Building A Battery-powered Motion Alarm

September 27, 2011 by Mike Szczys 15 Comments

[Brad] was asked by his Sister to design a motion-based alarm that would help her catch her son sneaking out of the house at night. Obviously this didn’t need to be a long-term installation so he decided to throw something together that is only active at night and can be battery-powered. What he came up with is a light-sensitive motion sensor that uses very little power.

He knew that an Arduino would be overkill, and decided to try his hand at using the Arduino to develop code for an ATtiny85. It has an external interrupt pin connected to the output of the PIR module, which triggers action when motion is detected. The first thing it does is to check the photoresistor via the ADC. If light levels are low enough, the buzzer will be sounded. [Brad] measured the current consumption of his circuit and was not happy to find it draws about 2.5 mA at idle. He spent some time teaching himself about the sleep functions of the AVR chips and was able reduce that to about 500-600 uA when in sleep mode. Now all he has to do is find a nice place behind the house to mount the alarm and there’ll be no more sneaking around at night.

If you’re trying to keep a tight leash on your own kids you could always make them punch the time clock.

Flip Off Your Alarm Clock!

September 23, 2011 by Mike Nathan 33 Comments

[Corbin] hates fumbling around in the dark with his alarm blaring, looking for the off switch. He was so annoyed with regular alarm clocks that he decided to build his own simpler timepiece.

The FlipClock resides in a simple black plastic case lacking any buttons whatsoever. When the alarm goes off, all one needs to do is flip the clock over to disable it. The digits automatically right themselves using an accelerometer to detect when the clock has been turned upside down, and an indicator LED lets you know that the alarm has been turned off.

The clock is based around a Propeller chip, which manages all of the clock’s operations. Instead of using a real time clock IC, [Corbin] is using a GPS module to keep accurate time, something we don’t recall seeing in an alarm clock before. That’s a good thing though, since there are no buttons with which to set the clock. In fact, there are no buttons to set the alarm either – the clock is configured to sound the alarm at the same time each day.

While this clock would certainly be too dangerous for a chronic snooze button abuser like myself, it’s an interesting concept nonetheless!

Check out the video below to see the FlipClock in action.

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Defusable Alarm Clock – Wastes Wire But Fun For The Kids

September 7, 2011 by Mike Szczys 36 Comments

Nothing makes you feel the pressure of getting out of bed in the morning like a ticking-time-bomb on the bedside table. It may look like it came in the mail from ACME, but all that went into this is some wooden dowels covered in craft paper and an Arduino-compatible board. The 7-segment display can act as a clock, or count down to your doom. You can set an alarm that requires you to clip the wires to shut it off. Each time that alarm is set the wires are randomly chosen; one will set of the bomb, one will safely defuse it, and the others do nothing. See for yourself after the break.

The wires are easily replaced because they are connected via terminal blocks. It still seems like an awful waste of wire. We like the Think Geek bomb clock concept that works in much the same way but uses wires that have a male/female RCA plug pair that can be disconnected and reconnected without waste.

This one will apparently be available as a kit, at which point the schematics and code will be released. But it shouldn’t be too hard to build one from scratch yourself, and it’s an obvious winner if you’ve got kids.

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The “AlarmTock”, A Chumby Hacker Board Alarm Clock

August 28, 2011 by Jeremy Cook 6 Comments

[Thomas] wrote in to tell us about his latest project, the “AlarmTock”. Like many hacks, this was inspired by some outdated hardware, a radio alarm clock from 1992.

After finally getting fed up with his old alarm clock, [Thomas’] wife purchased him a new one for around $10 from a local retail store. Although most likely an improvement, [Thomas] wondered why after so many years he still had to listen to either an annoying “beep” sound or whatever song the DJ on the radio decided to play.

In true hacker form, he decided to do something about it. [Thomas] crammed a [Chumby Hacker Board], which has much of the same hardware as the [Chumby One] device, into his clock radio. RSS-driven text-to-speech was used to tell him exactly what he wanted to know every morning. A sample .wav file is provided as well as the python script used to execute his morning wakeup routine. For another fun hack from [Thomas] check out his Google treadmill hack here!

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.

Alarm Clock Forces You To Play Tetris To Prove You Are Awake

July 4, 2011 by Mike Nathan 28 Comments

Oversleeping sucks, but we’ve all been there. Whether its a matter of hitting the snooze button a dozen times too many, or turning off the alarm and drifting back to sleep – sooner or later, you are going to wake up late.

Instructables user [nolte919] has overslept a time or two in his life, and he set out to design a clock that would make it nearly impossible to wake up late. His clock is Arduino-based and shares many features with off the shelf models including multiple alarms, a backup battery, and snooze features. His alarm however goes one step further and ensures you are fully awake each morning.

If you hit the user-defined snooze limit, the alarm sounds and will not turn off until you have cleared 4 lines in Tetris. That’s right, you have to prove to the clock that you are awake and coherent before it will shut off. Technically you can silence the alarm for a 30 second period so you can focus on Tetris, but that’s all the break you get.

It really is a novel way of ensuring you are awake in the morning, and heck, how bad can the day be when you start off by playing video games for a few minutes?

Stick around to see a quick video of his Tetris alarm clock in action.

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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.