HAL is Duct Tape for Home Automation

HAL Home Automation

When it comes to home automation, there are a lot of different products out there that all do different things. Many of them are made by different companies, and they don’t often play very well together. This frustration ultimately led [Daniel] to develop his own Python based middleware solution to get these various components to work as a single cohesive system. What exactly did [Daniel] want to control?

First up was the door lock. [Daniel] lives in an apartment building, so there are actually two locks. First, a visitor must be allowed into the building by pressing a button on the intercom system in the apartment. Second, the apartment door has its own dead bolt lock that needs to be opened and closed. [Daniel] was able to control the building’s front door using just a transistor hooked up to an Arduino to simulate the press of the physical button. The original button remains in tact so [Daniel] can still easily “buzz” in a visitor.

The apartment’s dead bolt was a bit trickier. There are off-the-shelf solutions to control a dead bolt, but they are often expensive. [Daniel] built his own solution using a simple servo motor bolted to the door. The servo is controlled by the Arduino which is in turn controlled via two broken intercom buttons that already existed within the apartment. The buttons were originally used to either speak to or listen to a visitor before buzzing them into the building. They had never worked for [Daniel] so he re-purposed them for his own project. The whole DIY door locker is enclosed in a custom-made laser cut wooden box.

Click past the break for the rest of [Daniel's] story.

[Read more...]

A Smart Clothes Dryer

dryer6 Here’s a question that will rack your brain: does your clothes dryer stop when the clothes are dry? It seems if you have a machine that guzzles power for one single purpose, you’d like it to stop when its job is done, or for the sake of convenience, keep going until the clothes are dry. Temperature and humidity sensors are cheap, and if you don’t have an auto sensing clothes dryer, a DIY smart clothes dryer seems both efficient and convenient.

[Andy] figured when clothes are dry, they stop emitting moisture. Based on that premise, he could monitor the operation of a clothes dryer and either shut off the machine or send a message that it’s time to take the clothes out. It’s a simple enough idea, and with an Arduino and a DHT11 temperature and humidity sensor, it was pretty easy to put together.

The clothes dryer used for this experiment was a self-ventilating model that doesn’t vent to the outside. Instead, it condenses the water in your towels and jeans into a tub to be emptied by hand later. This might introduce a little error into tests, but [Andy] did come up with a way to mount the temperature sensor without modifying his dryer in any way. From the initial data, the ventless dryer might be introducing a little experimental error, but it’s still too good of an idea to not try out with a traditional dryer that vents to the outside. Here’s the code should you want to try this yourself.

A WiFi Home Power Meter

acFor his masters at Cornell, [Christopher McNally] designed a simple, non intrusive home power meter capable of doing everything a ‘smart meter’ can do – log power consumption throughout a home, and display a log of a home’s power consumption over WiFi. He’s even testing out some interesting ideas, like automatically detecting when specific devices turn on by reading the current data.

From [Chris]‘[Jeramy] developed his system around the Arduino and a Ethernet shield, taking care of networking and choosing a micro, leaving him more time to develop the more interesting part of the project: sensing current. For this he used a small, clip-on current transducer. This sensor generates up to 10 VAC across a resistor, but the Arduino doesn’t play well with AC, requiring a small rectifier built around an op amp.

While the project works as a homebrew smart meter, [Jeramy] wasn’t able to automatically detect when certain devices were powered on. This is partly due to the fact that changes in current were only seen in magnitude and not waveform. Also, if two devices were powered on at the same time, the software would see that as a larger device that draws the sum of the current of two smaller devices. Still, [Jeramy] came up with a cheap way of metering power in any home, and the cost of his solution is cheaper than a lot of professional systems out there.

All the code, files, and design report are available on [Jeramy]‘ git.

A Low Cost, Solar-Powered Swamp Cooler

swampCooler2014

A looming, torturous summer is preparing to bear down on many of us, making this dirt-cheap swamp cooler build an attractive hack to fend off the heat.

Though this is a pretty standard evaporative cooler, the design comes together in a tidy and transportable finished product. The base is a ~$3, 5-gallon bucket from a local hardware store with its accompanying Styrofoam liner. Three 2 1/8″ holes carved into the side of both the bucket and liner will snugly fit some inch-and-a-half PVC pipe with no need for glue.

One last cut into the lid to seat a small desk fan rounds off this build—or you can chop into the styrofoam liner’s lid if you prefer. The video demonstrates using a 15W solar panel to run the fan, and we have to admit that the cooler seems to be an excellent low-cost build. It does, however, require a frozen gallon jug inside to pump out the chilled air for around 5-6 hours per jug. Maybe one of our frugal and mathematically-inclined readers can throw out some guesstimations for the cost of stocking the bucket with a jug of frozen water a couple times a day? Video after the jump.

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Mirror Mirror on the Wall…

 

MagicMirror

Who wouldn’t want a mirror that compliments them first thing in the morning? [Michael]‘s  Magic Mirror does this and more.  [Michael] got the idea for his mirror during an epic Macy’s shopping trip with his girlfriend. While looking for a boyfriend chair, [Michael] noticed a mirror with a lighted sign behind it. Intrigued by the effect, [Michael] realized he could build it – and build it better!

Back at home [Michael] set to work. The Magic Mirror uses a piece of one-way mirror, similar to infinity mirrors. Instead of LED’s and another mirror, [Michael] wanted to embed an entire monitor behind the glass. In order to keep the mirror thin, [Michael] needed a monitor with cables exiting toward the side or bottom rather than directly out the back. He found what he was looking for in an Iiyama monitor. Yanking the case off a brand new LCD can be a bit nerve-wracking, but [Michael] pulled it off in pursuit of a thin final product.

Magic Mirror’s frame is built with standard 2×4 lumber. [Michael] had the foresight to include some cooling holes for the heat generated by the monitor. The heavy 6.5Kg final product required a double mounting point.

With a good-looking case, it was time to get some equally good-looking data to display. [Michael] used a Raspberry Pi to drive his display. He switched the Pi’s display mode to portrait and installed Chromium  in kiosk mode. The entire mirror is essentially a web page. [Michael] used some simple HTML, CSS and Javascript to pull time and weather data down from various feeds. The page is rendered in a clean Helvetica Nueve Neue font with matching icons. A handsome build indeed!

Electric Imp Locks and Unlocks your Door Automatically

2013-11-19 14.23.18

When the folks over at PinMeTo moved into a new office, they were dismayed to find out an extra key would run them a whopping 500 sek (~$75 USD). Instead, they decided to build their own automatic door lock using the Electric Imp system.

If you’re not familiar, the Electric Imp is a small SD card designed to provide internet (Wi-Fi) functionality to consumer devices. While it looks like an SD card, you cannot just plug it into any SD card slot and expect it to work — it still needs a prototyping board. We’ve seen it used to make a wireless thermal printer, or even make a tweeting cat door to let you know of any feline intruders!

Anyway — back to the hack. To move the lock cylinder they’re using a basic RC servo connected directly to the Imp. A flex sensor is installed on the side of the door over-top the lock — this provides feedback to the Imp whether or not the door is in fact locked. The Imp then communicates to Everymote to allow for keypad access from your mobile phone.

It probably ended up costing more in time and money than a new key, but hey, it looks like it was a fun project to do!

The Ultimate Workstation That Folds Up

ultimate maker station

Looking for an easy way to keep on making stuff even though you’re living in a tiny dorm room? [Matt Silver] was tired of not having a dedicated work-space, so he spent some serious time designing this modular, re-configurable and collapsible portable workstation ready for almost anything.

He started out by sketching ideas, playing around with 3D models in SketchUp, and eventually building a few prototypes using trial and error — and what he’s come up with is pretty darn impressive. It folds down to just under a foot by three feet squared and has casters to roll it around. Once unfolded, you stabilize it by placing your chair on one of the walls that folds down, and the desk itself is also re-configurable for different work surfaces. He’s included a power bar, an LED work-light, and it even has storage racks for tools on the side.

It’s a very thorough Instructable, and definitely worth a look through — especially to see how it magically unfolds! And if you’re wondering about how much it would cost to build, you’re probably looking at around $200 depending on what you already have on hand. What we really like is how it’s almost entirely made out of a single 4’x8′ panel of plywood — it’s like this guy works for IKEA or something!

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