Collecting Radon Data In The Name Of Science And Safety

March 27, 2012 by Mike Nathan 32 Comments

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When [Chris Nafis] built an addition onto his historical home he found that a Radon problem, previously mitigated with plenty of concrete, seemed to rear its ugly head yet again. He eventually resigned himself to installing a Radon fan and detector – the latter of which offered no way to store measurement data. He wanted to get a better feel for the short and long-term Radon measurements in his house, in hopes of finding some correlation between temperature, moisture levels, and the total amount of Radon emitted from the ground.

To do this, he disassembled a pair of Radon detectors located in different parts of his house, each of which he wired up to an Arduino. Using his oscilloscope to determine which PCB leads controlled the different LED segments on the displays, he quickly had the Arduinos scraping measurement data from the sensors. [Chris] figured the best way to keep track of his data was to do it online, so he interfaced the microcontrollers with Pachube, where he can easily analyze his historical readings.

An additional goal he set for himself is to trigger the Radon fan only when levels start rising in order to save a little on his electric bill. With his data logging operation in full swing, we think it should be a easy task to accomplish.

Aquarium Water Exchanger Built From Keurig Parts

March 21, 2012 by Mike Szczys 22 Comments

We keep seeing commercials for those Keurig coffee makers that use a plastic pod of grounds to brew just one cup of coffee. We’re pretty sure this is a fad, and absolutely sure that the extra packaging created by brewing with this method is a waste. But to each his own. [Danman1453] has two of the devices. One he bought, the other is a warranty replacement. He decided to scrap the malfunctioning unit and see if he could put it to good use. What he ended up with is the aquarium pumping system you see above.

It is conceived as tidier way to swap out the water in the fish tank. He had been using tubing to siphon the water, but found he almost always made a mess. This system uses an air pump to prime the water pump by pressurizing the tank which forces water into the lines. Once the water pump is primed he switches over to that for the rest of the work. He used an old metal tool box as an enclosure, using the cover to mount the push-buttons which route power to various components when pressed. Many of the parts were transplants from the coffee maker, but even if you sourced all of the components new this wouldn’t cost too much to put together.

Tearing Down A Failed LED Bulb

March 20, 2012 by Mike Nathan 45 Comments

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[Todd Harrison] was thinking of replacing some incandescent light bulbs in his house with LED models, so and his wife picked up a single candelabra bulb to test before they spent the cash to swap them all out. The bulb died in about a week’s time, so [Todd] got out his trusty electronic disassembly device (his hammer), sharing his post-mortem examination with us.

After taking a cursory look at it, [Todd] found that the circuit powering the bulb was not overly complicated. A small bridge rectifier along with a few caps and resistors are all that was used to power the device, making it’s failure a bit puzzling. When [Todd] wired it up to his power supply, the bulb lit up, much to his surprise. His best guess as to why it died is that the shrink wrap around the PCB managed to cause a short, though he also noticed that one of the bridge rectifier’s legs was not soldered down.

He started tooling with the light to find out more about it, but he managed to blow out a handful of LEDs in the process. All in all the LED lighting swap was a disappointment, but at least he had some fun along the way!

Continue reading if you’re interested in seeing [Todd’s] diagnosis in its entirety.

Continue reading “Tearing Down A Failed LED Bulb” →

EL Wire Piping On A Party Couch

March 19, 2012 by Mike Szczys 10 Comments

If you’ve been putting off that reupholstering project here’s a little incentive to get started. Adafruit now has some electroluminescent wire which is perfect for use as piping. They’ve outfitted a small sofa with the glowing material and we think it looks great whether switched on or not.

The installation process is really quite easy. The EL wire is covered with clear material that provides a continuous tab running the length of the wire. This can be stapled on like you see in the image above, or sewn into a fabric seam. So you could take an existing sofa cover, remove all the stitching, and sew it back together with the EL wire replacing the original piping. The video after the break shows how simple the process is.

This will be a nice complement to that Daft Punk table we’ve been meaning to build. Continue reading “EL Wire Piping On A Party Couch” →

Color Changing Coaster Has A Built-in Drink Detector

March 15, 2012 by Mike Szczys 14 Comments

[Robert] put together his own illuminated coasters that know when they hold a drink. They look fantastic, thanks to professionally produced PCBs and a layered, laser-cut acrylic case. They’re much like the pagers given to restaurant-goes who are waiting for tables, but this version is much fancier (and doesn’t include the vibrating/paging feature).

The RGB-LED board is a previous project which was developed using eight surface mount RGB LED modules around a circular board. It uses an ATmega168 paired with an MBI5168 constant-current LED sink driver. The coaster enclosure gave him room for a few more items, like the pair of AA batteries which work in conjunction with a boost converter to power the device. It also houses an IR reflectance sensor which is used to detect the presence of a drink on the coaster. This is important since an on-occupied coaster looks like it would be blindingly bright if there wasn’t a glass to diffuse the intensity of the LEDs.

He mentions that incandescent light bulbs mess with the IR reflectance sensor. But there must be some way to account for ambient conditions with the code, right?

Wireless Solar Water Heater Controller Ensures Hot Water Every Time

March 9, 2012 by Mike Nathan 8 Comments

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[Peter Sobey] had a solar hot water heater installed in his home, which worked great until he relocated his kitchen to a neighboring room. Now a good bit further from the tank, the hot water reaching his sink was tepid at best due to the increased distance and temperature limiting mixer valve in the new heater.

He installed a salvaged solar panel and water tank solely for use in his kitchen, but as the panel was located above the tank, he had to find a way to actively monitor and control the water temperature. His pump and valve system was originally driven with an off the shelf PICAXE-based controller, but he eventually got the urge to add a wireless display and control panel to the mix.

A pair of Arduino Nanos run the show now, one of which resides in the pump controller box, while the other is used in the temperature display box in his kitchen. He uses a set of Bluetooth modules to link the Arduinos together, relaying temperature data and allowing him to send the pump controller manual commands if needed.

He says the system works a treat, and he’s much happier with his homebrew controller than the one he used originally.

PushingBox Alerts You Of Your Cat’s Roaming Habits

March 9, 2012 by Mike Szczys 5 Comments

Dogs may be man’s best friend, but cats are certainly a hacker’s best muse. They provide so many ‘reasons’ for projects, like this cat door which [Clement] augmented to monitor the comings and goings of his feline friend (translated). He’s using a web service we hadn’t heard of before called PushingBox to send notifications like Tweets and Emails from the Arduino monitoring that door.

The two white rectangles attached to the cat door in the image above are magnets commonly used for entry door monitoring. Using a pair of them along with reed switches lets the system differentiate between an incoming or outgoing cat. The Arduino is web-connected and running the PushingBox API to manage the notification messages. See a demo of the system in the clip after the break.

This would be a nice addition to the cat door we saw [Dino] build. Of course, if you really want to go all out with the cat hacks the next project should be a GPS tracking collar. Continue reading “PushingBox Alerts You Of Your Cat’s Roaming Habits” →