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March 25, 2008

iNoteBook: repurpose an old laptop

It seems like I end up updating my laptop every couple of years, but as cool as new hardware is, sometimes the challenge of finding a new use for the old machine is more interesting. The iNoteBook mod is a classic example, transforming a broken, screenless iBook into a stealth desktop machine.

What's your favorite laptop reuse project? If you've got one, please share in in the comments.

The iNoteBook

February 27, 2008

Wiindow curtain control

Hackszine reader clickthegoogleads wrote to us about a set of Wiimote controlled curtains:

The curtain control system is an existing system from Goelst and is called "G-Rail 6200". Normally it is controlled by infrared or wallswitches. However, it can also be controlled with a CAN bus. I used this CAN bus to interface with an old PC. ... GlovePIE has no function to send messages to a CAN bus. So I started up my good old visual basic and made a little program that handles the CAN messaging. In the first version I used the keypressed event. I made a GlovePIE script that sends out keyboard keys when the Wiimote has a certain orientation and voila... L is for left, R is for Right and S is for Stop.

Is there anything that Wiimote can't do?

Wiindow Curtain Control - Link
GlovePIE - Link

February 25, 2008

Botanicalls Twitter: flora tweets

With Monday finally wrapping up, it's time to start thinking about next weekend. Why not spend it Twitter-enabling your house plants?

Botanicalls Twitter answers the question: What's up with your plant? It offers a connection to your leafy pal via online Twitter status updates that reach you anywhere in the world. When your plant needs water, it will post to let you know, and send its thanks when you show it love.

I've managed to make it through the winter with only two plant casualties so far. There isn't a whole lot I can do about the scarcity of light in Minneapolis, but with a little Arduino hacking I could at least remove watering issues from the equation.

Botanicalls Twitter - Link

February 15, 2008

Hack request: electronic cat door

An anonymous reader requested a hack today to solve a particular kind of kitty problem. Specifically, the reader wants to know if there's a way to have a cat door that grants access to particular cats while restricting entry or exit for others. Not being a cat owner, I don't follow cat electronics too closely, but I have heard of a project or two that are similar in nature, and I'd like to open this up for further discussion in the comments.

The photo above is from the Flo Control project. This cat, Flo, had a nasty habit of bringing in dead mice to the house. Her owner created a computer controlled system that captures an image of the cat as it approaches the door. The PC does some image recognition to determine if the cat's silhouette is atypical (ie. carrying something nasty) and only unlocks the door if the cat is sans-mouse.

One element that's used in the Flo Control setup is a cat door product made by Cat Mate. They make a few different models of cat doors that require your cat to wear a special collar to be allowed through. These are typically operated by a magnet or infra-red beacon in the collar which is able to mechanically or electronically unlock the door. My guess is that something like this will probably will do the job, but if your neighbors start doing the same thing, there's nothing to keep other cats with a collar from getting in.

A more interesting idea is to use RFID to uniquely identify a particular cat and grant access accordingly. There's a commercial product called Pet Porte that is able to do this with the RFID chip implants that some owners are sticking on their animals these days, but I figure it might be more fun to make your own, perhaps using a tag on a collar.

There are a number of RFID sensors for the Arduino and Basic Stamp microcontrollers. It'd be straightforward to program one of these to accept specific RFID tags and then trip the lock switch in a slightly hacked Cat Mate door. The only problem I see is devising a collar that wouldn't bug the cat and would also place the RFID tag in close enough proximity to the reader. Any readers out there with thoughts on this?

The Flo Control Project - Link
RFID Enabling Your Front Door - Link
Using the Arduino with the Parallax RFID reader - Link

February 13, 2008

Apartment-friendly bike rack

It's hard to find a good place to store your bikes when you're an apartment dweller. Here's a nice looking bike rack made from a few cheap Ikea shelving parts.

All you need to get from ikea is one stolmen post, two brackets and four hooks. you'll also need some screws and some aluminium 20x20mm square pipe, maybe some foam rubber.

I think I'll give this a try in my garage to clear up some needed floor space.

Stolmen Bike Rack - Link

February 3, 2008

Rebuild a Roomba battery

Before you buy a replacement battery for your dead Roomba, you might want to consider rebuilding the pack yourself. You can get a couple of 6 cell Sub-C NIMH packs for less money and more amp hours than the stock battery.

I've been wondering whether it would be economical to just rebuild the battery pack, versus buying a new one. From the looks of it, all it takes is 12 NiMH cells, and from the looks of the case, it looks to be C-Size form factor. For less than $36, I can pick up 12 4500 mAh C cells. I can see iRobot has tried to prevent people from doing this by using TRIANGLE bits for their battery cases, but that's simple to get through.

To remove the triangle bits, just find a small flathead screwdriver that you can wedge in nicely.

Rebuilding a Roomba Battery for Less - Link, Photos

January 14, 2008

Roly Poly Pot

Sometimes the solution for an everyday problem is so simple it takes thousands of years for someone to fail to overlook it. Take this clever concept for a flower pot that leans over to signal you when your plant needs watering. Jonah @ Makezine writes:

Unlike some plants that call you on the phone when they are thirsty for water, The "Roly-Poly Pot" concept by Samgmin Bae begins to tilt over when its water levels are low, thus serving as a visual reminder of their thirst. Each pot can be adjusted to work with the plant's watering needs and schedule.

Roly Poly Pot - Link

November 19, 2007

Hamster-powered night light

Here's a little howto on building a low-RPM generator from scratch. I assume that not all of you have extra hamsters lying around to power your night lights, but a similar design could be used for creating a small generator for wind or other energy sources.

Though it's hard for the hamster to make higher voltages with his low-rpm wheel, he has torque to spare. 2 LEDs are barely taxing him......we are drawing only about 30 milliamps into the LEDs at Skippy's top speed. If we add more electrical load to the circuit, he could make more power, with a resulting increase in physical resistance on the wheel---like running uphill. We have yet to try small incandescent flashlight bulbs in the circuit--something that draws more power and makes more physical resistance against the wheel spinning. We did try more LEDs -- he had no trouble lighting up 6 of them. Next we plan to try an array of low-voltage incandescent flashlight bulbs to get optimum power output without tiring Skippy out too much. DanF is guessing that Skippy is good for 200 milliamps without tiring...

One cool thing is that the author uses a bicycle computer to track the hamster wheel's average and top speeds over time. This is a nice tool to have if you're trying to monitor and optimize the environment for your generator setup.

Hamster-Powered Night Light - Link

November 1, 2007

Save a half-gallon of water on each flush

If you have an older toilet with a 5 gallon tank, there's an old trick that you can use to convert it to use less water. By simply filling a half gallon container and submerging it in the tank, you can cut your toilet water usage by 10 percent or more. Lifehacker's Gina T. points us to a wikiHow artcile on the topic:

If you, like most Americans, flush 5 times daily, your family of 5 will save 350 gallons (1325 liters) of water every month [2]. These savings will significantly cut your water bill, too.

Adjusting the tank volume will affect your toilet's ability to flush more, uh, serious business, so your mileage may vary. A lot of folks have a second bathroom that's used more often for lighter work, in which case this hack could save quite a bit of water over a year's time.

How to Convert Any Toilet to a Low Flush Toilet - [via] Link

September 21, 2007

Use Compact Fluorescent Bulbs in a Ceiling Fan

I bought some GE bulbs that are supposed to work in ceiling fans, but they flicker and flash big time. I was able to get them to stop, oddly enough, by activating the dimmer and finding a sweet spot for the settings, but that was a hassle. So I did some trial and error tests and as you can see in the embedded video, 3 CF bulbs + 1 incandescent is the magic recipe.

I think the problem is in the fine print that says the bulbs aren't designed for dimmer switches; even though the lights are set on full power by default, I think there's something in there that interferes. So a future project might be to remove the dimmer from the fixture, get a new fixture, or find a CF bulb that supports dimmers and ceiling fans.

August 8, 2007

Earthship - extreme off-grid architecture

This looks almost like having your own biosphere. Earthships are a pretty unique form of sustainable architecture that are compatible with a wide range of environments around the world. Each home is custom built to fit its particular environment, but there are a few things they all seem to have in common:

They are built from primarily reused materials. The load-bearing walls are actually constructed from old tires packed with dirt, and recycled cans and bottles are used as filler throughout non load-bearing concrete structures.
Passive-solar energy is used for heat regulation. They are smartly placed semi-embedded in a hill with south facing windows. This helps regulate the temperature even through drastic external temperature changes.
Off-grid solar and wind power are used to supply all electricity needs.
A rainwater capture system provides drinking water, which is then recycled into greenhouse water, then to toilet/waste water, before finally exiting to a self contained septic system.
The south side of the home functions as a greenhouse, which assists with water treatment as well as aesthetics and supplemental food.

I'm pretty sure this wouldn't fly in the middle of a metropolitan area, but I love it all the same.

Earthship Biotecture - [via] Link

May 17, 2007

Use bread to remove crayon marks from the wall

Hackszine reader Keith Hanshaw sent in a tip for a safe way to remove scribble marks from your walls. Just grab a piece of bread, roll it into a tight ball, and start rubbing. It looks like it takes a bit of elbow grease, but it's a cheap and chemical free way to clean up after the kids - Link.

February 2, 2007

Microwave Hacks

Did you know that your microwave is more than just a simple leftover reheater?

A couple weeks ago I heard about a study which showed that nuking a grungy sponge for 2 minutes was effective at sterilizing it. This was quickly followed by reports of a number of small fires involving dry sponges. Lesson learned: wet your grubby sponges before superheating them.

There are a number of interesting things to do with the household microwave. Of course, there are a number of materials which will spark or ignite, but my personal favorite is David Reid's method for casting small amounts of soft metals like bronse, silver, and gold. On the less dangerous side, there's also the strange and unexpected growth phenomena of marshmallows or bars of soap, though I'm not sure what this is good for besides entertaining the kids with Peep battles.

Finally, you can do a lot of conventional things with a microwave as well. The guardian recently released a top 10 list on the subject. There are hacks for softening citrus fruits for juicing, heating up plates for serving, and sterilizing potting soil before planting seedlings.

What's your favorite microwave hack? Let us know in the comments!