Converting PWM To DC Signaling For More Precise Fan Control

August 15, 2011 by Mike Nathan 24 Comments

pwm_to_dc_fan_control

[hedgehoginventions] wrote in to share a little modification he made to his video card in order to keep it from overheating during strenuous 3D tasks. Having swapped out the stock cooler on his Nvidia 9600GT graphics card, he found that it did not need to utilize the fan while doing mundane things like checking email, but that it still required extra air flow while playing games.

He figured he get the fan to shut off by tweaking the PWM signal, but he found that he could not get the duty cycle under 20% using software, which still caused the fan to run at all times. The circuit he built takes the PWM signal output by the card, cleaning it up before converting it to a corresponding DC voltage. The fan then runs at the same speed it would if driven directly by the PWM signal, though it can now turn off completely when not required.

It’s a nice way to do automatic fan control when you can’t otherwise get your GPU fan to shut off. Nice work!

Simple Device Answers Questions Just Like Your Boss Does

August 15, 2011 by Mike Nathan 17 Comments

executive_decision_maker

Like many of us, [Bertho] has had plenty if interaction with “Executive” types who seem to make decisions randomly, and most certainly not based upon any sort of reason. As he was picking through parts bins at his local hackerspace, he thought it would be fun to build an “Executive Decision Maker”. The device he had in mind would answer questions at the push of a button, with the kind of randomness that could only be carefully honed through years of barking orders from a corner office.

Constructed from third-rate LEDs and old CMOS chips that were lying around, the operation of the device is quite simple. Much like a Magic 8 Ball, a question is posed, and as [Bertho] states, “The Executive Decision maker automatically tunes into the aether and the subconscious of the user” pressing the “Decide” button. The device then makes a judgement, relaying its answer to the user via an LED display.

We definitely got a good laugh out of this one, so be sure to check out the video after the break to see the Executive Decision Maker in action.

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Automated Aquarium Chemical Dispenser Is Extremely Precise

August 14, 2011 by Mike Nathan 17 Comments

precision_doser_nano_doser_espresso_pump

[Robovergne] prides himself on the beautiful reef aquarium that he has set up in his home. These sorts of water displays require constant maintenance due to the mineral requirements of living coral. Rather than add mineral solutions manually, he decided to build a nano-doser using espresso machine pumps (Google Translation).

These vibration pumps run on mains voltage, so he had several options as far as how to control them. Using relays would likely make things pretty noisy, so he chose to use a zero crossing detection circuit to precisely control the pumps’ duty cycles and output.

His setup uses a PIC to control everything from the zero crossing circuit to the display LCD. An amount of product and the distribution time frame are entered using a handful of buttons mounted on the front of his control box, leaving the PIC to do the heavy lifting. It will calculate the proper length of time to run the pump based on several factors, including fluid viscosity and height of release.

It really is an impressive system, and while his needs are very precise, we imagine this sort of setup would be quite useful in building less complicated dispensers, such as those found in an automated bar.

Continue reading to see a few videos of his Nano-doser in action.

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Juice Bridge Powers Your Breadboard In A Snap

August 13, 2011 by Mike Nathan 28 Comments

juice_bridge_breadboard_power_bridge

[Quinn Dunki] got tired of messing around with wires when connecting things to her benchtop power supply, so she built herself useful little power bridge that plugs directly into any standard breadboard.

The board is small and simple, but quite useful all the same. It was built to power both sides of the breadboard, and it can be easily switched between an unregulated power supply and a regulated 5v supply. An ammeter can be attached to the board via a pair of pins she set aside, allowing her to easily measure the current draw of the entire circuit.

We think her “Juice Bridge” would be very useful to anyone who frequently prototypes on breadboards. In fact, it would be a fantastic beginner project since it involves etching and developing PCBs as well as some simple soldering, while resulting in a handy takeaway tool at the same time.

If you want to build one of your own, [Quinn] has the schematics and Eagle PCB files available for download on her site.

Stream Music Anywhere In Your House With These WiFi Speakers

August 12, 2011 by Mike Nathan 27 Comments

wifi_speakers

[Rui] needed an easy way to play music in several different zones from one centralized location, but he didn’t want to run any new wiring in the process.

He figured that the best way to do this would be to stream his music directly to his speakers over Ethernet. Earlier this year, he put together a handful of Ethernet-connected speaker nodes using a few Arduinos equipped with both Ethernet and MP3 shields. To interface with these speaker nodes, he wrote an application utilizing VLC’s network streaming engine. This software monitors his network for newly attached speakers, adding them to his inventory automatically. He can choose to play music on any set of speakers using a multicast audio stream.

The setup was pretty slick, but what about locations that didn’t already have Ethernet drops? He thought of that too, revising his design just recently. The newest set of speakers he constructed ditches the Ethernet board for a Wifly shield, all of which he crammed inside the speaker cabinets. Now, he has the ability to stream music anywhere he’d like, no matter what sort of infrastructure is in place.

If you have a need to do this in your home, [Rui] has made his software available for free on his site, so be sure to grab a copy.

Continue reading to see a short video of the speakers in action.

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Two-axis Panning Time Lapse Rig Built From Lego

August 12, 2011 by Mike Nathan 14 Comments

2_axis_lego_timelapse_dolly

[Jochem] wrote in to share a neat time lapse camera dolly he constructed out of Lego bricks. He is a big fan of the two-axis panning time lapse effect where the camera moves while recording images. He figured it would be easy enough to construct one of his own, so he dug out his pail of Lego and got to work.

The rig consists of a stationary motor platform which pulls a movable sled using a simple gear and string. The motor platform is controlled by an Arduino, which pulls the movable sled along every so often, snapping pictures along the way. [Jochem’s] Nikon D80 supports shutter release via IR, so he programmed the Arduino to send a quick IR pulse each time it has finished moving the dolly.

The rig looks like it works pretty well as you can see by the video below, but [Jochem] says that it still needs a bit of work. We just can’t wait to see what other time lapse movies he puts together once he finds an “interesting” time lapse subject.

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Wii Homebrew Hack – No Game Discs Required

August 12, 2011 by Mike Nathan 50 Comments

Jailbreaking hacks have come and gone for the Wii, ever changing as Nintendo tweaks their software to prevent homebrew from running. Piracy concerns aside, there is a legitimate Wii homebrew scene, and a new, easy to use tool has been released for those looking to give it a try.

Many of the previous jailbreaks relied on bugs found within official Wii games, but there’s a new kid on the block that requires nothing more than an Internet connection and an SD card. LetterBomb is the latest jailbreaking tool, which was created by an individual named [blasty]. It seems incredibly easy to use, requiring little more than entering your Wii’s MAC address into a web form. The site generates a customized jailbreak file, which your run on your Wii via the SD card – that’s all there is to it!

If I had a Wii, I would be hesitant to enter any sort of globally-unique number that could identify my console into a random web site, but perhaps I am being overly paranoid. Either way, it would be great to see an open-source version of this tool released so that jailbreaks could be done offline, without any risk of having your MAC address recorded.

[Thanks, blurry]