Star Trek Style Pneumatic Doors That Don’t Require A Stagehand

November 27, 2011 by Brian Benchoff 63 Comments

In 1966, [Gene Roddenberry] introduced fully manual doors powered by a stagehand on Star Trek. The fwoosh sound of the door was later dubbed into each show, but progress marches on, and now [Alex] created his own Star Trek-style automatic doors for his house.

The build includes a ‘control panel’, and [Alex]’s door operates in three modes: Open, and stay open; Close, and stay closed; and Automatic. The control panel itself is fairly remarkable. A small puck interacts with a magnetometer underneath [Alex]’s counter. If the puck is pointed towards ‘Open’, the door stays open. If the door is pointed towards ‘Closed’, the door stays closed. If the puck isn’t near the magnetometer, the door operates in automatic mode with the help of a few IR sensors to detect someone trying to get in or out of [Alex]’s kitchen.

For the mechanical portion of the build, [Alex] used a One meter long piston with the quietest air compressor he could find. We can’t tell from the video after the break if the compressor ever kicks in, but [Alex] says it’s about the same volume as his fridge. As a small added bonus, the new automatic door does have a fwoosh sound, just like [Gene] would have wanted.

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A Doorbell Pleasing To Both The Ears And Eyes

November 22, 2011 by Mike Nathan 15 Comments

campanello-doorbell

When [David] moved into his new house, one of the things he noticed was that his doorbell was pretty lame. Coming from a home equipped with a solenoid and chime bell, his new wireless solid state doorbell sounded terrible to him.

Crummy sound aside, the doorbell hardly ever worked properly, but alas, other projects cropped up and years went by before [David] addressed his doorbell problem. Like many things that take a long time to come to fruition, we think his resonator bell based solution was well worth the wait.

One of his main goals was to make a nice sounding doorbell that also looked great. He mounted a kid’s resonator bell toy on a sheet of wood, creating his own wooden mallets for the job. He initially had a tough time locating actuators for his doorbell, but found a solution in geared pager motors as featured in another xylophone hack on Make. With the hardware taken care of he focused on the electronics, which consist of a pair of Arduino clones – one on the display and one in his basement.

Stick around to see [David’s] Campanello doorbell in action, and be sure to check out his site for more details if this sounds like something you would like to have in your home.

[via Make]

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Jarvis Opens The Door At P-Space

November 10, 2011 by Mike Szczys 8 Comments

It seems like every Hackerspace should have some type of kludged together access system on their entry door. [Vasilis] wrote in to share the system called Jarvis that controls access to P-Space, a Hackerspace in Patras, Greece. It’s an RFID-based system that offers a few nice features.

They already have a server running the webpage, so basing their entry system off of a computer was an easy option. You can get in one of two ways; by presenting your valid RFID tag to a reader at the front door, or by ringing the bell and having a member inside press the Big Button of Doom (BBoD) which is a wireless controller.

The BBoD has an Xbee module inside which lets it send an unlock command back to the computer. The remote is powered by two AA batteries, and since it’s never on unless the button is pressed the team estimates these batteries should last around one year.

There’s even a feedback system. The computer posts the last few events to the webpage. So you can go online and see when the BBoD was used, or who’s tag has recently unlocked the entrance to tell if your friends are there.

Garage Door Monitoring And Control Using A Dedicated Android Phone

October 11, 2011 by Mike Szczys 29 Comments

[Sean] happened to have an extra Android phone sitting around and wanted to see what type of home automation he could use it for. One simple hardware modification, and some apps from the Android Market let him monitor and control his garage door remotely.

The hardware modification is a hack we’ve already looked at. The BTmate uses a Bluetooth headset with an added transistor to short the connections on your garage door opener. The only issue is that you need to be within range for the Bluetooth to work. [Sean] adds a layer of abstraction by using two Android phones. One is permanently mounted in the garage and handles the Bluetooth connectivity, while the other uses VNC to tunnel in anywhere he has an Internet connection.

But why stop there? He knew that this one feature was overkill, and added a second which the phone was perfect for. Since it has its own camera, he used the tinyCam app to create a webcam server. This even allows him to turn the LED on and off for a better view in dim light conditions. See [Sean’s] demonstration after the break.

Overkill? Maybe, but if you’ve got a phone with a broken LCD, this might be just the thing to give it a new purpose.

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Simple Circuit Reminds You To Lock The Door As You Rush Out Of The House

October 11, 2011 by Mike Nathan 24 Comments

door_lock_minder

It seems that [pppd] is always rushing out of his apartment to catch the bus, and he finds himself frequently questioning whether or not he remembered to lock the door. He often doubles back to check, and while he has never actually forgotten to lock the door, he would rather not deal with the worry.

Since he finally had some free time on his hands, he decided to put together a simple device that would help end his worry once and for all. Using an ATtiny13, [pppd] designed a circuit that would detect when his door has been unlocked and opened, beeping every few seconds until the lock is reengaged. The circuit relies on a reed switch installed inside the door frame, which is tripped by the magnet he glued to his door’s deadbolt.

He says that the system works well so far, though he does have a few improvements in mind already.

How To Build Your Own Cat Door

October 2, 2011 by Mike Szczys 29 Comments

[Dino] continues his to satisfy his weekly hacking goal by building a cat door for his pets. He has a Habitat For Humanity resale store nearby that was doing a 50% off sale on doors. So he picked up a six-panel door and set to work.

The first step is drawing out the opening and cutting it with a jigsaw. Once he was done, there’s some reinforcement work to be done because this is a hollow-core door. Since he had already cut a bit of the bottom off of the door to fit his jamb opening, he had some wood stock that was already the right thickness. That bit was secured to the top and bottom of the opening with glue and some brads. The same was done on the sides with a different piece of scrap, then the door was hung in the opening to reach the point in the project seen above.

Here [Dino] prepares to add a flap to cover the opening. He used acrylic for the flap because it’s light-weight and clear. A piece of piano hinge makes it easy to swing in both directions. The final touch is a magnet which keeps the flap from swinging in the breeze using parts from a magnetic cabinet latch. No sooner does he have the flap in place than a brave kitty gives it a test run.

Hopefully he doesn’t have the kind of pests that caused other hackers to build facial recognition cat door locks.

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Easily Movable RFID Door Lock Is Great For Dorm Rooms

September 19, 2011 by Mike Nathan 15 Comments

One of the first things that [Eric] hacked together when he got to college was an RFID door locking system. He found that he was often in a rush to get in and out of his dorm room, and that using a simple wireless key was a great way to streamline his days.

Over the years, he has refined his design, and while his original prototype was functional, it was a bit rough around the edges. In the video posted on his site, he thoroughly explains how his system was built, and shows off the revisions he has made over time. One key consideration when building this system was the fact that the installation had to be non-permanent. Since schools typically frown on physically altering your rooms, he found a non-intrusive means to mount his system in the way of zip ties and foam board.

His RFID door lock looks to work quite nicely, and we especially like the inclusion of the reed switch to ensure that the system knows if the door has been opened or not. If you have about half an hour to spare and are interested in building an RFID entry system of your own, be sure to check out [Eric’s] video below for all the details.

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