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SparkFun will be closed May 25, 2015 for Memorial Day. Orders placed after 2pm on Friday the 22nd will ship out on Tuesday. Thanks!

Rob

Member Since: May 25, 2008

Country: United States

  • So, if I’m reading your estimates right, we the people contributed $195,000 towards your solar array (via a federal rebate)? And even so, the investment isn’t more profitable than putting the money into some other average investment?

    Um… awesome.

  • Hmmm… I guess so. I always just use a coin cell.

  • Parity bits aren’t used much because there’s nothing to do about the error. The hardware layer isn’t that useful of a spot to catch the error. These days, errors are usually detected at a higher layer, where a resend can be requested. The UART counts the 1-bits in the message, the parity bit is then used to make the total even or odd, depending on how it’s set. It’s not particularly good at catching errors, either. Parity was just a bad idea and that’s why no one uses it any more (well, I’m sure SOMEone does).

  • You might want to google “markov chains”. The trick to getting nice sentences out of the thing is to pick random words, but only random words that tend (in normal english sentences) to come after the word you’ve just picked. It might take more than the processing power of the arduino in question, however.

  • I don’t know if this would produce enough electricity to be worth the power company’s time. Lance Armstrong can produce about 500 watts. If you lined up 10 Lance Armstrongs and got them to pedal for eight hours, that would be 40 kWh. That’s less than five bucks worth of power in an average market.
    How about a better model: let people plug in their phones and laptops and iPods and charge them up? That way you don’t have to deal with bureaucracy of the power company and people can get an immediate, personal benefit. Plus they can go the rest of the day with that smug, holier than thou feeling, knowing their phone is “green” powered.

  • Also, distributed power generation IS NOT good for the power grid – it’s a nightmare that is driving grid operators crazy all over the country. The grid must always, always balance: the exact same power must go in as comes out. This is very difficult when you don’t control what goes in. Texas almost had a major outage in March 2008 because the wind died suddenly in west Texas and took about 4,000 megawatts of generation offline in a few minutes.

  • You did the math right. There’s an online calculator at http://findsolar.com/ that leads to similar conclusions. The payoff is about 20 years, even for the most optimistic assumptions (eg, that the solar panel itself adds value to your house, even though it is a depreciating asset).

No public wish lists :(