Author: Adam Fabio

733 Articles

Repairing A Sunburned Game Boy Screen

January 26, 2018 by 23 Comments

The original Game Boy is a classic. Sure, it had no backlight, but there is something special about playing on that classic green screen. Unfortunately, some of these older systems are suffering a terrible fate — screen burn. Game Boy’s played best with lots of light — especially out in the sun. But that same sun did terrible things to the screen. A black splotch in the center of the LCD is the telltale sign of a burned Game Boy. You might think that screen replacement is the only option, but [The Retro Future] shows us how to repair this issue.

A reflective LCD is a layer cake made up of polarizers, two panes of glass, and a reflector. The burns often seen on Game Boy screens usually are in the polarizer and the optically clear glue which attaches the plastic polarizer to the glass. We’re guessing these burns happen when someone leaves their Game Boy out in the sun. Between the sun rays directly striking the top polarizer and the rays bounced back from the reflector at the rear of the screen, that poor polarizer doesn’t stand a chance.

Repairing the burn is a delicate operation, as one false move could crack the thin LCD glass. The first step is to carefully peel off the burned polarizer. This leaves a mess of dried glue, which can be scraped off or dissolved with alcohol. A new linear polarizer can then be placed on the front of the screen. [The Retro Future] chose not to glue the polarizer, but we’re betting some UV cure LOCA (Liquid Optically Clear Adhesive) from a cell phone screen protector would do the trick.

If you love the look of the classic Game Boy, but want to play just about any classic game, grab a Raspberry Pi zero, and build a retro Pi Boy.

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Cardboard Wall Is Surprisingly Well Built

January 18, 2018 by 48 Comments

We all built cardboard forts when we were kids. [Paintingcook] has taken it into adulthood with a hand built cardboard wall. He and his wife leased a loft apartment. Lofts are great — one giant space to work with. Plans changed a bit when they found out they had a baby on the way. A single living, working, and sleeping space definitely wouldn’t be good for a newborn, so the couple set about separating a section of the room with a wall.

Sheetrock and steel or wood lumber would be the normal path here. They instead decided to recycle their cardboard moving boxes into a wall. The boxes were formed into box beams, which created the framework of the wall. The two pillars were boxed in and incorporated into the wall itself. The skin of the wall is a random patchwork of cardboard pieces. Most of the construction is completed with 3/8 ” screws and masking tape. Tape won’t last forever, but this is a temporary wall after all.

You might be wondering about fire hazards — sure, cardboard burns more readily than gypsum board, but the apartment is outfitted with sprinklers, which should help on this front. A few commenters on [Paintingcook’s] Reddit thread asked about formaldehyde and other gasses emitting from the cardboard. Turns out he’s an inorganic chemist by trade. He says any outgassing happens shortly after the cardboard is manufactured. It should be safe for the baby.

Cardboard is a great material to work in. You can build anything from robots to computers to guns with it. So get hop the couch, grab that Amazon box, and get hacking!

Flying The Friendly Skies With A Hall Effect Joystick

January 18, 2018 by 15 Comments

There are plenty of PC joysticks out there, but that didn’t stop [dizekat] from building his own. Most joysticks measure position mechanically using potentiometers or encoders. Only a few high-end models use Hall effect sensors. That’s the route [dizekat] took.

Hall effect sensors are non-contact devices which measure magnetic fields. They can be used to measure the position and orientation of a magnet. That’s exactly how [dizekat] is using a trio of sensors in his design. The core of the joystick is a universal joint from an old R/C car. The center section of the joint (called a spider) has two one millimeter thick disc magnets glued to it. The Hall sensors themselves are mounted in the universal itself. [Dizekat] used a small piece of a chopstick to hold the sensors in position while he found the zero point and glued them in. A third Hall effect sensor is used to measure a throttle stick positioned on the side of the box.

An Arduino micro reads the sensors and converts the analog signal to USB.  The Arduino Joystick Library by [Matthew Heironimus] formats the data into something a PC can understand.

While this is definitely a rough work in progress, we’re excited by how much [dizekat] has accomplished with simple hand tools and glue. You don’t need a 3D printer, laser cutter, and a CNC to pull off an awesome hack!

If you think Hall effect sensors are just for joysticks, you’d be wrong – they work as cameras for imaging magnetic fields too!

Spectre And Meltdown: How Cache Works

January 15, 2018 by 15 Comments

The year so far has been filled with news of Spectre and Meltdown. These exploits take advantage of features like speculative execution, and memory access timing. What they have in common is the fact that all modern processors use cache to access memory faster. We’ve all heard of cache, but what exactly is it, and how does it allow our computers to run faster?

In the simplest terms, cache is a fast memory. Computers have two storage systems: primary storage (RAM) and secondary storage (Hard Disk, SSD). From the processor’s point of view, loading data or instructions from RAM is slow — the CPU has to wait and do nothing for 100 cycles or more while the data is loaded. Loading from disk is even slower; millions of cycles are wasted. Cache is a small amount of very fast memory which is used to hold commonly accessed data and instructions. This means the processor only has to wait for the cache to be loaded once. After that, the data is accessible with no waiting.

A common (though aging) analogy for cache uses books to represent data: If you needed a specific book to look up an important piece of information, you would first check the books on your desk (cache memory). If your book isn’t there, you’d then go to the books on your shelves (RAM). If that search turned up empty, you’d head over to the local library (Hard Drive) and check out the book. Once back home, you would keep the book on your desk for quick reference — not immediately return it to the library shelves. This is how cache reading works.

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Fail Of The Week: Engine Flips Out

January 11, 2018 by 66 Comments

A few weeks ago an incredible video of an engine exploding started making the rounds on Facebook. This particular engine was thankfully in a dyno room, rather than sitting a couple of feet away from a driver on a track. We’ve all seen engine carnage videos before, but this one stands out. This diesel engine literally rips itself apart, with the top half of the engine flipping and landing on one side of the room while the bottom half sits still spinning on the dyno frame.

Building performance engines is part science, part engineering, and part hacking. While F1 racing teams have millions of dollars of test and measurement equipment at their disposal, smaller shops have to operate on a much lower budget. In this case, the company makes their modifications, then tests things out in the dyno room. Usually, the tests work out fine. Sometimes though, things end spectacularly, as you can see with this diesel engine.

The engine in question belongs to Firepunk diesel, a racing team. It started life as a 6.7 liter Cummins diesel: the same engine you can find in Dodge Ram pickup trucks. This little engine wasn’t content to chug around town, though. The Firepunk team builds performance engines — drag racing and tractor pulling performance in this case. Little more than the engine block itself was original on this engine. Let’s take a deeper look.

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Henrietta Lacks And Immortal Cell Lines

January 9, 2018 by 80 Comments

In early 1951, a woman named Henrietta Lacks visited the “colored ward” at Johns Hopkins hospital for a painful lump she found on her cervix. She was seen by Dr. Howard W. Jones, who indeed found a tumor growing on the surface of her cervix. He took a tissue sample, which confirmed Henrietta’s worst fears: She had cancer.

The treatment at the time was to irradiate the tumor with radium tubes placed in and around the cervix. The hope was that this would kill the cancerous cells while preserving the healthy tissue. Unbeknownst to Henrietta, a biopsy was taken during her radium procedure. Slivers of her tumor and of healthy cervix cells were cut away. The cancer cells were used as part of a research project. Then something amazing happened: the cancerous cells grew and continued to grow outside of her body.

As Henrietta herself lay dying, the HeLa immortal cell line was born. This cell line has been used in nearly every aspect of medical research since the polio vaccine. Millions owe their lives to it. Yet, Henrietta and her family never gave consent for any of this. Her family was not informed or compensated. In fact, until recently, they didn’t fully grasp exactly how Henrietta’s cells were being used.

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The Secret Of Twinkling Christmas Lights

January 7, 2018 by 26 Comments

With the holidays over, many of us are braving the elements to take down all those holiday lights. LED lights have largely taken over the market, but in some places, you can still get classic incandescent bulbs. There are some effects that LEDs can’t quite mimic yet. One of those is the magic of “twinkling” light sets, which [Alec Watson] explains in a Technology Connections video. Everyone has seen bulbs that flash, and strings that dim. But the twinkle effect until recently has been hard to describe.

Typical flashing bulbs use a bimetallic strip. As the filament of the bulb heats up, the strip bends, opening the circuit. Then the strip cools and closes the circuit again. Twinkling lights do exactly the opposite. The bimetallic strip shorts the bulb out rather than open the circuit. Twinkling sets also use a lot of bimetallic strip bulbs – typically every fifth bulb has a strip. The result of the bulbs being shorted out is that all be the bulbs in set see a higher voltage. This makes the entire strip shimmer in time with the flashing. That’s where the twinkling magic comes from.

It occurs to us that the voltage on the strip would be a great source of random seeds. Sure, you’d have to replace bulbs now and again, but how many people can say they get their random numbers from a set of Christmas lights?

If you’re curious how incandescent Christmas lights can blow and not take out the whole strip, check out this article about anti-fuses.

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