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Comment Re:Net energy? (Score 1) 580

Some places might not have enough green energy. But some states have an excess:

The wind power boom in Texas has outstripped the capacity of the transmission systems in place, and predicted shortages in transmission capability may dampen the growth of the industry in years to come. It is said that until now, the growth in wind power "piggybacked" on existing lines, but has now almost depleted spare capacity.[22] As a result, in winter the west Texas grid often has such a local surplus of power that the price falls below zero.

Comment Re:Net energy? (Score 1) 580

You won't fuel the modern era with something that takes as long to renew as plants do

What is this nonsense. We're currently fueling the modern era with fossils that take millions of years to renew. Windmills take a decade to break-even. And solar photovoltaics several decades. Ethanol is one of the fastest-renewing energy sources we have.

Comment This is a great direction for Open Source (Score 1) 117

I've spent the last couple of years working on a system similar to this. I've designed a modular aquaponics/microponics system with a portable greenhouse, custom biofilter, gravity-fed drip irrigation and solar and geothermal heating, all based on UNIX principles: modularity, simplicity, standard interfaces, robustness, ease of repair and maintenance, extensibility, and of course automation. I haven't had time to document much so far, but I made a little introduction video you can see here.

I use Arduinos to monitor temperature and soil moisture, and to control pumps, heaters, and irrigation valves. There's a modular chicken coop, with automated doors also controlled by an Arduino. The Arduino is a great platform for this type of thing. It's extremely reliable, easy to program, and extensible. For example, I decided I didn't like any of the existing relay shields available, so I created my own shield that controls eight standard irrigation solenoids. That was very simple thanks to the openness of the Arduino platform.

The garden isn't quite year-round yet, but that's the eventual goal. If you setup everything right, it really isn't much work to maintain, just like Open Source software. My concentration has been on automating as much as possible, while sticking with organic and permaculture growing principles. I started out by eliminating daily chores, then moved on to automating weekly tasks. At the moment, my system can go for a month or so without intervention, and most work is bi-annual.

Everything is interconnected in one way or another. Grass clippings go into the chicken coop. Chicken litter goes into the compost bin, along with paper trash and kitchen waste. Compost goes on the garden. The chicken coop and compost bin provide shelter for beneficial insects. Fresh water goes into the fish tanks. Fish-fertilized water goes onto the garden, and into the duckweed ponds. Duckweed supplements the fish and chicken feed, and provides clean, fresh water.

I think this is just one of many great directions for the future of the Open Source movement. It's easy to predict that projects like Arduino, RepRap and Open Source Ecology are going to make a huge impact on the world in the coming years, in much the same way that Free and Open Source software have shaped technology over the last decade.

Comment Re:Both an Arduino *and* a Raspberry Pi ? (Score 1) 96

Okay, take this with a grain of salt since I'm not really an expert on web design. But it should be possible to write your web interface in Javascript, store it locally, and use it to communicate via JSON with the Arduino over USB.

If you're considering producing an Arduino shield, it's not too costly to add a bit of memory as well for data logging and storage.

Just something to consider. It seems like it would make your design cheaper and more robust, for the cost of a bit of programming.

Comment Both an Arduino *and* a Raspberry Pi ? (Score 2) 96

This seems like overkill. If you just want a web interface, there is an Arduino library that will allow you to establish a SLIP connection over USB to connect to the Arduino via a webbrowser, no ethernet shield required: SerialIP. It does take up a bit of memory, though, which leads to the next suggestion...

How did you max out the program memory on your Arduino? Why on earth would you use 16 bits (0.001953125 dC precision) to store temperatures, when your thermometer only has +/-0.5 dC resolution? Does it really matter that you turn on your refrigerator compressor at the exact nanosecond it needs to come on?

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