Destroy My Vegetable Garden? Oh Hail No!

January 20, 2020 by Kristina Panos 13 Comments

Building and maintaining a garden takes a lot of work. And unless you have a greenhouse, you’re forced to leave your hard work outside to fend for itself against the double-edged sword of the elements. Rain and sun are necessary, but hard, pelting hail is never welcome. Just ask [Nick Rogness]. He didn’t go through all the trouble of building a 12’x12′ garden and planting tasty vegetables just to have Mother Nature spew her impurity-filled ice balls on it every other night during the summertime.

[Nick] did what any of us would do: fight back with technology. His solution was to build a retractable roof that covers the garden with a heavy duty tarp. A Raspberry Pi Zero W controls pair of linear actuators via motor controllers, and [Nick] put a limit switch in each of the four corners to report on the roof status. He can run the roof manually, or control it with his phone using MQTT. The whole thing runs on a 12V marine battery that gets charged up by a solar panel, so part of the interface is dedicated to reporting the battery stats.

[Nick] ran out of time to implement all the features he wanted before the season started, but there’s always next year. He has big plans that include soil moisture sensors, rain detection sensors, and an automatic watering system that collects and uses rain water. We planted the bite-size demo video for you after the break — just wash the dirt off and you’re good to go.

Maybe someday [Nick] will create a system that can automate the entire garden, like the FarmBot. Hey, we’re just trying to plant seeds of ideas.

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Gradient Infill Puts More Plastic Where You Want It

January 20, 2020 by Al Williams 13 Comments

It is always tricky setting the infill for a 3D printed part. High infill parts are strong but take longer to print, while low infill prints take less time, but are weaker internally and in danger of surface layer droop between the infill pattern. [Stephan] has a better answer: gradient infill. You can see a video below and find his Python code on GitHub.

The idea is simple enough. In most cases, parts under stress see higher stress near the surface. Putting more material there will make the part stronger than adding plastic in places where the stress is lower. [Stephan] has done finite element analysis to determine an optimal infill pattern before, but this is somewhat difficult to do. Since the majority of parts can follow the more at the edges and less at the center rule, gradient infill makes sense except for a few special cases.

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Random Numbers From Outer Space

January 20, 2020 by Kristina Panos 22 Comments

Need a random number? Sure, you could just roll a die, but if you do, you might invite laughter from nearby quantum enthusiasts. If it’s truly, unpredictably random numbers you need, look no farther than the background radiation constantly bombarding us from the safety of its celestial hideout.

In a rare but much appreciated break from the Nixie tube norm of clock making, [Alpha-Phoenix] has designed a muon-powered random number generator around that warm, vintage glow. Muons are subatomic particles that are like electrons, but much heavier, and are created when pions enter the atmosphere and undergo radioactive decay. The Geiger-Müller tube, mainstay of Geiger counters the world over, detects these incoming muons and uses them to generate the number.

Inside the box, a 555 in astable mode drives a decade counter, which outputs the numbers 0-9 sequentially on the Nixie via beefy transistors. While the G-M tube waits for muons, the numbers just cycle through repeatedly, looking pretty. When a muon hits the tube, a second 555 tells the decade counter to stop immediately. Bingo, you have your random number! The only trouble we can see with this method is that if you need a number right away, you might have to go get a banana and wave it near the G-M tube.

Whether this all makes sense or not, you should check out [Alpha-Phoenix]’s project video, which is as entertaining as it is informative. He’s planning a follow-up video focused on the randomness of the G-M tube, so look out for that.

Looking for a cheaper way to catch your random numbers? You can do it with a fish tank, some air pumps, and a sprinkle of OpenCV.

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Electric Unicorn Is Our Kind Of Rideable

January 20, 2020 by Lewin Day 8 Comments

When [Charlyn] took a unicorn rocking horse in to work, it was an instant hit. Naturally, the people wanted more, and suggested it needed electric propulsion. Naturally, she rose to the challenge, and Rocky the Unicorn got a motorized upgrade.

The build consists of a frame built out of PVC pipes, hooked up with Formufit fittings. These are a great way to build useful structures out of PVC pipe, and made the build a cinch. The frame has a footrests for the rider, and the rocking horse already has a comfortable seat. For propulsion, a hoverboard is installed in the base, with the frame sporting a pair of casters to avoid tip over. Twin PVC handles are used to interface with the footplate of the hoverboard, allowing the user to drive and steer, as well as turn on the spot. A bouquet of fake flowers round out the aesthetic and hide some of the zipties.

It goes to show that PVC pipe can be an excellent material for quick, fun projects – all you need is the right fittings to make it all happen! It’s also fun to see a hoverboard used in such a way that doesn’t end with severe injuries. Unicorns always bring a nice flair to a project, too. Video after the break.

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Testing Your Grit: Tales Of Hacking In Difficult Situations

January 20, 2020 by Dan Maloney 14 Comments

What’s your work area like? Perhaps you’re mostly a software person, used to the carpeted land of cubicles or shared workspaces, with their stand-up desks and subdued lighting. Or maybe you’ve got a lab bench somewhere, covered with tools and instruments. You might be more of a workshop person, in a cavernous bay filled with machine tools and racks of raw material. Wherever you work, chances are pretty good that someone is paying good money to keep a roof over your head, keeping the temperature relatively comfortable, and making sure you have access to the tools and materials you need to get the job done. It’s just good business sense.

Now, imagine you’ve lost all that. Your cushy workspace has been stripped away, and you’ve got to figure out how to get your job done despite having access to nothing but a few basic tools and supplies and your own wits. Can you do it? Most of us would answer “Yes,” but how many of us have ever tested ourselves like that? Someone who has tested her engineering chops under difficult conditions — and continues to do so regularly — is Laurel Cummings, who stopped by the 2019 Hackaday Superconference to tell us all about her field-expedient life with a talk aptly titled, “When It Rains, It Pours”.

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Teardown: BilBot Bluetooth Robot

January 20, 2020 by Tom Nardi 16 Comments

Historically, the subject of our January teardown has been a piece of high-tech holiday lighting from the clearance rack; after all, they can usually be picked up for pocket change once the trucks full of Valentine’s Day merchandise start pulling up around the back of your local Big Box retailer. But this year, we’ve got something a little different.

Today we’re looking at the BilBot Bluetooth robot, which over the holidays was being sold at Five Below for (you guessed it) just $5 USD. These were clearly something the company hoped to sell a lot of, with stacks of the little two-wheeled bots in your choice of white and yellow livery right by the front door. With wireless control from your iOS or Android device, and intriguing features like voice command, I’d be willing to bet they managed to move quite a few of these at such a low price.

For folks like us, it can be hard to wrap our minds around a product like this. It must have a Bluetooth radio, some kind of motor controller, and of course the motors and gears themselves. Yet they can sell it for the price of a budget hamburger and still turn a profit. If you wanted to pick up barebones robotics platform, with just a couple gear motors and some wheels, it would cost more than that. The economies of scale are a hell of a thing.

Which made me wonder, could hackers take advantage of this ultra-cheap robot for our own purposes? It’s pretty much a given that the software for this robot will be terrible, and that whatever control electronics live inside it will be marginal at best. But what if we write those off and just look at the BilBot as a two-wheeled platform to carry our own electronics? It’s certainly worth $5 to find out.

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Austere Engineering Hack Chat

January 20, 2020 by Dan Maloney 6 Comments

Join us on Wednesday, January 22 at noon Pacific for the Austere Engineering Hack Chat with Laurel Cummings!

For most of us, building whatever it is that needs building is something that occurs in relative comfort and abundance. Sure, there are cold workshops and understocked parts bins to deal with, but by and large, we’re all working in more or less controlled environments where we can easily get to the tools and materials we need to complete the job.

But not all engineering is done under such controlled conditions. Field operations often occur miles from civilization, and if whatever you need is not in the back of the truck, it might as well not exist. At times like this, the pressure is on to adapt, improvise, and overcome to get the job done, especially if people’s lives and well-being are at stake.

All of this is familiar territory for Laurel Cummings, an electrical engineer and an associate at Building Momentum, a technology development and training concern based in Virginia. Her job is to get out in the field and work with the company’s mainly military and corporate clients and help them deal with the challenges of austere environments, including disaster response efforts.

From a North Carolina beach ravaged by Hurricane Florence to the deserts of Kuwait, Laurel has had to think her way out of more than a few sticky situations. Join us as we discuss what it takes to develop and deploy field-expedient solutions under less-than-ideal situations, learn how to know when good enough is good enough, and maybe even hear a few war stories too.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, January 22 at 12:00 PM Pacific time. If time zones have got 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.