For all their capacity, shutting down a Raspberry Pi can be a bothersome routine depending on how you have it set up — historically and abrupt cut to the power risks corrupting the SD card. [madlab5] had to make a few changes to a Pi running in headless mode, requiring them to access it externally to shut it down to prevent any damage from pulling the plug. So, why not take the opportunity to whip up a soft shut-down switch?
This is a great beginner project to get one accustomed to working with a Pi. With this in mind, [madlab5] went through two revisions of this idea: the simple way, and the fun way. For the simple way just press the button and the Pi activates a script which shuts it down in thirty seconds. Job done. But, realizing there may be a few circumstances where they’d need more functionality, [madlab5] decided to take a second swing at this.
[madlab5]’s fun way involves a button with a built-in LED and a speaker to blare an announcement that the Pi will
self destruct shut down after a short time. Setting the switch up this way takes a little more doing, but you get to add a little more character to your Pi with a custom shutdown report, as well as the option to cancel an accidental button-press.
For any newbies out there, [madlab5] is kind enough to provide their code and diagrams in their blog post. If remotes are more your thing, we have also featured a similar beginner project to shut down your Pi.
[Alberto Piganti], aka [pighixxx] has been making circuit diagram art for a few years now, and has just come out with a book that’s available on Kickstarter. He sent us a copy to review, and we spent an hour or so with a refreshing beverage and a binder full of beautiful circuit diagrams. It doesn’t get better than that!
[pighixxx] started out making very pretty and functional pinout diagrams for a number of microcontrollers, and then branched out to modules and development boards like the Arduino and ESP8266. They’re great, and we’ll admit to having a printout of his SMD ATMega328 and the ESP-12 on our wall. His graphical style has been widely copied, which truly is the sincerest form of flattery.
But after pinouts, what’s next? Fully elaborated circuit diagrams, done in the same style, of course. “ABC: Basic Connections” started out life as a compendium of frequently used sub-circuits in Arduino projects. But you can take “Arduino” with a grain of salt — these are all useful for generic microcontroller-based projects. So whether you want to drive a 12 V solenoid from a low-voltage microcontroller, drive many LEDs with shift registers, or decode a rotary encoder, there is a circuit snippet here for you. Continue reading “First Look at ABC: Basic Connections”
[Decino] made a nice LED animated blinking heart box for his girlfriend. That’s a nice gesture, but more to the point here, it’s a nice entrée into the world of custom hardware. The project isn’t anything more than a home-etched PCB, a custom 3D-printed case, a mess of LEDs and current-limiting resistors, a shift register, and a microcontroller. (OK, we’re admittedly forgetting the Fifth Element.) The board is even single-sided with pretty wide traces. In short, it’s a great first project that ties together all of the basics without any parts left over. Oh, and did we mention Valentine’s day?
Once you’ve got these basics down, though, the world is your oyster. Building almost anything you need is just a matter of refining the process and practice. And if you’ve never played around with shift registers, a mega-blinker project like this is a great way to learn hands-on.
Not everything we write up on Hackaday has to be neural nets and JTAG ports. Sometimes a good beginner project that hits the fundamentals with no extra fat is just the ticket. What’s your favorite intro project?
You’d think that we’ve posted every possible clock here at Hackaday. It turns out that we haven’t. But we have seen enough that we’ve started to categorize clock builds in our minds. There are the accuracy clocks which strive to get every microsecond just right, the bizzaro clocks that aim for most unique mechanism, and then there are “hello world” clocks that make a great introduction to building stuff.
Today, we’re looking at a nice “hello world” clock. [electronics for everyone]’s build uses a stepper motor and a large labelled wheel that rotates relative to a fixed pointer. Roll the wheel, and the time changes. It looks tidy, it’s cyclical by design, and it’s a no-stress way to get your feet wet driving stepper motors. And it comes with a video, embedded below.
Continue reading “Simple Clock is Great Stepper Motor Project”
Do you have loved ones who live far away? Or do you just want an interesting starter ESP8266 project to get your feet wet? If the answer to either of these questions is “yes”, we’ve got just the project for you. [Craig Lindley] built a “thinking of you” button-and-LED display device that helps people keep in touch, in a very simple way.
We like the minimalism of the design. One party presses their button, electrons flow, WiFis WiFi, data travels through a set of tubes, and an LED far away glows a pre-arranged color. The other side can signal back to say “hi” as well. It’s a cute item to have on your desk, or wherever you spend the most time. If you’re new to all of this, you can hardly beat the circuit for its simplicity.
Yeah, you could totally just send the other person a text message or an e-mail. But then you don’t get an excuse to play around with NodeMCU, and it just lacks the personal hacker touch. The code is available in a zip file here, and if you want to stay in touch with someone other than [Craig]’s sisters, you’ll probably want to customize it a bit.
So you’re looking to buy your first 3D printer, and your index finger is quivering over that 300 US Dollar printer on Amazon.com. Stop! You’re about to have a bad time. 3D printing has come a long way, but most 3D printers are designed through witchcraft, legends, and tall tales rather than any rigorous engineering process. I would say most 3D printer designs are either just plain bad, or designed by a team of Chinese engineers applying all their ingenuity to cost cutting. There are a few that are well designed, and there is a comparatively higher price tag attached.
I’ll start by going through some of the myths and legends that show up in 3D printers. After that I’ll go through some of the common, mostly gimmick, features that typically hinder your printer’s ability, rather than adding any useful function. Next I’ll go onto the things that will actually make your printer better. Finally, I’ll add some special consideration if you’re a beginner buying your first printer.
Continue reading “Kicking The Tires Before You Buy: 3d Printers”
I was surfing the web looking for interesting projects the other day when I ran into [SkyKing’s] exquisite transistor demodulator radio builds. He mentioned that they were “Alfred P. Morgan-style” and that brought back a flood of memories about a man who introduced a whole generation to electronics and radio.
[Morgan] was born in 1889 and in the early part of the twentieth century, he was excited to build and fly an airplane. Apparently, there wasn’t a successful flight. However, he eventually succeeded and wrote his first book: “How to Build a 20-foot Bi-Plane Glider.” In 1910, he and a partner formed the Adams Morgan company to distribute radio construction kits. We probably wouldn’t remember [Morgan] for his airplanes, but we do recognize him for his work with radio.
By 1913, he published a book “The Boy Electrician” which covered the fundamentals of electricity and magnetism (at a time when these subjects were far more mysterious than they are today). [Morgan] predicted the hacker in the preface to the 1947 edition. After describing how a boy was frustrated that his model train automated to the point that he had nothing actually to do, [Morgan] observed:
The prime instinct of almost any boy at play is to make and to create. He will make things of such materials as he has at hand, and use the whole force of dream and fancy to create something out of nothing.
Of course, we know this applies to girls too, but [Morgan] wrote this in 1913, so you have to fill in the blanks. I think we can all identify with that sentiment, though.
Continue reading “Alfred P. Morgan: A Generation’s Radio Hacker”