Regarding the breaker box - were these past "homeowner" jobs that you did, or the previous homeowner (or the current one, if you are renting)? I ask this because of my statement about the nail through the wire - the owner of the house was a "do-it-yourselfer", and I have the feeling that he may have accidentally driven the nail through (can't ask him now - he passed away about 3 weeks prior to the house burning - talk about tragedies to befall a family), having seen his handy work on other projects in a house me and my wife rented from them. So, the statement about a high resistance issue is something to think about.
As far as the A/C is concerned, I was told this by a trusted and respected A/C repairman I personally know (an old irish dude that will talk your ear off if you let him - but is one of the most honest men I know). I tried this on the house that I rented from my brother-in-law's parents, which had two large A/C units (big house - 3500 sf or so), and cut my bill way down. It makes sense (think of a bicycle - how much effort it takes to get going, but how much easier it is to keep going, or to speed up).
If you have a pool pump, then there is another power drain. I don't know much about pools, as I don't own one yet, but I do know that/. had an article on a guy who was using a homebrew Linux system to monitor and control the pool pump and chemicals in his pool to help save money, as well as to keep the pool properly maintained. Look into it - pretty involved project, but might be worth it.
One thing I forgot to mention (though you are probably doing this) is to remember to only use lights when you need them, shut them off when you don't. Also, you might look into compact flourescents for certain lights. For those lights where CFs won't work, try to put in electronic dimmers (ie, the ones that vary the cycle of the current going through the bulb, rather than use a rheostat, which wastes the energy as heat), and dim them as needed (like at night when you want to provide a bit of light for a hallway or something).
I don't know what you are paying in electricity there in CA, but here in Phoenix, AZ - my bill hasn't been much over $200.00/month, the entire summer, and that is with two heatpumps (while expensive to buy - heatpumps are supposedly more efficient than AC/heater units - so you might look into them). Of course, like I said, I don't have a pool pump...
First off, turn everything off, including any stoves, dishwashers, hot water heaters, A/C units, refrigerators, etc - in fact, what might be easiest (but make sure you have surge protectors for computers and electronics) is to simply turn off the breakers. The disk (if your meter has it) should be not be turning at all - if it is, then you have a parasite load attached (alarm system backup power or doorbell most likely), but it should only turn really slow with those. If it is turning faster, then someone is either tapping your power in some manner (for whatever reason), or you have some kind of short in the system somewhere (of course, if you have all the breakers off, and it is still turning, you have big problems) - which is a bad thing (don't laugh - it is possible to have a high-resistance short in a line that goes for years without any noticing, other than a high electric bill - my brother-in-law's parent's house recently had a fire due to a drywall nail that had been driven through the wires of one of the circuits - it had been that way for YEARS before the fire happened).
Anyhow, that is one way to find out what circuit or appliance is sucking the power. Another way is deduction - the biggest power users in a house are typically the hot water heater, the refrigerator/freezer, and the air conditioning unit (which means AC/heater if equipped). Not much you can do on any of those except replace them.
One thing to remember on a hot water heater is whether it has been flushed/cleaned recently (ie, do it every year) - if not, sediment can build up on the coils, insulating them from the water, meaning it takes more energy to bring the water up to temperature.
Regarding the AC unit - how are you running it? In the summer, set it for about 77 degrees when at home, but raise it to about 85 when nobody is at home (reverse for winter) - DON'T TURN IT OFF. If you turn it off, the house heats up (or cools down in winter), and it takes that much more energy to bring the air, and EVERYTHING ELSE in the house, including the walls, back down to the proper temperature. Remember as it warms up/cools off, adjust the temperature accordingly to raise/lower it - so that the outside temperature keeps your house comfortable. One other thing - make sure you don't have any "leakage" or drafty areas - break out the weatherstripping/caulk, and go to it! Also - do you have a combo A/C and swamp cooler (or separate heater/cooler units) that use the same duct works? If you do, then there are probably auto-dampers to shut the air flow off from each unit when one is in use, but not the other. If this is the case, check to make sure those dampers are working properly, and shutting off the air flow - no sense in cooling or heating the neighborhood (this also goes for fireplace flue dampers - shut 'em!). Also, if you have a "whole house" fan (which vents air from inside the house through windows and into the attic), that it's damper is shutting when it is off (and don't turn it on when the AC is on).
Those are going to be your main energy wasters. The other appliances about all you can do is replace them with newer appliances (main the fridge - if you stove/oven is using a lot, then don't worry too much about it, because it isn't on all the time).
One more thing about parasitic loads - if someone is stealing the power, check to see how it is hidden, and where it is going. If it is a neighbor, it may be for grow lights (work out a trade?)...
There are also a couple of other links on that page - basically it is a "meter reader" that counts the pulses coming from the spinning disk in the reader (for some reason, meters in America use spinning disks, even if they are digital - this probably isn't the case everywhere - the link to the British dude, when it was up and I visited - showed what appeared to be a fully digital meter, no mechanical parts). He has it hooked up to a Linux box that reads these pulses via the parallel port.
Such a setup, while not as advanced as what is being offered by Obvious (which seems to allow for monitoring of multiple circuits and other such niceties - which would be cool to do, because then you could get the monitoring down to circuit, and almost device, level), would still be useful for a homeowner and such.
What I am wanting to do, though, is figure out how digital meters work. The meter on my house is one of the digital/mechanical hybrids. I could use Sean's circuit, but there is a "plug" on the front, that looks optical in some regard, that the meter reader guy uses to interface a handheld data logger device to - I would rather be able to use that interface, since it is what should be used, rather than a clunky external laser and detector system (though I wonder what my power company would think - one thing I wonder, is if you can program/reset through that interface - they wouldn't like that).
Something that I remember seeing a while back, then it just up and died, with no fanfare - was web "desktops". Does anybody here remember the desktops that showed up in a browser, and used a combination of javascript, html, possibly css, and cgi to create a windowing desktop within the browser?
Today, such applications are much easier, and with Mozilla at least (XUL, etc), should become more common.
My question is, what happened to the early stuff? Some of it was amazing and fascinating, even if a bit crufty. I assume it died off because it just didn't catch on, or it really wasn't up to the task of better (read: full blown) applications. But the idea of having a remotely accessible desktop anywhere, web based, etc - seemed interesting (and yes, I know about VNC, as well as X)...
You say this is your ex-wife, so you have something available to you that is typically made available to every blasted corporation and government entity known to man - a social security number. So does your child. Leverage these. What you need to find is somebody or groups of somebodys that know how to leverage these bits of information.
Basically, what you are wanting to track is the ripples the use of these numbers generate in databases throughout the system. Assuming your child is of age, and still in your state, and is not being home schooled, look into school registrations for the state/local level. Perhaps also look into insurance coverages (more difficult), credit card use/signups, etc. Another possibility you might look into is a reverse catch, in a way - in other words, using her social, get a copy of birth records, then look into getting a female accomplice to do an identity theft - maybe even in cooperation with a credit issuing agency or something. Start racking up the bills on the card, and get the credit reporting agencies involved - they will alert the ex to possible identity fraud, and contact the issuer of the false cards to hold them - then there has to be some way of getting the real person, thus the address or location of them, for the police, private investigator or whatnot.
The SSN is a big piece of leverage, and providing she is not hiding out at an old friend's house you don't know about in another state, and sponging off of them as well - it is a piece that will most likely let you narrow down the search and find your child.
Depending on the answer to that question, will tell you what you need to do. You don't say what you already know (in terms of coding such engines), whether you are zero knowledge (ie, you know what vectors are and how to add and multiply them using matrices, etc) or know much more (ie, you know how to code a demo of a cube rotating with full texturing).
The problem with even a 3D engine is that you start to get into a ton of other areas that you wouldn't think would be a part of it, but are. One biggie is databases - essentially your world you are rendering exists as a database, but it has to be a high speed one, typically will be custom, and may even be specially geared toward 3D operations on the data sets that inhabit it. That is just one quick example, there are tons more.
Other posters have pointed out what goes into a game engine, which covers even more ground, so I won't go into it here again. Even for 3D engines, if you have little or no knowledge of the subject, don't expect to gain it overnight. One thing when I tried learning this stuff that I figured out quickly was that I couldn't learn it just reading a book on vectors and matrix multiplication. Sure, that helped, but it didn't tell me WHY. So, I struck out on my own - first learning what rotation was. I started out creating apps that rotated things in 2D (using SIN and COS) and why that worked (ie, unit circles, etc play a big part here - if you are lacking in geometry or trig, brush up on those), then learned how to expand that into 3D, so I could do all of that. Then, I learned the hows and whys of projection, then back-face culling, then face/object culling based on intersections with the view frustum, etc - on and on and on...
It never seemed to end, and in the end (I was wanting to make a 3D game engine, which never went far) I was finding I was taking up too much time on this, when there were tons of engines available that could do all I did, plus tons more I just didn't have the time to learn to do, that I realized that I was wasting my time on this hobby, rather than looking into wheels that already existed.
Now, let me say that I never went anywhere with building a 3D game, and game building isn't my main thing anymore (though it is still something I think about - one of those "back burner" projects) - but I would never give up the learning I was able to come away with in my brief foray into 3D game engine mechanics. It gave me a lot of insights into the kind of things game engine coders face, and a respect to what they do, and what they know. It also taught me how complex the world really is, what it takes to even try to model things. It also helped me think of how to do new ways in coding to gain speed and tightness of code, which are useful in more ways than just pushing pixels.
So, I don't want to discourage you - if what you are wanting to do is learn, then go for it. If you are wanting to learn enough to get a job in the field, then go for it. If what you are wanting in the end though is to create a game, then I would advise you to learn the basic mechanics (ie, enough to code a simple texture mapped cube spinner, possibly with cameras, maybe even a world database, etc - which was as far as I got - maybe even though in simple face lighting), to know how it all works at a basic level, and to understand what is being talked about - then find a free or GPL'd engine and work with it from there to create your game.
As has been shown by countless examples scattered across the net, a game engine by itself is useless without a good playable game to go along with it...
I am not sure these will be appropriate for your audience, because when I was a part of them, it was during high school. However, all of them left a great impression on me that I will never forget.
To be honest, I have forgotten the details of most of these experiments, so while I cannot give you exact methods or reasonings, the gist of the experiments should come through enough for you to consult with other sources and collegues to fill in the gaps of my mind.
To that end, the experiments:
1) Measuring the speed of sound - from this one I remember we first determined in class how you could measure the speed of sound, variables, and how you would set up the experiment, then what the answer would work out to be if done a certain way. Then, the class was led outside, and one person held two sticks and banged them together. Another person was instructed to listen for the return sound from the science building we were standing away from some number of feet. Someone else was timing with a stopwatch. I am not sure of the process, but from all of this we got data that we used in class to determine the speed of sound, based on how we should do it - we weren't that far off, if I remember right, for our height above sea level and the condition of the weather outside - and we were real close to what we had gotten in the classroom.
2) Hitting a target - perhaps a little closer to home today than then - basically calculating trajectories, parabolas, etc. In the classroom, we calculated given a certain amount of pressure in a rocket (we used an air powered rocket for safety and distance reasons), angle, etc - what was needed to be put into the rocket in order for it to hit a target set some distance away. Once we had calculated that, we then went out on the football field (to the amusement of the PE class of the period), and launched the rocket. We hit the target, as our calculations said we would (now, class, can anyone tell me how an ICBM works?).
3) Measuring the mass of an electron - OK, this one is REALLY fuzzy in my mind, and in the end, we were off by a whole heck of a lot, but not as much as you would think given the equipment. All I really remember about this was some very complex mathematics, a bit of reasoning, and the use of an old occiliscope and power supply.
4) Water below freezing - in this experiment, which involved more than I am letting on here - we showed in individual labs how you could keep water liquid, even though you brought it down below freezing. We used stainless steel containers, regular water, ice and salt in a styrofoam container to bring the water down that was in the stainless steel container, some thermometers, etc. I also remember another part of the lab that involved a different substance, that you heated, it went from solid to liquid, then you gradually cooled down to room temperature (by lowering the bunsen burner flame), but it stayed liquid. Then you let it cool off really well, still liquid, then you put in a seed of the solid substance, and it immediately crystalized solid again (in time for the next class, I suppose). Cool thing to watch.
Those are the ones among my favorites. They could be enhanced in different ways (like the trajectory one - build a spud cannon instead for the demo, on a stand that permits tilting it like a mortar, at known angles). Hope these help - good luck!
My first impression after seeing the robot on the site was "what the hell are those wires doing out in the open?". Given the conditions of the area they are doing the run in (where daytime/nighttime temp fluctuations are large), exposed wires would be in for a real beating. Even if well protected, with metal sheilding or whatnot, they still will be flexed a lot - here's hoping they have an efficient AI that can change tactics when a leg motor fails.
I also question when they will be doing this run of 25 miles. If they don't pick the right time of season, they will run into either dust storms (strong enough to rip the paint off your car and needing a new windshield), thunderstorms (dropping a lot of water in mere hours), or a combo of both if they are really unlucky.
This robot is going to take a few days to go the distance. It will have to deal with desert conditions (both day and night conditions, and weather) and desert obstacles (brush, trees, loose soil, rocks, animals, washes, etc).
I really question the whole project - was the goal to make a legged vehicle or to go a distance autonomously?
I think about the DARPA Grand Challenge, and I think what would be the best vehicle for such a thing. Then I thought it would be a challenge to go any distance autonomously. For the terrain, legs are OK, but use a lot of power. Considering the obstacles likely to be encountered, a much better and more efficient system would seem to use wheels.
I would go for a system similar to what the Mars Rover used, the suspension system with six wheels, but scale it up a bit to use larger ATV wheels. Keep the engine, but throttle it back greatly (under computer control) to maximize fuel consumption (properly tuned, etc with proper throttling, you can get hundreds of miles per gallon of fuel). Keep solar panels and batteries on-board, which at minimum could run the system in the event of an emergency to "call home". Such a system would be able to make a 25 mile run in probably a day or two maximum, and could possibly compete in the DARPA challenge.
At the end of the day, though - regardless of whether this legged wonder does it, or somebody builds another device, wheeled or legged, that does it, even over a much shorter distance, they will have come up with a solution, and proved that solutions exist, to several "grand problems" in autonomous robotics that would prove useful in a number of other situations (ground rescue, factory work, planetary rovers, underwater exploration, etc).
It's too bad, that - a few months back I bought an extreme, just because it was cheap enough (clearance rack, but the battery was dead - though I managed to get a couple built for it - yeah, had to crack the case and solder it in).
I wanted an ultra-cheap PDA to store a small DB for things like "books I want" vs "books I have" (expand to VCDs, etc). I didn't want to spend a butt load of money on a real PDA, and besides the extreme seemed to have more than enough for my needs. Someday I plan on getting it working with USB and Linux (there is a GPLd serial port interface for Linux for the older cybiko, but it doesn't work with USB, though the author thinks it would be easy to mod to get it to work - anyone with more experience than I want to take a crack at it?).
It is too bad it didn't take off - it is really a VERY interesting device, light on memory, but it has expansion options, it is quite sleek looking (extreme), and has a lot of free software for it. There is dev tools for the thing, plus a version of BASIC (yeah, yeah, I know - but I just think about how it has as much memory as the old skool boxes, and text adventures would be a fun thing to put on it, etc). It really wasn't that expensive when it first came out, compared to similarly marketed products. It was one of those products that didn't really have a niche - it doesn't seem like it would make that great a PDA (because it has a tiny keyboard which is hard to use), nor a game machine (though it is better here), plus for kids it wouldn't be tolerated in schools (I doubt any PDA is, though). But the price was great - I wish I could get a Palm or something for $30.00 with all the functionality, etc.
Does anybody know of a PDA (that isn't WinCE) that is under $100.00?
I already said I had my doubts whether my device would work or not. Also, understand that I wasn't thinking about slaving it, rather making it be an "always-on, broad coverage" device (hence, why I hinted at using high-brightness non-focused IR LEDs and mirror).
Besides, even if it didn't work - that doesn't mean you couldn't sell it. Think of all the "crap" they sell down at auto zone or such, and how this device I described could be built super-cheap, and sell for $20-30.00 or so - you could make a mint (even if it didn't work).
Ok, I understand what you mean about the wavelength issue - someone else brought up the idea of using a green laser pointer from Thinkgeek as opposed to the red/IR systems. If these stoplight systems really do use a filter system as you say, then my idea goes kaput, because I was thinking of something cheap and easy to manufacture.
With that said, however, you don't seem to understand that I was envisioning an "always-on, broad spread" laser or LED system for illuminating the license plate - ie, it would be illuminated at all times, cover the whole plate, and thus a portion of the light (whether visible red or IR) would be seen from any angle.
Heck, maybe somebody could build these things anyhow, sell them at auto-zone and make money, even if they don't work - after all, people do buy those hanging fuzzy dice (amongst other junk you see).
Maybe - and here is how you could design one (I hereby donate this idea to the public domain):
Basically, this will only work for vehicles with an area immediately in front of the license plate to put a ball-type tow hitch. What you want to do is create a realistic looking "fake hitch", that can be "bolted" on in place of a normal ball hitch. Mold the casing from plastic, the ball hitch preferably "chromed", or possibly given a fake finish to simulate a used hitch (better for an older beater vehicle). Now, for the goodies:
Inside the base of the fake hitch (what would be the bolt shaft) put in a relatively high-power IR or Red laser LED or regular LED facing up (toward the ball end). In the ball portion, mount a small motor with a tilted mirror attached to the shaft (ie, a typical right-angle scanner system). On the side of the ball facing the plate, make a clear window, or cut away a window area (or mold it). If using an LED laser, you will need a diffraction grating or something to spread the beam in a line. It might also be possible to build it with a simple or curved mirror, no motor needed. Hook it up to a source of 12VDC in the car.
The idea is that the mirror spins, bathing the license plate in light - but the whole system looks like a trailer hitch to the "uninitiated" (which, note, some communities/states have laws against driving a vehicle with only a hitch, but no trailer - gotta love that).
To be honest, I don't know if this would work or not - something tells me that LED lasers and/or LEDs wouldn't be bright enough to illuminate the license plate and still reflect enough to white-out the camera system. But it might be worth trying out!
With the posters who have said "keep it" as a reminder of your grandfather. At the same time, I would get it appraised, and if valuable, put it in a bank vault or something.
I have only seen a few meteorites, all except one in museums (that one was owned by a mail clerk at my work, who asked me if I thought it was a meteorite and what should she do - I told her it certainly looked like one, felt and weighed like one - iron, bubbled - told her to get it looked at by someone at ASU). I don't know if all meteorites look like this (I could only describe it as "porous" or "spongy" iron chunk - looks almost like lava rock, but bigger, and iron - stick a magnet to it), but every one I have seen looked like that (which don't mean jack).
So, get it appraised - but keep it. If you liked your grandpa, and you have memories of it as being interesting as a kid, then it is something worth keeping (but hey, if it is valuable, use it for collateral or something)...
This device, called TWISTER, was at the Siggraph 2002 - it consists of a drum made of of panels of LEDs that spin around the viewer standing in the middle. It was created by Kenji Tanaka, et al at Tachi Lab, University of Tokyo. I would imagine such a device could even be built to do full 3D, perhaps by using shutter glasses of some sort synched to the scanning of the LEDs. What would also be cool is to add a head tracker that could tell which direction you are looking in, and only activate an "arc" of panels such that the view went beyond your peripheral vision, but didn't wrap around, lessening the load on the computer driving the system (why display what you can't see?)...
Anyhow, this image was taken by Jerry Isdale, a long-time graphics/VR researcher, who attended the show (sadly, I was unable to attend - can't afford it).
The rest of his report is also interesting, showcasing other 3D and VR technologies presented...
Where have you been? Were you alive circa-1992-94? Were you of an age to understand what was going on then?
I can only guess that you must have been a little kid to have missed out on Virtual Reality. Really, what is today Q3A and UT grew out of the want for better 3D graphics for those systems (I am not saying VR begat Quake, but it did influence the development of 3D engines, etc). HMD's, head tracking, glove input devices, 3/6DOF position sensors, etc.
I have a wierd feeling - I mean, back then (and less so now, but still happenning) a lot of people were developing VR systems AT HOME - using 386/486 machines, Amigas, LCD TVs (for HMDs), potentiometers and wooden arms (for head tracking) and Powergloves to interact with 3D worlds they created (most of the time using Rend386 or other homebrew 3D software).
What has happened? Has all of this knowledge, not to mention the knowledge of the existence of this knowledge, been lost? Heck, I KNOW that can't be the case, my website has a ton of the old stuff on it - I still see new stuff appearing now and then (such as that Linux PowerGlove driver that works great with my modded PG). It seems crazy - but it is almost like you are one of a growing cadre of people who are TOTALLY unaware of this technology - and furthermore of the fact that today one can build a homebrew VR rig ULTRA-CHEAP, given some time, materials, and a little knowledge. Even if everything was bought off-the-shelf, it still would cost less than $5000.00 to do it. Buying used, or building, that cost could easily drop to below $1000.00.
I am wondering if VR isn't undergoing something like the concept of a windowing desktop - I mean, the first such desktop didn't come about until 1969 (or was it 68?), but it took another 15-20 years before it really started to catch on, and another 10 still before it became ubiquitous - perhaps around, oh, say 2015 to 2030 I should expect VR to hit BIG, and it will be NEW and FLASHY!
I am sure that you, like most of the rest of us, have seen the effects, both good and bad, that the internet has had upon the world.
With this in mind, especially given all of the issues surrounding p2p filesharing and intellectual property rights - if you were given the chance to do it again, knowing what you now know, would you?
At my day job I code in VB - and I have played with XUL in Mozilla. The one nice thing Mozilla/XUL has over IE/VB is that the dev environment is the browser - really, you only need Mozilla, a text editor (I prefer NEdit, but vi will work fine too) - and that's it! I don't have to buy some insanely costly VB IDE system in order to code up my application (and really, when you couple XUL with PHP on Apache, and add MySQL for the backend - you are talking web applications). It's cheap! It's Free! It's Open! What the hell more could I ask for? To be anally raped by Bill?
Why have a LAN camera?
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LAN Camera Review
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· Score: 3, Insightful
I can see very little need for any of these cameras by home users. In the commercial realm, there are more uses, but they still seem waaay overpriced for what you get, compared to what it would cost to build a comparable system.
A wired LAN camera (with built in web server) is only really needed if you are doing something where you have a nearby network connection and don't want to run a long run of coax or other cable for video (though CAT5 should handle video fine), same for the wireless (though it is better if you need such a camera in an area where you can't get wires to AT ALL). I can see using these cameras for a quick setup/takedown for a "fly-by-night" live-webcam porno operation, or in a warehouse, or on a remote ranch - but not much else. Maybe I am short-sighted - where else would these be justified for the expense that a cheaper system wouldn't be worth it?
At home? You have to be kidding. This winter I plan on installing security cams in my house - I am going to use cheap b/w (maybe a single color cam for the front door) cams, most "single-board", which supply 1 Vpp composite video, and need a 12VDC hookup, all of which can be run over CAT5. I will terminate the cameras back at a central location where I plan to hook them up to a custom parallel port driven relay (or IC) based switcher, and into a video capture card for recording. I plan on running the wires in the attic - no big deal. I figure the total cost of this thing will be in the realm of $200 total - the computer is free (junk from work), the video capture card I have lying around, the cameras cost about $25.00 - $50.00 each - why should I buy a LAN camera?
Maybe, maybe not - I thought about this when I posted, that it would be out of focus, but many scanners actually have good focus up to about an inch away from the surface. I am not saying perfect, obviously if you move away from the surface it will be worse, but if you scan at a high enough res, when you reduce the res (why would you want ultra-high res - storage would be tougher, and you would start to pick up the grain of the photo), what little focus issue there is wouldn't matter.
That said, I do like your idea, it is the most logical thing to do - but I was trying to think up some way that photos could be loaded quickly off-bed as one set is scanning, so that you could scan/swap/load/swap/scan/swap, etc...
One thing that I want to build or buy is a backlight for my scanner for negatives/slides. However, this need is becoming less and less as I use my cheapo digital camera...
How about a thin piece of glass with a grid made from black pinstripe tape - sandwitch the pictures between the glass and a piece of cardboard (or similar material), then place the sandwitch on the scanner, and scan - use software to pull the images based on coordinate or edge detection (detecting the grid)...
Many people are selling the electro-luminescent "wire" on there, in 15, 20 and even 30 foot lengths, pretty cheap, too - try this search.
Also, if you search on Ebay for "pc neon" - you will get some references to various clear LED lit fans that would make for interesting case mods (provided you keep the fans clean).
Aside from the legality of copying and distributing copyrighted works (which is really just a statutory law, no basis under common law, which requires real victims and damages in most cases - though I might be wrong) - did your accusors in court prove you stole from them?
In other words, did they demonstrate, to all present, that your actions caused them a quantifiable loss of money which they would have received had you not done what you did?
I take it that if they did, then those companies involved made the proper notations on the quarterly SEC filings? And if not, wouldn't that be similar to the fraud of hiding losses to inflate gains for shareholders?
...that I didn't watch the special, but considering most of the comments here about how the two hours were "wasted time" (plus I have seen similar Hawiss "specials" that were just as wasteful) - I am glad I didn't. With that out of the way...
What is this talk of fingerprint(s) on the sarcophagus? Was this a marking, or an impression? One comment seems to indicate that the print was an impression or something - so what was the sarcophagus made from? Clay? Were such things made from clay? I had always thought they were carved from stone?
But if the sarcophagus was stone, why the print? What if it was a concrete substance, rather than "stone"? You could certainly make a print in that...
There is a theory that the Egyptians had the technology and resources (ie, sand, limestone, something from the Red Sea) to make concrete, and the theory would explain how some of the pyramids (esp the Great Pyramid) and temple structures could have been built, even though they are so large - they were simply "poured" into place. At least, that's the theory...
I am trying to figure out why all the doors on the tunnel - what theory fits this, what the tunnel may have been for (I have seen a site that claims the Great Pyramid was a giant water pump - but that doesn't make much sense since it was built when the area had plenty of water and was fertile), those handles on the doors (why?), among other things...
Finally, I do have to wonder about that robot - that is a TON of money for what should be a relatively simple robot - I can understand that the sides of the tunnel were smooth, and at an angle (ie, needs more than a standard robot wheel drive), but quarter of a mil? Right - time to find the person who pocketed the dough...
Well, as has been pointed out NUMEROUS times, the answer is to replace the battery pack. But, apparently your technical ability is somewhat lacking - but that is the answer. If you really want to make the thing shine - do a complete teardown, check/replace motor bearings, brushes (if it isn't a brushless motor), sharpen or replace the blade, clean the deck, etc - make it like new. The thing will probably run a long while if you do this regularly.
If I was going to by the iMow, it is obvious from reviews and such that while the mower may work, it works in a really crappy, non-intelligent manner. Just a random walk, with simple sensors. I would buy one of those, rip out the standard "electronics" (something tells me that the iMow doesn't really have a real computer in it), and replace them with a good micro-controller, add some good sensors (I think it only has a simple non-directional "bump" sensor - I would replace that with an array of bump sensors around the perimeter). Leave the wire, then add code the controller to tell it to go around the perimeter, measure the distance, then make another lap inside the first one (with a few inches of overlap). If obstacles are encountered, add code to go around the obstacle, but map it for later - the code would be similar to a generalised paint/fill algorithm...
Slashdot Mirror
As far as the A/C is concerned, I was told this by a trusted and respected A/C repairman I personally know (an old irish dude that will talk your ear off if you let him - but is one of the most honest men I know). I tried this on the house that I rented from my brother-in-law's parents, which had two large A/C units (big house - 3500 sf or so), and cut my bill way down. It makes sense (think of a bicycle - how much effort it takes to get going, but how much easier it is to keep going, or to speed up).
If you have a pool pump, then there is another power drain. I don't know much about pools, as I don't own one yet, but I do know that /. had an article on a guy who was using a homebrew Linux system to monitor and control the pool pump and chemicals in his pool to help save money, as well as to keep the pool properly maintained. Look into it - pretty involved project, but might be worth it.
One thing I forgot to mention (though you are probably doing this) is to remember to only use lights when you need them, shut them off when you don't. Also, you might look into compact flourescents for certain lights. For those lights where CFs won't work, try to put in electronic dimmers (ie, the ones that vary the cycle of the current going through the bulb, rather than use a rheostat, which wastes the energy as heat), and dim them as needed (like at night when you want to provide a bit of light for a hallway or something).
I don't know what you are paying in electricity there in CA, but here in Phoenix, AZ - my bill hasn't been much over $200.00/month, the entire summer, and that is with two heatpumps (while expensive to buy - heatpumps are supposedly more efficient than AC/heater units - so you might look into them). Of course, like I said, I don't have a pool pump...
Anyhow, that is one way to find out what circuit or appliance is sucking the power. Another way is deduction - the biggest power users in a house are typically the hot water heater, the refrigerator/freezer, and the air conditioning unit (which means AC/heater if equipped). Not much you can do on any of those except replace them.
One thing to remember on a hot water heater is whether it has been flushed/cleaned recently (ie, do it every year) - if not, sediment can build up on the coils, insulating them from the water, meaning it takes more energy to bring the water up to temperature.
Regarding the AC unit - how are you running it? In the summer, set it for about 77 degrees when at home, but raise it to about 85 when nobody is at home (reverse for winter) - DON'T TURN IT OFF. If you turn it off, the house heats up (or cools down in winter), and it takes that much more energy to bring the air, and EVERYTHING ELSE in the house, including the walls, back down to the proper temperature. Remember as it warms up/cools off, adjust the temperature accordingly to raise/lower it - so that the outside temperature keeps your house comfortable. One other thing - make sure you don't have any "leakage" or drafty areas - break out the weatherstripping/caulk, and go to it! Also - do you have a combo A/C and swamp cooler (or separate heater/cooler units) that use the same duct works? If you do, then there are probably auto-dampers to shut the air flow off from each unit when one is in use, but not the other. If this is the case, check to make sure those dampers are working properly, and shutting off the air flow - no sense in cooling or heating the neighborhood (this also goes for fireplace flue dampers - shut 'em!). Also, if you have a "whole house" fan (which vents air from inside the house through windows and into the attic), that it's damper is shutting when it is off (and don't turn it on when the AC is on).
Those are going to be your main energy wasters. The other appliances about all you can do is replace them with newer appliances (main the fridge - if you stove/oven is using a lot, then don't worry too much about it, because it isn't on all the time).
One more thing about parasitic loads - if someone is stealing the power, check to see how it is hidden, and where it is going. If it is a neighbor, it may be for grow lights (work out a trade?)...
Sean Adams Laser Meter Reader
There are also a couple of other links on that page - basically it is a "meter reader" that counts the pulses coming from the spinning disk in the reader (for some reason, meters in America use spinning disks, even if they are digital - this probably isn't the case everywhere - the link to the British dude, when it was up and I visited - showed what appeared to be a fully digital meter, no mechanical parts). He has it hooked up to a Linux box that reads these pulses via the parallel port.
Such a setup, while not as advanced as what is being offered by Obvious (which seems to allow for monitoring of multiple circuits and other such niceties - which would be cool to do, because then you could get the monitoring down to circuit, and almost device, level), would still be useful for a homeowner and such.
What I am wanting to do, though, is figure out how digital meters work. The meter on my house is one of the digital/mechanical hybrids. I could use Sean's circuit, but there is a "plug" on the front, that looks optical in some regard, that the meter reader guy uses to interface a handheld data logger device to - I would rather be able to use that interface, since it is what should be used, rather than a clunky external laser and detector system (though I wonder what my power company would think - one thing I wonder, is if you can program/reset through that interface - they wouldn't like that).
Today, such applications are much easier, and with Mozilla at least (XUL, etc), should become more common.
My question is, what happened to the early stuff? Some of it was amazing and fascinating, even if a bit crufty. I assume it died off because it just didn't catch on, or it really wasn't up to the task of better (read: full blown) applications. But the idea of having a remotely accessible desktop anywhere, web based, etc - seemed interesting (and yes, I know about VNC, as well as X)...
Basically, what you are wanting to track is the ripples the use of these numbers generate in databases throughout the system. Assuming your child is of age, and still in your state, and is not being home schooled, look into school registrations for the state/local level. Perhaps also look into insurance coverages (more difficult), credit card use/signups, etc. Another possibility you might look into is a reverse catch, in a way - in other words, using her social, get a copy of birth records, then look into getting a female accomplice to do an identity theft - maybe even in cooperation with a credit issuing agency or something. Start racking up the bills on the card, and get the credit reporting agencies involved - they will alert the ex to possible identity fraud, and contact the issuer of the false cards to hold them - then there has to be some way of getting the real person, thus the address or location of them, for the police, private investigator or whatnot.
The SSN is a big piece of leverage, and providing she is not hiding out at an old friend's house you don't know about in another state, and sponging off of them as well - it is a piece that will most likely let you narrow down the search and find your child.
Good luck, and I hope this helps in some manner.
The problem with even a 3D engine is that you start to get into a ton of other areas that you wouldn't think would be a part of it, but are. One biggie is databases - essentially your world you are rendering exists as a database, but it has to be a high speed one, typically will be custom, and may even be specially geared toward 3D operations on the data sets that inhabit it. That is just one quick example, there are tons more.
Other posters have pointed out what goes into a game engine, which covers even more ground, so I won't go into it here again. Even for 3D engines, if you have little or no knowledge of the subject, don't expect to gain it overnight. One thing when I tried learning this stuff that I figured out quickly was that I couldn't learn it just reading a book on vectors and matrix multiplication. Sure, that helped, but it didn't tell me WHY. So, I struck out on my own - first learning what rotation was. I started out creating apps that rotated things in 2D (using SIN and COS) and why that worked (ie, unit circles, etc play a big part here - if you are lacking in geometry or trig, brush up on those), then learned how to expand that into 3D, so I could do all of that. Then, I learned the hows and whys of projection, then back-face culling, then face/object culling based on intersections with the view frustum, etc - on and on and on...
It never seemed to end, and in the end (I was wanting to make a 3D game engine, which never went far) I was finding I was taking up too much time on this, when there were tons of engines available that could do all I did, plus tons more I just didn't have the time to learn to do, that I realized that I was wasting my time on this hobby, rather than looking into wheels that already existed.
Now, let me say that I never went anywhere with building a 3D game, and game building isn't my main thing anymore (though it is still something I think about - one of those "back burner" projects) - but I would never give up the learning I was able to come away with in my brief foray into 3D game engine mechanics. It gave me a lot of insights into the kind of things game engine coders face, and a respect to what they do, and what they know. It also taught me how complex the world really is, what it takes to even try to model things. It also helped me think of how to do new ways in coding to gain speed and tightness of code, which are useful in more ways than just pushing pixels.
So, I don't want to discourage you - if what you are wanting to do is learn, then go for it. If you are wanting to learn enough to get a job in the field, then go for it. If what you are wanting in the end though is to create a game, then I would advise you to learn the basic mechanics (ie, enough to code a simple texture mapped cube spinner, possibly with cameras, maybe even a world database, etc - which was as far as I got - maybe even though in simple face lighting), to know how it all works at a basic level, and to understand what is being talked about - then find a free or GPL'd engine and work with it from there to create your game.
As has been shown by countless examples scattered across the net, a game engine by itself is useless without a good playable game to go along with it...
To be honest, I have forgotten the details of most of these experiments, so while I cannot give you exact methods or reasonings, the gist of the experiments should come through enough for you to consult with other sources and collegues to fill in the gaps of my mind.
To that end, the experiments:
1) Measuring the speed of sound - from this one I remember we first determined in class how you could measure the speed of sound, variables, and how you would set up the experiment, then what the answer would work out to be if done a certain way. Then, the class was led outside, and one person held two sticks and banged them together. Another person was instructed to listen for the return sound from the science building we were standing away from some number of feet. Someone else was timing with a stopwatch. I am not sure of the process, but from all of this we got data that we used in class to determine the speed of sound, based on how we should do it - we weren't that far off, if I remember right, for our height above sea level and the condition of the weather outside - and we were real close to what we had gotten in the classroom.
2) Hitting a target - perhaps a little closer to home today than then - basically calculating trajectories, parabolas, etc. In the classroom, we calculated given a certain amount of pressure in a rocket (we used an air powered rocket for safety and distance reasons), angle, etc - what was needed to be put into the rocket in order for it to hit a target set some distance away. Once we had calculated that, we then went out on the football field (to the amusement of the PE class of the period), and launched the rocket. We hit the target, as our calculations said we would (now, class, can anyone tell me how an ICBM works?).
3) Measuring the mass of an electron - OK, this one is REALLY fuzzy in my mind, and in the end, we were off by a whole heck of a lot, but not as much as you would think given the equipment. All I really remember about this was some very complex mathematics, a bit of reasoning, and the use of an old occiliscope and power supply.
4) Water below freezing - in this experiment, which involved more than I am letting on here - we showed in individual labs how you could keep water liquid, even though you brought it down below freezing. We used stainless steel containers, regular water, ice and salt in a styrofoam container to bring the water down that was in the stainless steel container, some thermometers, etc. I also remember another part of the lab that involved a different substance, that you heated, it went from solid to liquid, then you gradually cooled down to room temperature (by lowering the bunsen burner flame), but it stayed liquid. Then you let it cool off really well, still liquid, then you put in a seed of the solid substance, and it immediately crystalized solid again (in time for the next class, I suppose). Cool thing to watch.
Those are the ones among my favorites. They could be enhanced in different ways (like the trajectory one - build a spud cannon instead for the demo, on a stand that permits tilting it like a mortar, at known angles). Hope these help - good luck!
I also question when they will be doing this run of 25 miles. If they don't pick the right time of season, they will run into either dust storms (strong enough to rip the paint off your car and needing a new windshield), thunderstorms (dropping a lot of water in mere hours), or a combo of both if they are really unlucky.
This robot is going to take a few days to go the distance. It will have to deal with desert conditions (both day and night conditions, and weather) and desert obstacles (brush, trees, loose soil, rocks, animals, washes, etc).
I really question the whole project - was the goal to make a legged vehicle or to go a distance autonomously?
I think about the DARPA Grand Challenge, and I think what would be the best vehicle for such a thing. Then I thought it would be a challenge to go any distance autonomously. For the terrain, legs are OK, but use a lot of power. Considering the obstacles likely to be encountered, a much better and more efficient system would seem to use wheels.
I would go for a system similar to what the Mars Rover used, the suspension system with six wheels, but scale it up a bit to use larger ATV wheels. Keep the engine, but throttle it back greatly (under computer control) to maximize fuel consumption (properly tuned, etc with proper throttling, you can get hundreds of miles per gallon of fuel). Keep solar panels and batteries on-board, which at minimum could run the system in the event of an emergency to "call home". Such a system would be able to make a 25 mile run in probably a day or two maximum, and could possibly compete in the DARPA challenge.
At the end of the day, though - regardless of whether this legged wonder does it, or somebody builds another device, wheeled or legged, that does it, even over a much shorter distance, they will have come up with a solution, and proved that solutions exist, to several "grand problems" in autonomous robotics that would prove useful in a number of other situations (ground rescue, factory work, planetary rovers, underwater exploration, etc).
I wanted an ultra-cheap PDA to store a small DB for things like "books I want" vs "books I have" (expand to VCDs, etc). I didn't want to spend a butt load of money on a real PDA, and besides the extreme seemed to have more than enough for my needs. Someday I plan on getting it working with USB and Linux (there is a GPLd serial port interface for Linux for the older cybiko, but it doesn't work with USB, though the author thinks it would be easy to mod to get it to work - anyone with more experience than I want to take a crack at it?).
It is too bad it didn't take off - it is really a VERY interesting device, light on memory, but it has expansion options, it is quite sleek looking (extreme), and has a lot of free software for it. There is dev tools for the thing, plus a version of BASIC (yeah, yeah, I know - but I just think about how it has as much memory as the old skool boxes, and text adventures would be a fun thing to put on it, etc). It really wasn't that expensive when it first came out, compared to similarly marketed products. It was one of those products that didn't really have a niche - it doesn't seem like it would make that great a PDA (because it has a tiny keyboard which is hard to use), nor a game machine (though it is better here), plus for kids it wouldn't be tolerated in schools (I doubt any PDA is, though). But the price was great - I wish I could get a Palm or something for $30.00 with all the functionality, etc.
Does anybody know of a PDA (that isn't WinCE) that is under $100.00?
Besides, even if it didn't work - that doesn't mean you couldn't sell it. Think of all the "crap" they sell down at auto zone or such, and how this device I described could be built super-cheap, and sell for $20-30.00 or so - you could make a mint (even if it didn't work).
With that said, however, you don't seem to understand that I was envisioning an "always-on, broad spread" laser or LED system for illuminating the license plate - ie, it would be illuminated at all times, cover the whole plate, and thus a portion of the light (whether visible red or IR) would be seen from any angle.
Heck, maybe somebody could build these things anyhow, sell them at auto-zone and make money, even if they don't work - after all, people do buy those hanging fuzzy dice (amongst other junk you see).
Basically, this will only work for vehicles with an area immediately in front of the license plate to put a ball-type tow hitch. What you want to do is create a realistic looking "fake hitch", that can be "bolted" on in place of a normal ball hitch. Mold the casing from plastic, the ball hitch preferably "chromed", or possibly given a fake finish to simulate a used hitch (better for an older beater vehicle). Now, for the goodies:
Inside the base of the fake hitch (what would be the bolt shaft) put in a relatively high-power IR or Red laser LED or regular LED facing up (toward the ball end). In the ball portion, mount a small motor with a tilted mirror attached to the shaft (ie, a typical right-angle scanner system). On the side of the ball facing the plate, make a clear window, or cut away a window area (or mold it). If using an LED laser, you will need a diffraction grating or something to spread the beam in a line. It might also be possible to build it with a simple or curved mirror, no motor needed. Hook it up to a source of 12VDC in the car.
The idea is that the mirror spins, bathing the license plate in light - but the whole system looks like a trailer hitch to the "uninitiated" (which, note, some communities/states have laws against driving a vehicle with only a hitch, but no trailer - gotta love that).
To be honest, I don't know if this would work or not - something tells me that LED lasers and/or LEDs wouldn't be bright enough to illuminate the license plate and still reflect enough to white-out the camera system. But it might be worth trying out!
I have only seen a few meteorites, all except one in museums (that one was owned by a mail clerk at my work, who asked me if I thought it was a meteorite and what should she do - I told her it certainly looked like one, felt and weighed like one - iron, bubbled - told her to get it looked at by someone at ASU). I don't know if all meteorites look like this (I could only describe it as "porous" or "spongy" iron chunk - looks almost like lava rock, but bigger, and iron - stick a magnet to it), but every one I have seen looked like that (which don't mean jack).
So, get it appraised - but keep it. If you liked your grandpa, and you have memories of it as being interesting as a kid, then it is something worth keeping (but hey, if it is valuable, use it for collateral or something)...
This device, called TWISTER, was at the Siggraph 2002 - it consists of a drum made of of panels of LEDs that spin around the viewer standing in the middle. It was created by Kenji Tanaka, et al at Tachi Lab, University of Tokyo. I would imagine such a device could even be built to do full 3D, perhaps by using shutter glasses of some sort synched to the scanning of the LEDs. What would also be cool is to add a head tracker that could tell which direction you are looking in, and only activate an "arc" of panels such that the view went beyond your peripheral vision, but didn't wrap around, lessening the load on the computer driving the system (why display what you can't see?)...
Anyhow, this image was taken by Jerry Isdale, a long-time graphics/VR researcher, who attended the show (sadly, I was unable to attend - can't afford it).
The rest of his report is also interesting, showcasing other 3D and VR technologies presented...
I can only guess that you must have been a little kid to have missed out on Virtual Reality. Really, what is today Q3A and UT grew out of the want for better 3D graphics for those systems (I am not saying VR begat Quake, but it did influence the development of 3D engines, etc). HMD's, head tracking, glove input devices, 3/6DOF position sensors, etc.
I have a wierd feeling - I mean, back then (and less so now, but still happenning) a lot of people were developing VR systems AT HOME - using 386/486 machines, Amigas, LCD TVs (for HMDs), potentiometers and wooden arms (for head tracking) and Powergloves to interact with 3D worlds they created (most of the time using Rend386 or other homebrew 3D software).
What has happened? Has all of this knowledge, not to mention the knowledge of the existence of this knowledge, been lost? Heck, I KNOW that can't be the case, my website has a ton of the old stuff on it - I still see new stuff appearing now and then (such as that Linux PowerGlove driver that works great with my modded PG). It seems crazy - but it is almost like you are one of a growing cadre of people who are TOTALLY unaware of this technology - and furthermore of the fact that today one can build a homebrew VR rig ULTRA-CHEAP, given some time, materials, and a little knowledge. Even if everything was bought off-the-shelf, it still would cost less than $5000.00 to do it. Buying used, or building, that cost could easily drop to below $1000.00.
I am wondering if VR isn't undergoing something like the concept of a windowing desktop - I mean, the first such desktop didn't come about until 1969 (or was it 68?), but it took another 15-20 years before it really started to catch on, and another 10 still before it became ubiquitous - perhaps around, oh, say 2015 to 2030 I should expect VR to hit BIG, and it will be NEW and FLASHY!
I am sure that you, like most of the rest of us, have seen the effects, both good and bad, that the internet has had upon the world.
With this in mind, especially given all of the issues surrounding p2p filesharing and intellectual property rights - if you were given the chance to do it again, knowing what you now know, would you?
At my day job I code in VB - and I have played with XUL in Mozilla. The one nice thing Mozilla/XUL has over IE/VB is that the dev environment is the browser - really, you only need Mozilla, a text editor (I prefer NEdit, but vi will work fine too) - and that's it! I don't have to buy some insanely costly VB IDE system in order to code up my application (and really, when you couple XUL with PHP on Apache, and add MySQL for the backend - you are talking web applications). It's cheap! It's Free! It's Open! What the hell more could I ask for? To be anally raped by Bill?
A wired LAN camera (with built in web server) is only really needed if you are doing something where you have a nearby network connection and don't want to run a long run of coax or other cable for video (though CAT5 should handle video fine), same for the wireless (though it is better if you need such a camera in an area where you can't get wires to AT ALL). I can see using these cameras for a quick setup/takedown for a "fly-by-night" live-webcam porno operation, or in a warehouse, or on a remote ranch - but not much else. Maybe I am short-sighted - where else would these be justified for the expense that a cheaper system wouldn't be worth it?
At home? You have to be kidding. This winter I plan on installing security cams in my house - I am going to use cheap b/w (maybe a single color cam for the front door) cams, most "single-board", which supply 1 Vpp composite video, and need a 12VDC hookup, all of which can be run over CAT5. I will terminate the cameras back at a central location where I plan to hook them up to a custom parallel port driven relay (or IC) based switcher, and into a video capture card for recording. I plan on running the wires in the attic - no big deal. I figure the total cost of this thing will be in the realm of $200 total - the computer is free (junk from work), the video capture card I have lying around, the cameras cost about $25.00 - $50.00 each - why should I buy a LAN camera?
That said, I do like your idea, it is the most logical thing to do - but I was trying to think up some way that photos could be loaded quickly off-bed as one set is scanning, so that you could scan/swap/load/swap/scan/swap, etc...
One thing that I want to build or buy is a backlight for my scanner for negatives/slides. However, this need is becoming less and less as I use my cheapo digital camera...
How about a thin piece of glass with a grid made from black pinstripe tape - sandwitch the pictures between the glass and a piece of cardboard (or similar material), then place the sandwitch on the scanner, and scan - use software to pull the images based on coordinate or edge detection (detecting the grid)...
Also, if you search on Ebay for "pc neon" - you will get some references to various clear LED lit fans that would make for interesting case mods (provided you keep the fans clean).
That makes sense...
In other words, did they demonstrate, to all present, that your actions caused them a quantifiable loss of money which they would have received had you not done what you did?
I take it that if they did, then those companies involved made the proper notations on the quarterly SEC filings? And if not, wouldn't that be similar to the fraud of hiding losses to inflate gains for shareholders?
What is this talk of fingerprint(s) on the sarcophagus? Was this a marking, or an impression? One comment seems to indicate that the print was an impression or something - so what was the sarcophagus made from? Clay? Were such things made from clay? I had always thought they were carved from stone?
But if the sarcophagus was stone, why the print? What if it was a concrete substance, rather than "stone"? You could certainly make a print in that...
There is a theory that the Egyptians had the technology and resources (ie, sand, limestone, something from the Red Sea) to make concrete, and the theory would explain how some of the pyramids (esp the Great Pyramid) and temple structures could have been built, even though they are so large - they were simply "poured" into place. At least, that's the theory...
I am trying to figure out why all the doors on the tunnel - what theory fits this, what the tunnel may have been for (I have seen a site that claims the Great Pyramid was a giant water pump - but that doesn't make much sense since it was built when the area had plenty of water and was fertile), those handles on the doors (why?), among other things...
Finally, I do have to wonder about that robot - that is a TON of money for what should be a relatively simple robot - I can understand that the sides of the tunnel were smooth, and at an angle (ie, needs more than a standard robot wheel drive), but quarter of a mil? Right - time to find the person who pocketed the dough...
If I was going to by the iMow, it is obvious from reviews and such that while the mower may work, it works in a really crappy, non-intelligent manner. Just a random walk, with simple sensors. I would buy one of those, rip out the standard "electronics" (something tells me that the iMow doesn't really have a real computer in it), and replace them with a good micro-controller, add some good sensors (I think it only has a simple non-directional "bump" sensor - I would replace that with an array of bump sensors around the perimeter). Leave the wire, then add code the controller to tell it to go around the perimeter, measure the distance, then make another lap inside the first one (with a few inches of overlap). If obstacles are encountered, add code to go around the obstacle, but map it for later - the code would be similar to a generalised paint/fill algorithm...