Chilean Teen Builds Automatic Earthquake Alarm

July 19, 2011 by Mike Nathan 27 Comments

When an earthquake is about to strike in Chile, who do you think is first to sound the alarm? You might be surprised that it’s not the government, but rather a 14 year old boy.

After living through an earthquake in 2010 and seeing the devastation this spring in Japan, Chilean teenager [Sebastian Alegria] decided that he wanted to construct something similar to Japan’s earthquake warning system. He purchased an off the shelf earthquake detector for less than $100, and connected it to his computer via an Arduino.

Now, whenever seismic activity is detected, his sensor tweets an alert letting his 29,000+ followers know that a perceptible earthquake is 5 to 30 seconds away. Apparently the Chilean government is working on a similar system that is still at least a year away, so in the meantime his fellow citizens rely on [Sebastian] instead.

While it might seem like a relatively easy hack to pull off compared to other earthquake detectors, we’re impressed by [Sebastian’s] creativity, and his will to help others. He’s been pounding away at computers since he was about 4 years old and has several other popular Twitter-based projects under his belt already, so we won’t be surprised if we hear from him again in the future.

Tweeting Home Alarm System

June 30, 2011 by Mike Nathan 9 Comments

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.

Automotive Backup Alarm

June 26, 2011 by Mike Szczys 11 Comments

[Dino’s] project of the week is a backup alarm for your car. This is a feature that has become popular on many large vehicles like SUVs where visibility is an issue when moving in reverse. But it doesn’t sound like he was motivated by the need to have this in his own car. Instead, he was looking for something to build using a laser range finder.

[Joe Grand] (the brains behind DEFCON badges) has been working on an inexpensive laser range finder for Parallax. He sent one of the first-run prototype boards to [Dino] for beta testing and we’re glad that [Dino] decided to show it off. It uses a small red laser diode and a camera module to measure distance in millimeters. The board communicates serially and this particular project uses an Arduino along with a character LCD and speaker to display distance and sound an alarm when the car is within a meter of an object.

Check out the video after the break to see the build in its entirety. The system works reasonably well, if the object you’re about to hit is perfectly lined up with the laser dot.

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Modular Security System Is Portable Too

May 5, 2011 by Mike Nathan 11 Comments

diy_security_system

Hackaday reader [Oneironaut] wrote in to share a modular, portable security system he built for himself.

He likes visiting the Caribbean, but his favorite vacation spot is apparently rife with cat burglars. He enjoys sleeping with the windows open and wanted to find a way to scare off ne’er do wells. At home, there are a few different buildings on the property he owns, and he was looking to keep curious trespassers away.

The alarm system was built using a matrix keypad that interfaces with an ATMega88 micro controller. The micro controller handles all the logic for the system, triggering an attached “pocket alarm” when ever the sensor is tripped. Like most household alarms, it is armed and disarmed via the keypad, giving the user 60 seconds to enter the disarm code if the alarm has been mistakenly tripped. A wide array of trigger methods can be used, from mercury switches to motion detectors, since his alarm uses a simple plug interface that accepts any two-wire sensor.

Now, no one is claiming that this is high security by any means – the alarm addresses a couple of specific scenarios that apply to [Oneironaut], which may also be applicable to others out there. At the end of the day, the alarm is more meant to scare an intruder into fleeing than anything else, and in that respect, it works perfectly.

Continue reading to see a quick video demonstration of his alarm system in action.

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DIY Sunrise Alarm Clock

May 4, 2011 by Mike Nathan 15 Comments

As a project for an embedded systems class, [Alan] recently built himself a sunrise-simulating alarm clock. You are probably familiar with these sorts of timepieces – they gradually light up the room to awaken the sleeping individual rather than jarring them awake with a buzzer or the radio. Since many commercial units with this feature are sold for $70 and up, his goal was to replicate the functionality at a fraction of the cost, using only open source components.

An Arm Cortex M3 processor runs the show, displaying the time via a pair of 8×8 LED matrix panels on the front of the device. The clock is programmed to gently wake up its user by simulating a sunrise over a period of 5, 15, 30, 45, or 60 minutes. If the user has not woken up before the sunrise simulation is complete, the clock resorts to a traditional piezo alarm to rouse the heavy sleeper.

The project is nicely done, and after looking at his bill of materials it seems to be far cheaper than many sunrise alarm clocks you will find in stores.

Laser Tripwire Alarm System Uses Mirrors To Increase Coverage

April 18, 2011 by Mike Nathan 15 Comments

laser_tripwire_alarm

Instructables user [EngineeringShock] has been hard at work building a laser trip wire security system, complete with a combination lock. The security system works just like you see in the movies, employing an array of mirrors to bounce the laser across an opening several times in order to secure the space.

A PIC18F1220 micro controller sits at the center of the alarm and handles the majority of its functions. It takes input from the laser detection circuit, triggers the buzzer, as well as arms and disarms the entire alarm system. An LS7222 digital lock handles the passcode verification side of things, taking input from a 16-button matrix keypad, and telling the PIC when the proper code has been entered.

As you can see in the video below, the alarm system works and the buzzer is quite loud. There is one small problem however – the alarm only arms itself after the proper code has been entered and the lights have been turned off. The light sensing circuit he uses is too sensitive and can only operate in darkness, though he discusses the ability to add a more accurate sensing solution.

If you are interested in reading more about laser tripwire security systems, check out this similar passcode-based system, this alarm system built into a toy, and this Arduino-based alarm system.

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Power-sipping MSP430 Mini Alarm Clock

April 4, 2011 by Mike Nathan 12 Comments

[Markus] had a TI MSP430 sitting around from the LaunchPad kit he bought a while back. He didn’t know what to do with it, but eventually decided that it would make a great miniature alarm clock.

He added a shift register to the mix in order to drive his 7-segment LCD display, using two of the MSP430’s output pins in the process. Four more pins were tied to the display’s cathodes, while the remaining two pins are connected to push buttons which register user input.

He crammed the clock’s logic as well as an alarm tune into the chip’s scant 2KB of memory space, literally occupying everything up to the last available byte. The clock is quite a power-miser, using just 2 µA in standby mode. According to [Markus’] calculations, that should enable the clock to use one set of batteries for 10+ years.

While this isn’t the first MSP430 clock we have seen, it certainly is the smallest and most simple. Stick around to see a quick video of his clock in action.

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