Automated Watering Machine Has What Plants Crave: Fertilizer

May 14, 2021 by 19 Comments

We’ve seen countless automated plant care systems over the years, but for some reason they almost never involve the secret sauce of gardening — fertilizer. But [xythobuz] knows what’s up. When they moved into their new flat by themselves, it was time to spread out and start growing some plants on the balcony. Before long, the garden was big enough to warrant an automated system for watering and fertilizing.

This clever DIY system is based around a 5L gravity-fed water tank with solenoid control and three [jugs] of liquid fertilizer that is added to the water via peristaltic pump. Don’t worry, the water tank has float switches, and [xythobuz] is there to switch it off manually every time so it doesn’t flood the flat.

On the UI side, an Arduino Nano clone is running the show, providing the LCD output and handling the keypad input. The machine itself is controlled with an ESP32 and a pair of four-channel relay boards that control the inlet valve, the four outlet valves, and the three peristaltic pumps that squirt out the fertilizer. The ESP also serves up a web interface that mimics the control panel and adds in the debug logs. These two boards communicate using I²C over DB-9, because that’s probably what [xythobuz] had lying around. Check out the demo video after the break, and then go check on your own plants. They miss you!

Don’t want to buy just any old peristaltic pumps? Maybe you could print your own.

Continue reading “Automated Watering Machine Has What Plants Crave: Fertilizer” →

Wood Enclosure Lends Warmth To This DIY Ribbon Microphone

May 14, 2021 by 7 Comments

We love it when someone takes an idea they’ve seen on Hackaday and runs with it, taking it in a new and different direction. That’s pretty much what we’re here for, after all, and it’s pretty gratifying to see projects like this wooden ribbon microphone come to life.

Now, we’re not completely sure that [Maya Román] was inspired by our coverage of [Frank Olson]’s homage to the RCA Model 44 studio mic rendered in walnut veneer, but we’re going to pat ourselves on the back here anyway. The interesting thing with [Maya]’s build is that she chose completely different materials and design styles for her project. Where [Frank] built as much of his mic from wood as possible, [Maya] was fine with a mixed media approach — CNC-milled plywood for the case and stand, laser-cut acrylic for the ribbon motor frame, and 3D-printed pieces here and there as needed. The woven brass cloth used as a windscreen is a nice detail; while the whole thing looks — and sounds — great, we think it would be even better with a coat of dark stain to contrast against the brass, as well as a nice glossy coat of polyurethane.

The video below shows the whole design and build process, which was a final project for [Maya]’s audio production class this semester at college. Here’s hoping that it got as good a grade as we would give it.

Continue reading “Wood Enclosure Lends Warmth To This DIY Ribbon Microphone” →

A Stackable Planetary Gearbox You Can Print At Home

May 14, 2021 by No comments

In one little corner of YouTube is a small but vibrant community sharing videos about gearboxes of their own design, particularly those with very high ratios or other quirky features. Adherents of the subculture are known as gearheads, and [Let’s Print] is among them. His latest creation is a 3D printed planetary gearbox design with a focus on easy assembly and versatile ratio choice. (Video, embedded below.)

The gearbox came about as [Let’s Print] grew weary of designing bespoke geartrains for each of their individual projects.  The planetary design they landed on has the benefit of being stackable, with each reduction block fitted adding a 1:3 stepdown to the train.

For testing purposes, four stages were ganged up for a total reduction ratio of 1:81. The resulting gearbox was able to lift 40 kg before its output coupler failed, no mean feat for some plastic squirted out of a hot nozzle. It’s a common problem with huge ratio gearboxes made out of plastic – often, the very components of the gearbox can’t hold up to the huge loads generated.

Regardless of the limitations of the material, we’re sure the gearbox will prove useful in future projects from [Let’s Print]. We’ve seen other tough 3D printed gearbox builds before too, such as this anvil-lifter from the aptly-named [Gear Down For What]. Dive into the online gearbox subculture yourself.

Continue reading “A Stackable Planetary Gearbox You Can Print At Home” →

Increased Neutron Levels At Chernobyl-4: How Dangerous Is Corium?

May 14, 2021 by 60 Comments

When the Chernobyl nuclear plant suffered the power output surge that would destroy its #4 reactor, a substance called ‘corium‘ was formed. This originally lava-like substance formed out of the destroyed fuel rods along with surrounding materials, like concrete, that made up the reactor. The corium ultimately cooled down and left large amounts of solid corium in the rooms where it had pooled.

Over the past few days there have been numerous reports in the media regarding a ‘sudden surge’ in neutron flux levels from this corium, with some predicting a ‘second Chernobyl disaster’. Obviously, this has quite a few people alarmed, but how dire are these neutron output changes exactly, and what do they tell us about the condition of the corium inside the ruins of the #4 reactor building? Continue reading “Increased Neutron Levels At Chernobyl-4: How Dangerous Is Corium?” →

Hackaday Podcast 118: Apple AirTag Hacked, Infill Without Perimeters, Hair-Pulling Robots, And Unpacking The 555

May 14, 2021 by 5 Comments
Elliot’s keeb: ortho, offset, thumby.

Hackaday editors Elliot Williams and Mike Szczys gather to ooh and aah over a week of interesting hacks. This week we’re delighted to welcome special guest Kristina Panos to talk about the Inputs of Interest series she has been working on over the last couple of years. In the news is the effort to pwn the new Apple AirTags, with much success over the past week. We look at turning a screenless Wacom tablet into something more using a donor iPad, stare right into the heart of a dozen 555 die shots, and watch what happens when you only 3D print the infill and leave the perimeters out.

 

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (~55 MB)

Places to follow Hackaday podcasts:

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Go Ape With A Banana Macropad

May 14, 2021 by 14 Comments

The super fun thing about macro pads is that they’re inherently ultra-personalized, so why not have fun with them? This appealing little keeb may have been a joke originally, but [dapperrogue] makes a valid point among a bunch of banana-related puns on the project page — the shape makes it quite the ergonomic little input device.

Inside this open-source banana is that perennial favorite for macro pads, the Arduino Pro Micro, and eight switches that are wired up directly to input pins. We’re not sure what flavor of Cherry those switches are, hopefully brown or green, but we suddenly wish Cherry made yellow switches. If you want to build your own, the STLs and code are available, and we know for a fact that other switch purveyors do in fact make yellow-stemmed switches.

Contrary to what the BOM says, we believe the sticker is mandatory because it just makes the build — we imagine there would be fewer double takes without it. Hopefully this fosters future fun keyboard builds from the community, and we can’t wait to sink our teeth into the split version!

There are a bunch of ways to make a macropad, including printing everything but the microcontroller.

Via r/mk and KBD

This Week In Security: Fragattacks, The Pipeline, Codecov, And IPv6

May 14, 2021 by 26 Comments

Some weeks are slow, and the picking are slim when discussing the latest security news. This was not one of those weeks.

First up is Fragattacks, a set of flaws in wireless security protocols, allowing unauthenticated devices to inject packets into the network, and in some cases, read data back out. The flaws revolve around 802.11’s support for packet aggregation and frame fragmentation. The whitepaper is out, so let’s take a look.

Fragmentation and aggregation are techniques for optimizing wireless connections. Packet aggregation is the inclusion of multiple IP packets in a single wireless frame. When a device is sending many small packets, it’s more efficient to send them all at once, in a single wireless frame. On the other hand, if the wireless signal-to-noise ratio is less than ideal, shorter frames are more likely to arrive intact. To better operate in such an environment, long frames can be split into fragments, and recombined upon receipt.

There are a trio of vulnerabilities that are built-in to the wireless protocols themselves. First up is CVE-2020-24588, the aggregation attack. To put this simply, the aggregation section of a wireless frame header is unauthenticated and unencrypted. How to exploit this weakness isn’t immediately obvious, but the authors have done something clever.

First, for the purposes of explanation, we will assume that there is already a TCP connection established between the victim and an attacker controlled server. This could be as simple as an advertisement being displayed on a visited web page, or an image linked to in an email. We will also assume that the attacker is performing a Man in the Middle attack on the target’s wireless connection. Without the password, this only allows the attacker to pass the wireless frames back and forth unmodified, except for the aggregation header data, as mentioned. The actual attack is to send a special IP packet in the established TCP connection, and then modify the header data on the wireless frame that contains that packet.

When the victim tries to unpack what it believes to be an aggregated frame, the TCP payload is interpreted as a discrete packet, which can be addressed to any IP and port the attacker chooses. To put it more simply, it’s a packet within a packet, and the frame aggregation header is abused to pop the internal packet out onto the protected network. Continue reading “This Week In Security: Fragattacks, The Pipeline, Codecov, And IPv6” →