Hackaday Columns

4706 Articles

This excellent content from the Hackaday writing crew highlights recurring topics and popular series like Linux-Fu, 3D-Printering, Hackaday Links, This Week in Security, Inputs of Interest, Profiles in Science, Retrotechtacular, Ask Hackaday, Teardowns, Reviews, and many more.

A Wild Hackaday Belgrade Confirms Status As One Of World’s Greatest Hardware Cons

June 1, 2018 by 15 Comments

Hackers, Designers, and Engineers flooded into Dom Omladine on Saturday for what can only be described as an epic celebration of hardware culture. This is the second time Hackaday has organized a huge conference in Belgrade, and lightning really did strike twice.

A Gathering of New Friends and Old

We got things started off with a meetup the night before the conference. The first Hackaday Belgrade was held in 2016 and we didn’t reserve a bar on Friday night — we ended up taking over one just through sheer numbers. This year we called ahead for a large outdoor space, then made good use of it.

A great kickoff to the weekend
LED cube animation emulation demo
*No beers were wasted during this meetup

Everyone was giddy with anticipation of the next day to come. There is always a sizzling energy of meeting up in real life. Most of this group hangs out on Hackaday.io, but only some of them have met in person. Add to that the reunions of those who became friends at the previous Hackaday Belgrade and at other cons around Europe and you have the feeling of coming home. These really are your people.

Yes, a Conference. But the Cool Kind

Hackaday conferences are more than just parties… they’re conferences. If you approach it the right way you can get your employer on board with you attending because you’re going to meet incredible people, learn lots of stuff, and come back excited to take on the Universe. Actually, bring your boss along for the ride too!

Flooding into Hackaday Belgrade
Breakfast spread as the doors open

This year we had thirteen incredible talks. As is our practice, we started off with a super-technical talk as Rachel Wong (aka @konichiwakitty) discussed her Ph.D research which involves growing eye tissue in the lab. But like all incredibly brilliant minds, she has a creative outlet which she also covered as part of her Keynote address. Rachel has a passion for building wearables that are reaching for the future by embracing things we really do need in our garments and gear.

Main hall packed for the keynote address
The workshop area full to the brim

From drone monitoring networks to robot soldering machines, and concepts for designing meaningful hardware to using code to automate tedious PCB layout, there was plenty in these talks for everyone.

Rachel Wong on the growing of eye tissue
Elliot Williams demos Logic Noise live on stage

I really enjoyed Elliot Williams’ talk on Logic Noise for his live demos using simple logic chips to build up complex music. Marcel van Kervinck took us on a journey of TTL computer design. And Sophi Kravitz’s talk on building non-rigid airships had at least two people at the con get inspired and spin their own blimp design during the conference! There was a live-feed of the talks so keep your eye on Hackaday as we pull those out to be featured individually.

Some of the demo hardware: Acoustic levitation for lab work

The workshops were standing room only as people who weren’t able to grab a ticket audited the course. We had three hands-on session that built wearable circuitry, brough art to PCB design, and dove into the world of FPGAs.

Welcome, Here’s Your Neck-Mounted Retro Computer

Everyone through the door received a custom electronic badge to hack on during Hackaday Belgrade. Voja Antonic designed the hardware and oversaw the manufacture. We had excellent yield which is great because we had nearly (if not more than) 100% attendance at the conference. We ended the day with just 5 badges to spare!

Hackaday Belgrade badge and user guide put to use

These handheld computers are truly hot! The badges each have 55 really clicky keys. With at least 350 people in the room, that’s approaching 20k momentary push switches and at one point, a brief “silence” fell and all that could be heard were clicking buttons. That and we asked everyone to play the Mario Overworld tune at the same time as hundreds of badges rose in a glorious chorus. There’s also a 16-page user manual to go along with them which included sample code to get started.

Hacking went on throughout the day but as the talk session wrapped up we transformed the hall into a Hacker Village. Tables were brought in and immediately filled. Live music filled the room as Bogdan Rosu and Richard Hogben each played IDM sets. If you’ve been watching Hackaday videos you’ve heard their work and their performances this night were epic.

What is better than hacking to live music?
Still going strong as midnight approaches
Rich and Bogdan join forces for the final live music set
So much hacking, so little time
Head to head game called ‘Shoot my Valentine’
Head to head Tic Tac Toe
There were other hardware demos on display too
This badge was put on WiFi by lunchtime
[Flummer]’s badge displays minimalist style
Detail of [Larissa Koncz]’s Interactive Poetic Glove from the workshop
The world’s slowest sinewave, calculated in BASIC: [Tom van Dijk]
So much ASCII art!
[Frederic] and [Manoel] got their badges talking over AFSK, when the RF interference didn’t get them…
The RevSpace crew at work in the quiet workshop room

There was food, there was beer, and there were the tools of our lifestyle; laptops, programmers, jumper wires, blinky add-ons, and the excitement that goes along with all of them. The badge hacking presentations began at midnight and the place was still alive with excitement. It is truly great to see how supportive our community is of exploring hardware and trying things out. Publish your badge hacks and stories from the conference on Hackaday.io as we’ll be featuring those in the coming days and want to make sure we have all the juicy details.

Why Belgrade?

Keep your eye on Hackaday as there is much more coverage to come on this wonderful event. Many have asked: “Why Belgrade?”. It’s a fantastic city and the engineering community in the area is passionate about getting together to learn and share ideas. This includes the Supplyframe engineers who live in Belgrade and did the heavy lifting to organize and staff Hackaday Belgrade. You all did an amazing job and everyone at the con owes you a debt of gratitude, thank you so much! We also want to thank Supplyframe and SevenBridges, our sponsors for the event.

To all who attended, it wouldn’t have happened without you! I can speak for everyone on the Hackaday crew in saying the culture we share is energizing, encouraging, and humbling. It’s exactly the kind of recharge everyone looks for to keep life interesting! We’ll see you at the next one. Now over the next five months we have our sights set on the Hackaday Superconference. See you there!

Linux Fu: Counter Rotate Keys!

June 1, 2018 by 22 Comments

If you’ve done anything with a modern Linux system — including most variants for the Raspberry Pi — you probably know about sudo. This typically allows an authorized user to elevate themselves to superuser status to do things.

However, there is a problem. If you have sudo access, you can do anything — at least, anything the sudoers file allows you to do. But what about extremely critical operations? We’ve all seen the movies where launching the nuclear missile requires two keys counter-rotated at the same time and third firing key. Is there an equivalent for Linux systems?

It isn’t exactly a counter-rotating key, but the sudo_pair project — a prelease open-source project from Square — gives you something similar. The project is a plugin for sudo that allows you to have another user authorize a sudo request. Not only do they authorize it, but they get to see what is happening, and even abort it if something bad is happening.

Continue reading “Linux Fu: Counter Rotate Keys!” →

VCF East 2018: The Mail Order App Store

May 30, 2018 by 16 Comments

Today we take the concept of a centralized software repository for granted. Whether it’s apt or the App Store, pretty much every device we use today has a way to pull applications in without the user manually having to search for them on the wilds of the Internet. Not only is this more convenient for the end user, but at least in theory, more secure since you won’t be pulling binaries off of some random website.

But centralized software distribution doesn’t just benefit the user, it can help developers as well. As platforms like Steam have shown, once you lower the bar to the point that all you need to get your software on the marketplace is a good idea, smaller developers get a chance to shine. You don’t need to find a publisher or pay out of pocket to have a bunch of discs pressed, just put your game or program out there and see what happens. Markus “Notch” Persson saw his hobby project Minecraft turn into one of the biggest entertainment franchises in decades, but one has to wonder if it would have ever gotten released commercially if he first had to convince a publisher that somebody would want to play a game about digging holes.

In the days before digital distribution was practical, things were even worse. If you wanted to sell your game or program, it needed to be advertised somewhere, needed to be put on physical media, and it needed to get shipped out to the customer. All this took capital that would easily be beyond many independent developers, to say nothing of single individuals.

But at the recent Vintage Computer Festival East, [Allan Bushman] showed off relics from a little known chapter of early home computing: the Atari Program Exchange (APX). In a wholly unique approach to software distribution at the time, individuals were given a platform by which their software would be advertised and sold to owners of 8-bit machines such as the Atari 400/800 and later XL series computers. In the early days, when the line between computer user and computer programmer was especially blurry, the APX let anyone with the skill turn their ideas into profit. Continue reading “VCF East 2018: The Mail Order App Store” →

Friday Hack Chat: Logic Noise

May 30, 2018 by 2 Comments

If you like your synthesizers glitchy, squawky, or simply quick-and-dirty, you won’t want to miss this week’s Hack Chat with Hackaday’s own [Elliot Williams], because he’ll be brain-dumping everything he knows about making music with 4000-series CMOS logic chips. Break out your breadboards!

Continue reading “Friday Hack Chat: Logic Noise” →

Badge Bling And More At LayerOne 2018

May 29, 2018 by 4 Comments

The security conference LayerOne 2018 took place this past weekend in Pasadena, California. A schedule conflict meant most of our crew was at Hackaday Belgrade but I went to LayerOne to check it out as a first-time attendee. It was a weekend full of deciphering an enigmatic badge, hands-on learning about physical security, admiring impressive demos, and building a crappy robot.

Continue reading “Badge Bling And More At LayerOne 2018” →

Biasing That Transistor: The Emitter Follower

May 25, 2018 by 29 Comments

We were musing upon the relative paucity of education with respect to the fundamentals of electronic circuitry with discrete semiconductors, so we thought we’d do something about it. So far we’ve taken a look at the basics of transistor biasing through the common emitter amplifier, then introduced a less common configuration, the common base amplifier. There is a third transistor amplifier configuration, as you might expect for a device that has three terminals: the so-called Common Collector amplifier. You might also know this configuration as the Emitter Follower. It’s called a “follower” because it tracks the input voltage, offering increased current capability and significantly lower output impedance.

The emitter follower circuit
The emitter follower circuit

Just as the common emitter amplifier and common base amplifier each tied those respective transistor terminals to a fixed potential and used the other two terminals as amplifier input and output, so does the common collector circuit. The base forms the input and its bias circuit is identical to that of the common emitter amplifier, but the rest of the circuit differs in that the collector is tied to the positive rail, the emitter forms the output, and there is a load resistor to ground in the emitter circuit.

As with both of the other configurations, the bias is set such that the transistor is turned on and passing a constant current that keeps it in its region of an almost linear relationship between small base current changes and larger collector current changes. With variation of the incoming signal and thus the  base current there is a corresponding change in the collector current dictated by the transistor’s gain, and thus an output voltage is generated across the emitter resistor. Unlike the common emitter amplifier this voltage increases or decreases in step with the input voltage, so the emitter follower is not an inverting amplifier.

Continue reading “Biasing That Transistor: The Emitter Follower” →

VCF East 2018: The Desktop ENIAC

May 24, 2018 by 23 Comments

The ENIAC, or Electronic Numerical Integrator and Computer, is essentially the Great Great Grandfather of whatever device you’re currently reading these words on. Developed during World War II for what would be about $7 million USD today, it was designed to calculate artillery firing tables. Once word got out about its capabilities, it was also put to work on such heady tasks as assisting with John von Neumann’s research into the hydrogen bomb. The success of ENIAC lead directly into the development of EDVAC, which adopted some of the now standard computing concepts such as binary arithmetic and the idea of stored programs. The rest, as they say, is history.

But ENIAC wasn’t just hugely expensive and successful, it was also just plain huge. While it’s somewhat difficult for the modern mind to comprehend, ENIAC was approximately 100 feet long and weighed in at a whopping 27 tons. In its final configuration in 1956, it contained about 18,000 vacuum tubes, 7,000 diodes, 70,000 resistors, 10,000 capacitors, and 6,000 switches. All that hardware comes with a mighty thirst for power: the ENIAC could easily suck down 150 kW of electricity. At the time this all seemed perfectly reasonable for a machine that could perform 5,000 instructions per second, but today an Arduino would run circles around it.

This vast discrepancy between the power and size of modern hardware versus such primordial computers was on full display at the Vintage Computer Festival East, where Brian Stuart demonstrated his very impressive ENIAC emulator. Like any good vintage hardware emulator, his project not only accurately recreates the capabilities of the original hardware, but attempts to give the modern operator a taste of the unique experience of operating a machine that had its heyday when “computers” were still people with slide rules. Continue reading “VCF East 2018: The Desktop ENIAC” →