Month: April 2017

The Other Way To Brick A Mac Classic

April 5, 2017 by 7 Comments

Why would you build a mini Mac Classic using LEGO and a Raspberry Pi? Well, why wouldn’t you?

[Jannis Hermanns] couldn’t find a reason to control this outburst of nostalgia for the good old days of small, expensive computers and long hours spent clawing through the LEGO bin to find The Perfect Piece to finish a build. It turns out that the computer part of this replica was the easy part — it’s just an e-paper display driven by a Raspberry Pi Zero. Building the case was another matter, though.

After a parti-colored prototype with whatever bricks he had on hand, a session of LEGO Digital Designer led him to just the right combination of bricks to build an accurate case, almost. It turns out that the stock selection of bricks in LDD won’t allow for the proper proportions for the case, so he ordered the all-white bricks and busted out the Dremel. LEGO purists may want to avert their eyes from the ABS gore within, but in the end the case worked out and the whole build looks great.

Fancy a full-size Mac Classic reboot? How about this iPad docking station? Or if tiny and nostalgic is really your thing, this retro-future terminal build is pretty keen too.

[via r/raspberry_pi]

Introducing The MENSCH Microcomputer

April 5, 2017 by 62 Comments

A few weeks ago, I was browsing Tindie on one of my daily trawls for something interesting to write about. I came across something I hadn’t seen before. The Mensch Microcomputer is a product from Western Design Center (WDC) that puts a microcontroller based on the 65xx core on a small breakout board.

I’ve played around with some of WDC’s tools and toys before, back when the sent me a few dev boards to review. They’re cool, and I have considered building a little breakout board for this weird cross between a microcontroller and a system on a chip. Life gets in the way, and that project sat on the shelf. The Mensch, however, was cheap and well into impulse purchase territory. After buying one, one of the VPs at WDC asked if I’d be interested in doing another review on their latest bit of hardware. Sure. I got this.

Continue reading “Introducing The MENSCH Microcomputer” →

Landscape To Portrait At The Click Of A Mouse

April 5, 2017 by 40 Comments

Modern 16:9 aspect ratio monitors may be great for watching a widescreen movie on Netflix, but for most PDFs, Word documents, and certain web pages, landscape just won’t do. But if you’re not writing the next great American novel and aren’t willing to commit to portrait mode, don’t — build an auto-rotating monitor to switch your aspect ratio on the fly.

Like many of us, [Bob] finds certain content less than suitable for the cinematic format that’s become the standard for monitors. His fix is simple in concept, but a little challenging to engineer. Using a lazy susan as a giant bearing, [Bob] built a swivel that can be powered by a NEMA 23 stepper and a 3D-printed sector of a ring gear. Due to the narrow clearance between the top and bottom of the lazy susan, [Bob] had to do considerable finagling to get through holes for the mounting hardware located, but in the end the whole thing worked great.

Our only quibble would be welding galvanized pipe for the stand, which always gives us the willies. But we will admit the tube notching turned out great with just a paper template. We doubt it would have been much better if he used an amped-up plasma-powered tubing notcher.

Continue reading “Landscape To Portrait At The Click Of A Mouse” →

Learn Neural Network And Evolution Theory Fast

April 5, 2017 by 32 Comments

[carykh] has a really interesting video series which can give a beginner or a pro a great insight into how neural networks operate and at the same time how evolution works. You may remember his work creating a Bach audio producing neural network, and this series again shows his talent at explaining the complex topic so anyone may understand.

He starts with 1000 “creatures”. Each has an internal clock which acts a bit like a heart beat however does not change speed throughout the creature’s life. Creatures also have nodes which cause friction with the ground but don’t collide with each other. Connecting the nodes are muscles which can stretch or contract and have different strengths.

At the beginning of the simulation the creatures are randomly generated along with their random traits. Some have longer/shorter muscles, while node and muscle positions are also randomly selected. Once this is set up they have one job: move from left to right as far as possible in 15 seconds.

Each creature has a chance to perform and 500 are then selected to evolve based on how far they managed to travel to the right of the starting position. The better the creature performs the higher the probability it will survive, although some of the high performing creatures randomly die and some lower performers randomly survive. The 500 surviving creatures reproduce asexually creating another 500 to replace the population that were killed off.

The simulation is run again and again until one or two types of species start to dominate. When this happens evolution slows down as the gene pool begins to get very similar. Occasionally a breakthrough will occur either creating a new species or improving the current best species leading to a bit of a competition for the top spot.

We think the series of four short YouTube videos (all around 5 mins each) that kick off the series demonstrate neural networks in a very visual way and make it really easy to understand. Whether you don’t know much about neural networks or you do and want to see something really cool, these are worthy of your time.

Continue reading “Learn Neural Network And Evolution Theory Fast” →

Project 54/74 Maps Out Logic ICs

April 4, 2017 by 4 Comments

Integrated circuits are a fundamental part of almost all modern electronics, yet they closely resemble the proverbial “black box” – we may understand the inputs and outputs, but how many of us truly understand what goes on inside? Over the years, the process of decapping ICs has become popular – the removal of the package to enable peeping eyes to glimpse the mysteries inside. It’s an art that requires mastery of chemistry, microscopy and photography on top of the usual physics skills needed to understand electronics. Done properly, it allows an astute mind to reverse engineer the workings of the silicon inside.

There are many out there publishing images of chips they’ve decapped, but [Robert Baruch] wants more. Namely, [Robert] seeks to create a database of die images of all 5400 and 7400 series logic chips – the eponymous Project 54/74.

These chips are the basic building blocks of digital logic – NAND gates, inverters, shift registers, decade counters and more. You can build a CPU with this stuff. These days, you may not be using these chips as often in a production context, but those of you with EE degrees will likely have toyed around a few of these in your early logic classes.

There’s only a handful of images up so far, but they’re of excellent quality, and they’re also annotated. This is a great aid if you’re trying to get to grips with the vagaries of chip design. [Robert] is putting in the hard yards to image as many variations of every chip as possible. There’s also the possibility of comparing the same chip for differences between manufacturers. We particularly like this project, as all too often manufacturing techniques and technologies are lost and forgotten as the march of progress continues on. It looks like it’s going to become a great resource for those looking to learn more about integrated circuit design and manufacture!

EDM For The Cheap And Adventurous

April 4, 2017 by 24 Comments

Laser cutters, waterjets, plasma cutters, CNC routers – most hackerspaces and even many dedicated home-gamers seem to have some kind of fancy tool for cutting sheet goods into intricate shapes. But with no access to a CNC machine and a need to cut a complex shape from sheet metal, [AlchemistDagger] cooked up this bare-bones and somewhat dangerous EDM rig to get the job done.

Electric discharge machining has been around for decades and is used a lot for harder metals like titanium and tool steel. The process makes sense to anyone who has seen contacts pitted and corroded by repeated arcing – an electric arc is used to remove metal from the workpiece, with a dielectric fluid used to cool the workpiece and flush away debris. For [AlchemistDagger]’s purposes, a lot of the complicated refinements, like high-frequency power supplies and precise tool positioning, were ignored. He built a simple linear slide to manually control the tool position, and the power supply was just a bridge rectifier connected to the 120-volt mains with some filter capacitors and a big light bulb as a ballast resistor. While the video below shows electrical conduit being notched, [AlchemistDagger] also made a brass cookie-cutter style tool to cut the Instructables logo from steel.

Obviously, mixing water and electricity is a recipe for disaster is you’re not careful, but this low-end EDM technique is a good one to file away for a rainy day. And if you’re looking for a little more sophistication in your homebrew EDM rig, we’ve got you covered there too. Continue reading “EDM For The Cheap And Adventurous” →

How To Trick Your Electrical Meter By Saving Power

April 4, 2017 by 95 Comments

A group of Dutch scientists have been testing out some of today’s “smart” electrical meters to check their accuracy, among other things. Not ones to disappoint, the scientists have found consistently false readings that in some cases are 582% higher than actual energy consumption.

With experiments lasting for six months, the researchers tried to focus on meters representative of those commonly used in the Netherlands and manufactured between 2004 and 2014. Moreover, the researchers tried to reproduce standard household energy consumption patters rather than focusing on stress tests.

Their results? Well, “results varied wildly, with some meters reporting errors way above their disclosed range, going from -32% to +582%. Tests with uncommon results were repeated several times and the results were within a few percents of the original.” Moreover, “The greatest inaccuracies were seen when researchers combined dimmers with energy saving light bulbs and LED bulbs.” Not constrained to energy saving light bulbs, the inaccuracies are, ironically, tied to devices with integrated energy saving features. (Certainly makes us want to keep a close eye on our electric meters.)

“The reason for faulty readings appears to be the current sensor, and the associated circuitry,” said researchers. “The experimental results […] show that static energy meters can be pushed into faulty reading (positive and negative) if sufficiently fast pulsed currents are drawn by the consumer”

It is worth noting that there is contradictory research published by “the European voice of the providers of smart energy solutions” that maintains that “there is no reason to question smart metering technology”. Still, we wouldn’t blame you if you wanted a second opinion.

Thanks [acs] for sending this in!