Hackaday Links: March 20, 2011

SNES Arcade Cabinet

arcade_cabinet

[Daniel] let us know that he finished up a SNES arcade cabinet he has been working on for awhile. It looks so good, he says that his wife has even agreed to let him keep it in the house!

DIY Overhead projector beamer

diy_beamer

[Liquider] sent us some information about a DIY beamer he built using an overhead projector and an old LCD panel. It looks like a great way to get a big-screen wall display set up in no time.

WordClock gets a makeover

wordclock

[Doug] wrote in to share with us some progress he has made on his WordClock. You might remember our coverage of this creative timepiece a little while back. This time around, he has built a new control board, and is using vinyl stencils for a much cleaner look.

Interactive water fountain

interactive_fountain

[Gerry Chu] is well known for his water-based imagery and projects. His most recent project is a water fountain that interacts with passers by. There are no real build details as of yet, but we hope to see some soon.

Sixty Symbols explains why glass is transparent

glass

Do you think you know why glass is transparent, but a brick is not? If you looked it up via Google, you are likely mistaken. A professor from the University of Nottingham explains why the Internet is so, so wrong about this, as well as how energy gap determines if photons of light can make it through a piece of glass. [via i09]

Automatic dog dish filler never goes dry

automatic_water_dish

[Avatar-X] has a Siberian Husky that gets a lot of exercise throughout the day, and as you would imagine, drinks a ton of water as well. We all suffer from memory lapses at one time or another, and while he is normally good about keeping the bowl filled, he occasionally forgets. He has tried a handful of various auto-filling dog dishes, but none of them seemed to work all that well, and they often rapidly built up healthy bacterial colonies.

With the help of some friends, he rigged up an automatic water dish filler, that ensures his pup always has a sufficient supply of water. He tapped into his kitchen water supply with a standard refrigerator hookup kit, and ran some tubing up into his cabinets, where he placed a garden irrigation valve. The valve is controlled using an Arduino which senses the bowl’s water level using a pair of wires.

The system looks like it works pretty well if the video embedded below is any indicator. [Avatar-X] provides code and schematics for the water control circuit on his site, free to anyone looking to build a similar system for their pets.

If you are interested in learning more about automating some of your pet’s care, be sure to check out these hacks we featured in the past.

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Water-dosing coffee maker augmentation

[Arthur Benemann] has the worst part of making coffee licked. His add-on for a drip coffee maker fills the water to the proper levels for you, saving the drudgery of rinsing out the carafe, carefully filling it to the appropriate level, then pouring it into the machine without getting everything wet. This isn’t limited to a full pot, but is user selectable by the cup based on how many times in a row you hit that red button. One LED gives feedback on the selected mode, then the device uses a washing machine water valve to turn on the tap for the appropriate amount of time. We’re a little bit leery of connecting homebrew hardware to the water pipes in our house. Make sure you’ve done a good job of debugging so that an infinite loop doesn’t flood you out.

Oxyhydrogen water rocket

[cmwslw] built a soda-bottle water rocket that uses the ignition of oxyhydrogen gas to quickly expel the water, as opposed to the usual compressed air and water mixture. His project contains excellent documentation with photos and it builds on other articles he’s written about generating the flammable HHO gas used to launch his craft into the skies. Every aspect of this project uses items most of us have at home or could score cheaply at most hardware stores.

We love seeing projects that re-purpose everyday materials into something fun. Just be sure to dodge the missile pop bottle as it speeds back to Earth!

Christmas tree low-water monitor

The end of the year is rapidly approaching and there’s a good chance you have a slowly dying tree in your living room. Help it hold on a little longer by using [Eric Ayars'] Christmas Tree water monitor. He’s built a sensor out of a piece of strip board. Three bus strips on the board allow for a variety of alerts. When all three are submerged everything is ok. When the two longer traces are still under water but the third is not an LED will blink to let you know it’s time. If you don’t pay attention and there’s no water left, a piezo buzzer makes noise until you add water (or the coin cell runs out of juice).

This project centers around an ATtiny85 that [Eric] programmed using an Arduino, one of the methods we covered in our AVR Programming Tutorial. But if this simple circuit isn’t high-tech enough for you, we saw a similar method last year that will send an alert to your iPhone.

Water use feedback changes behavior

How much water do you use when showering, or washing your hands, or washing the dishes? Not how much does the average person use, but how much to you use? That’s what the team over at Teague Labs set out to find with this water usage feedback system. The sensor used is a Koolance flow meter which is intended to measure coolant flow in PC liquid cooling systems. At $20, it makes a nice low-cost sensor which was paired with a WiFi enabled Arduino. In the image above they’re using an iPad as a screen so that you can see how much water you’re using (or wasting) as you wash your hands. This resulted in saving 1/2 gallon of water every time someone washed their hands.

The project code, schematic, and board files are all available for download. Along with the hardware build there’s some nice server-side software that gathers and graphs the data over time. We’ve seen a lot of power-meter hacks, but it’s nice to have the option to track water usage, even if this is tailored to just one tap at a time.

Hydropower generator

[Paul] wanted to have access to renewable energy at his cabin. It’s a relaxing place, nestled in a tall forest that shelters him from the sun and wind. This also means that solar and wind energy aren’t an option. But there is a stream running through the property so he decided to build his own version of a small water-powered generator.

He tapped into a reservoir about 200 feet upstream, split the flow into four smaller hoses, and channeled that into a five-gallon bucket. Inside the bucket you’ll find a Pelton wheel he built which turns a low-RPM generator. He manages to generate 56 VDC at 10 A with this setup, more than enough to charge a bank of batteries.

He does a great job of explaining his setup in the video after the break. If you’re looking for other ideas of how to cut down on your environmental impact check out this compost-powered water heater.

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