Flip Your Desktop Over To Boot Linux

February 1, 2016 by Gerrit Coetzee 27 Comments

[Andy France] built his computer into a Windows XP box. (Yes, this is from the past.) He needed to run windows most of the time, but it was nice to boot into Linux every now and then. That’s where the problem lay. If he was running Linux on his Windows XP case mod, he’d get made fun of. The only solution was to make a Linux sleeve for his computer. He would slide the sleeve over the case whenever he ran Linux, and hide his shame from wandering eyes. Once his plan was fully formed, he went an extra step and modified the computer so that if the sleeve was on, it would automatically boot Linux, and if it was off it would boot Windows.

The Linux sleeve could only slide on if the computer was flipped upside down. So he needed to detect when it was in this state. To do this he wired a switch into one of the com ports of his computer, and attached it to the top of the case mod. He modified the assembly code in the MBR to read the state of the switch. When the Linux sleeve is on (and therefore the computer is flipped over) it boots Linux. When the sleeve is off, Windows. Neat. It would be cool to put a small computer in a cube and have it boot different operating systems with this trick. Or maybe a computer that boots into guest mode in one orientation, and the full system in another.

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Fingerprint Scanner For Laptop And Raspberry Pi (or Giving The Finger To Your Computer)

January 29, 2016 by Rud Merriam 28 Comments

We’ve got two hacks in one from [Serge Rabyking] on fingerprint scanning. Just before leaving on a trip he bought a laptop on the cheap. He didn’t pay much attention to the features and was disappointed it didn’t have a fingerprint scanner. Working in Linux he uses sudo a lot and typing the password is a hassle. Previously he just swiped his finger on the scanner and execution continued.

He found a cheap replacement fingerprint scanner on hacker’s heaven, also known as eBay. It had four wires attached to a 16 pin connector. Investigation on the scanner end showed the outer pair were power and ground which made [Serge] suspect it was a USB device. Wiring up a USB connector and trying it the device was recognized but with a lot of errors. He swapped the signal lines and everything was perfect. He had sudo at his finger tip.

Next he wonder if it would work with a Raspberry Pi. He installed the necessary fingerprint scanning software, ran the enrollment for a finger, and it, not terribly surprisingly, worked.

On Linux the command fprintd-enroll reads and stores the fingerprint information. By default it scans and saves the right index finger but all ten fingers can be scanned and stored. Use libpam-fprintd to enable account login using a finger. Anyone know how you can trigger other events using a different finger? A quick search didn’t turn up any results.

In true hacker style, [Serge] created his own fingerprint reader from a replacement part. But you can jump start your finger usage by purchasing one of many inexpensive available readers.

Basically, Its Minecraft

January 19, 2016 by Al Williams 40 Comments

[SethBling] really likes Minecraft. How can you tell? A quick look at his YouTube channel should convince you, especially the one where he built a full-blown BASIC interpreter in Minecraft. It is not going to win any speed races, as you might expect, but it does work.

For novelty and wow factor, this is amazing. As a practical matter, it is hard to imagine the real value since there are plenty of ways a new programmer could get access to BASIC. Still, you have to admire the sheer audacity of making the attempt. One Hackaday poster (who shall remain nameless) once won a case of beer by betting someone he or she could write a BASIC compiler in BASIC, so we aren’t sticklers for practicality.

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Stallman’s One Mistake

January 13, 2016 by Brian Benchoff 147 Comments

We all owe [Richard Stallman] a large debt for his contributions to computing. With a career that began in MIT’s AI lab, [Stallman] was there for the creation of some of the most cutting edge technology of the time. He was there for some of the earliest Lisp machines, the birth of the Internet, and was a necessary contributor for Emacs, GCC, and was foundational in the creation of GPL, the license that made a toy OS from a Finnish CS student the most popular operating system on the planet. It’s not an exaggeration to say that without [Stallman], open source software wouldn’t exist.

Linux, Apache, PHP, Blender, Wikipedia and MySQL simply wouldn’t exist without open and permissive licenses, and we are all richer for [Stallman]’s insight that software should be free. Hardware, on the other hand, isn’t. Perhaps it was just a function of the time [Stallman] fomented his views, but until very recently open hardware has been a kludge of different licenses for different aspects of the design. Even in the most open devices, firmware uses GPLv3, hardware documentation uses the CERN license, and Creative Commons is sprinkled about various assets.

If [Stallman] made one mistake, it was his inability to anticipate everything would happen in hardware eventually. The first battle on this front was the Tivoization of hardware a decade ago, leading to the creation of GPLv3. Still, this license does not cover hardware, leading to an interesting thought experiment: what would it take to build a completely open source computer? Is it even possible?

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Pump Up The Volume With Lead Shot And LEDs

January 6, 2016 by Kristina Panos 35 Comments

One of the redeeming qualities of many modern cheap keyboards is the built-in volume control buttons. But this is Hackaday, and many of us (and you) have Model Ms or newfangled mechanical keyboards that only have the essential keys. Those multimedia buttons only adjust the system volume anyway. We would bet that a lot of our readers have sweet sound systems as part of their rig but have to get up to change the volume. So, what’s the solution? Build a color-changing remote USB volume knob like [Markus] did.

Much like the Instructable that inspired him, [Markus] used a Digispark board and a rotary encoder. The color comes from a WS2812 LED ring that fits perfectly inside a milky plastic tub that once held some kind of cream. When the volume is adjusted, the ring flashes white at each increment and then slowly returns to whatever color it’s set to. Pushing the button mutes the volume.

The components are pretty lightweight, and [Markus] didn’t want the thing sliding all over the desk. He took an interesting approach here and filled the base with the lead from a shotgun round and some superglue. The rotating part of the button needed some weight too, so he added a couple of washers for a satisfying feel. Be sure to check out the demonstration after the break.

Digispark board not metal enough for you? Here’s a volume knob built around a bare ATtiny85 (which is the same thing anyway).

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Driving WS2811 LEDs With…VGA?

January 4, 2016 by Elliot Williams 12 Comments

We thought we’d seen it all. All the ways to drive WS2811/2812 “Neopixel” LEDs, that is. And then [Steve Hardy] comes up with a new one: hacking a computer’s VGA output to drive 500 WS2811s in a string. And it’s quite a hack. You can check out the video (it’s worth enduring the horrible wind noise) below the break.

[Steve]’s big realization was that he could send the digital data that the Neopixels needed by carefully selecting a resolution and clock rate for the VGA to match the timings that the WS2811 modules wanted. A resolution of 840×1000 at 28MHz produces 70 pixels per WS2811 bit, or 12 bits per line. This means two VGA lines need to be sent for the RGB triple for each LED, hence the 1000 rows.

There are some further tricks before [Steve] got around to writing a custom OpenGL shader that converts regular graphics to his strange black-and-white bit pattern to drive the LEDs, but you’re going to have to read [Steve’s] blog for all that. If you’re waiting for a full code write-up, [Steve] says that one’s pending.

We’re just stoked to see the computing power that lies within a video card used for other purposes. Once you think of the VGA output as a general-purpose high speed (analog!) output, it opens up a whole bunch of possibilities if you can write the corresponding video software. As [Steve] points out, he’s only using the red channel right now — he could trivially add another 1000 LEDs just by tweaking his video code.

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3D Printed Computer Case Brings Sexy Back

January 3, 2016 by George Graves 21 Comments

We know what you’re thinking – case modding is so 2004. You can forget all the silly paint jobs, windows, and lighted spinning fans that’s you’ve seen in the past. That all seems like child’s play compared to what [Complx] has created over on the overclock.net forum.

Using a mixture of 3D-printed plastic corners and a laser-cut acrylic top, bottom and sides, [Complx] was able to create a very pleasing design. He didn’t have access to a 3D printer large enough that would make the parts, though, so he decided to outsource that task. His first set of parts were printed on a Makerbot Replicator, but came out too coarse and so he set out to find a better printing method. After getting quotes of $2000 or more, he was about to call it quits when he found someone with Stratasys Fotus 250 who was willing to work with him on the price, but still provide a quality print.

The guts of the machine aren’t too shabby either. We know everyone loves a parts list so here you go: It’s an ASUS Z97I-Plus and a i7-4790K, running a GTX 970 with a 600 Watt power supply, 8GB RAM and a couple of SSD drives.

We have to commend [Complx] on his documentation, photos and videos. It really makes this build shine. You can watch an 3d animation of the build after the break.

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