The Easiest Way To Put Your Doorbell On The Internet

June 1, 2020 by Tom Nardi 39 Comments

Thanks to low-cost WiFi enabled microcontrollers such as the ESP8266 and ESP32, it’s never been a better time to roll your own smart home system. But that doesn’t mean it isn’t daunting for new players. If you’re looking for an easy first project, putting your old school doorbell on the Internet of Things is a great start, but even here there’s some debate about how to proceed.

Most people stumble when they get to the point where they have to connect their low-voltage microcontroller up to the relatively beefy transformer that drives a standard doorbell. We’ve seen a number of clever methods to make this connection safely, but this tip from [AnotherMaker] is probably the easiest and safest way you’re likely to come across.

His solution only requires an inductive current sensor, which can be had for less than $1 from the usual overseas suppliers. One leg of the doorbell circuit is passed through the center of this sensor, and the sensor itself is connected up to your microcontroller of choice (here, and ESP32). The rest is software, which [AnotherMaker] explains in the video after the break. With the addition of a little debounce code, your microcontroller can reliably determine when somebody is out there jabbing the bell button; what you do with this information after that is up to you.

If you’re worried this method is too easy you could always try it with an optocoupler, or maybe convert the low-voltage AC to something your microcontroller can handle.

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Cast Metal From Prints To Solidify Childhood Memories

June 1, 2020 by Kristina Panos 32 Comments

As far as the hacker’s toolbox goes, the 3D printer is way up there in terms of utility. Sure, it takes time to learn the ins and outs of designing, slicing, and extruding, but after that, the world is pretty much your additive oyster. Follow those design dreams, or use it to replace the things that break. The icing on the cake? You can chase those dreams into other materials, because 3D prints can be used to cast metal.

[RetroTech Journal] wanted to fry up some rosette cookies, a Scandinavian delight from his youth that look a lot like fancy, personal funnel cakes. They’re made with special aluminium irons that shape the dough while it fries, as opposed to the jumbled chaos that is funnel cake.

Rosette irons come in a few traditional shapes, but once you get tired of those, it’s up to you to cast them in aluminium. And how would you go about doing that? By creating a firmly-packed sand mold using a mounted 3D print.

In the endlessly entertaining video after the break, [RetroTech Journal] takes you through the entire process from CAD to cookies. It has everything you could possibly want: LEGO stop-motion, claymation, a little bit of cooking, and a whole lot of knowledge. We can’t wait to see what comes next.

We’ve seen quite a few sand casting projects over the years, but this lathe is among the most useful.

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RC Lawn Mower Keeps The Grass Greener On Your Side Of The Fence

June 1, 2020 by Sven Gregori 23 Comments

For some people, mowing the lawn is a dreaded chore that leads to thoughts of pouring a concrete slab over the yard and painting it green. Others see it as the perfect occasion to spend a sunny afternoon outside. And then there are those without the luxury of having a preference on the subject in the first place. [elliotmade] for example has a friend who’s sitting in a wheelchair, and would normally have to rely on others to maintain his lawn and form an opinion on the enjoyability of the task. So to retain his friend’s independence, he decided to build him a remote-controlled lawn mower.

After putting together an initial proof of concept that’s been successfully in use for a few years now, [elliotmade] saw some room for improvement and thought it was time for an upgrade. Liberating the drive section of an electric wheelchair, he welded a frame around it to house the battery and the mower itself, and added an alternator to charge the battery directly from the mower’s engine. An RC receiver that connects to the motor driver is controlled by an Arduino, as well as a pair of relays to switch both the ignition and an electric starter that eliminates the need for cord pulling. Topping it off with a camera, the garden chores are now comfortably tackled from a distance, without any issues of depth perception.

Remote-controlling a sharp-bladed machine most certainly requires a few additional safety considerations, and it seems that [elliotmade] thought this out pretty well, so failure on any of the involved parts won’t have fatal consequences. However, judging from the demo video embedded after break, the garden in question might not be the best environment to turn this into a GPS-assisted, autonomous mower in the future. But then again, RC vehicles are fun as they are, regardless of their shape or size.

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Linux Fu: Raspberry Pi Desktop Headless

June 1, 2020 by Al Williams 32 Comments

It seems to me there are two camps when it comes to the Raspberry Pi. Some people use them as little PCs or even laptops with a keyboard and screen connected. But many of us use them as cheap Linux servers. I’m in the latter camp. I have probably had an HDMI plug in a Pi only two or three times if you don’t count my media streaming boxes. You can even set them up headless as long as you have an Ethernet cable or are willing to edit the SD card before you boot the machine for the first time.

However, with the Raspberry Pi 4, I wanted to get to a desktop without fishing up a spare monitor. I’ll show you two ways to get a full graphical KDE desktop running with nothing more than a network connection.

The same principle applies to most other desktop environments, but I am using KDE and Ubuntu on the Pi, even though something lighter would probably perform better. But before we get there, let’s talk about how X11 has had a big identity crisis over the years.

The Plan

There are many ways to remotely access X programs, many of which are rarely used today. However, for this purpose, we are going to use SSH tunneling along with some special tricks to get the entire desktop running. It is easy to just run a single X program over SSH, and you’ve probably done that often. If so, you can skip to the next section.

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Physical Security Hack Chat With Deviant Ollam

June 1, 2020 by Dan Maloney 1 Comment

Join us on Wednesday, June 3 at noon Pacific for the Physical Security Hack Chat with Deviant Ollam!

You can throw as many resources as possible into securing your systems — patch every vulnerability religiously, train all your users, monitor their traffic, eliminate every conceivable side-channel attack, or even totally air-gap your system — but it all amounts to exactly zero if somebody leaves a door propped open. Or if you’ve put a $5 padlock on a critical gate. Or if your RFID access control system is easily hacked. Ignore details like that and you’re just inviting trouble in.

Once the black-hats are on the inside, their job becomes orders of magnitude easier. Nothing beats hands-on access to a system when it comes to compromising it, and even if the attacker isn’t directly interfacing with your system, having him or her on the inside makes social engineering attacks that much simpler. System security starts with physical security, and physical security starts with understanding how to keep the doors locked.

To help us dig into that, Deviant Ollam will stop by the Hack Chat. Deviant works as a physical security consultant and he’s a fixture on the security con circuit and denizen of many lockpicking villages. He’s well-versed in what it takes to keep hardware safe from unauthorized visits or to keep it from disappearing entirely. From CCTV systems to elevator hacks to just about every possible way to defeat a locked door, Deviant has quite a bag of physical security tricks, and he’ll share his insights on keeping stuff safe in a dangerous world.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, June 3 at 12:00 PM Pacific time. If time zones have you down, we have a handy time zone converter.

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 Wednesday; join whenever you want and you can see what the community is talking about.

Why Does Solder Smoke Always Find Your Face?

June 1, 2020 by Jenny List 38 Comments

For some of us the smell of rosin soldering flux vaporizing from the tip of an iron as a project takes shape is as evocative as the scent of a rose on a summer’s day. We’ve certainly breathed enough of it over the years, as it invariably goes from the piece of work directly into the face of the person doing the soldering. This is something that has evidently troubled [AlphaPhoenix], who has gone to extravagant lengths to research the problem using planar laser illumination and a home-made (and possibly hazardous) smoke generator.

He starts with a variety of hypotheses with everything from a human-heat-driven air vortex to the Coandă effect, but draws a blank with each one as he models them using cardboard cut-outs and boxes as well as himself. Finally he has the light bulb moment and discovers that the key to the mystery lies in his arms coming across the bench to hold both iron and solder. They close off an area of lower-pressure dead space which draws the air current containing the smoke towards it, and straight into his face. It’s something that can be combated with a small fan or perhaps a fume extractor, as despite some video trickery we have yet to master soldering iron telekinesis.

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NASA’s Long-Delayed Return To Human Spaceflight

June 1, 2020 by Tom Nardi 55 Comments

With the launch of the SpaceX Demo-2 mission, the United States has achieved something it hasn’t done in nearly a decade: put a human into low Earth orbit with a domestic booster and vehicle. It was a lapse in capability that stretched on far longer than anyone inside or outside of NASA could have imagined. Through a series of delays and program cancellations, the same agency that put boot prints on the Moon and built the iconic Space Shuttle had been forced to rely on Russia to carry its astronauts into space since 2011.

NASA would still be waiting to launch its own astronauts had they relied on America’s traditional aerospace giants to get the job done. The inaugural flight of the Boeing CST-100 “Starliner” to the International Space Station in December was an embarrassing failure that came perilously close to losing the unmanned capsule. A later investigation found that sloppy software development and inconsistent testing had caused at least two major failures during the mission, which ultimately had to be cut short as the vehicle couldn’t even reach the altitude of the ISS, to say nothing of making a docking attempt. NASA and Boeing have since agreed to attempt another test of the CST-100 sometime before the end of the year, though a delay into 2021 seems almost inevitable due to the global pandemic.

But America’s slow return to human spaceflight can’t be blamed on the CST-100, or even Boeing, for that matter. Since the retirement of the Space Shuttle, NASA has been hindered by politics and indecisiveness. With a constantly evolving mandate from the White House, the agency’s human spaceflight program has struggled to make significant progress towards any one goal.

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