Reverse Engineering Radio Controlled Outlets

January 26, 2011 by Mike Szczys 31 Comments

[Chr] picked up a pack of remote control outlets in order to reverse engineer them and build control into his own projects. These can be plugged into outlets around your house and a relay inside each module will switch whatever device is plugged into it after receiving a command from the remote. Once he cracked open the control housing it was easy to find the data line for the RF module which was on its own board. He used a logic analyzer to capture data from various button presses and then spent some time deciphering the communication protocol. He used what he learned to roll the module and code into an interface box where an ATmega8 connects via USB and passes commands from a computer to the RF board. Now he’s added home automation via a computer quite inexpensively. After the break you can watch a clip of the outlets switched using a smartphone.

So why not just patch into the buttons on the remote? Well, this same project was attempted at our local hackerspace earlier this month and the buttons don’t just pull a pin to ground. They use tri-state logic and are arranged into a matrix that is a lot harder to mimic (if not impossible) with a microcontroller. Analyzing the communications going into the RF module is definitely the less labor-intensive of the two approaches.

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Refurbishing A Refrigerator For Fermenting

January 25, 2011 by Caleb Kraft 12 Comments

[Mikey Sklar] wrote in to show us how he refurbished a neighbors useless refrigerator as a fermentation chamber. [Mikey] is a fan of making breads, kemchi, yogurt, and tempeh. To make these, it helps to have a completely controlled temperature for them to ferment in. [Mikey] developed a temp controller for this in the past, but had to either build a control box or use a giant chest freezer. This is not optimal for limited space, such as a kitchen. He got lucky when a neighbor tossed a wine cooler into the trash. These little coolers are perfectly sized for a kitchen and even have a glass front so you can keep an eye on what is going on inside without having to open it and effect your temps. [Mikey] ripped it open, replaced the peltier cooler with a large heat lamp and his temp controller. Since he was making yogurt with this one, he needed only to heat it. The final product turned out pretty effective.

Keyless Entry Via SMS

January 24, 2011 by Mike Szczys 15 Comments

[Billy’s] work got new keys which he didn’t want to carry around with him. Instead he built this system to unlock the door via text message. It is based around a Spinneret Web Server which drives a servo motor. He’s rigged up a pipe hanger to add some leverage to the lock’s knob. We’re surprised that the servo has enough power to do the job here but the video after the break shows there’s really no problem. On the communication side of things [Billy] set up Twilio to wait for text messages from an approved list of senders, then used an HTML form to issue the unlock commands to the webserver.

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Fertilizing A Planted Aquarium Using Air Freshener Hardware

January 21, 2011 by Mike Szczys 34 Comments

Keeping live plants in an aquarium happy can be quite a chore. One of the frequent rituals is adding fertilizer, which is called dosing. [Majstor76] came up with a creative way to automatically dose using an air freshener. He got rid of the canister that holds the scent and re-purposed a hand soap pump to move the nutrient-rich liquid. After the break you can see that there’s no shortage of power to actuate the pump and the powered air freshener base has a delay circuit, allowing for a few different time-release options. As long as the volumetric output is fairly consistent we figure you can dilute your fertilizer to fine-tune the dose.

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The Lunchtime Clock Gives You 12 Extra Minutes

January 18, 2011 by Caleb Kraft 41 Comments

The Lunchtime clock is a hacked clock that pulls a sneaky little trick to get you a longer lunch. In this instructible, [Randofo] shows us how he uses an Atmega168 and a realtime clock kit from Adafruit to slow the clock down 20% starting at 11:00 and then speed it back up at 11:45, gaining you an extra 12 minutes of sweet delicious lunch. Not really sure how noticeable this would be? Check out the video after the break. This is pretty hilarious and we can actually think of a few offices where this might work. However, many offices rely on their main network server for actual time keeping leaving this as just an amusing novelty. Still, those with luddite bosses can rejoice in your new-found extended lunch.

[via Gizmodo]

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Aquarium Water Exchanger

January 17, 2011 by Mike Szczys 25 Comments

If you want happy fish you’re going to need to do regular aquarium maintenance. Part of this is exchanging a portion of the tank’s water on a regular basis. [Bill Porter] came up with a water exchanger that means less manual labor, but makes the process just a bit more complicated.

So, what he would do before is fill a few buckets from the aquarium and dump them down the toilet. Then mix up a few buckets of salt water and add them back to the aquarium. This meant carrying several trips worth of heavy, dripping buckets through the house. What he has now is a gravity fed system into the orange bucket with a bilge pump to evacuate the old water from that bucket into the kitchen sink. The bilge can then be used to circulate water through the aquarium and the bucket, while filling with a hose from the kitchen sink and mixing in salt and chemicals. Less trips, no drips, but you’ve got to know what you’re doing with all of those valves.

We love seeing aquarium hacks like [Bill’s], or cooling the tank lights while heating the water, or just a fancy lighting setup in general. So if you’ve got some of your own, don’t forget to send in a tip about them.

Halloween Hangover: Talking Heads

January 10, 2011 by Mike Szczys 17 Comments

Here’s a Halloween prop leftover; [Chris] built his own version of singing heads from Disney’s Haunted Mansion on his porch for last year’s ghoulish decor. A projected image of actors singing a spooky song gives each of the four Styrofoam mannequin noggins its own digital life. There’s an optical sensor on the porch stairs that is tripped by unsuspecting candy-seekers. An Arduino monitors the sensor and uses AutoHotkey to start the video clip on a netbook. Check out the video after the break to see the finished display do its thing after dark.

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