Re:"Impossible to drive" says the article
on
BYO Battlebot
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· Score: 2
A PCM radio is just as vulerable to interference as a FM radio -- in fact, it sends it's signal the exact same way that a FM radio does. The signal itself is different, however -- it has servo signals, checksums and failsafe information.
If the signal is lost for a fraction of a second, servos stay in the location of their last known `good' signal. If the signal is lost for longer, they go to the `failsafe' setting, which probably turns off all the motors if the bot is configured properly.
With FM, interference usually just causes your servos to stop moving and stay where they were -- but sometimes the right interference can cause `glitches' -- which could be dangerous. Normally they don't occur under normal conditions, but from what you said, a BattleBots tournament isn't a normal condition.
PCM radios have higher latency than FM radios -- your imputs translate to servo movement more slowly -- but it's a pretty small difference and most people don't even notice.
That all being said, having a 300 lb robot with a chainsaw in front, having a PCM radio (with it's failsafe settings correctly set) is probably a good precaution, especially if the interference is as bad as you say it is.
So, what frequency band was your radio equipment on?:) What did most people use? (do you know?)
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Re:"Impossible to drive" says the article
on
BYO Battlebot
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· Score: 4
why the hell don't the operators use pistol-grip style controllers?
Many battlebots drive like tanks. With no steering servo, these pistol-grip controllers won't work well, unless you do some sort of mixing (where the steering control adjusts the speed of the two wheels/tracks.) Could be done, but adds complexity, making things less reliable.
Also, you'll be very hard pressed to find a pistol grip controller with more than 3 channels. Of course, if you have a seperate driver and gunner, giving the driver a pistol grip controller and the gunner a standard two stick airplane controller (on two different channels, of course) would probably work great.
Also, the two stick controllers aren't bad for R/C cars at all. I've got both, and while I do prefer the pistol grip, it's not that big of a deal. But then again, maybe I'm biased because I mostly fly R/C planes rather than drive R/C cars.
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Re:"Impossible to drive" says the article
on
BYO Battlebot
·
· Score: 3
Three channels typically isn't enough for a serious battlebot.
For a car, two channels is the norm and you can get a third channel for more money -- but that's it. For more channels, you'll have to get plane equipment or spend a *lot* of money on specialised hardware.
`All digital' isn't required (I assume you mean PCM?) FM or even AM ought to be fine (but BattleBots prohibits AM, so it's moot) -- after all, modern R/C equipment has an effective range of around 1.5 miles -- far further than you can even *see* your plane. For a bot, it's unlikely to ever go more than 100 yards from you. At that range, interference isn't much of a problem, even for AM, unless somebody is on your exact frequency.
One thing to note that they don't seem to tell you -- in the US, airplane radios use the 72mhz band, which the FCC has designated for aircraft only. To use it for a ground craft is *illegal*. For ground craft, you're supposed to use the 75mhz band. (There's also the 27mhz band, but few people use it because it's also used by CB radios and there's only 6 channels there anyways. And there's also the 50 and 53mhz bands, but you need to have a ham radio license to use these.)
Futaba will convert some of their higher end radios from the 72mhz band to 75mhz band for $40.
If you do actually make your own robot, please don't use 72mhz equipment! There may be a flying field a half mile away that you don't know about, and you could crash somebody's plane without even knowing it.
(I emailed the coolrobots.com guy about this, and his email bounced -- mailbox full. Guess it got/.ed...)
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Re:"Impossible to drive" says the article
on
BYO Battlebot
·
· Score: 2
Actually, this wouldn't help much at all. You'd have a narrow little view of the action.
Much better to practice with your bot and learn how to use the 3rd person perspective to your advantage.
People have tried putting cameras on R/C planes and cars with various degress of success -- but it rarely works as well as an experienced pilot/driver with a good view of the craft.
Traditional advertising has been loosly targeted -- they know that this pop station is popular with 13-18 year olds, so they advertise pimple cream. The jazz station over there is listened to older people, so they advertise bars and life insurance.
This is not a `giant leap forward'... it's a little step. They don't even know what to ask yet, so they're asking for the kind of information that they already know how to use.
Give them time, and they'll probably give you a questionaire to fill out, with a lot more specific questions than just a/s/l (age/sex/location) -- but the odds are that it'll *still* ask those three questions.
When you click on the original news story, a pop-up appears with a `Task Bar Update' that downloads an application that puts `live temperature and storm warnings next to your PC clock along with live news updates'.
It also says these are `100% safe and completely free.' This program is just as dangerous as Seti@HOME could be.
TVA is right -- Seti@HOME is a risk. It's probably a small risk, but for all we know, the client could have code in it that allows Seti@HOME to take control of your box at will, for example.
It also will cause your computer to use more power, and to run slower (ok, just a tiny bit slower, but still.) All this, and it offers the company *nothing* (after all, it's not TVA's job to help SETI.)
And the boxes belong to TVA. Therefore, they're completely in their rights to ban Seti@HOME, and they're doing the right thing.
Yes, things like Linux do have support for a serial console, but that won't help you if you need to get at the BIOS. There are a few BIOS's that support serial consoles too, but they're rare.
And then there's NT. Alas, people do run servers on NT, and NT has no concept of a serial console that I'm aware of.
I seem to recall a flap about the resolver library that was included with ircd. Darren was the maintainer of ircd (and still might be for the IRCnet ircd) and he had put the resolver library under a different license or something, something that didn't mesh with the rest of ircd, which was under the GPL.
The details escape me now, however. Anybody remember?
... given that over a ton of Martian material enters our atmosphere every year, spit up from meteor impacts on Mars.
Do you have a source for this?
This seems rather unlikely. Mars has 3/8ths the gravity of Earth -- a lot less, but it would still take a *massive* amount of energy to launch something from it's surface to escape velocity. It also has a thin atmosphere, requiring even more energy and making it unlikely that anything small (like dust) could make it out of the atmosphere.
This atmosphere also will greatly reduce the number of meteors that make it to Mars's surface in the first place. Yes, it's thin, but it's much better than nothing.
It would take a MASSIVE meteor (we're talking `Deep Impact' or `Armageddon' type meteor) to hit Mars to be able to send anything from the surface into space. Let's hope this doesn't happen too often -- because if it did, similar meteors would be hitting the Earth too.
Also, Mars is rather far away. The odds of any particle escaping from Mars making it all the way to Earth are *incredibly* small.
The only Martian material that would be likely to escape Mars in any quantity would be the atmosphere itself. Of course, atmospheric gasses wouldn't burn up in our atmosphere -- they'd just float around with all the other atmospheric gasses. Any bacteria/virii in them would do similarly (assuming it survived space in the first place.)
Re:Does it also work for FedEX vehicles?
on
Flywheel UPS
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· Score: 1
Maybe you're the only one having problems? Yes, the general public tends to be bery naive about what games they buy, but typically something doesn't typically make it to #1 in sales without either 1) being really really cheap, or 2) being a good game for most people (word of mouth IS important.)
Does the technology even exist yet to beam energy like this from one dish and collect it in another dish in an efficient and cost effective manner? Nevermind beaming energy from orbit to the ground -- how about beaming it from one dish to another one mile away?
Not only that, but putting solar cells in orbit is expensive. Orders of magnitude more expensive than deploying them here on the ground.
Wouldn't it make more sense to just deploy solar cells here on the ground? If you don't want to set up miles of cells that cover the ground, put them on the roofs of buildings...
That would cost orders of magnitude less per KWh produced, and it totally bypasses the need for the microwave-beaming-power-technology which I don't think even exists in a usable form yet. That, and we can do it TODAY.
Dragged into court, all context is stripped away and -- while he narrowly escapes conviction as a domestic terrorist -- he is convicted of using the threat of force against people who may never have actually read what he wrote.
Why was all context stripped away? Yes, the prosecuting attorney could show only the parts that supported their argument, but wouldn't the defense attorney then insist that the jury be given the entire thread if they felt that it helped their case (and it should have.)
The easiest way I've found to do this is to convert your PDF files into a `text file approximation' of the original PDF file and index that.
I'm currently doing this, and it works pretty well. I use pstotext
run by a perl script of my creation that makes sure that every.pdf file has a corresponding.pdf2.html file (html, txt, doesn't matter -- both are easily indexed.)
I then use glimpse to index the.html (or.txt, again, doesn't matter) those. Once I have the search results, a perl script merely replaces.pdf2.html with.pdf, and it all works fine. Yes, there's an extra file on the file system, one for each pdf file, but nobody notices.
Just so there's no confusion, glimpse is a tool for indexing text files on a file system. webglimpse is a tool for indexing a web site -- and it uses glimpse in the `back end'. Ultimately, since a web site often looks like a file system, the two problems -- indexing a file system and indexing a web site -- are very similar.
glimpse is not free for commercial use, so you may want to use another tool. swish++ comes to mind, but I've not done much with it.
User connection logs should contain the following:
1. Connection time and date;
2. Disconnect time and date;
3. Method of connection to system (e.g., SLIP, PPP, Shell);
4. Data transfer volume (e.g., bytes);
5. Connection information for other systems to which user connected via , including:
a. Connection destination;
b. Connection time and date;
c. Disconnect time and date;
d. Method of connection to/from system (e.g.,
telnet, ftp, http);
e. Data transfer volume (e.g., bytes);
I don't know about your web server, but mine certainly don't log all that stuff. It especially doesn't log other web site visits other than my own (Some info like that might leak into the Referrer: header, though.)
But in large volumes you should be able to make this material for about $1 per square centimetre.
That may sound cheap, but it's not -- for a square meter, that's $10,000. Above the atmosphere, the sun's energy is about 1300 Watts/m^2, so assuming that you have a 100% efficient solar cell (and conventional cells are 5-10% efficient if I recall correctly) it's obvious to see that this isn't going to be very cost effective down here on the ground. Up in space though, things are different.
The goal of the project is to produce a prototype cell that is a centimetre squared in size and produces 10 watts of power at 1,000 degrees Celsius.
Such a cell will certainly not be powered by sunlight, unless you use a big mirror/lens to concentrate the light on it. 1 cm^2 of sunlight has well under one watt of power.
You'll probably need at least 16mb of ram, and Windows 95 (alas these people probably aren't ready for Linux or anything other than Windows.) You may be able to canibalize other computers for memory. Windows 95 is a better choice than Windows 98 or NT for computers like these, and Windows 3.1 is really too old for anything anymore.
500mb of disk is a bit tight, but it might be enough if managed carefully (i.e. you don't install lots of junk.) If not, pull another 500mb disk out of another box and put it in here for a total of 1gb.
Don't try to use Office 2000. Find some old copies of Office 95. It'll do most of what everybody needs, and should work with 16mb of ram.
The biggest problem with Office 95 is likely to be that it won't load Office 97 or Office 2000 files -- which may or may not be a problem.
Being able to get on the net from wherever you are sounds great, but there's a few problems -
1- most ISP AUP's won't allow this
2- what happens when somebody abuses the
connection? It'll come from YOUR IP address, so
you'll get blamed for it. Naughty things they
could do include :
- sending spam
- sending threatening emails to the President
- posting copywrited stuff to Usenet
- hacking remote systems.
You get the idea. The authorities would come after you, and you wouldn't even have any way of knowing who did it (does the wireless ethernet spec have the equivilent of MAC addresses? If so, that might provide a unique identifier, but even so...)
3- the least of the problems, they could use up all `your' bandwidth:)
Slashdot Mirror
If the signal is lost for a fraction of a second, servos stay in the location of their last known `good' signal. If the signal is lost for longer, they go to the `failsafe' setting, which probably turns off all the motors if the bot is configured properly.
With FM, interference usually just causes your servos to stop moving and stay where they were -- but sometimes the right interference can cause `glitches' -- which could be dangerous. Normally they don't occur under normal conditions, but from what you said, a BattleBots tournament isn't a normal condition.
PCM radios have higher latency than FM radios -- your imputs translate to servo movement more slowly -- but it's a pretty small difference and most people don't even notice.
That all being said, having a 300 lb robot with a chainsaw in front, having a PCM radio (with it's failsafe settings correctly set) is probably a good precaution, especially if the interference is as bad as you say it is.
So, what frequency band was your radio equipment on? :) What did most people use? (do you know?)
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Also, you'll be very hard pressed to find a pistol grip controller with more than 3 channels. Of course, if you have a seperate driver and gunner, giving the driver a pistol grip controller and the gunner a standard two stick airplane controller (on two different channels, of course) would probably work great.
Also, the two stick controllers aren't bad for R/C cars at all. I've got both, and while I do prefer the pistol grip, it's not that big of a deal. But then again, maybe I'm biased because I mostly fly R/C planes rather than drive R/C cars.
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For a car, two channels is the norm and you can get a third channel for more money -- but that's it. For more channels, you'll have to get plane equipment or spend a *lot* of money on specialised hardware.
`All digital' isn't required (I assume you mean PCM?) FM or even AM ought to be fine (but BattleBots prohibits AM, so it's moot) -- after all, modern R/C equipment has an effective range of around 1.5 miles -- far further than you can even *see* your plane. For a bot, it's unlikely to ever go more than 100 yards from you. At that range, interference isn't much of a problem, even for AM, unless somebody is on your exact frequency.
One thing to note that they don't seem to tell you -- in the US, airplane radios use the 72mhz band, which the FCC has designated for aircraft only. To use it for a ground craft is *illegal*. For ground craft, you're supposed to use the 75mhz band. (There's also the 27mhz band, but few people use it because it's also used by CB radios and there's only 6 channels there anyways. And there's also the 50 and 53mhz bands, but you need to have a ham radio license to use these.)
Futaba will convert some of their higher end radios from the 72mhz band to 75mhz band for $40.
If you do actually make your own robot, please don't use 72mhz equipment! There may be a flying field a half mile away that you don't know about, and you could crash somebody's plane without even knowing it.
(I emailed the coolrobots.com guy about this, and his email bounced -- mailbox full. Guess it got /.ed ...)
--
Much better to practice with your bot and learn how to use the 3rd person perspective to your advantage.
People have tried putting cameras on R/C planes and cars with various degress of success -- but it rarely works as well as an experienced pilot/driver with a good view of the craft.
This is not a `giant leap forward' ... it's a little step. They don't even know what to ask yet, so they're asking for the kind of information that they already know how to use.
Give them time, and they'll probably give you a questionaire to fill out, with a lot more specific questions than just a/s/l (age/sex/location) -- but the odds are that it'll *still* ask those three questions.
--
--
It also says these are `100% safe and completely free.' This program is just as dangerous as Seti@HOME could be.
TVA is right -- Seti@HOME is a risk. It's probably a small risk, but for all we know, the client could have code in it that allows Seti@HOME to take control of your box at will, for example.
It also will cause your computer to use more power, and to run slower (ok, just a tiny bit slower, but still.) All this, and it offers the company *nothing* (after all, it's not TVA's job to help SETI.)
And the boxes belong to TVA. Therefore, they're completely in their rights to ban Seti@HOME, and they're doing the right thing.
Well, for the year 2001 you may want to use `ssh' instead of `rsh', and /dev/dsp instead of /dev/audio for Linux, but the idea is still the same ...
Almost as much fun as making the Sun next to you belch while the newbie is using it!
Yes, things like Linux do have support for a serial console, but that won't help you if you need to get at the BIOS. There are a few BIOS's that support serial consoles too, but they're rare.
And then there's NT. Alas, people do run servers on NT, and NT has no concept of a serial console that I'm aware of.
The details escape me now, however. Anybody remember?
This seems rather unlikely. Mars has 3/8ths the gravity of Earth -- a lot less, but it would still take a *massive* amount of energy to launch something from it's surface to escape velocity. It also has a thin atmosphere, requiring even more energy and making it unlikely that anything small (like dust) could make it out of the atmosphere.
This atmosphere also will greatly reduce the number of meteors that make it to Mars's surface in the first place. Yes, it's thin, but it's much better than nothing.
It would take a MASSIVE meteor (we're talking `Deep Impact' or `Armageddon' type meteor) to hit Mars to be able to send anything from the surface into space. Let's hope this doesn't happen too often -- because if it did, similar meteors would be hitting the Earth too.
Also, Mars is rather far away. The odds of any particle escaping from Mars making it all the way to Earth are *incredibly* small.
The only Martian material that would be likely to escape Mars in any quantity would be the atmosphere itself. Of course, atmospheric gasses wouldn't burn up in our atmosphere -- they'd just float around with all the other atmospheric gasses. Any bacteria/virii in them would do similarly (assuming it survived space in the first place.)
UPS trucks are brown. Not FedEx trucks.
Windows is not the only OS out there. And Myst III is available on the Macintosh too -- which does not label it's drives A:, B:, C: ...
And Myst 3 is the #1 Best Selling Game right now.
Maybe you're the only one having problems? Yes, the general public tends to be bery naive about what games they buy, but typically something doesn't typically make it to #1 in sales without either 1) being really really cheap, or 2) being a good game for most people (word of mouth IS important.)
Not only that, but putting solar cells in orbit is expensive. Orders of magnitude more expensive than deploying them here on the ground.
Wouldn't it make more sense to just deploy solar cells here on the ground? If you don't want to set up miles of cells that cover the ground, put them on the roofs of buildings ...
That would cost orders of magnitude less per KWh produced, and it totally bypasses the need for the microwave-beaming-power-technology which I don't think even exists in a usable form yet. That, and we can do it TODAY.
Why was all context stripped away? Yes, the prosecuting attorney could show only the parts that supported their argument, but wouldn't the defense attorney then insist that the jury be given the entire thread if they felt that it helped their case (and it should have.)
Am I missing something here?
That, and they appear to be DVDs. :)
Damn. Thanks for posting that -- very interesting (and scary.)
I'm currently doing this, and it works pretty well. I use pstotext run by a perl script of my creation that makes sure that every .pdf file has a corresponding .pdf2.html file (html, txt, doesn't matter -- both are easily indexed.)
I then use glimpse to index the .html (or .txt, again, doesn't matter) those. Once I have the search results, a perl script merely replaces .pdf2.html with .pdf, and it all works fine. Yes, there's an extra file on the file system, one for each pdf file, but nobody notices.
Just so there's no confusion, glimpse is a tool for indexing text files on a file system. webglimpse is a tool for indexing a web site -- and it uses glimpse in the `back end'. Ultimately, since a web site often looks like a file system, the two problems -- indexing a file system and indexing a web site -- are very similar.
glimpse is not free for commercial use, so you may want to use another tool. swish++ comes to mind, but I've not done much with it.
User connection logs should contain the following:
1. Connection time and date;
2. Disconnect time and date;
3. Method of connection to system (e.g., SLIP, PPP, Shell);
4. Data transfer volume (e.g., bytes);
5. Connection information for other systems to which user connected via , including:
a. Connection destination;
b. Connection time and date;
c. Disconnect time and date;
d. Method of connection to/from system (e.g.,
telnet, ftp, http);
e. Data transfer volume (e.g., bytes);
I don't know about your web server, but mine certainly don't log all that stuff. It especially doesn't log other web site visits other than my own (Some info like that might leak into the Referrer: header, though.)
500mb of disk is a bit tight, but it might be enough if managed carefully (i.e. you don't install lots of junk.) If not, pull another 500mb disk out of another box and put it in here for a total of 1gb.
Don't try to use Office 2000. Find some old copies of Office 95. It'll do most of what everybody needs, and should work with 16mb of ram. The biggest problem with Office 95 is likely to be that it won't load Office 97 or Office 2000 files -- which may or may not be a problem.
Being able to get on the net from wherever you are sounds great, but there's a few problems -
...)
:)
1- most ISP AUP's won't allow this
2- what happens when somebody abuses the
connection? It'll come from YOUR IP address, so
you'll get blamed for it. Naughty things they
could do include :
- sending spam
- sending threatening emails to the President
- posting copywrited stuff to Usenet
- hacking remote systems.
You get the idea. The authorities would come after you, and you wouldn't even have any way of knowing who did it (does the wireless ethernet spec have the equivilent of MAC addresses? If so, that might provide a unique identifier, but even so
3- the least of the problems, they could use up all `your' bandwidth