Aquarium Overflow Sensor Saves Your Fish And Your Floors

April 15, 2011 by Mike Nathan 31 Comments

If you’ve ever had a water leak in your home, you know the sinking feeling that comes over you as you walk through the door to the sound of running water. [Greg] knows this feeling quite well, having returned home to a sopping wet floor and an overflowing reef aquarium on more than one occasion.

Both of the overflows he experienced were due to a clogged drain in his display, but there was little he could do as far as walling off the drain from potential blockages. With all of the delicate creatures living in the tank, the only possible solution that came to mind was monitoring the aquarium’s water level.

Unfortunately he had no idea how to get this done aside from using probes (which would rust in the salt water) or expensive off the shelf systems. [erich_7719] from the All About Circuits forums helped [Greg] out and designed a circuit for him which would monitor the water level using an IR sensor. The circuit simply shuts off the pump if the water level gets precariously high. As you can see in the video below it works quite well, and as a safety measure, requires a manual restart of the pump once the high water sensor has been tripped.

If you have a need for the same sort of setup, swing by his site for a detailed schematic as well as a bill of materials.

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Dishwasher Notifier For The Absent-minded

April 12, 2011 by Mike Nathan 28 Comments

dish_o_tron_6000

[Quinn] over at BlondiHacks is admittedly pretty absent-minded when it comes to household chores such as emptying the dishwasher. She often can’t remember if the dishes are dirty or ready to be put away, so she decided it was time to devise a mechanism that would help keep her on task. She originally considered a double-sided sign that said “Clean” on one side, “Dirty” on the other, but she chose the fun option and decided to over-engineer the problem instead.

She ultimately focused on two conditions that she needed to monitor: when the dishwasher had been run, and when the dishes have been emptied. To tackle the first condition, she used a thermistor to detect when the door of the dishwasher got hot from the wash cycle. The second wasn’t quite as easy, since she often peeks into the dishwasher to grab a clean dish when needed, unloading the rest later. She eventually settled on using a tilt switch to monitor the angle of the door, assuming that the dishes have been removed if the door was open for over a minute.

[Quinn] reports that her Dish-o-Tron 6000 works well, and she had a good time building it. Sure the whole thing is kind of overkill, but where’s the fun in moderation?

Brainwave-based Assistive Technology In The Home

April 10, 2011 by Mike Nathan 11 Comments

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Amyotrophic lateral sclerosis (ALS) is a debilitating disease that eventually causes the afflicted individual to lose all control of their motor functions, while leaving their mental faculties intact. Those suffering from the illness typically live for only a handful of years before succumbing to the disease. On some occasions however, patients can live for long periods after their original diagnosis, and in those cases assistive technology becomes a key component in their lives.

[Alon Bukai and Ofir Benyamin], students at Ort Hermalin Collage in Israel, have been working hard on creating an EEG-controlled smart house for ALS patients under the guidance of their advisor [Amnon Demri]. The core of their project focuses around controlling everyday household items using brainwaves. They use an Emotiv EPOC EEG headset which monitors the user’s brainwaves when focusing on several large buttons displayed on a computer screen. These buttons are mapped to different functions, ranging from turning lights on and off to changing channels on a cable box. When the user focuses on a particular task, the computer analyzes the headset’s output and relays the command to the proper device.

As of right now, the EEG-controlled home is only a project for their degree program, but we hope that their efforts help spur on further advancements in this field of research.

Continue reading to see a pair of videos demonstrating their EEG-controlled smart house in action.

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Growling Doorbell Lets You Know Guests Have Arrived

April 9, 2011 by Mike Nathan 16 Comments

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[Sean] was screwing around online looking for nothing in particular when he came across a mailbox hacked to notify the homeowner when the mail had been delivered. Since his mail is delivered via a slot in the door, he had no use for the hack as is, but something similar soon came to mind.

His dog isn’t too keen on visitors, and he figured that he could save himself a bit of grief (and a lot of unnecessary barking) if he were to wire up his doorbell to notify him of guests via his iPhone. He stopped by the local hardware store and picked up a wireless doorbell. It was quickly disassembled and wired up to an Arduino he had set aside for a different project. Tweaking some code he found online, he soon had the doorbell talking with the Arduino and was ready to interface it with his iPhone. He decided that he wanted to deliver notifications to his phone via Growl and found a Perl script online that was close to what he needed. A few tweaks later, and he had a Growling doorbell.

As you can see in the video below, it works, though there seems to be a bit of a delay in the notification. We don’t think that it would be enough to send his visitors packing before he made it to the door, but the lag can likely be reduced with a few small modifications.

As for the post that started this whole thing, we’re pretty sure this is it.

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Compost Heap Temperature Logger Helps Keep Things Hot

April 8, 2011 by Mike Nathan 12 Comments

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HackHut user [lackawanna] is looking to start his own compost pile, but as many urban composters discover, things can get quite smelly if you don’t manage it properly. The process of composting is broken up into two phases, aerobic and anaerobic decomposition. The former is the first stage to occur and produces plenty of heat, but should be scentless. The latter gives off less heat and is more of a stink due to putrefaction. Carefully monitoring the temperature of the pile and restarting the aerobic phase when necessary helps to keep the process “healthy” and scent-free.

[lackawanna] built a simple temperature monitor that he plans on using to track the status of his compost pile once he gets started. It uses an ATmega328 as the brains of the operation and an old metal can transistor as his temperature sensor. Using relative measurements of the compost pile taken in 10 minute intervals, he can determine when the aerobic phase is underway, as well as when things begin turning anaerobic. At that point, the sensor alerts him that the pile needs to be turned.

The build is pretty simple, but leaves plenty of room for expansion. It should be relatively easy to add a more friendly notification interface as well as install multiple sensors to the pile for obtaining aggregate temperature data.

Converting From Clutter Closet To Dreamy Datacenter

April 8, 2011 by Mike Szczys 51 Comments

[DocDawning] had a nice home network up and running, but the messy pit housing the hardware made him avoid that part of the house. In an effort to cut down on noise, and clean up the clutter, he built himself a very nice data center inside a small closet.

One of the biggest changes in the setup provides adequate cooling. He cut a vent hole into a wall shared between the closet and a hallway. This was just the right size for a few large cooling fans which suck air into the enclosed space. But cool-air intake must be accompanied by hot-air outflow so he added an exhaust vent in the ceiling. This also received a trio of big fans, and as you can see above, the integrated LEDs act as a light source for the server farm.

The final part of the plan involved machine-specific brackets mounted to the walls of the enclosure. These racks were built out of 1×1 white wood. They hold the hardware in place leaving plenty of room to run cables. The new setup even opened up enough wall space to mount power and networking hardware. Now everything has its place, and [DocDawning] can finally close the door on his noisy servers.