I’m at the beach this week – finally on vacation. Thanks to DD-WRT, I’ve got a handy wireless repeater to keep the beach house covered with network access. [sprite_tm]’s doing his best to make my vacation easier. He built this knock activated automatic door opener for a friend who wanted easy access to some locked, but empty flat (think british apartment) rooms. He used an ATTINY with some fets to drive the stepper (you can find those in old dot matrix printers for free) and a small transistor amped mic circuit to pick up the knocks. Knock the right code, and you’ll get let right in.
Electronic Door Lock
[Dheera] sent in his electronic door lock. The current version is purely microcontroller based, but I loved this crazy iteration. Seeing something like this evolve is fantastic. I really wanted a keypad door lock when I was old enough to dream of electric sheep.
Ultimate Garage Door Monitor
Want your home automation system to know the exact position of your garage door not just whether it is open or closed? Then the ultimate garage door monitor is for you. There has got to be at least one person that needs that, right? Well for the rest of you it is a handy guide for how-to implement analog sensors (like this potentiometer) into your home automation by way of an analog to digital converter.
[thanks ledtester]
Client/server Door Opener
You can thank reader [Alexandre Novello]’s laziness for generating this hack. Actually, as a self-proclaimed “software guy” he would have never approached this project if it wasn’t for the situation he was in: having to walk across the room to open the door for people, a door which has an electric opener right next to it. He’s got a thorough write-up on how he built the client and server portions of his software in Delphi. He also covers the hardware switch which is attached to the server via parallel port.
Cellphone Controlled Door Opener
Looking for a way to demonstrate his AutoIt script that allows Windows control using a cellphone, zerocool60544 put together this automatic door opener/closer. It uses two water bottles as counterweights and two LEGO motors to drive the door. The motor control is a parallel port connected relay board. It’s a pretty simple demo, but I’ll definitely be looking into AutoIt in the future.
[thanks emdy]
Java Ring: One Wearable To Rule All Authentications
Today, you likely often authenticate or pay for things with a tap, either using a chip in your card, or with your phone, or maybe even with your watch or a Yubikey. Now, imagine doing all these things way back in 1998 with a single wearable device that you could shower or swim with. Sound crazy?
These types of transactions and authentications were more than possible then. In fact, the Java ring and its iButton brethren were poised to take over all kinds of informational handshakes, from unlocking doors and computers to paying for things, sharing medical records, making coffee according to preference, and much more. So, what happened?
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Static Electricity And The Machines That Make It
Static electricity often just seems like an everyday annoyance when a wool sweater crackles as you pull it off, or when a doorknob delivers an unexpected zap. Regardless, the phenomenon is much more fascinating and complex than these simple examples suggest. In fact, static electricity is direct observable evidence of the actions of subatomic particles and the charges they carry.
While zaps from a fuzzy carpet or playground slide are funny, humanity has learned how to harness this naturally occurring force in far more deliberate and intriguing ways. In this article, we’ll dive into some of the most iconic machines that generate static electricity and explore how they work.
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