Tiny Audio Switcher Eliminates Repetitive Plug Swapping

December 9, 2011 by Mike Nathan 30 Comments

usb-audio-switcher

[Phil] uses both his computer’s speakers and a set of headphones while working at his desk, but he was growing tired of constantly having to remove the headset from his sound card in order to insert the speaker plug. He’s been meaning to rig something up to make it easier to switch outputs, but never seemed to get around to it until he recently saw this LAN-enabled audio switcher we featured.

His USB-controlled switch features a single audio input and two audio outputs, which he mounted on a nicely done homemade double-sided PCB. The switch can be toggled using any terminal program, sending commands to the on-board ATtiny13A via an FT232R USB to serial UART chip.

The switch’s operation is really quite simple, merely requiring [Phil] to type in the desired audio channel into the terminal. The ATiny and a small relay do the rest, directing the audio to the proper output.

Power Strip Hack Reduces Standby Electricity Consumption

November 21, 2011 by Mike Nathan 31 Comments

computer-standby-circuit

For years, [Rasmus] has left his computer connected directly to the mains power so that he can turn it on via Wake on Lan. While powered down, it would still continuously consume about 6W of electricity, but now that he didn’t need it to be on standby so often, he wanted to make it more energy efficient.

In Denmark, where he lives, many people use power strips that have an onboard USB cable. These strips are meant to reduce the standby power consumption of PC peripherals such as monitors by powering on the mains sockets only when the computer is active. He decided the easiest way to cut his standby energy consumption to 0W would be to power his computer via this strip as well.

While it sounds great in theory, it presented a sort of chicken/egg problem. If the computer needs to be turned on for the power strip to recognize it, then how could he also supply power to the computer from the same strip? His solution was a small circuit that would charge up while the computer was running, and still hold enough juice to kickstart the PC’s boot process, thus turning on the power strip.

It really is an ingenious way to go about things, nice job!

PC Temperature Monitoring System Lights Up When Things Get Hot

October 4, 2011 by Mike Nathan 23 Comments

gpu_overheating_warning_system

[Taylor] popped a new graphics card into his computer, but before he could settle in for a round of gaming, his card started to overheat. He eventually tracked the problem down to an undersized power supply, but the prospect of cooking his new GPU to death made him think twice about how he was monitoring his system’s health.

To continually keep tabs on his video card’s temperature going forward, he put together a small circuit that will alert him if things start to get too hot. He mounted a small temperature sensor on his graphics card near the GPU, wiring it to an Arduino. The Arduino monitors his video card, lighting an RGB LED blue if conditions are alright. If the temperature rises above 50C, the LED changes to red, signaling a problem.

We’re aware that there are all sorts of software applications that can monitor component temperatures for you, but the appeal of [Taylor’s] system is that it can be easily seen from across the room rather than via the desktop. That said, we think that his system could take advantage of his PC’s case fan lighting for a more visible warning, and it wouldn’t hurt to wire in an auto-shutdown feature in case his computer overheats while he’s away.

Broken Vintage Record Player Reborn As A Portable MP3 Cabinet

September 7, 2011 by Mike Nathan 23 Comments

old_record_player_pc_jukebox

[Julian] picked up an old record player that was sitting in somebody’s trash pile, and brought it home to see if it could be restored to working order. When he got it home he discovered that it didn’t work at all, so he and his wife decided to modernize it a bit.

In an effort to simultaneously reunite himself with his music collection and piss off audiophiles/antique collectors in the process, he gutted the radio and began rebuilding it to serve as an MP3 jukebox. Once the innards were removed, his wife refinished the cabinet and gave the front grill a new cloth cover.

An old PC was installed inside the cabinet, along with a set of relatively cheap (but better than paper cone) speakers. A pair of custom cut plexi panels were used to cover the computer, while providing space for the monitor and Apple wireless keyboard + trackpad [Julian] uses to manage the jukebox.

The refurbed record player came out looking quite nice, and although it likely raises the ire of several different groups of purists, we think it’s pretty cool.

Fixing POST Errors With A Single Key

May 29, 2011 by Mike Nathan 60 Comments

one_key_keyboard

Instructables user [Mike Craghead] was in the middle of building a very compact public computer kiosk when he ran into a problem with the processor fan. It was too big for the enclosure and had to be swapped out with a fan that did not allow the motherboard to monitor its rotational speed.

Motherboards don’t like this situation very much, and each time the computer was started, it would hang at the BIOS screen waiting for someone to press the F1 key to continue. Knowing that everything was just fine, and that there were no BIOS options which would allow him to ignore the error, he crafted a simple solution to the problem.

Since the computer just needed someone to press the F1 key, he figured he could rig up a small dongle that would always hold down the key for him. After verifying that the OS would ignore the stuck key, he tore apart a keyboard and traced the circuit matrix to identify which pins he had to short in order to represent the F1 key press.

Satisfied with his handiwork, he plugged the board into his computer and found that everything worked just fine. Sure it might not be the most elegant solution to the problem, but it gets the job done at a cost of zero dollars – you can’t beat that!

My Desk IS My Computer Case

May 26, 2011 by Mike Nathan 39 Comments

If you think that your water cooled rig is pretty sweet, check out this creation by Dutch PC enthusiast [Peter Brands] (Google Translation).

With his computer tweaked as far as he could imagine, he decided to spruce up his office a bit. In the process, he ended up tweaking his computer just a little bit more. After seeing a build put together by another computer enthusiast, he set off to construct a desk in which he could show off his computer. He spent some time drawing up plans with Google Sketchup and with the help of a friendly neighbor, started construction of his desk/PC case.

The desk is constructed from 3mm thick aluminum, and houses most of his computer’s components under a thick piece of glass. The only portion of the computer that is not enclosed in the desk is the 9-fan radiator he used for his water cooling setup. That part resides in his crawl space, which he connects to his PC via a pair of large water hoses he punched through his tile floor. If you are interested, you can see all 800+ pictures of the build here.

Simply awesome!

[Thanks duchie]

The Origin Of CTRL-ALT-DELETE

April 15, 2011 by Mike Szczys 32 Comments

You may not have ever thought about it, but the far-too-often-used keyboard combination of Control + Alt + Delete had to have been brought into existence by some random coder at some point in technological history. But wait, it wasn’t just a random coder. The keystroke combo is attributed to [David Bradley]. He was one of the original designers of the IBM Personal Computer. You can even hear his own recount of the story in the video after the break.

He came up with the idea after growing weary of waiting for the Power-On Self Test (POST) routine to finish during each reboot of his software testing regiment. We remember the old days of slow hardware and can understand his frustration at the lost time. He decided to throw in a shortcut that allowed the software to reboot without power cycling the hardware. The original implementation used CTRL-ALT-ESC, but was later changed so that one frustrated keyboard mash couldn’t accidentally reboot the system.

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