Hackaday Links: August 17, 2014


[wjlafrance] recently picked up an old NeXTstation, complete with keyboard, mouse, display… and no display cable. The NeXT boxes had one of the weirder D-sub connectors a still weird DB-19 video connector, meaning [wjla] would have to roll his own. It’s basically just modifying a pair of DB-25 connectors with a dremel, but it works. Here’s the flickr set.

The guys at Flite Test put on a their first annual Flite Fest last month – an RC fly-in in the middle of Ohio – and they’re finally getting around to putting up the recap videos. +1 for using wacky waving inflatable arm flailing tube men as an obstacle course.

My phone’s battery is dead and my water pressure is too high.

Stripboard drawing paper, written in [; \LaTeX ;].

Remember the Commodore 16? [Dave] stuck a PicoITX mother board in one. He used the Keyrah interface to get the original keyboard working with USB. While we’re not too keen on sacrificing old computers to build a PC, it is a C16 (sorry [Bil]), and the end result is very, very clean.

A Chromecast picture frame. [philenotfound] had a 17″ LCD panel from an old Powerbook, and with a $30 LVDS to HDMI adapter, he made a pretty classy Chromecast picture frame.


29 thoughts on “Hackaday Links: August 17, 2014

    1. And isn’t he effectively stealing power from the water company?

      Increasing the difficulty to pump water to people’s homes means an increase in power usage by the water company.

      1. No, because the pressure drop is inside your house. The water company doesn’t care what happens to the water inside your house, they aren’t going to increase your water pressure because you installed some device.

      2. Probably he’s just stealing gravitational potential energy (typical case is a tank on top of a hill supplies the town) which would have otherwise dissipated as heat on his premises anyway. That’s assuming it recovers energy only from water you use anyway; if you leave this thing running down the drain then yes you are wasting epic quantities of water and energy.
        It does look like there could be a fair bit of instantaneous power available, depending on your circumstances. My house has 105psi water and we can get about 10L/min from the tap, which is about 120W. Say 85W if the outlet has 30psi of pressure, which is pretty usable.
        The problem is that most people use only about 300L/day, which is 43W-h, also known as 0.043kWh, or about 1c of electricity assuming 100% efficiency. So the capital cost of the plant will never pay off unless you set out to waste a whole city’s worth of water.

        1. If I ran my tap 24/7 down the drain, that’d be 2.4kW-h (72c) per day of electricity generated, at the cost of $72 per day in water bill (Australian pricing: 30c/kWh electricity and $5/kL water). Woot, ROI of -99%!

          There’s a reason people attach hydropower to rivers and dams, not household supplies.

          1. I have ~100 psi water pressure and we regulate it down to 60 psi. If I put a generator in line instead of a regulator, I would have power, just intermittent with water use.

          2. @W Agree entirely on your financial assessment, though nobody conserves water in my Canberra apartment block as the bill goes to the apartment body corporate and is split equally via strata fees. A bit like charging an electric car from a carpark slot, I’m sure someone will realise this is a typical “Tragedy of the Commons” case and act accordingly.

          3. > Here (Bay Area, California) that would be $3.12 for 5KL (1.76hcf)

            yeah,but California has water shortage and constant drought problems, so its only logical you would be pa… wait a minute, I think I just figured out source of your problem.
            Only in US :/

    2. My phone’s battery is dead and my water pressure is too high.

      This is how the Hover Damn project started. Besides, who needs water pressure?
      At least this guy has set a small goal, isn’t making any claim to endless energy (unless he’s started looping the wat

  1. As terrible as it is to say, the place where you COULD make this sort of work is in an apartment where water is included in the rent and they can’t tell who is using all the water. At least you could probably charge your phone off the sink…

    1. “This is not without its challenges; we need to create enough electricity to make it viable for use. But, this obstacle can be overcome through a little trial and error.”

      And a lot of ignoring of all types of logic, math, and physics.

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