Halloween Props: Dancing Spider

[Isaac] grabbed the motor from an old printer and used it to make a spider run up and down the wall for Halloween. A PIC 12F683 uses a MOSFET to drive the motor. The program loop has a little bit of dramatic flare to it, raising the arachnid with a bit of a jerky motion to give it some life, then wait for a time before quietly lowering the spider (hopefully onto an unsuspecting party-goer).  The driver board is set up for two motors, making it easy to reuse in future projects. This is quite effective, and the only addition we might suggest is to add a couple of red LEDs as some glowing eyes.

Take a look at the finished product after the break.

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Window Curtain Moves To Screen Pedestrians

[Niklas Roy] built a motorized window curtain to screen out foot traffic in front of his window. When you hear “motorized curtain” you may think that this will move up and down but it doesn’t. Instead, the small curtain move horizontally to cover passersby as they travel down the sidewalk. This is accomplished using a camera in conjunction with some motion sensing software. In the video after the break you can see that the software also anticipates the movement, and ends up doing a good job of keeping the target covered. That’s thanks to the Processing sketch working in conjunction with a rotary encoder on the hardware setup. Details for both are available on the page linked above.

This harkens to other community involvement hacks we’ve seen like the subway stair piano, or the bottle recycling video game. It’s fun and quirky, which is not too much of a surprise as we saw a glimpse of that when we looked at [Niklas’] public fountain hydropower generator.

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Halloween Props: Puking Pirate

With everyone’s favorite free-candy holiday approaching, [Slouriesr] set to work building a vomiting ghoul for his Halloween display. He’s calling it a puking pirate and it centers around a pump and some simple plumbing fixtures.

First, the vomit receptacle was made by adding a sink drain with a pop-up stopper to the bottom of a kitty litter bucket. The drain slows the evacuation of liquid into a five gallon bucket below. In that bucket you’ll find a float switch pump used to keep water off of a pool cover. As the bucket fills up the pump turns on and empties the water through a hose ending at the ghoul’s mouth. The result is a 20-second puke cycle sure to delight the trick-or-treaters. Sure, there’s a lot of work to be done to get this guy looking the part, but what a great idea!

Help keep us in the holiday spirit by sending the details on your latest prop build.

Beefy Battery Backup Still Running After A Decade

In 1997 [Michael Butkus Jr.] found an uninterruptible power supply in the dumpster. The batteries were shot, but he needed a backup to keep his pellet stove running for heat, drive the exhaust fan to keep the smoke out of the house, and power his computer and other electronics. After a bit of head scratching he decided to beef up the UPS using deep-cycle batteries.

He actually built two of these. One is smaller, and similar to what we’ve seen before. The other is larger and uses four batteries, two pairs in parallel which are then connected in series. He’s careful to use heavy gauge wiring and 50 amp fuses for each battery, both of which will protect against the risk of fire. One thing we found interesting is that the batteries are stored in the basement, directly below the UPS which is connected via a short run of 12 gauge home electrical wire.

We were happy to see that he’s done updates at the top of his post over the years. He lost a few batteries due to neglectfully letting the water levels drop too much. He did switch over to sealed automotive batteries sometime in 2004 or 2005. Looks like things have been going strong ever since.

[Thanks Spencer]

Wood Burning House Heater

Dabbling in alternative heating technology, [Rob Steves] built a wood stove to dispose of his scrap wood while negating his home’s fire insurance at the same time. As the leftover bits from his wood projects started to stack up he wondered how he would dispose of them. Burning the bits for heat means he’s using every last bit of the lumber. The internal tank from an electric water heater was repurposed as a combustion chamber, with exhaust gases escaping through some high-temperature flexible tubing. The glass panes were removed from one of the fireplace doors to give the off-gases a place to go. The result is a rocket stove that burns very hot and does a great job of warming his house.

It’s not the safest way to heat a home, and there may be coding issues with your municipality. But this might go well in a remote location, like that cabin where you have to generate your own electricity.

[Thanks HybridBlue]

Gutting An Air Freshener For The Parts

[Doug Paradis] took a good look inside the Air Wick Freshmatic Compact i-Motion and then stole all the parts for other projects. We’ve looked at adding a manual spray button or making air fresheners Internet enabled before. Those models didn’t have parts that were all that interesting, but this one has a passive infrared motion sensor. You’ll also gain three switches, a PNP transistor, and an LED.

Price seems to be all over the map for this model, but [Doug] says you can find it for $8 or less. After showing how to make a tool to bypass the triangular security screws, he explains how to access the PIR sensor. But if you want to be all you can be with the hardware, he details the modifications needed to patch into the analog and digital circuitry on the rest of the board too.

Low-power Wireless Home Automation Sensors

The line between serious research and well-executed hacks has been getting pretty blurry lately. The device above could have been designed in your basement but it actually comes from researchers at the University of Washington. They are working on low-power home automation sensors for monitoring things like humidity, temperature, air quality, and light. The key point in their research has been the use of a home’s electrical system for wireless communication. Operating at 27 MHz has proven quite efficient to the point that one of these modules placed within 10-15 feet of an electrical run can communicate with the rest of the home, powered only by a watch battery projected to last ten years.

That’s kind of exciting, it’s a heck of a lot easier to produce and distribute a set of small boards like this than to run communication wiring throughout the house. Now we just need to pair this with the Air Force’s parasitic power work and there’ll be no need for a battery at all.

[Thanks Sidhant]