Have you ever accidentally left your front door ajar and had a pet escape? BlackCow at Homebrew Tech came up with a simple solution to this problem. The circuit is fairly rudimentary but a great example of using the basics to get the job done. Now, instead of having an alarm that sounds as soon as the door is open, he has a 30 second delay. This helps avoid the “boy who cried wolf” effect also known as the “vista security warning” effect of being bothered too many times for a non issue. We also have to say that we like his taste in blog layouts.
It’s tough work to find a small scale wind energy charger that works. While we’ve seeninnovative designs pop up over the last few years, it’s simply difficult to get enough wind coming through such a little device to charge devices. However, thanks to a company called Humdinger Wind Energy LLC, that might change with their new device called the microBelt. It is a piezoelectric turbine-based system that is purportedly 10 times more effective at gathering energy than other systems of the same size.
Humdinger is a start-up of of just 6 people, and they’ve developed a new method of gathering wind energy on a small scale. The system uses aeroelastic flutter and vibration of a membrane - rather than a spinning turbine - is at the core of the Microbelt, which is intended to replace the batteries used in wireless sensor networks (WSN). It can be used in applications such as HVAC systems, using the airflow to power the device and therefore skipping the need for more expensive batteries. And because the system doesn’t mess with spinning turbines that can break more easily, it expects a long lifespan - as much as 20 years.
It’s inexpensive as well as efficient. Ecofriend writes “Power is produced in air flows from as little as 3 m/s. At 5.5 m/s of wind flow the power output is 2mW. Apart from efficiency, another advantage of the system is that it is cheap to produce, as the materials are very simple. Humdinger is progressing applications such as building monitoring and transit monitoring that will rely on such wind turbines.”
The Ferret is a high-altitude balloon tracking hardware package. Created by [Adam Greig] and [Jon Sowman], it uses an Arduino to gather NMEA data from a GPS unit, format the data into a string, and transmit that string on narrow-band FM. The project, built in one afternoon, is a tribute to the prototyping simplicity the Arduino provides.
The unit was powered by four AA batteries, using the Arduino’s on board voltage regulator. This provided a bit of heat which helps in the frigid reaches of the upper atmosphere. The bundle above was put in a project box and attached to the outside of the balloon’s payload, then covered with foam for warmth and moisture resistance. This tracking is a lot less complicated than some of the photography setups we’ve seen for balloons. It’s also more versatile because it broadcasts the GPS data so that many people can track it, rather than just logging its location.
Stumble upon MultiDisplay car monitoring system. Unlike traditional systems that rely on interfacing with the OBD-II protocol and existing car computer, the MultiDisplay uses an Arduino and custom shield with a combination of sensors; including temperatures, pressures, throttle, Boost, and etc. The data collected can then be displayed on a 20×4 LCD or streamed to a PC with visualization and event recording. It’s an Arduino based open source display for interesting measurand´s of a car hosted on Google Code.
The idea behind this project is to see what the iPhone’s serial is capable of and to try and have a little fun with RFID along the way. This reader works with the low frequency (125Khz) tags but I have a half working version for MiFARE Hi-Frequency as well.
For this project you will need:
An iPhone USB Cable (genuine one is best and probably at least 3!)
[Anders] tipped us off about his hack that re-purposes a smoke alarm as a burglar alarm. Unfortunately, he came home in the middle of a burglary but wanted to be ready the next time someone tries to break in. By cleverly patching into the test button on an old smoke detector he created a circuit-trip alarm. One side of each piece of wire is secured to the frame and jam of a window. A paper clip completes the circuit by pinching the two bare conductors. If the window is opened the connection is lost and the alarm sounds.
We see a few problems with this system. First off, never hack your ONLY smoke detector, you are putting lives at risk by doing so. But [Anders] says he’ll have a replacement detector and since these things need to be replace every ten years or so, chances are you can find an old one kicking around. We’d recommend disguising the case so that people aren’t confused about it being a smoke detector. Secondly, he’s mounted the alarm right in the window frame so most likely an invader will just smash the thing to bits.
Anyway, it’s still an interesting reuse of these ubiquitous, and life-saving, devices.
[Tom Lee] and his colleagues of Sunlight Labs just moved to a new office. The doors are setup like a security checkpoint with electronic strikes and buttons on the inside to allow entry. The button simply completes a low-voltage circuit, activating the strike which made it quite easy to patch into. They build an interface board with a small relay to complete that circuit. As we’ve seen before, Linksys routers have plenty of extra room in the case so there was no problem housing the new circuit in this tiny network device. Now [Nicko] and his friends can use a custom app to input an access code or to verify a device ID from a cell phone and gain entry. The door still has keyed locks in case of a power outage. In fact, the only change made to the system was the addition of two wires to the “door release” button as seen above. See the one-touch device ID authentication in the video after the break.
This hack is similar to the GSM door entry from last year. In this case, the phones are communicating with the door via web interface and not the GSM network.
Will O’Brien at Biobug.org has been doing some cellphone integration work. He recently picked up some Motorola c168i cellphones from eBay. It turns out there is a serial port that uses TTL communication with a standard head-phone jack as an interface. [Will] soldered up a connector and used a USB to FTDI cable to interface with the phone. To his surprise he was able to read off the stored text messages even though they were PIN protected in the phone’s operating system. The messages on these units were trivial but this is another example of the importance of clearing your data before discarding your devices.
What if you could point your cellphone’s camera at someone’s face, and then know that person’s name, schedule, profile, and latest tweets? That’s the promise of Recognizr, an Android app prototype using a 3D model to recognize facial features, find a match on its server, and then superimpose that person’s social networking preferences around his or her face.
Created by Swedish mobile software designers The Astonishing Tribe, it’s astonishing indeed. Problem is, unless everyone opts into this service, it won’t be particularly useful. However, if it were ubiquitous, imagine how easy it would be to act like you’re using your cellphone, but actually be finding out that person’s name standing in front of you — while you snoop around her Facebook profile.
Finally, Facebook stalking finds its way to meatspace! On a smaller scale, this could be useful at, say, a trade show or a party. Electronic nametags would be lots of fun, if everyone would submit to them.
Apple has not made it easy to let the iphone communicate with external devices. Basically, you need a jailbroken phone to do anything. This post covers the current state of serial communication on the iphone.
A succesful example of making an application that uses the serialport on the iphone is xGPS, which let you connect to an external GPS.
