Smartphone Operated Garage Door Is Beginning Of Arduino Home Automation System

March 20, 2011 by Mike Szczys 15 Comments

[Tim] is showing off the first step in his home automation projected with this smart-phone garage door interface. In the video after the break you can see him open and close the garage door with the touch of a button. There’s also an open or closed indicator that he can check when away from home.

An Arduino takes care of a portion of the control for this project. Like the post we saw yesterday, he’s using PHP code on a webpage to manipulate the Arduino via its USB connection in order to open and close the door using a relay. The door status is also monitored by the Arduino and sent to the PC over the serial connection. The computer uses a Python script to monitor the incoming data and update a text file which is merged into the web interface using a PHP include. Future plans for the system include adding control for heating and air conditioning systems.

If you’re looking to do something like this but wirelessly here’s some advice on ditching the Arduino and using an XBee module instead.

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Clap To Remove This Brassiere

February 14, 2011 by Mike Szczys 71 Comments

Like some strange manga come to life, you can remove this brassiere with a clap of your hands. Under the red bow is a not-so-small mechanical clasp that replaces the original on the strapless front-clasping undergarment. We hate to criticize, but [Randofo] really went off the deep end of hardware overkill on this project. The clasp itself is the electromagnetic coil removed from the case of a mechanical relay. An ATmega168 listens for a spike in sound pressure from a microphone, then drives the relay to release the feminine support system.

It is Valentine’s day. The question being is this romantic or sleazy? Watch the NSFW video after the break and let us know your opinion in the comments.

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Electromechanical Computer Built From Relays

November 18, 2010 by Mike Szczys 41 Comments

This is Zusie, a computer built out of electromechanical relays. [Fredrik Andersson] picked up a lot of about 100 telephone exchange circuit boards, each with about 16 relays on them. After getting to know a heat gun really well he ended up with 1500 working relays with which to play. The machine runs slowly, it iss noisy, but it definitely works. After the break you can see it running and assembly code program that he wrote.

The instruction set is based on boards running microcode. These store the operational commands for each instruction the processor has available to it and they run in parallel with the rest of the operations.

We’re always surprised to see that these home-built processors work. Mostly because of the complexity involved in assembling them. How hard is it to find a shorting connection or a malfunctioning relay? Those problems aren’t limited to this application either, what do you do if a transistor-logic CPU has a malfunctioning chip?

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Snapping Pics At The Right Moment With A Pressure Plate

August 11, 2010 by Mike Szczys 22 Comments

[BiOzZ] built a pressure sensitive camera accessory to snap pictures at just the right moment. Before turning out all the lights the camera is set up with a twenty-second timer and a three-second exposure. The pressure plate doesn’t take the photo, but fires the flash to catch an image in the middle of the action.

The hack uses a piece of acrylic as the base of the pressure plate. A switch is constructed by placing aluminum tape on the base, and attaching a thin metal strip that is bent to add just a bit of spring. When an object is place on the plate the thin metal contacts the aluminum tape completing the circuit, a change in the weight breaks it. A simple circuit connects to this, using a relay to actuate the flash from a disposable camera. This is perfect for documenting the moment when you exercise that fruit-induced rage that has been consuming you lately.

Doorbell Combo Lock Can Open Your Garage Door

August 2, 2010 by Mike Szczys 24 Comments

Sometimes I get enough away from writing about other people’s accomplishments long enough to actually do my own hacks. Most recently I developed a combination lock that opens the garage door. The idea isn’t original, it is based on [Alan Parekh’s] button code project, but I did develop my own hardware and software. A four digit code is entered by pressing the button a number of times for the first digit, and waiting for a flash of an LED inside before moving on to the next digit. If the correct code is entered the door opens.

My version centers around an ATtiny13. I originally downloaded [Alan’s] code in hopes that I could port the PIC firmware over pretty easily. Unfortunately it was written in BASIC so I just took what I knew about the interface and wrote my own program. I developed on an ATmega168 so that I would have no trouble running out of programming space, and was able to optimize my code down to 964 bytes to fit on the tiny13.

The hardware is quite simple. I purchased a lighted doorbell from Home Depot and swapped out the light bulb for an LED. I choose this because the doorbell mounts in a 5/8″ hole in the trim of the garage door and is easily overlooked. I’m quite happy with the results, and if you want to play around with the idea, you can easily build the circuit on a breadboard and use another LED for the load rather than including a relay. Hit the link at the top of this post for the schematic, code, and build images.

Air Freshener Hacking

July 27, 2010 by Mike Szczys 35 Comments

In an effort to improve his marital standing [Tech B] hacked an air freshener to make it Internet controllable. The main component here is a Glade Sense and Spray. It cost him $7 and is meant to spray out some sweet smells when it senses motion in the room. The unit also has a manual spray button which he patched into with the help of a relay. From there some Arduino code and an IRC bot take over, letting him unleash freshness from anywhere he has IRC access.

When reading about this we were also thinking: “motion sensing circuitry available at local stores for just $7?”. We may have to conduct an investigation into the alternative usefulness of that package.

If you have another brand of automatic freshener around it should be just as easy to hack as this one was.

Power Cycling A Problematic Modem

June 29, 2010 by Mike Szczys 53 Comments

[Gigawatts] struggled against a shoddy Internet connection for quite some time. Changing modems, having the line serviced, and spending far too much time on the phone didn’t do any good. In fact, the only thing that fixed the problem was power cycling the modem once it stopped responding. His solution was to automate the power cycling process. He added a cron task to his router which is running DD-WRT, a favorite firmware alternative for hacked routers. The script monitored the WAN connection and when it went down it would toggle one of the serial port pins. He whipped up an outlet box with a relay in it and used that serial pin to cut the power going to the modem. A workaround yes, but it was the only thing that brought an end to his frustration.