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466  Community / Bar Sport / Re: Your opinion on piracy? on: September 06, 2012, 05:23:21 pm
I think Locke was correct when he stated that the basic human rights are 'Life, Liberty, and Property' and Jefferson did a disservice in his paraphrasing of Locke.

It is possible to have a societies where there is little concept of personal property so it is not a basic human right.

You have to pare things back to the bare bones of do most people feel morally wrong doing something.
If they don't then do not let somebody pass a law that makes that thing illegal.
By sticking to the principle of having laws that uphold moral views you will have good laws and avoid manipulation of the legal system for the benefit of a few.

What is regarded as moral will change with time and will vary from place to place and laws must be adjusted accordingly.
467  Using Arduino / Project Guidance / Re: Pet Feeder with RFID on: September 06, 2012, 04:50:32 pm
You have not said what kind of pets you have, or how smart they are.

Looking at the posts by PaulS and DRBArduino made me think about a couple of things.
You probably don't want to feed the pets every time they want fed.
However the animal needs to learn how to operate the feeder and that could be tricky if sometimes the animal gets fed and sometimes it does not.

For the animal to learn to use the feeder I think the feeder needs to indicate that it is "willing" to dispense food.
So when the feeder is prepared to dispense food it needs to have an LED, flag, sound or something, that tells the animal I will feed you if you wish. When the animal sees the indication it can then do whatever is required to trigger the food release.
468  Using Arduino / Project Guidance / Re: Motion based light switch on: September 06, 2012, 04:35:37 pm
Don't forget that your Arduino needs power.

Have you thought about using  pressure pads rather than a motion detector as that eliminates issues about beam widths.
You probably also want to monitor ambient light or include a clock as there is no point putting the lights on in broad daylight.

Build everything on the bench and fully test it before installing it for real.
469  Topics / Interactive Art / Re: how to make three-dimensional objects completely touch sensitive on: September 05, 2012, 05:53:43 pm
2) where exactly the three-dimensional surface got touched (the main problem!).

That does sound like the main problem to me.
The only solution to this problem that I know of is skin, either nerves in skin or hairs attached to nerves in skin.
You should define the size of your object and the resolution of touch you want to detect.

My gut feeling is that flexible conductive hairs would offer the best solution, but how you would fabricate something like that I have no idea.
470  Community / Bar Sport / Re: I propose a new language. on: September 05, 2012, 05:20:10 pm
I believe VALGOL is a derivative of LAIDBACK which  was developed at the Marin County Center for T'ai Chi,
Mellowness, and Computer Programming.

LAIDBACK responded to syntax errors with the message,
471  Community / Bar Sport / Re: I propose a new language. on: September 05, 2012, 03:51:24 pm
lithp ith a utheful programming language for protheththing lithtth and maketh reading the code out eathy if you have a thpeach impediment. I think thith jutht thhows compiler writerth are a pretty weird bunch.
472  Community / Bar Sport / Re: I propose a new language. on: September 05, 2012, 08:41:52 am
Anyway, PROFANITY is the language all programmers know best!
Not heard of that one, is it similar to Brainfuck?
The compiler is very compact, 200 bytes;
473  Using Arduino / Project Guidance / Re: Tips on writing efficient code for Arduino on: September 04, 2012, 04:14:52 pm
Technically, a non sequitur here.
Yes, but you knew what he meant.

"non sequitur",  "feducial", "sophistry", the forum is expanding my vocabulary much faster than my electronics/programming knowledge - no bad thing.
474  Using Arduino / Project Guidance / Re: Tips on writing efficient code for Arduino on: September 04, 2012, 09:19:55 am
In fact a slight haze on a sunny day is the best light you can get. We get several amps more under those conditions.

That is interesting. I suppose instead of a concentrated "image" of the sun hitting a small area on the panels the haze is spreading the energy more evenly over the panel.
Water cooling definitely sounds like a bad idea in Oz. I saw photo of a sign from the Nullarbor that said "please don't ask for water as refusal can offend"!

I wonder if you could put an infra-red filter in front of panels, or would that block the frequencies the PV cells use?
475  Using Arduino / Project Guidance / Re: Tips on writing efficient code for Arduino on: September 04, 2012, 09:08:54 am
JimB on the tilt front you could have two positions Winter---Summer but with just three positions you could have Winter----Spring/Autumn----Summer.
The reflector is a very good idea and, who knows, it might be possible to take advantage of reflective objects in the landscape e.g. sea or other body of water.
Reflectors are not as much fun as heliostats though, imagine three or four following the sun and focusing on the panels.

I have been reading and the efficiency of PV panels does fall with temperature, the losses can be high. Trying to keep the panels cool makes sense.
Ideas might be convection, a heat sink, maybe evaporative cooling. Pumping water for cooling probably does not make sense as it might be better just to buy another panel, but any free flowing water could be used.

Another big saving is keeping the panels clean. So some detector for when the panels need a wash might be worthwhile.
476  Using Arduino / Project Guidance / Re: "lazy Suzan" return to zero on: September 04, 2012, 07:13:17 am
I'm not sure I see the problem.
There is 36deg between cartridges. If the stepper is stepped slowly it will take a while to increment round. On the other hand if the stepper is stepped quickly then the inertia of the lazy Suzan may cause it to make the motor slip if you try to come to a dead stop. The Suzan does not look very massive so a lot depends on the strength of the motor. However in my (limited) experience of stepper motors they behave in a very reproducable way. The code could accelerate the rotation up to a maximum then decelerate down when a microswitch triggers and I bet you you would hit the spot every time - at least to the mechanical accuracy of when the switch triggers. My first idea of two switches may be overkill.

the turntable stops at the station so the case can be rotated
- neat, I understand how it works now.
477  Community / Bar Sport / Re: Your opinion on piracy? on: September 04, 2012, 06:33:57 am
Sorry meant to add
It's also thought he's [Bruce Willis] planning to support legal action currently ongoing in the US that is aiming to give more rights to people to share music they have bought.
478  Community / Bar Sport / Re: Your opinion on piracy? on: September 04, 2012, 06:32:25 am
It is being reported that Bruce Willis may sue Apple over ownership of music. Apparently he has thousands of hours of music on ipods and wants to leave his collection to his children.
"It's thought that he's looking into legal ways of passing the music to Rumer, Scout and Tallulah, but if family trusts can't be set up to redistribute the files once he's dead, he will take Apple to court in order to do it instead."
479  Using Arduino / Project Guidance / Re: Help a Noob out? Marine application of robotix on: September 04, 2012, 06:26:30 am
If you search this site for ROV there are some useful posts including links to sites where people have built working systems.
480  Using Arduino / Project Guidance / Re: Tips on writing efficient code for Arduino on: September 04, 2012, 06:12:04 am
Surely from the GPS position and time of day / month, you can get a very good approximation of the position the Sun
Yes, you can calculate it exactly.

The solar panels don't move around so you only need to know latitude and longitude at installation time.
You also need to know the direction of true (not magnetic) north.

A program called SunAlign was written in QBasic by David Williams:
      David Williams
      P.O. Box 48512
      Long Branch P.O.
      Toronto, Ontario. M8W 4Y6

This was converted to c by Marius Gundersen, January 25 2009.
The conversion to C was quite faithful to the structure of the original QBasic program, some variable names were changed.
I think there may have been some bugs in the C code I found.

I was intending converting Gunderson's code to run on the Arduino adding in comments derived from an explanation of the original QBasic program by David Williams, again with minimal alteration. unfortunately I got bogged down on other things.

If somebody wanted to collaborate on getting the thing running I would be interested to hear from them and might pick it up again.
There is enough info here to find the original code and explanation.
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