Tweeting Home Alarm System

tweeting_home_alarm_system

Instructables user [willnue] wanted to build a DIY Tweeting alarm system from the ground up, but reconsidered after taking a close look at the scope of such a project. He settled on using an off the shelf security system, taking care of the Twitter interface on his own. He bought a GE 45142 Wireless alarm and promptly disassembled it to see how he might retrieve status messages from the unit.

He figured that monitoring the alarm’s LEDs would make the most sense, so he used a bit of Ethernet cable and wired all of the system’s indicators to his Arduino board. He hooked up an Ethernet shield to the Arduino, then wrapped the pair up in a plastic project box that closely matched the look of the security system. Once that was done, he wrote some simple code for the Arduino that monitors each of the alarm system’s six status lights, sending updates to Twitter via the ThingTweet service.

With this system you might not get your status messages in time to foil whoever is carrying off your plasma TV, but at least you will know what to expect once you get home!

If you want to keep tabs on [Will’s] security system to find out the best time to rob him see how things are going, check out his Twitter feed here.

DIY Servo Activated Door Lock With Capacitive Touch Keypad

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Since he was a kid [Giorgos Lazaridis] has always loved the idea of having an electronic door locking mechanism, and now that he has the means, he’s decided to construct one for securing the door to his apartment. He calls the project “simple and cheap”, though we’re not sure about the first part. Taking a look at his very detailed build log, you can see that he has invested quite a bit of time and effort into this impressive project.

Buying an off the shelf product was expensive and not a whole lot of fun, so [Giorgos] disassembled his door’s locking mechanism to see how he might be able to actuate the lock electronically himself. With minimal modifications to the lock, he was able to add a servo which reliably opens the it when triggered.

With the mechanical portion of the project out of the way, he spent a great deal of time working on the door’s electronic components, including the PIC-based controller and capacitive keypad. The keypad proved to be a bit of a problem, but after a few revisions he found a design that was both reliable and pleasing to the eye.

The locking mechanism works pretty well, as you can see in the video below, and [Giorgos] is quite pleased with the results.

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Google Android ADK Bluetooth Wireless Communications

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Once the Google ADK was announced, the team over at [ElectFreaks] jumped right in and started experimenting to see what they could do with the new Arduino/Android interface. While the ADK was great for allowing the two devices to interact over a USB connection, they felt that the system would be far better if it allowed for wireless communications instead.

They added a Bluetooth Bee to their Arduino setup and got busy writing an Android application that uses the handset’s built in Bluetooth module to communicate using the ADK. The application configures your phone to act as either a client or server when pairing. This does not affect data flow, as communications are bi-directional, it merely decides which device is placed in discoverable mode.

As you can see in the second part of their post, once the phone and Arduino are connected, it is quite easy to send serial data back and forth between the two devices.

As of right now, their Bluetooth API is in Beta, so things might still be a bit rough around the edges. They do encourage anyone to download and modify the code, which is freely available on their site.

Gigantic 555 Footstool

The team at Evil Mad Scientist Laboratories needed a footstool. Obviously not content with buying one, they came across the idea of building a 555 footstool.

After finding some dimension drawings of the 555 timer IC, the team scaled everything up 30 times. While a normal DIP-8 555 is around 0.4 inches long, the footstool is over a foot long and eight inches high. The stool was cut on a CNC mill out of 1/2″ plywood, glued together, and finally panted with the correct date code and the logo of Evil Mad Scientist Labs. The finished product is amazing. We’ve been looking for a nice table, and the idea of an 8 foot long wooden 64-pin Motorola 68000 is pretty appealing.

While there’s no electronics in the footstool, it’s not hard to imagine fabricating some aluminum pins and a hollow body so a huge, functional 555 could be built. It would be possible to use discreet components following the block diagram of the 555 to build a huge Atari Punk Console; the gigantic capacitors are fairly easy to build in any event.

Alternative Phone Charging Devices

We’ve all heard of solar cells that charge your devices, or the odd flashlight that charges when you shake it, but this style charger should be new to almost everyone. This “pan charger” is reportedly capable of charging a cell phone or other mobile device using a USB connection in 3 to 5 hours.  It also has a built-in radio and lantern. This should be a great tool for surviving a zombie apocalypse or if you simply live in a region without readily available power.

A second charger, currently being used in Africa, is an adaptation of a small generator hooked up to a bicycle. As this form of transportation is quite common in developing nations, this simple idea definitely shows promise.  Check out the video of the bike cell phone charger after the break. Continue reading “Alternative Phone Charging Devices”

A Doorbell Loud Enough To Wake The Dead

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[Ed Nauman] runs a machine shop, which we imagine can be quite loud at times. Sick of never hearing the doorbell when he was busy working on things, he decided that the solution to his problem was a new doorbell…an incredibly loud doorbell.

His Really Loud Doorbell (RLD for short) is actually a pretty simple device. We imagine he could have wired up an old alarm bell instead, but where’s the fun in that? The doorbell was built using a PIC16F876 uC, which is used to control the air flow through a pneumatic valve. When someone rings his doorbell, the pneumatic actuator pulses up and down, rapidly striking a piece of 1/4” thick steel pipe. As you can see in the video below, it is quite loud and likely to cut through any shop noise without much trouble.

We have seen some extremely loud doorbells before, but we figured that at least a handful of you work in similar environments – have you implemented any inventive ‘notification’ systems in your workspace? Let us know in the comments.

[via Adafruit Blog]

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Did you get the tickets? To what? The gun show.

Detecting Muscles With Electromyography

The folks at Advancer Technologies just release a muscle sensor board with a great walk through posted on Instructables describing how this board measures the flexing of muscles using electromyography.

Using the same electrode placement points as the remote controlled hand we covered earlier, the muscle is measured by sensing the voltage between the muscle and its tendon. The result is a fairly fine-grained sensing of the output – more than enough to provide some analog control for a project.

The board itself is relatively simple – an INA106 differential amp is used to sense if a muscle is flexing or not. This signal is then amplified and rectified, after which it can be connected to the analog input of your favorite microcontroller. The video demo shows the board connected to a Processing app running from an Arduino, but it wouldn’t be hard to adapt this towards remote Nerf sentry turret controlled by your biceps.

Check out the video after the break to see the muscle sensor board in action.

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