Automated Doors For Theatre Effect

January 30, 2013 by 15 Comments

Door Actuator

For a theatre production, [Jason] needed a way to automatically open and close doors as a special effect. His solution, hosted on Github, lets him remotely control the doors, and put them into a ‘freak out’ mode for one scene in the play.

Two Victor 884 motor controllers are attached to an Arduino that controls the system. A custom controller lets [Jason] actuate the doors remotely, and LEDs are used to display the state of the system.

On the mechanical side, two wind shield wiper motors are used. These are connected to custom arms that were printed using a Lulzbot AO-100. The arms allow for the door to be automatically actuated, but also allow for actors to open the door manually.

The result is a neat special effect, and the 3D models that are included in the repository could be useful for other people looking to build automated doors. In the video after the break, [Jason] walks us through the system’s design and demonstrates it in action.

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Communication Protocol For An Indoor Helicopter

January 21, 2013 by 6 Comments

propel-execuheli-ir-protocol-revealed

There’s a special type of satisfaction that comes from really understanding how something works at the end of a reverse engineering project. This grid above is the culmination of [Spencer’s] effort to reverse engineer the IR protocol of a Propel ExecuHeli indoor helicopter toy.

The first thing he looked at was the three different controller channels which can be selected to allow multiple helicopters to be used in the same area. [Spencer] was surprised that they all used the same carrier frequency. The secret must be in the coded packets so his next challenge was to figure out how the data was being transmitted via the Infrared signal. It turns out the packets are using pulse-length coding (we were unfamiliar with this protocol but you can read a bit more about it here). The last piece of the puzzle was to capture packets produced by each unique change of the control module. With each bit (except for bit 11) accounted for he can now format his own codes for a controller replacement. Perhaps he’s looking to make the helicopter autonomous?

Electric Imp Makes A Cat Door Tweet Its Activities

January 4, 2013 by 11 Comments

electric-imp-tweeting-cat-door

This Tweeting cat door uses the Electric Imp to read a sensor and report back to the server. The hardware is pretty neat. The board hosts an ARM Cortex-M3 processor and gets on your home network via WiFi. The mini-USB cable simply provides the power. Programming is done over the network. Our own [Brian Benchoff] had a chance to try the Imp out earlier in the Fall.

Monitoring a cat door is as good a reason as any to undertake a project. The hardware added to the board includes a reed switch mounted on the jamb along with a magnet on the door itself. There is also a blue LED that gives a bit of user feedback. The software isn’t quite as easy but it still wasn’t that bad. As with most web-connected projects getting all the parts to talk to each other was a bit of a chore. The Imp reports back to a server on the local network which then activates a PHP script that uses Sen.se to push out a Tweet.

[Thanks Pat]

Garage Door Opener Using Siri And Raspberry Pi

December 11, 2012 by 27 Comments

Screenshot from 2012-12-11 09:54:36

[DarkTherapy] wrote in to tell us about his garage door opener that works with Siri and a Raspberry Pi. It’s pretty hard to find a picture that tells the story of the hack, but here you can see the PCB inside the housing of the garage door opener. He patched the grey wires into the terminal block. On the other end they connect to a relay which makes the connection.

On the control side of that mechanical relay is a Raspberry Pi board. This seems like overkill but remember the low cost of the RPi and the ability to communicate over a network thanks to the WiFi dongle it uses. We think it’s less outrageous than strapping an Android phone to the opener. To make the RPi work with Siri he chose the SiriProxy package. We’ve seen this software before but don’t remember it being used with the Raspberry Pi.

There is certainly room to extend the functionality of a system like this one. It would be trivial to add a combination lock like this one we build using an AVR chip. It would also be nice to see a sensor used to confirm the door is closed. Even if you don’t need to control your garage this is a great reference project to get the RPi to take commands from your iOS devices.

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Simple Hack Plays Any Sound As Your Door Chime

November 23, 2012 by 12 Comments

[Jim’s] technique for turning a wireless doorbell into a custom ringtone player is so simple. He manages to get the entire thing done using only a screwdriver and wire clippers as tools. But if you’re looking to use this over the long-term we’d recommend soldering the connections rather than relying only on the twisted wires.

Above you can see all the components used in the project. The wireless doorbell unit is no different from most battery-operated units on the market today. Inside the Radio Shack box is a recording module that lets you play up to 20 seconds of audio. This is powered by the 9V battery on the right. [Jim] removes the speaker from the doorbell and clips off one of the wires that connected it to the board. This is reused as the ground connection for the recording module. The other speaker wire is connected to the ‘Play’ button on the module’s PCB. That’s it, just record your custom sound and pack everything back into the doorbell’s case. You can see the entire hack and hear a demonstration after the break.

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Wristband RFID Unlocks Car Door And Starts Engine

November 14, 2012 by 19 Comments

[João Ribeiro] is an electronics engineer by day, but in his free time he likes to ply his trade on everyday items. Recently he’s been integrating his own microcontroller network to unlock and start his car via RFID. In addition to the joy of pulling apart the car’s interior, he spent time designing his own uC breakout board and developing an RFID reader from a single chip.

He’s working with a 1988 Mercedes that has very little in the way of electronics. It sounds like the stock vehicle didn’t even include a CAN bus so the prelude to the RFID hack had him installing a CAN bus network made up of two microcontrollers. One reads the velocity and RPM while the other displays it on the tachometer. When he began the tag-based entry system he used an RFID reader module for prototyping, but eventually built his own reader around the TRF7960 chip. This included etching his own receiver coil which was mounted in the side-view mirror bracket. To unlock the doors he holds the bracelet up to the mirror and the vehicle lets him in. The video after the break starts with a demonstration of the completed project and moves on to some build videos.

We certainly like the idea of using a bracelet rather than implanting the tag in the meaty part of your hand.

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Camera Gantry Rides On Garage Door Tracks

November 9, 2012 by 4 Comments

For as many garage and workshop videos we feature here on Hackaday, we’re surprised we haven’t seen this sooner.

[Todd] makes a bunch of videos in his garage shop, but using a tripod is a pain; he’s always tripping over his camera setup and it is just generally in the way all the time. His solution was to mount his camera to an overhead gantry, using the unused tracks for his garage door to move the camera around his workshop.

The build started with [Todd] taking his tripod and fabbing a mounting plate for it to be suspended in mid-air. This would leave the camera upside-down, so [Todd] also made a 90 degree bracket with a 1/4-20 bolt to hold the camera in position.

The actual gantry part of the build is fairly clever. First, [Todd] got a piece of square tubing the same length as the distance between his two garage door tracks. He made a truck that rides on six casters for this tube, then mounted this tube on garage door wheels.

The result allow [Todd] to move his camera anywhere within the footprint of his garage door tracks, including over his workbench and welding area. An ingeniously useful build that’s sure to provide a stable platform for his vlog-type thingies.

Vidia after the break.

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