Day: August 6, 2018

More Suspension Than Necessary

August 6, 2018 by 20 Comments

The triangular frame of a traditional mountain bike needs to be the most rigid structure, and a triangle can be a very sturdy shape. So [Colin Furze] throws a spanner in the works, or, in this case, a bunch of springs. The video is below the break, but please try to imagine you are at a party, eyeballing some delicious salsa, yet instead of a tortilla chip, someone hands you a slab of gelatin dessert. The bike is kind of like that.

Anyone who has purchased springs knows there are a lot of options and terminology, such as Newton meters of force, extension, compression, and buckling. There is a learning curve to springs so a simple statement, for example “I want to make a bicycle of springs,” doesn’t have any easy answers. It is a lot like saying, “I want to make a microprocessor out of transistors“. This project starts with springs roughly the diameter of the old bike tubes, and it is a colossal failure. Try using cooked spaghetti noodles to make a bridge.

The first set of custom springs are not up to the task, but the third round produces something rideable. The result seems to be a ridiculous way to exercise your abs and is approximately a training unicycle mated with a boat anchor.

What makes this a hack? The video is as entertaining as anything [Colin] has made, but that does not make it a hack by itself. The hack is that someone asked a ridiculous question, possibly within reach of alcohol, and the answer came by building the stupid thing. A spring-bicycle could have been simulated six ways from Sunday on an old Android phone, but the adventure extracted was worth the cost of doing it in real life.

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FxSolver Is A Math Notebook For Engineers

August 6, 2018 by 12 Comments

If you like to rely on the web to do your electronics and computer math, you’ll want to bookmark FxSolver. It has a wide collection of formulae from disciplines ranging from electronics, computer science, physics, chemistry, and mechanics. There are also the classic math formulations, too.

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Dog-Or-Catapult Controls The Speed Of The Feed

August 6, 2018 by 9 Comments

[NathanKing] has a cute, rambunctious pupper who eats way too fast for her own good. He’s tried various distribution methods intended to get her to slow down, but she’s just too excited to eat. [Nathan]’s latest solution is to launch the food piece by piece using a catapult. The dog loves the gamified feeding method, which is sort of like one-way fetch. She gets a bit of exercise, and everyone is amused for the half hour it takes to fling 1.5 cups of food one piece at a time.

Electronics-wise, this food flinger doesn’t use much more than three servos and an Arduino Uno. Servo #1 pulls the arm back until it hits a limit switch. Servo #2 holds the arm down , and servo #3 rotates the food tube until it drops a unit of kibble into the spoon. Then servo #2 lets the arm go, and the tasty morsel flies about 30 feet (10 meters).

[Nathan] doesn’t offer step-by-step instructions, but there is more than enough detail to replicate this project. He used what he had on hand, such as scrap aluminium from another project for the frame. Future plans include swapping out the 6V lantern battery for rechargeable AAs, and downsizing to a Nano. We’ve fetched a couple of videos for you and thrown them in after the break. Go get ’em, reader!

Pets need plenty of water, especially during the summer. Here’s a no-sweat automatic watering solution we saw a few years ago.

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VCF West: All The Floptical Disks

August 6, 2018 by 47 Comments

Nowadays, if you want to transfer a file from one computer to another, you’d just send it over the network. In those rare occasions where that won’t work, a USB thumb drive will do. It wasn’t always this way, and it was much more confusing; back in the day when we had floppy drives. We had floptical drives. A single unlabeled 3.5″ floppy disk could be formatted as 360, 720, or 1440k IBM drive, a 400, 800, or 1440k Macintosh drive, an Apple II volume, or an Amiga, or an Acorn, or a host of other logical formats. That’s just one physical format of a floppy disk, and there are dozens more.

For this year’s VCF West, [Foone], hardware necromancer and collector of rare and esoteric removable storage formats, brought out the goods. He has what is probably the most complete collection of different floppy drive formats on the planet, and they were all out on display this weekend.

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The “P Cell” Is Exactly What You Might Suspect

August 6, 2018 by 34 Comments

[Josh Starnes] had a dream. A dream of a device that could easily and naturally be activated to generate power in an emergency, or just for the heck of it. That device takes in urea, which is present in urine, and uses it to generate a useful electrical charge. [Josh] has, of course, named this device the P Cell.

An early proof of concept uses urine to create a basic galvanic cell with zinc and copper electrodes, but [Josh] has other ideas for creating a useful amount of electricity with such a readily-available substance. For example, the urea could be used to feed bacteria or micro algae in a more elegantly organized system. Right now the P Cell isn’t much more than a basic design, but the possibilities are more than just high-minded concepts. After all, [Josh] has already prototyped a Hybrid Microbial Fuel Cell which uses a harmonious arrangement of bacteria and phytoplankton to generate power.

[Josh]’s entries were certainly among some of the more intriguing ones we saw in the Power Harvesting Challenge portion of The Hackaday Prize, and we’re delighted that his ideas will be in the running for the Grand Prize of $50,000.

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DSO Nano 3 Review: A 20 MHz Pocket ‘Scope For Not A Lot

August 6, 2018 by 45 Comments

The oscilloscope is an essential tool of any electronics bench, and it is also an instrument whose capabilities have expanded exponentially over the decades. Your entirely analogue CRT ‘scope of a few decades ago has now been supplanted by a digital device that takes on many of the functions of both an expensive multimeter a frequency counter, and more. At the top end of the market the sky is the limit when it comes to budget, and the lower end stretches down to low-bandwidth devices based upon commodity microcontrollers for near-pocket-money prices.

These super-cheap ‘scopes are usually sold as kits, and despite their very low bandwidth are surprisingly capable instruments with a useful feature set due to well-written software. I  reviewed a typical model last year, and came away lamenting its lack of an internal battery and a decent quality probe. If only someone would produce an inexpensive miniature ‘scope with a decent bandwidth, decent probe, and an internal battery!

As it happens, I didn’t have long to wait for my wish to be satisfied, with news of the release of the DSO Nano 3. Let’s see what you can do with a portable scope for less than $50.

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Learn FPGA Fast With Hackaday’s FPGA Boot Camp

August 6, 2018 by 36 Comments

FPGAs have gone from being a niche product for people with big budgets to something that every electronics experimenter ought to have in their toolbox. I am always surprised at how many people I meet who tell me they are interested in using FPGAs but they haven’t started. If you’ve been looking for an easy way to get started with FPGAs, Hackaday’s FPGA boot camp is for you. There’s even a Hackaday.io chat in the group specifically for FPGA talk for questions and general discussion!

While it is true FPGAs aren’t for everything, when you need them you really need them. Using FPGAs you can build logic circuits — not software simulations, but real circuits — and reap major performance benefits compared to a CPU. For digital signal processing, neural networks, or computer vision applications, being able to do everything essentially in parallel is a great benefit. Sometimes you just need the raw speed of a few logic gates compared to a CPU plodding methodically through code. We expect to see a lot more FPGA activity now that Arduino is in the game.

These boot camps gather together some of the material you seen spread over many articles here before, plus new material to flesh it out. It’s designed for you to work through more like a training class than just some text to read. There’s plenty of screenshots and even animations to help you see what you are supposed to be doing. You’ll be able to work with simulations to see how the circuits we talk about work, make changes, and see the results. We’ll focus on Verilog — at least for now — as it is close to C and easier for people who know C to pick up. Still not convinced? Let’s run though the gist of the boot camp series.

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