If you’re at all like us, or like [Vadim], you’ve got a stash of development boards in a shoebox on a shelf in your closet. If you’re better organized that we are, it might even be labeled “dev boards”. (Ah well, that’s a project for another day.) Anyway, reach into your box and pull one out, and put it to use. Do something trivial if you need to, but a dev board that’s driving a silly blinker is better than a dev board sitting in the dark.
[Vadim]’s good example to us all is going to serve as the brains for an automated plant watering system. That’s a low-demand application where the microcontroller can spend most of the time sleeping. [Vadim]’s first step, then was to get a real-time clock working with the hibernation mode. There’s working code inline in his blog.
If you use Arduino, you’ll feel at home in the Energia ecosystem. But it’s like ordering a Quarter Pounder with Cheese in Paris: Energia is a Royale with Cheese (YouTube) — it’s the little differences. And maybe that’s the point of the exercise; it’s always a good thing to try out something new, even if it’s only minimally different.
So grab that unused dev board off the shelf, struggle through the unfamiliar development environment and/or toolchain, but remember to keep an eye out for the sweet little differences. The more tools that you’re familiar with, the more solutions will spring to mind when you’re hacking on your next project.
It’s no secret that we love bizarre robot locomotion, so we are naturally suckers for BALLU (YouTube link, also embedded below) the Bouyancy-Assisted Lightweight Legged Unit. The project started with a simple observation — walking robots are constrained by having to hold themselves up — and removing that constraint make success much easier. Instead of walking, BALLU almost floats and uses what little net weight it does have to push against the ground.
How many integrated circuits do you need to build up a power supply that’ll convert mains AC into a stable DC voltage? Would you believe, none? We just watched this video by [The Current Source] (embedded below), where he builds exactly that. If you’re in the mood for a very well done review of diode bridges as well as half- and full-wave rectifiers, you should check it out.
First off, [TCS] goes through the basics of rectification, and demonstrates very nicely on the oscilloscope how increasing capacitance on the output smooths out the ripple. (Hint: more is better.) And then it’s off to build. The end result is a very simple unregulated power supply — just a diode bridge with some capacitors on the output — but by using really big capacitors he gets down into the few-millivolt range for ripple into a constant load.
The output voltage of this circuit will depend on the average current drawn, but for basically static loads this circuit should work well enough, and the simplicity of just tossing gigantic capacitors at the problem is alluring. (We would toss in a linear regulator somewhere.)
Quibbling over circuit designs isn’t why you’re watching this video, though. It’s because you want to learn something. Check out the rest of his videos as well. [TCS] has only been at it a little while, but it looks like this is going to be a channel to watch.
[Markus Gritsch] and his son had a fun Sunday putting together a little toy airboat from a kit. They fired it up and it occurred to [Markus] that it was pretty lame. It went forward and sometimes sideward when a stray current influenced its trajectory, but it had no will of its own.
The boat was extracted from water before it could wander off and find itself lost forever. [Markus] did a mental inventory of his hacker bench and decided this was a quickly rectified design shortcoming. He applied a cheap knock-off arduino, equally cheap nRF24L01+ chip of dubious parentage, and their equivalent hobby servo to the problem.
Some quick coding later, assisted by prior work from other RC enthusiasts, the little boat was significantly upgraded. Now the boat could be brought back to shore using any R/C controller that supported the, “Bayang,” protocol. He wouldn’t have to face the future in which he’d have to explain to his son that the boat, like treacherous helium balloons, was just gone. Video after the break.
One of the takeaway ideas that we got from BEAM robotics was the idea that the machine itself, rather than tons of processing power, can do a lot. Your hand affords gripping, and humans have made a pretty good living out of manipulating things (he says, typing). None of this is about the brain; it’s all about the mechanism.
Which brings us to the one-motor “Runner” robot. We’ll admit that we were a little bit disappointed to see that it doesn’t run so much as hop, flop, or scoot along on the two legs and that front wheel-nose. Still, it’s an awesome mechanism, and gets the locomotion job done in a very theatrical way. We’re left wondering if using two motors would allow it to steer or just flip over and flail around on its back. Going to a six “leg” design will definitely get the job done, as demonstrated by Boston Dynamics RHex robot. Continue reading “Simplest Jumping Kangaroo Bot”→
[Chandler Dickinson] did his monthly sweep of the floor in his blacksmith’s shop when it occurred to him that all that metal dust had to go somewhere, didn’t it? So he did the only reasonable thing and made a crude foundry out of cinder blocks, melted his dirt in it, and examined what came out the other end.
His first step was to “pan” for steel. He rinsed all the dirt in a bucket of water and then ran a magnet at the bottom of the bucket. The material that stuck to the magnet, was ripe for reclaimation.
Next he spent a few hours charging a cinderblock foundry with coal and his iron dust. The cinderblocks cracked from the heat, but at the end he had a few very ugly brittle rocks that stuck to a magnet.
Of course there’s a solution to this non-homogenous steel. As every culture with crappy steel eventually discovered, you can get really good steel if you just fold it over and over again. So he spend some time hammering one of his ugly rocks and folding it a bit. He didn’t get to two hundred folds, but it was enough to show that the resulting slag was indeed usable iron.
He did a deeper examination of the steel last week, going as far as to etch it, after discovering that the metal sparked completely differently when sanded on one side versus the other. It definitely needed work, but all seemed to have worked in the end.
We featured 3D printer projects on last week’s Hacklet. This week, we’re looking at a few awesome projects created with those printers. Trying to pick great 3D printed projects on Hackaday.io is a bit like staring at the sun. There are just way too many to choose from. To make things a bit easier, I’ve broken things down into categories. There are artistic prints, complex mechanical or electronic prints, and then there are simple functional prints, which is the topic we’re featuring today. Simple functional prints are designs which perform some function in the world. By simple, I mean they have only a few moving parts or electronic components. Let’s get right to it!
We start with [Scott] and L Extrusion Endcaps. Every Home Depot, Lowes, or hardware store has a selection of extruded aluminum. Typically there are a few flat bars, and some L brackets. L brackets are great, but they can be a pain to work with. Most of us don’t have the skills or the tools to weld aluminum, so nuts and bolts are the only way to go. [Scott’s] given us another option. He’s designed a set of 3D printable brackets that slip onto the ends of the brackets. The brackets make quick work of building boxes, racks, or anything with 90° or 45° angles.
Next up is [Joe M] with 3D Printed Molds: Custom Silicone Earbuds. [Joe] had a set of Bluetooth earbuds he enjoyed, but the rubber tips left a bit to be desired. Not a problem when you have a 3D printer on hand. [Joe] measured the plastic part of his earbuds and the rubber tips from a different set he liked. A bit of CAD magic later, and he had a model for the perfect earbud tip. While he could have directly printed the tip in a flexible filament like NinjaFlex, [Joe] opted for a pure silicone tip. He printed molds, then mixed silicone caulk with cornstarch (as a catalyst). The resulting earbuds sound and feel great!
Next we have [Jetty] with Highly Configurable 3D Printed Helmholtz Coil. Helmholtz coils are used to create uniform magnetic fields. Why would you want to do that? It could be anything from measuring magnets to cancelling out the effect of the earth’s magnetic field on a device being tested. [Jetty’s] wrote an OpenScad program which allows the user to enter parameters for their coil. [Jetty’s] program then calculates the coil’s magnetic properties, and outputs a printable .stl file. Building the coil is as simple as printing it and wrapping some copper wire. [Jetty] found that his coil was within 60nT (nanoTesla) of the expected value. Not bad for a bit of plastic and wire!
Finally we have StickScope, [SUF’s] entry in the 2016 Hackaday Prize. Like many of us, [SUF] loves his StickVise. Sometimes you need a bit of magnification to see those tiny 0201 resistors though. [SUF] had a cheap USB microscope on hand, so he designed StickScope, a USB microscope mount designed especially for the StickVise. Two 6mm steel rods are the backbone of the design. 3D printed clamps hold the system together like a miniature boom microscope. This is actually the third revision of the design. [SUF] found that the original design couldn’t be used with parts close to the bar which holds the microscope. A small jaw extender was the perfect tweak.