Simple Hack Reuses An Air Freshener PIR Sensor

October 11, 2011 by Mike Nathan 5 Comments

pir_sensor_room_greeter

A year ago [Lochie] bought an Airwick automatic air freshener, and while he thought it was a cool gadget, the freshening spray and the novelty ran out in short order. The device collected dust in his room for some a while until he recently unearthed it, and noticed that a perfectly good PIR sensor was looking him in the face all this time.

He disassembled the air freshener, then set out to figure out how he could interface with the PIR sensor. After finding a helpful Instructable on the topic, he had full access to the sensor’s signals, allowing him to easily wire it up to an Arduino. He decided it would be fun to trigger some simple music any time someone entered his room, so he encoded a short bit of the Super Mario Brothers theme in RTTTL, as he explains in the video below.

It’s a simple little hack, but [Lochie] is pleased with it, and we imagine that he likely has a long list of other creative ideas in mind for his newly discovered PIR sensor.

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Simple Circuit Reminds You To Lock The Door As You Rush Out Of The House

October 11, 2011 by Mike Nathan 24 Comments

door_lock_minder

It seems that [pppd] is always rushing out of his apartment to catch the bus, and he finds himself frequently questioning whether or not he remembered to lock the door. He often doubles back to check, and while he has never actually forgotten to lock the door, he would rather not deal with the worry.

Since he finally had some free time on his hands, he decided to put together a simple device that would help end his worry once and for all. Using an ATtiny13, [pppd] designed a circuit that would detect when his door has been unlocked and opened, beeping every few seconds until the lock is reengaged. The circuit relies on a reed switch installed inside the door frame, which is tripped by the magnet he glued to his door’s deadbolt.

He says that the system works well so far, though he does have a few improvements in mind already.

Link Spam Your Friends With Printed QR Codes

October 10, 2011 by Mike Nathan 39 Comments

qr_printer_sharing_links

While [Oryx] is down with social media like Facebook and Twitter, there are times when he wants to share things with people he is hanging out with in the real world. Sure, he could always email his friends links to the latest video of a cat doing something totally hilarious, but he wanted something a bit more tangible.

He had a small thermal printer from SparkFun kicking around, and thought it would be the ideal medium for sharing things with others. He sat down and put together a bit of code that allows him to interface the printer with his computer, generating QR codes from his web browser with the simple click of a button. Now, when he wants to pass something along to a friend, he can quickly print out a label bearing both a QR code and URL for easy access later on.

All in all it’s an interesting idea, though we would be curious to see what would happen if we handed our non-techie friends a printed QR code.

Retrofitting A 60-year Old Electric Heater

October 10, 2011 by Mike Nathan 22 Comments

electric_heater_retrofit

[John] found an old Kenmore electric heater at a junk store one day, and thought it would look great in his bathroom. The only problem with the unit is that it was built back in the 1940s/1950s, so it lacked any sort of modern safeguards that you would expect from an indoor heater. There was no on/off switch, no fuse, no thermostat, and no tip switch – though it did have a nice, flammable cloth-covered power cord.

Since [John] wasn’t too keen on burning his house down in the name of staying warm, he decided to retrofit the old unit’s shell with a new ceramic heater. He found a $20 unit that looked like it would fit, so he disassembled both heaters and got to work. The Kenmore’s innards were scrapped, then he gave the unit a nice fresh coat of high-temp paint. The new heater was cut to fit inside the old unit’s shell, controls and safety features intact.

He says that it works very well, and that it looks great in his bathroom. If you’re considering doing something similar, be sure to check out his writeup – it is very thorough and has plenty of details that will help you along the way.

Open-source Sprinkler Controller Keeps Your Lawn Looking Great

October 9, 2011 by Mike Nathan 16 Comments

open_source_sprinkler_controller

[Ray] wrote in to share a great project he just recently wrapped up, an open-source sprinkler valve controller. Built in collaboration with Wired Magazine’s editor-in-chief [Chris Anderson], the sprinkler controller is designed to replace the limited commercial sprinkler timers that typically come with a new home sprinkler setup.

Their system greatly expands on the idea of a standard sprinkler timer, adding Ethernet connectivity, web-based scheduling, and 8 separate controllable zones. At the heart of the controller is an ATmega328 running the Arduino bootloader, which means that the system is easily tweakable to fit your specific needs. The controller works off a standard 24V AC sprinkler transformer, which means that the controller can easily act as a drop-in replacement for your existing system.

The pair sells kits through the web site, but you can always simply download the schematics, PCB layout files, and BoM to build one yourself. Whichever path you choose, be sure to swing by [Ray’s] site and take a good look around – there is an incredibly detailed assembly and programming guide there that will be a great resource as you go along.

Continue reading to see a video of the sprinkler controller in action.

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Workbench Overhead Camera Boom Made From PVC

October 9, 2011 by Mike Nathan 10 Comments

pvc_overhead_camera_ boom

It looks like [Dino] is getting settled into his new digs, and while the moving process has kept him pretty busy, he’s slowly but surely getting his workshop area set up. One thing that he really wanted from his new bench was a better way to record video, for both his Hack a Week series as well as broadcasting over Ustream.

He bought a nice little Hi-Def web cam for making videos and set out to build a camera boom for his bench. The boom is constructed mostly from PVC piping along with some other odds and ends for mounting. In the video below, he walks through the construction step by step, making it easy for anyone to follow along and build one of their own.

The boom looks like it works very well, and is a bargain at under $40. It articulates every which way giving him complete coverage of his workbench, and makes it easy to film whatever he’s working on – big or small.

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Upgrading An Old Super Scope

October 9, 2011 by Mike Nathan 14 Comments

rechargeable_super_scope

[Brian Knoll] still uses his Super Nintendo with relative frequency, and he just can’t get enough Super Scope action. If you never owned one, the Super Scope can be a ton of fun, but it’s also an incredible battery hog. It eats through AA batteries by the caseful, so [Brian] wanted to make the switch to rechargeable cells. Since NIMH AA batteries just don’t cut it in the Super Scope, he put together a rechargeable solution of his own.

He started off by calculating what sort of battery he would need for 8 hours of game play, then he started work on designing his circuit. The board he built contains both a DC/DC converter to provide the 9V required by the Super Scope, as well as built-in LiPo charger. He had his board made by BatchPCB, and after working through a small production error, he put everything together and gave his revamped scope a shot.

Things worked great, and while he says that he really should have built a low-voltage shutoff into his circuit, he is very happy with the results.