Laser Trip Wire – The Bare Essentials

April 19, 2011 by Mike Szczys 12 Comments

[Gordon] sent us a tip about this simple laser trip wire system after reading yesterday’s post on a more complicated laser security unit. That build did a lot to provide functionality, such as a system to disarm the trip wire, and a robust light detection circuit. This time around there’s more happening with smoke and mirrors than with electronics.

[The Timmy] built this simpler version based on a laser trip system from Afrotechmods (video of that one is embedded after the break). He had a bag full of small square mirrors which he attached to a wall with some poster putty. A laser module shines a beam of light onto a cadmium sulfide sensor after it bounces around the optical network for a while. That CdS sensor controls an N-channel MOSFET, switching it off when light is detected and on when the intensity of the laser is absent. This example just turns an LED on and off, but since it uses logic-level voltages you can choose to add a microcontroller to the mix if you have other plans in mind.

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Simple FM Transmitter That Shows Off Its Own Circuitry

April 19, 2011 by Mike Szczys 8 Comments

[Sean Michael Ragan] built this FM transmitter which shows off its circuitry via a clear plastic dome. The device is electrically identical to one we looked at in September. That version championed a construction method that used small squares of copper clad as solder points which were each super-glued to a large copper-clad platform serving as a ground plane. [Sean] is using a printed circuit board that was laid out by Sonodrome. You can check out their own glass-jar transmitter build where the board artwork is available for download.

One of the tips we enjoyed from [Sean’s] step-by-step build is the coil wrapping. He used the threads of a 1/4-20 bolt to guide copper wire as he wrapped a total of four turns. Once the bending is done, just unthread the bolt to separate it from the coil and gently stretch the wire for a 12mm distance between the two leads. Not only is this visually pleasing, but it will help with transmission clarity.

Powering Vehicles With Aluminum

April 19, 2011 by Mike Szczys 83 Comments

Pop a few aluminum bits into this little RC racer and you’ll have power for around forty minutes. This concept, which has been patented, is the result of a college research project. It uses a chemical reaction between aqueous Sodium Hydroxide and aluminum. The result of that reaction is hydrogen, which is gathered and directed to a fuel cell that drives the car.

Novel? Yes. Interesting? Absolutely. But you should be raising an eyebrow at the dubious choice of fuel that is aluminum.

If you don’t know what we’re talking about let us paint you a picture. Aluminum is a metal that is refined from bauxite ore. It takes an immense amount of electricity to smelt the metal. This is usually justified because aluminum is one of the most recyclable substances on earth, capable of being melted down and reformed countless times. But dissolving it in drain cleaner breaks it down and then it’s gone. So what we have here simply must be the least efficient disposable battery so far developed. It’d probably use less resources to grow and harvest lemons as a power source.

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EagerFeet Lets You Scrape Your Nike+ Data From The Web

April 19, 2011 by Mike Szczys 4 Comments

Runners that wear shoes with the Nike+ system can upload GPS data about their runs to the proprietary website. If you’ve been using this for a while you may be reluctant to switch to another service that works with the hardware because you don’t want to lose the historical data. Faced with this issue, [Robert Kosara] developed some software that can scrape Nike+ data. Not only did he write the code, but he also threw up a website that shows how well it works. EagerFeet lets you copy and paste your Nike+ ID for mapping on Google Maps.

Data is scraped from Nike+ and assembled as GPX files, which are backups of GPS data. From there you can use it for whatever you like. Since the code is available in a Git repository it’s easy to depend on it with your own projects, and still get updates if the scraping system needs to be changed in the future. Even if you don’t want to use the GPX files in your own projects, they can be imported on some third party exercise tracking sites if that’s what you’re interested in.

Of course you could try to pull the data straight off of your iPod.

Ludum Dare 20 Starting April 29th

April 19, 2011 by Kevin Dady 9 Comments

Ludum Dare 20 is only 10 days away! Great, what the heck is Ludum Dare? Well its only the most awesome video game creation contest on the internet, thats what. While originally for the hardest of the hard core, it has recently been split up into 2 events so everyone gets to have some fun.

The Jam is pretty relaxed in the rules. Lets say you and 4 buddies want to make the ultimate zelda remix using fan sprites and free music. This is where you want to be. Its there to give people who want to join in the fun but not make serious obligations.

The Compo is the real deal for those who are insane, or really good. You are given a theme at the start of the contest and 48 hours. You must then work solo and create all original content to use within your game. You can however use premade frameworks, game engines, libraries etc to accomplish your goal, but if you really wanted to you could make a 3D engine with brain fu*k during the competition. (though I would not advise it)

Prizes include internet bragging rights, and quite possibility the best darn feeling of accomplishment possible IF you manage to come up with some form of game, based on a voted theme, by yourself, in less than 48 hours.

Be sure to check out the rules and guide page for all details and I hope to see you there.

Apple II Weather Display (part 2)

April 19, 2011 by Kevin Dady 1 Comment

In part one of the Apple II weather display I quickly went over how data is fetched and phrased. Now its time to do something with it in part 2. In the order of functions I do the text parts first, and though its very similar to the process that the radar image goes through, its in monochrome and a bit simpler to explain. Before I go into how it works I should explain how I am dividing the Apple II’s screen.

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Teaching Children To Walk Using Video Games

April 19, 2011 by Mike Nathan 11 Comments

team_equiliberator

Medical conditions that prevent individuals from being able to walk are difficult to handle, even more so if the patient happens to be a child. Shriner’s hospitals treat a good number of children suffering from cerebral palsy, spina bifida, or amputations. They are always looking for creative treatment methods, so their Motion Analysis Laboratory looked to some Rice University undergrads for help. They asked the group of engineers to design a system that would make physical therapy a bit more fun, while helping encourage the children along.

The team recently unveiled their project, called the Equiliberator. The game system incorporates a series of five Wii balance boards situated between a pair of pressure-sensitive handrails. The platform communicates with a computer via Bluetooth, registering the patient’s movements as he or she moves along the path. The software portion of the system consists of a monster-slaying game which requires the child to step on a particular section of the pathway to dispose of the oncoming enemies.

The game is designed to get more difficult as the child’s balance and coordination improve, encouraging them with an ever growing bank of points as they progress. The final goal of the project is to enable the pressure sensitive handrails to determine how much the child is relying on them for balance, offering in-game incentives to walk with as little support as possible.

We love seeing hacks like this which not only entertain, but truly help people in the process. Kudos to the team at Rice University – they have done a fantastic job here.

Continue reading to see a quick video describing the Equiliberator in the designers’ own words.

[via MedGadget]

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