The One-Transistor Flip-Flop

April 18, 2018 by Brian Benchoff 35 Comments

A flip-flop is one of the most basic digital electronic circuits. It can most easily be built from just two transistors, although they can and have been built out of vacuum tubes, NAND and NOR gates, and Minecraft redstone. Conventional wisdom says you can’t build a flip-flop with just one transistor, but here we are. [roelh] has built a flip-flop circuit using only one transistor and some bizarre logic that’s been slowly developing over on hackaday.io.

[roelh]’s single transistor flip-flop is heavily inspired by a few of the strange logic projects we’ve seen over the years. The weirdest, by far, is [Ted Yapo]’s Diode Clock, a digital clock made with diode-diode logic. This is the large-scale proof of concept for the unique family of logic circuits [Ted] came up with that only uses bog-standard diodes to construct arbitrary digital logic.

The single-transistor flip-flop works just like any other flip-flop — there are set and reset pulses, and a feedback loop to keep the whatever state the output is in alive. The key difference here is the addition of a clock signal. This clock, along with a few capacitors and a pair of diodes, give this single transistor the ability to store a single bit of information, just like any other flip-flop.

This is, without a doubt, a really, really weird circuit but falls well into territory that is easily understood despite being completely unfamiliar. The key question here is, ‘why?’. [roelh] says this could be used for homebrew CPUs, although this circuit is trading two transistors for a single transistor, two diodes, and a few more support components. For vacuum tube-based computation, this could be a very interesting idea that someone at IBM in the 40s had, then forgot to write down. Either way, it’s a clever application of diodes and an amazing expression of the creativity that can be found on a breadboard.

Tesselated Worklights Are Nifty, Modular

April 18, 2018 by Lewin Day 20 Comments

Electric lighting – is there anything it can’t do? Coming in all manner of forms and flavours, you can get everything from a compact reading lamp to a blindingly powerful worklight for your garage. Generally, different lights are built in different ways to suit their purpose, but it’s not the only way to do things. Enter [slisgrinder] and the MOSAIC Lighting System.

At its heart, MOSAIC is a way of building lighting rigs out of individual modules. Where it gets interesting is the design – they’re triangles! The boards carry a variety of LEDs and are laid out in a fashion that allows the power and data connections to be made between adjacent cells by laying them out next to each other. Many boards can be tesselated together to create larger, smaller, or unusually shaped arrays. The connections are well thought out, allowing the tiles to make a connection along any one of their 3 edges, regardless of orientation.

The project began out of a desire to grow okra in an otherwise inhospitable climate; to this end, there are both general work lighting modules as well as grow light versions with UV LEDs on board. The modules can be combined in different ways and command and control is done over RS-485.

It’s a tidy project that shows how a little thought can create a versatile design through the use of an unusual form factor. We’ve seen modular lighting projects before, too – like this entry to last year’s Hackaday Prize.

When Hackerspace Directors Burn Out

April 18, 2018 by Jenny List 78 Comments

A friend of mine once suggested that there should be a support group for burned-out former hackerspace directors. We could have our own Village of the Damned at summer camps, where we’d sit moodily in the gathering twilight sipping our bourbon and Club Mate and decrying whatever misfortunes came to our space to leave such visible mental scars, or gazing hollow-eyed into the laser-tinged haze and moving gently to the pulse of the chiptune music. “See that’s Jenny over there, she don’t say much“. Hackerspace noir, where the only entry criterion is being crazy enough to stand for election to your space’s board.

You can tell [Dr. Seuss] is thinking about his next volume: <em>How The Grinch Stole Whoville Hackspace</em>. Al Ravenna, World Telegram [Public domain]. — You can tell [Dr. Seuss] is thinking about his next volume: *How The Grinch Stole Whoville Hackspace*. Al Ravenna, World Telegram [Public domain].

There must be spaces somewhere that live in such perfect harmony, in which a happy membership support a board for whom everything falls into place. Maybe the makerspace in [Dr. Seuss]’s Whoville would have that kind of atmosphere, but the reality of life is that every group is made up of both Grinch and Who. Keeping a diverse group of people harmonious is a huge challenge, but that’s what hackerspaces are really about — the people make the space.

There are several defined periods in the gestation of a hackerspace, and at least from where I’m sitting they relate to its member count. Some spaces pass through them all as they grow, while others are lucky enough to reach an equilibrium and spare themselves some of the drama.

If you recognise yourselves in some of the following then you have my commiserations, while if your space hasn’t got there yet or has managed to dodge some of the bullets then consider yourselves lucky.

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Friday Hack Chat: Circuit Board Art

April 18, 2018 by Brian Benchoff 14 Comments

We are now in a golden age of printed circuit boards. It wasn’t too long ago that making your own circuit boards either involved a lot of money, or slightly less money and using some proprietary garbage PCB layout tool. Now, every board house speaks Gerber, and you can get a ten-pack of PCBs from China for five bucks. This incredible cost reduction means people are making art with printed circuit boards. We’ve seen portraits, landscapes, and memes. This is truly the beginning of a new artistic medium rendered in fiberglass and soldermask.

Check out this blinky bit of art nouveau. There is a facebook group for PCB paintings, and some of the Badgelife crew are relying on woodcut and linoleum engraving techniques to create works of art in copper and fiberglass.

For this week’s Hack Chat, we’re going to be talking all about PCB artwork. Our guest for this week’s Hack Chat will be [Andrew Sowa], an electrical engineer, a vocal advocate of KiCad, and the guy who made more of me money. The Benchoff Nickel was created by simply taking some of the fantastic illustrations from Hackaday’s own [Joe Kim] and applying KiCad’s Bitmap2Component tool. Since the creation of the nickel, [Andrew] has been working on extending his technique to cross-hatching, backlighting, and halftones.

In this Hack Chat, we’re going to be talking all about PCB artwork, including the very beginnings of PCB art where engineers hid a few easter eggs in the PCBs of Xboxen and other consumer electronics. Topics covered will be bitmap to SVG conversion (in Inkscape and Illustrator), KiCad footprint creation, and the more technical side of things with the limitations of PCB fabrication and the slightly different shades of beige FR4 comes in.

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week is just like any other, and we’ll be gathering ’round our video terminals at noon, Pacific, on Friday, April 20th. How can there be time zones when the Earth has four days simultaneously for each rotation? You erroneously measure time from one corner. Here’s a clock counting down the time until the Hack Chat starts.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Fire. Vortex. Cannon. Need We Say More?

April 18, 2018 by James Hobson 8 Comments

Tornadoes are a rightfully feared natural disaster. Fire tornadoes are an especially odious event to contend with — on top of whatever else is burning. But, a fire vortex cannon? That’s some awesome eye candy.

The madman behind this cannon belching huge gouts of fire is none other than Youtuber [JAIRUS OF ALL]. This build is actually an upgrade to one of his previous projects — a fire tornado gun that burned itself out and is now twice-revived — and is arguably better at creating a proper vortex to direct the flames. Built around a modified NERF gun, a pair of 60mm electric ducted fans with some additional venting — and tunable via a speed controller — direct the airflow through slits in a vortex chamber. A backpack of liquid propane literally fuels this phoenix of a flamethrower, so [JAIRUS] had plenty of time to put together some great footage. Check it out!

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Fix Your Insecure Amazon Fire TV Stick

April 18, 2018 by Tom Nardi 48 Comments

I recently spent a largely sleepless night at a hotel, and out of equal parts curiosity and boredom, decided to kill some time scanning the guest network to see what my fellow travelers might be up to. As you’d probably expect, I saw a veritable sea of Samsung and Apple devices. But buried among the seemingly endless number of smartphones charging next to their sleeping owners, I found something rather interesting. I was as picking up a number of Amazon-made devices, all of which had port 5555 open.

As a habitual Android tinkerer, this struck me as very odd. Port 5555 is used for Android Debug Bridge (ADB), a development tool used to control and perform various administrative tasks on an Android device over the network or (more commonly) locally over USB. The number of users who would have legitimately needed to enable network ADB on their devices is surely rather low, so to see a half dozen of them on the network at the same time seemed improbable to say the least.

Why would so many devices manufactured by Amazon all have network ADB enabled? I realized there must be a connection, and it didn’t take long to figure it out.

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This Thermal Printer Has Serious Game

April 18, 2018 by Brian McEvoy 11 Comments

[Dhole], like the fox, isn’t the first to connect his computer to a Game Boy printer but he has done a remarkable job of documenting the process so well that anyone can follow. The operation is described well enough that it isn’t necessary to scrutinize his code, so don’t be put off if C and Rust are not your first choices. The whole thing is written like a story in three chapters.

The first chapter is about hacking a link cable between two Game Boys. First, he explains the necessity and process of setting the speed of his microcontroller, a NUCLEO-F411RE development board by STMicroelectronics. Once the rate is set, he builds a sniffer by observing the traffic on the cable and listens in on two Game Boys playing Tetris in competition mode. We can’t help but think that some 8-bit cheating would be possible if Tetris thought your opponent instantly had a screen overflowing with tetrominoes. Spying on a couple of Game Boys meant that no undue stress was put on the printer.

Chapter two built on the first chapter by using the protocol to understand how the printer expects to be spoken to. There is plenty of documentation about this already, and it is thoughtfully referenced. It becomes possible to convince a Game Boy that the connected microcontroller is a printer so it will oblige by sending an image. Since there isn’t a reason to wait for printing hardware, the transfer is nearly instantaneous. In the image above, you can see a picture of [Dhole] taken by a Game Boy camera.

The final chapter, now that all the protocols are understood, is also the climax where the computer and microcontroller convince the printer they are a Game Boy that wants to print an image. In the finale, we get another lesson about measuring controller frequency without an oscilloscope. If you are looking for the hack, there it is. There is a handful of success in the form of old receipts with superimposed grayscale images since virgin thermal printer paper by Nintendo costs as much as a used printer.

This story had a happy ending but grab your reading glasses for the smallest Game Boy and here’s someone who wrote their own Game Boy color game.