Blinking LEDs On The Internet Of Printers

August 25, 2017 by 7 Comments

When you ask for recommendations on which 3D printer to buy, damn the cost, the Ultimaker is consistently at the top of the list. There’s a reason for the popularity of this printer — it’s easy to use, extremely high quality, and has an entire freakin’ Linux system running somewhere under the hood. That last bit is opening up a few doors to some interesting hacks, like using a 3D printer as an RGB LED.

The Doodle3D team has been playing around with the Ultimaker API to see if they can make their software work with the Ultimaker printer. The Ultimaker has RGB LEDs, so obviously the simplest proof of concept in futzing around with an API is to blink a few LEDs. The actual code was written in HTML, JavaScript, and Node in just two hours. The author admits it’s ugly, but it works. Can’t go wrong with that.

While this is just a simple test of the Ultimaker API, it’s surprisingly high up on the Google results when you search, ‘Ultimaker API’. That’s a shame, because there’s a lot of power under the hood of this printer. If you have some sort of mod you’d like to throw into the ring, here’s the Hackaday Tip Line.

You can check out the demo video of this hack below.

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Custom Cut Pinwheel Makes A Useful HVAC Duct Flow Meter

August 25, 2017 by 12 Comments

Everyone is familiar with pinwheels, and few of us haven’t crafted one from a square of paper, a stick, and a pin. Pinwheels are pretty optimized from a design standpoint, and are so cheap and easy to build that putting a pinwheel to work as an HVAC duct flow meter seems like a great idea.

Great in theory, perhaps, but as [ItMightBeWorse] found out, a homemade pinwheel is far from an ideal anemometer. His experiments in air duct flow measurements, which previously delved into ultrasonic flow measurement, led him to try mechanical means. That calls for some kind of turbine producing a signal proportional to air flow, but a first attempt at using a computer fan with brushless DC motor failed when a gentle airflow couldn’t overcome the drag introduced by the rotor magnets. But a simple pinwheel, custom cut from patterns scaled down from a toy, proved to be just the thing. A reflective optosensor counts revolutions as the turbine spins in an HVAC duct, and with a little calibration the rig produces good results. The limitations are obvious: duct turbulence, flimsy construction, and poor bearings. But for a quick and dirty measurement, it’s not bad.

Looking for an outdoor anemometer rather than an HVAC flow meter? We’ve got one made from an old electric motor, or a crazy-accurate ultrasonic unit.

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Hackaday Prize Entry: CPAP Humidifier Monitor Alarm

August 25, 2017 by 31 Comments

CPAP (Continuous Positive Airway Pressure) machines can be life-changing for people with sleep apnea. [Scott Clandinin] benefits from his CPAP machine and devised a way to improve his quality of life even further with a non-destructive modification to monitor his machine’s humidifier.

With a CPAP machine, all air the wearer breathes is air that has gone through the machine. [Scott]’s CPAP machine has a small water reservoir which is heated to humidify the air before it goes to the wearer. However, depending on conditions the water reservoir may run dry during use, leading to the user waking up dried out and uncomfortable.

To solve this in a non-invasive way that required no modifications to the machine itself, [Scott] created a two-part device. The first part is a platform upon which the CPAP machine rests. A load cell interfaced to an HX711 Load Cell Amplifier allows an Arduino Nano to measure the mass of the CPAP machine plus the integrated water reservoir. By taking regular measurements, the Arduino can detect when the reservoir is about to run dry and sound an alarm. Getting one’s sleep interrupted by an alarm isn’t a pleasant way to wake up, but it’s much more pleasant than waking up dried out and uncomfortable from breathing hot, dry air for a while.

The second part of the device is a simple button interfaced to a hanger for the mask itself. While the mask is hung up, the system is idle. When the mask is removed from the hook, the system takes measurements and goes to work. This makes activation hassle-free, not to mention also avoids spurious alarms while the user removes and fills the water reservoir.

Non-invasive modifications to medical or other health-related devices is common, and a perfect example of nondestructive interfacing is the Eyedriveomatic which won the 2015 Hackaday Prize. Also, the HX711 Load Cell Amplifier has an Arduino library that was used in this bathroom scale refurb project.

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Driverless Lorries To Be Tested On UK Roads By End Of 2018

August 25, 2017 by 43 Comments

The [BBC] is reporting that driverless semi-trailer trucks or as we call them in the UK driverless Lorries are to be tested on UK roads. A contract has been awarded to the Transport Research Laboratory (TRL) for the trials. Initially the technology will be tested on closed tracks, but these trials are expected to move to major roads by the end of 2018.

All  of these Lorries will be manned and driven in formation of up to three lorries in single file. The lead vehicle will connect to the others wirelessly and control their braking and acceleration. Human drivers will still be present to steer the following lorries in the convoy.

This automation will allow the trucks to drive very close together, reducing drag for the following vehicles to improve fuel efficiency.”Platooning” as they call these convoys has been tested in a number of countries around the world, including the US, Germany, and Japan.

Are these actually autonomous vehicles? This question is folly when looking toward the future of “self-driving”. The transition to robot vehicles will not happen in the blink of an eye, even if the technological barriers were all suddenly solved. That’s because it’s untenable for human drivers to suddenly be on the road with vehicles that don’t have a human brain behind the wheel. These changes will happen incrementally. The lorry tests are akin to networked cruise control. But we can see a path that will add in lane drift warnings, steering correction, and more incremental automation until only the lead vehicle has a person behind the wheel.

There is a lot of interest in the self driving industry right now from the self driving potato to autonomous delivery. We’d love to hear your vision of how automated delivery will sneak its way into our everyday lives. Tell us what you think in the comments below.

USB + μC = Peril?

August 25, 2017 by 50 Comments

You hear about people finding USB drives and popping them into a computer to see what’s on them, only to end up loading some sort of malware onto their computer. It got me to thinking, given this notorious vulnerability, is it really a great idea to make electronics projects that plug into a computer’s USB port? Should I really contribute to the capitulation-by-ubiquity that USB has become?

A of couple years ago I was working on an innocuous project, a LED status light running off of USB. It ran off USB because I had more complicated hopes for it–some vague notion about some kind of notification thing and also it was cool to have access to 5 V right from the ‘puter. This was about the time that those little RGB LEDs connected to USB were all the rage, like blink(1), which raised $130,000 on Kickstarter. I just wanted to make a status light of some sort and had the parts, so I made it.

My version was a small rectangular PCB from OSHPark packing a Tiny85, with a 10 mm RGB LED providing pretty much all of the functionality — no spare pins broken out. Honestly, for the amount of code on it, even the Tiny85 was overpowered. I recall thinking at the time, could my creation be misused for evil? Could some wicked programmer include malware alongside my LED-lighting Arduino sketch?

It’s absurd, of course. My meager engineering skills ought not interest anyone. On the other hand, couldn’t some heartless poltroon, the hardware equivalent of a script kiddie, make my creation into a malware-spewing Typhoid Mary of a project? It has always been the realistic consequence of building anything–that it could be misused. I’d be thrilled to the point of giddiness if someone remade one of my projects into something cool, but I’d really hate for a USB light I designed to turn into some vector into someone’s computer. But how much of that is my responsibility?

If you think I’m the only one who thinks this, go to SparkFun or Adafruit and count all of the boards with microcontrollers and USB A male plugs. Even the tiny boards like the Huzzah and Gemma use USB cables, rather than plugging directly into the computer. Granted, they are microcontrollers that realistically would be connected to a project and it might not be possible to physically move them into position and plug them in. Also requiring a charging cable does not in any way make a microcontroller board work any differently than one plugged right into the computer. I’m left wondering if I’m spazzing out over nothing, and there’s nothing we can do about our tendency to treat any electronic gizmo with a shiny case as being safe to plug into the same computer we use to pay bills.

If there is no data transfer taking place, and I’m just getting power, wouldn’t it be enough to disable (or not connect) the data pins of the USB on the circuit board? Or maybe we really have no business connecting a data connection to a microcontroller if we’re not reflashing the chip with fresh code–think I’m paranoid? Maybe you should just get power from a wall wart and leave the USB cord in the drawer. It’s one thing to urge our friends and family to steer clear of mystery plugs, but as engineers and tinkerers, do we not owe the community the benefit of our knowledge?

Of course, Hackaday contains numerous examples of USB projects, including canary for USB ports, tips on protecting your ports with two microcontrollers, a guide to stopping rubber ducky attacks, and removing security issues from untrusted USB connections. Also, has anyone used the USB condom?

Friends, let me know your thoughts on the subject. Am I a freak to steer clear of USB-powered project like my dumb LED? Leave your comments and weigh in with your opinions.

A 3D Printed Junction Transistor Model

August 25, 2017 by 10 Comments

Transistors are no doubt one of humankinds greatest inventions. However, the associated greatness brings with it unprecedented complexity under the hood. To fully understand how a transistor works, one needs to be familiar with some Quantum Mechanics! As perhaps any EE undergraduate would tell you, one of the hardest subject to fathom is in fact semiconductor physics.

Take your pick: Mathematical equations governing the various currents inside a BJT

A good place to start to comprehend anything complex is by having an accurate but most importantly, tangible model at hand. Semiconductors are hard enough to describe with elaborate mathematical tools, is a physical model too much to ask?

[Chuck] has designed, printed and explained the workings of a BJT transistor using a 3D printed model. We really like this model because it goes a long way to shed light on some of the more subtle features of BJT transistors for beginners.

For example, the simplest “electronic switch” model completely ignores the application of a transistor as a linear amplifier and cannot be used to explain important transistor parameters such as hfe (DC current gain Beta) or the VBE (voltage to forward bias the base-emitter junction). [Chuck’s] model on the other hand certainly offers better intuition on these, as the former can be linked to the length of the levers arm and the latter to the minimum force needed to rotate the lever. The Tee structure even signifies the combination of base current with the collector current during operation!

If physical models are not your thing, the classic pictorial depiction, the “Transistor Man” in the Art of Electronics might be of interest. If you’ve even outgrown that, its time to dig into the quantum mechanics involved.

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SHACamp 2017, A Personal Review

August 25, 2017 by 7 Comments

There are a series of stages to coming down from a festival. After the hectic rush of travel there are the several days of catching up on lost sleep and picking up the threads of your life again, then once a semblance of order has been regained there’s that few weeks of emptiness. Your life will never be the same again, it’s all so mundane.

I'm pleased to say the Hackaday and Tindie stickers were very popular.
I’m pleased to say the Hackaday and Tindie stickers were very popular.

It’s now a couple of weeks since the SHACamp 2017 hacker festival in the Netherlands was in full swing, and the write-up below has slowly taken shape over that time amid the other work of being a Hackaday scribe and editor. It’s early morning here in Southern England as I write this, so on the equivalent day while I was at SHACamp at this time I would have been carrying a large pack of stickers for distribution on the swapping table through the rising sunlight of a camp still largely asleep after the previous night’s revelry. Past our German and Dutch immediate neighbours, down the ramp from the dyke, the cardboard tent depot on my left and the food court on my right, to the information tent. Greet the bleary-eyed volunteer at the end of their graveyard shift, and spread plenty of Hackaday and Tindie stickers on the table for the masses. And then? Find a coffee, and sally forth into the field for another day among one of the most stimulating communities on Earth. My community. Your community.

The sticker table is a good place to start if you wish to get a handle on a large hacker camp. On it you will find the logos of a cross-section of the diverse organisations and groups present. There are a few commercial ones like my Jolly Wrenchers and Tindie the puppy, there are some from voluntary organisations or interest groups, but mostly they are the logos of a continent’s — even the wider world’s in some cases —  hackspaces and makerspaces. Here you see the breadth of the attendees, as the logos of spaces from thousands of miles away you’ve never encountered before mingle. This isn’t quite a global gathering, but there is a sense of global community around it.

How Do You Describe a Hacker Camp?

You shall find us by our clearly superior yet dangerous to barefoot pedestrians fused right-angled mains connector.
You shall find us by our clearly superior yet dangerous to barefoot pedestrians fused right-angled mains connector.

So before I take you through my experience of SHA, it’s best to start by describing a hacker camp in more general terms. When I’m describing a camp like SHA to the kind of people who don’t read Hackaday, I put it as similar to the music festivals they are used to but without the bands. Instead the audience provides the entertainment through the work they bring to the event or do at the event, and through a comprehensive program of talks and lectures. Oh — and this is the bit that makes their eyes open wide — every structure on site from the smallest one-man tent to the largest marquee has mains power and high-speed Internet. Sometimes people grasp what SHA is from this description, sometimes they don’t.

Different groups, be they individual hackspaces, people from a particular country, or other special interest groups, congregate in villages, collections of tents, marquees, and gazebos in which they set up whatever cool stuff they’ve brought along. My tent with its Hackaday flag was in a village composed of a mix of British hackspaces up on the dyke, which [Michael] from MK Makerspace had marked with a sign consisting of a huge BS1363A mains plug. More than one person pointed out it would have been better lying flat on the ground with pins in the air, ready to catch an unwary Monty Python foot.

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