Keyless Entry Using Touch Sensing

October 20, 2008 by Caleb Kraft 19 Comments

[Alex] sent us this slick little keyless entry system. He wanted a discreet way to trigger the door to unlock. Knocking was too loud, and would give away his secret access code. He decided that touch sensors would be the best. Initially he planned on using the doorknob itself, which would have been awesome, but it was just too much surface area for his touch sensor. Ultimately, he settled for a wire he could touch. An Arduino detects whether or not the correct code has been put in and initializes a high torque servo which turns the doorknob from the inside. In the video, after the break, you can see that it works fairly well.

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Parts: Chip Sockets For Dual In-line Package (DIP)

October 20, 2008 by Ian 14 Comments

DIP through-hole chips are an old package with instantly recognizable dual in-line pin rows. Beginners love these chips because they’re large and look easy to solder; we abhor them because we hate messing around with the drill. Whatever your motivation for using a through-hole chip, use a socket whenever possible. A circuit board with socketed chips is easy to test without endangering the parts, and ICs can be removed, tested, and replaced, without resorting to a soldering iron. This week, by request, we looked at several common through-hole chip sockets. Continue reading “Parts: Chip Sockets For Dual In-line Package (DIP)” →

Lasercut RepRap Kit

October 19, 2008 by Eliot 19 Comments

The RepRap is a self-copying 3D printer. The project has published plans for creating a lasercut acrylic version of the device. They call it a RepStrap since once assembled it could produce printed plastic versions of the machine components, bootstrapping true RepRaps. The plans are available for Ponoko an on-demand product service, and it would cost ~$380 if you used their service. The plans are free, so you could get them manufactured by other means. [vik] is still putting together the assembly instructions. He hopes to have an all inclusive electronics kit at some point too. This is another great step towards putting desktop manufacturing within reach of everyone.

Jar Of Fireflies

October 18, 2008 by Eliot 14 Comments

[Randomskk] has been attempting to make electronic fireflies for quite some time and finally settled on a design he liked. His jar of fireflies uses an ATtiny13 to control a set of 12 matrixed LEDs. The green SMD LEDs are each soldered to a pair of thin wires that hang down into the jar. The software picks an LED at random to flash and then flashes it 1-3 times. The random seed is incremented each time the jar is turned on, so you’ll get 255 different patterns. The power is just a standard coin cell. The project is fairly simple electrically, but the LED soldering could prove difficult. It was inspired by this firefly jar project. Check out [Alex]’s synchronizing fireflies too. A video of the jar is available below. Continue reading “Jar Of Fireflies” →

LED POV Hard Drive Clock

October 17, 2008 by Caleb Kraft 29 Comments

[Ian Smith] sent us this POV display made from an old hard drive. It works by flashing some LEDs under the platter, which has a line cut in it. Since the platter spins at roughly 90 rotations per second, we perceive a solid image. He was inspired by [Alan Parekh]’s project, but did several things differently. Mounting the LEDs was much simpler in this project as he had a strip of RGB LEDs that came with adhesive tape on the back. He also used a small magnet and a hall effect sensor to measure full rotations instead of an IR beam sensor. Check the video after the break.

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Internal Wireless Mouse On A Dell Mini 9

October 16, 2008 by Caleb Kraft 5 Comments

[strider_mt2k] sent in this new Dell Mini 9 hack. After seeing the recent GPS in a Dell Mini9 project, he decided to jump in and do some hacking of his own. His idea was to integrate his Logitech wireless mouse receiver internally. He basically added an internal usb port, allowing for future replacements if the mouse should it get broken or upgraded. The final result is completely hidden. There was plenty of space in the case, so there’s no bulge at all.

Cambridge Autonomous Underwater Vehicle

October 15, 2008 by Caleb Kraft 11 Comments

The Cambridge Autonomous Underwater Vehicle, built for the SAUC-E Challenge, is a fantastic example of UAV construction. The competition is to build a UAV that can complete an underwater assault course. This baby has a full computer inside it, based off of the worlds smallest full featured x86 motherboard, the Pico-Itx. It has a 1GHz EPIA PX 1000 Board, 1 GB of RAM, Wireless Network capabilities and runs Ubuntu server 8.04.

The CUAV suffered from leaks which ultimately cost it the competition, but the information on the build is fantastic. They have detailed pages upon pages of information about the Mechanical, Electronic, and Software aspects of the design. They even went back in and added notes from what they learned during the competition. The project is also outlined in much shorter form on the mini-itx website.

[thanks Vesaines]