onlinemetals.com/
  http://www.amqrp.com/
  http://www.princessauto.com/
  http://www.sherline.com/
  http://www.taigtools.com/