has put together this interesting project involving aluminium can recycling (translated, sortof). They’re using an arduino to tally up how much aluminium they have accumulated. That information is then passed on and displayed on a google map. There are families that go around collecting the cans as a means of income, and this system could be very helpful to them. They state that their goal is to eventually have restaraunts and more families included. We’re a bit curious about how helpful this really is. How is that information actually changing the actions of the collectors? Would a simple flag on your door or window signalling enough cans to pick up or not be just as effective?
Here is a classic project used to increase wireless signal strength. Cantennas focus using a waveguide very much like a magnifying glass focuses light. [Robert] made a Natural Light beer cantenna, pictured in the upper left. His approach used three beer cans, a paper towel holder, and a shower curtain rod. On the tipline, he noted a signal boost from 11Mbps to 54Mbps. This is certainly something we can hack together if our room lacks adequate signal. Read about parabolic and seeking versions after the break.
[Chris] wrote in to tell us about this project he did while living in the dorms. He built a system to automate his dorm room door. It handles unlocking and opening/closing the door via iPhone, secret knock, and even the key. The lock/knob portion is handled by a servo while the opening/closing action is hydraulic. After living with it for a year, he says that it never gets old, but there were a few bugs. Apparently it would randomly open in the middle of the night sometimes. If you’re interested in doing something like this, but not damaging the door, maybe you should check out the RFID dorm door lock project.
Reader [john] finished up his home power monitor over the holiday weekend. It uses a pair of current transducers clamped onto the mains. These output 0-3V and are read by the Arduino’s ADC. The Arduino averages samples over a 20 second period, calculates power used, and uploads it using an Ethernet Shield. The shield can’t do DNS lookups, so he uses a WRT54G to negotiate with the remote webserver. He admits that the system could be more accurate; it can’t detect small loads like wall warts. He also says that money could be saved by talking serial to the router instead of over ethernet. Here are the current usage charts.
You can find many power monitor projects like this in out Home Hacks category.
Capacitive discharge cutting provides more control than linear transformer versions. A very large capacitor is charged to a precise voltage and then discharged through the material to produce a controlled cut. The same device can also be used for spot and tab welding. A video of copper roof flashing being cut is embedded below. An example of a linear transformer can be found in our our How-to: build your own spot welder.
This antenna tuner is controlled remotely using geared motors and legos. The tuner needed to be closer to the antenna for performance reasons. This created a problem; most of the radio gear is inside while the tuner is outside. The gear motors and Legos combine to form a closed loop servo, operating two air core caps and an inductor switch. A control box placed near the radio is hard wired to the modded tuner outside. We would like to see something like this under gesture control using the Wii MotionPlus + Arduino.
Using an IR thermometer, there are two ways to go about building a thermographic camera. The first uses a pan and tilt head. Scan lines are emulated, as a computer controls panning from left to right, taking a temperature sample from each step. Vertical resolution is accomplished by tilting. Another method uses a web cam attached to the thermometer. The thermometer’s laser pointer is captured with temperature annotations, as the computer records the field of view. We think the best outcome can be found with a combination of both methods. The video embedded below demonstrates the results. This would be a good addition to the Autonomous paintball sentry.
Snow days are great, but generally you still have to wake up to find out if it is a snow day. [insingertech] decided to make a system to solve this problem. He made an alarm clock that would automatically de activate if school is cancelled. What a pleasant surprise it would be to just wake up and find that you had been allowed to sleep in. It is using an Arduino and a python script to control the state of the alarm based off of an online school closing announcement. You can download the software from the instructable.
[Michael] has a keypad in his previous car’s door and he missed it enough to hack one into his Dodge Caliber. He bought a Ford keypad and mounted it inside his door with some custom electronics. He started with an Arduino nano to receive and authenticate button presses. This then splices into wires in the door that control the door lock. The program has a 5-digit code to unlock the door, but simply pressing 1 twice will lock the doors. He also implemented a lockout feature to prevent people from brute-forcing the combination. Although it isn’t wireless, it’s significantly simpler.
Artists [James Auger] and [Jimmy Loizeau] have put out this display of carnivorous robots. Pictured above is a clock that is powered by a microbial fuel cell. The clock is equipped with a scroll of sticky paper for catching the flies which it then scrapes into it’s cell for digestion. The other pieces include a mouse eating coffee table, a strange mechanism for stealing spider’s meals, and a lamp shade inspired by pitcher plants.
For four years, this guy has been using this Pneumatic bed alarm clock to wake up. Apparently “I’m a really heavy sleeper” is an understatement. It is computer controlled and runs from two seperate air sources. He entered it in a radio show contest and we’re guessing he won. You can see the test run at the radio station after the break. We really can understand the fun of building this. But actually using it for four years, without suffering any major injuries, is an accomplishment of it’s own.
Our reader [Damir] built a home made soldering pot. It can be used to solder and desolder components. To remove a through hole component, the solder side is placed in the bath. Then the component is removed with pliers. It is also possible to solder components, by placing the leads in the molten solder; similar to wave soldering. Another common use is tinning self stripping wire. The insulation of the wire is designed to burn off, allowing the strip and tin phase to be single step. This solder pot would be a nice addition to the hacker’s soldering station we had covered in 2008. For more pictures, check out the photo gallery. In the video embedded below, a transformer is easily removed from a modem.
With a user interface consisting of two buttons and a three digit display, the GPS finder guides the user back to a saved location. Nine locations can be saved for navigation recall. Press a button to save location and press another button to recall. Each switch has a secondary function, for management purposes such as memory indexes and power features. An AarLogic GPS 3A module and AVR microcontroller make up the guts. With the popularity of Geocaching, this would make an impressive trinket; Leading the hunter to an undocumented treasure.
Reader, [Andres Leon], has two adorable cats with very specific dietary needs. Instead of altering his schedule, he donned his hacking hat and designed a very solid cat food dispenser. The dispenser consists of a rotating drum with a slot in it and a PVC pipe Y-fitting to distribute the food evenly. The brains of the machine is an Arduino Deumillanove and an XBee module. The unit can be controlled by a web interface or it can run completely standalone. [Andres] ran into a problem where the drum’s resistance to turning varied based on how much food was inside. He solved this with a clever laser position indicator. A piece of plywood is lined up with the slot at the top so that whenever the slot is facing up it keeps the laser from shining on a photoresistor. The cats were afraid of the servo noise at first, but now they run to their bowls whenever they hear it.
