Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?

Comment Gotta pay the bills somehow I guess (Score 1) 91

It seems like Hackaday is just throwing a bone to the places offering turnkey mini CNC machinery.

You can still get a bigger machine cheaper by DIY-ing it, but that depends on if you have more time or money really.

That, and the fact that with CNC {metal} machining,,,, it really isn't possible to get a fast & accurate machine by bolting together pieces of t-slot beams. (I don't think I've seen even one you-built-it CNC router that used ballscrews).

Comment Re:who gives a shit? (Score 1) 291

Despite your attempt at hand-waving, Bitcoin is already significant. Wishful thinking won't change that.

No, not really. Not compared to say,,,, the US dollar.

A major portion of the way that bigger countries control their citizens is by manipulating the value of currency. How long you work until you retire, what sort of work pays well, where and how you can spend your money and so on.

The people who run the governments of these countries know how critical this ability is, and they will never give it up willingly.

If bitcoin is a good concept for individuals is beside the point. It's a bad thing for governments trying to manage economies, and governments can change the rules of the game whenever they want.

Comment Re:Whoah, Delrin? (Score 3, Interesting) 28

Delrin is a thermoplastic; my first thought would not be to glue it with some other substance.

(assuming you are in the USA, which you may not be)
Harbor Freight makes a plastic welder for $65. There's better name-brand ones around for $300-$700.

Two other possibilities for cheaply welding plastic: cheap soldering irons (~15W - 30W heat, $20) and mini heat guns ($10 - $30).

If it is not a cosmetic issue, I have also seen thermoplastic parts repaired the following way... You get a small piece of aluminum screen, place it over the break and rub it in with a hot soldering iron.

Comment Re:truth is... (Score 1) 93

I had electronics in high school--"analog" electronics, I guess you could say. That was a lot of years ago and I never bothered with it since.

I got into Arduino-controlled stuff a couple years back, because I had a need to build some machines that would benefit from being digitally-controlled. I picked Arduinos for a few reasons:
1--they didn't need a separate programmer at all, just a USB cord. This makes them a lot more convenient for newbies to experiment with.
2--They were available cheap. The Italian ones cost some money but the copies on the direct-orient sites are available very cheap. And these are not just chips, but ready-to-use boards. Unos for $5, Megas for $9, Dues (ARM cpus!) for $15 and the shipping is free. They cost even less if you don't need the USB cable.
3--I had a need for such a device. Ever see where people post "I bought this Arduino (or rPi), what can I do with it?" ***

I'll never choose a PIC for hobby use, nor would I recommend them. Arduinos totally beat them on both cost and convenience.

***(By the by, the only two things that can be built with a rPi are (1) a MAME cabinet, and (2) a home file server. Any other claims are merely gratuitous falsifications)

Comment Re:truth is... (Score 4, Insightful) 93

... I have no doubt that an open source toolchain will be a great step forward in lowering that barrier ..

Yea, because open-source software is famous for having well-designed, easy-to-use comprehensive instructions. ;>)

After building a few things with atmel-chip Arduino boards in the last couple years I gave in to my curiosity and bought a couple cheaper CLPD and FPGA boards. On electronics forums there's always people moaning "oh god not another arduino user" and whining how "there's so many other boards that are faster/have more cores/ect ect/why are you still using atmel shit". I ended up choosing Altera-chip boards, for no particular reason. Lower-end Altera or Xlinix boards can be had for $10-$15 from the orient-direct sites. A USB JTAG programmer costs another $5, if one wasn't included. The cost isn't the problem here.

Part of the problem (as I see it) is the complexity of using the programming toolchains, yes. The boards seem to work, but I haven't actually gotten mine to 'do' anything yet.... I have not gone through the available Altera tutorials however.

But another part of it is that most people are hard-pressed to think up anything that would require an FPGA, so there's not a lot of incentive to learn. Myself included.
Most of the projects that most people build with Arduinos probably have the atmel processor sitting there idle most of the time. If an Uno isn't fast enough, the Mega is twice as fast as the Uno. And then the Due (with an ARM chip) is ~5x or more times faster than the Mega, depending on what your program does... And there are other ARM boards that are faster/have more cores than the Arduino Due.... so there are a lot of other easier-to-use options for a 'faster' board, if an Uno or Mega just can't handle the task.

So I think that FPGA's aren't going to advanced into the hobbyist market any time soon. At least. no more than they already are.
The concepts of FPGAs and CLPD's intrigues me, but currently it's a lot of hassle to learn just to gain processor speed that most projects I can imagine simply don't require.

Comment Re:Short-sighted refusal (Score 1) 698

If they don't rule in favor of allowing non-killing weapons they will have more people carrying killing weapons.

Yea, but,,, what effective non-killing electrical weapons are there?

The cheap stun-gun devices are not effective, and the only brand that is effective (Taser--the only one that the [US] police bother to use) regularly results in deaths*.

*('course, a lot of those deaths involve aggravating circumstances (obesity, drugs, ect),,,, but it is a rather odd concidence that a lot of people seem to..... die..... of heart-related causes.... after being shocked with Tasers)

Comment Re:One thing to keep in mind... (Score 1) 244

This is what I have seen with a lot of free/OSS also: the instructions weren't written for someone who doesn't know how to use the program; the instructions were written as reminders for someone who already knew how to use the program...

Or even more charming is when the instructions are very brief and just tell the 'new' differences with the previous version. So then the changelog becomes part of the help files...?

Lousy help files have cause me to uninstall more than a few open-source programs, and I bet I'm not the only one. If it costs money for decent documentation then I'm one of those corporate sheeple drones that's likely to pay.

Comment Re:marketting (Score 1) 92

... or a half-assed programming model for turning on and off gpios?

Why so mad?

I've seen this many times--where people insist that Arduino-related anything is somehow "not real electronics/programming". As if it were only a lot harder to use, it would somehow "build programmers with better morals and ideology, like me."
It's not the best hardware or software but it doesn't cost much to try.
And if people are doing it for fun, it doesn't need to be difficult or result in the adaptation of rigorous enterprise-level programming habits. If all they want is to blink the LEDs their way and it does that, how is that a bad thing?

There seems to be an odd perception that "the whole hobby of electronics would be better without all these Arduino people". If you feel this way, what is it they do that interferes with anything you wanted to do?

Comment But what does it mean, really? (Score 1) 215

Japan has long used forced auto obsolescence as a means to drive its economy, being prevented from significant military spending (as the USA does). Laws concerning cars in Japan make it prohibitively expensive for average people to keep any car more than a few years before replacing it, despite how good of condition it is still in.

Is it really that surprising that car owners there are being forced into using the latest/most-expensive option currently available?

Comment Re:I would think (Score 4, Insightful) 183

This is really the problem with evaporative coolers: they work best in desert/arid environments, where water is (usually) already in (relatively) short supply.

In humid climates water is plentiful--but they barely work at all in humid environments, where they mainly cause mildew growth (inside the home).

Comment Africa's problems won't be solved anytime soon (Score 1) 83

there was a book about that:
The Lords of Poverty: The Power, Prestige, and Corruption of the International Aid Business ~~~ by Graham Hancock --- Jan 10, 1994

it is the same reason there's always trouble in Israel/Gaza: there are people getting paid to "deal with the problem" (some of them quite wealthy). If the problem goes away, these people would stop getting paid.... So certain people in key positions make sure that the problem never goes away.

Sometimes, ignorance is the answer.

Comment Your men are already dead.... (Score 1) 523

The problem with foregoing handwriting for typing, is that typing itself should already be a dying skill. It is known to cause a particularly difficult-to-treat injury (RSI) and there is already voice recognition software available for PCs and even mobile phones.

The more-modern solution would be to skip intensive typing instruction in favor of using systems that mostly work on voice recognition or touch screens. It is acceptable to have a keyboard present, but for desktop computing it shouldn't be the primary means of character/text input anymore.

Comment Re:Interesting though not to be overinterpreted (Score 1) 252

1) All the participants had metabolic syndrome so the results might not be generally applicable.

...Except that the Eskimos have been eating zero-carb for 5000+ years. (search "zero carb diet" on wiki) Conversely, vegetarian diets have been a fad for thousands of years, but there has never been an established vegetarian or vegan culture for any sustained period. The only times ancient people didn't eat lots of animals was when there wasn't any animals to eat.

2) The meals were fixed portions, so we don't know how it affected appetite or how it compared to previous eating habits.

One of the odd effects of eating low-carb is that you can go much longer periods without eating, and yet you don't feel hungry. You have to try it for at least a few weeks to understand it.
Going 12 hours without eating isn't unusual, and even 18 hours is easily possible without discomfort. It kinda destroys the concept of meals as social settings, because you aren't eating every ~5 hours like everyone else is.

3) We don't know what would happen long term.

See #1 above

Eating low-carb all the time is still considered an extreme diet by medical standards, so (US) doctors won't tell you to try it. And they think you're borderline nuts if you ask about a zero-carb diet.... It is helpful to be under medical care to get your blood numbers tested because there are some conditions that it could easily aggravate instead of improve. Don't be too surprised if they get better however.

If you do try it, the easy rule to remember is that anything from plants is carbs, and is to be avoided--even fresh fruits and vegetables. Basically you can eat any meat (with fat!), milk, cheese and eggs. Lean meat is to be avoided; the traditional Inuit diet was over 50% fat.

The health books in school lied to you. If low-carbs and high-fat was bad for you, there wouldn't be any Eskimos today.

Comment Re:The rest of the country needs to face reality (Score 0) 554

... Our current culture in the US, where unsustainable transportation (driving personal automobiles) is prioritized over sustainable transit, needs to change, and the sooner the better. ...

It would have been easier to just type "Stop liking what I don't like...."

Mass-transit is itself unsustainable, though most advocates ignore the realities of it:
1) Most mass-transit systems have peak usage that is very high, but is rather low the rest of the time. To be utilized it must be operating as much hours of the day as possible and must be sized to handle the peak usage, but that also means that in many cases they run essentially empty most of the rest of the hours of the day. Running empty trains and buses in circles isn't efficient by any measure.
2) The usefulness of mass transit relies on the ability of it to transport people from where they are to where they want to go--but the more stops that are added, the slower the speed becomes, making it undesirable for that reason alone. So mass-transit engineers are forced to decide between making it inaccessible (with few stops) or making it slow (with too many stops).

The most efficient means of transporting one person is to move them from wherever they are, to wherever they want to go, as quickly and directly as possible, so they will favor using that transportation. It takes an individual vehicle to do that. A 1-person vehicle always has a 100% occupancy rate, and it isn't on the road at all when it's not actually being used. The only issue is technical matters of small vehicle design. It is easily possible right now to build a 1-person vehicle that can get 100 MPG and over 200 MPG is easily possible without any advances in technology.

Mass-transit suffers from utilization problems that are inherent in its use, and that cannot be solved.
Individual vehicles suffer from technological limitations that can be improved with engineering advances.

Slashdot Top Deals

% "Every morning, I get up and look through the 'Forbes' list of the richest people in America. If I'm not there, I go to work" -- Robert Orben