Printed Door Handle Turns Key With A Servo

[Madalin Valceleanu] had a somewhat unique problem. He wanted to make his front door a bit “smarter”, but none of the IoT door locks he found were compatible with the style of reinforced door he had. So he set out to design and 3D print his own Internet-controlled door handle.

Now we say handle and not lock because the internal mechanisms haven’t actually been replaced. Those aren’t exactly the kind of parts that lend themselves to being recreated in PLA, after all. The printed components simply replace the original plate and handle on the interior of the door.

In that case, you might be wondering what the point of all this was. If he’s still using the same internal mechanism, how does a new handle help? On his new handle, [Madalin] has integrated a servo that’s capable of turning the original key in the door. With the servo wired up to a Raspberry Pi, this allows him to lock and unlock the door through his home automation system.

[Madalin] has made the STLs for his printed handles available on Thingiverse, but like most of these “bolt on” style door modifications, we imagine the design is bespoke enough that it won’t be much practical use to anyone else. Still, it’s an excellent example of solving a real-world problem with some outside of the box thinking. Continue reading “Printed Door Handle Turns Key With A Servo”

Radio Free Blockchain: Bitcoin From Space

Cryptocurrencies: love them, hate them, or be baffled by them, but don’t think you can escape them. That’s the way it seems these days at least, with news media filled with breathless stories about Bitcoin and the other cryptocurrencies, and everyone from Amazon to content creators on YouTube now accepting the digital currency for payments. And now, almost everyone on the planet is literally bathed in Bitcoin, or at least the distributed ledger that makes it work, thanks to a new network that streams the Bitcoin blockchain over a constellation of geosynchronous satellites.

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Hackaday Links: March 24, 2019

It has come to my attention that a few of you don’t know about Crystalfontz, an online store where you can find displays of all types, from USB LCD displays to I2C OLEDs, to ePaper displays. Thanks to [arthurptj] for that tip. Yes, Crystalfontz is cool, but have you ever heard of Panelook? Oh boy are there some displays at Panelook. Here’s a 1024 by 768 resolution display that’s less than half an inch across.

The comments section of Hackaday has been pretty tame as of late, so here’s why Apple is the king of design. It’s a question of fillets. There are a few ways to add a fillet to the corner of an icon or a MacBook. The first is to draw two perpendicular lines, then add a fixed radius corner. The Apple way is to make everything a squircle. The ‘squircle’ way of design is that there are no sudden jumps in curvature, and yes, you can do this in Fusion360 or any other design tool. This is also one of those things you can’t unsee once you know about it, like the arrow in the FedEx logo.

The ESP8266 simply appeared one day, and it changed everything. The ESP32, likewise, also just arrived on the Internet one day, and right now it’s the best solution for a microcontroller, with WiFi, that also does things really fast. Someone over at Espressif is dropping hints of a new microcontroller, with a possible release on April 1st (the same date that Apple released their competitor to the Raspberry Pi). Is it RISC-V? Is it 5V tolerant? Who knows! (Editor’s note: it’s not RISC-V. Though they’re saying that’s in the pipeline.)

The Verge got their hands on an original iPhone engineering validation unit. It’s a breakout board for an iPhone.

San Dimas High School Football Rules

There’s a screwdriver in your toolbox that has a cast clear handle, a blue ferrule surrounding the shaft, and red and white lettering on the side. Go check, it’s there. It’s a Craftsman screwdriver. It’s an iconic piece of design that’s so ubiquitous that it’s unnoticeable. It’s just what a screwdriver is. It’s a prototypical screwdriver. Thanks to the rise of resin and turning craftsmanship, there’s now a gigantic version of this screwdriver.

[The 8-Bit Guy] posted the following message on his Facebook on March 19th: “Just FYI – somebody hacked and totally erased my website. So, it’s going to be down for a while.” At the time of this writing, everything looks okay, which brings up the larger question of why Facebook is still a thing. We’re on a gradient of coolness here, and the sooner you delete your Facebook, the cooler you are. I, for example, deleted my Facebook during the Bush administration, and we all know how cool I am. I’ll never get to the singularity of coolness of kids who never had a Facebook in the first place, but the point remains: delete your Facebook old man.

[SirEdmar] wants to bring Fusion 360 to Linux users. Autodesk wants the same, and they tried a web-based version of Fusion 360, but… it’s a web version of Fusion 360. Right now the best solution is Wine, and thanks to [SirEdamr] 360 works in Wine.

Bing translate does Klingon! How well does it work? Not bad, it could use some work, mostly with non-standard vocabulary:

Drops Of Jupyter Notebooks: How To Keep Notes In The Information Age

Our digital world is so much more interactive than the paper one it has been replacing. That becomes very obvious in the features of Jupyter Notebooks. The point is to make your data beautiful, organized, interactive, and shareable. And you can do all of this with just a bit of simple coding.

We already leveraged computer power by moving from paper spreadsheets to digital spreadsheets, but they are limited. One thing I’ve seen over and over again — and occasionally been guilty of myself — is spreadsheet abuse. That is, using a spreadsheet program to do something I probably ought to write a program to do. For those times that you want something quick but want something more than a spreadsheet, you should check out Jupyter Notebooks. The system is most commonly associated with Python, but it isn’t Python-specific. There are over 100 languages supported — many community-developed. You can even install a C++ interpreter backend for it. Because of the client/server architecture, it is very simple to share notebooks with other users.

You can — in theory — use Jupyter for anything you could use Python for. In practice, it seems to get a lot of workout with people analyzing large data sets, doing machine learning, and similar tasks.

The Good: Simple, Powerful, Extensible

The idea is simple. Think of a Markdown-enabled web page that can connect to a backend (a kernel, in Jupyter-speak). The backend can run on your machine or remotely and will support some kind of language — often Python. The document has cells that line up vertically (like a single wide spreadsheet column). For example, here’s a simple notebook I created to explain how a bunch of sine waves add up to a square wave:

Continue reading “Drops Of Jupyter Notebooks: How To Keep Notes In The Information Age”

Building A Simple Python API For Internet Of Things Gadgets

It’s no secret that I rather enjoy connecting things to the Internet for fun and profit. One of the tricks I’ve learned along the way is to spin up simple APIs that can be used when prototyping a project. It’s easy to do, and simple to understand so I’m happy to share what has worked for me, using Web2Py as the example (with guest appearances from ESP8266 and NodeMCU).

Barring the times I’m just being silly, there are two reasons I might do this. Most commonly I’ll need to collect data from a device, typically to be stored for later analysis but occasionally to trigger some action on a server in the cloud. Less commonly, I’ll need a device to change its behavior based on instructions received via the Internet.

Etherscan is an example of an API that saves me a lot of work, letting me pull data from Ethereum using a variety of devices.

In the former case, my first option has always been to use IoT frameworks like Thingsboard or Ubidots to receive and display data. They have the advantage of being easy to use, and have rich features. They can even react to data and send instruction back to devices. In the latter case, I usually find myself using an application programming interface (API) – some service open on the Internet that my device can easily request data from, for example the weather, blockchain transactions, or new email notifications.

Occasionally, I end up with a type of data that requires processing or is not well structured for storage on these services, or else I need a device to request data that is private or that no one is presently offering. Most commonly, I need to change some parameter in a few connected devices without the trouble of finding them, opening all the cases, and reprogramming them all.

At these times it’s useful to be able to build simple, short-lived services that fill in these gaps during prototyping. Far from being a secure or consumer-ready product, we just need something we can try out to see if an idea is worth developing further. There are many valid ways to do this, but my first choice is Web2Py, a relatively easy to use open-source framework for developing web applications in Python. It supports both Python 2.7 and 3.0, although we’ll be using Python 3 today.

Continue reading “Building A Simple Python API For Internet Of Things Gadgets”

Welcome To The Internet Of Swords

As has been made abundantly clear by the advertising department of essentially every consumer electronics manufacturer on the planet: everything is improved by the addition of sensors and a smartphone companion app. Doesn’t matter if it’s your thermostat or your toilet, you absolutely must know at all times that it’s operating at peak efficiency. But why stop at household gadgets? What better to induct into the Internet of Things than 600 year old samurai weaponry?

Introducing the eKatana by [Carlos Justiniano]: by adding a microcontroller and accelerometer to the handle of a practice sword, it provides data on the motion of the blade as it’s swung. When accuracy and precision counts in competitive Katana exhibitions, a sword that can give you real time feedback on your performance could be a valuable training aid.

The eKatana is powered by an Adafruit Feather 32u4 Bluefruit LE and LSM9DS0 accelerometer module along with a tiny 110 mAh LiPo battery. Bundled together, it makes for a small and unobtrusive package at the base of the sword’s handle. [Carlos] mentions a 3D printed enclosure of some type would be a logical future improvement, though a practice sword that has a hollow handle to hold the electronics is probably the most ideal solution.

A real-time output of sword rotation, pitch, and heading is sent out by the Adafruit Feather over BLE for analysis by a companion smartphone application. For now he just has a running output of the raw data, but [Carlos] envisions a fully realized application that could provide the user with motions to perform and give feedback on their form.

Incidentally this isn’t the first motion-detecting sword we’ve ever covered, but we think this particular incarnation of the concept might have more practical applications.

Learn About Blockchains By Building One

What do we curious Hackaday scribes do when we want to learn about something? First port of call: search the web.

When that something is blockchain technology and we’re looking for an explanation that expands our cursory overview into a more fundamental understanding of the basic principles, there is a problem. It seems that to most people blockchains equate to one thing: cryptocurrencies, and since cryptocurrencies mean MONEY, they then descend into a cultish frenzy surrounded by a little cloud of flying dollar signs. Finding [Daniel van Flymen]’s explanation of the fundamentals of a blockchain in terms of the creation of a simple example chain using Python was thus a breath of fresh air, and provided the required education. Even if he does start the piece by assuming that the reader is yet another cryptocurrency wonk.

We start by creating a simple class to hold all the Python functions, then we are shown a single block. In his example it’s a JSON object, and it contains the payload in the form of a transaction record along with the required proof-of-work and hash. We’re then taken through a very simple proof-of-work algorithm, before being shown how the whole can be implemented as very simple endpoints.

You are not going to launch a cryptocurrency using this code, and indeed that wasn’t our purpose in seeking it out. But if you are curious about the mechanics of a blockchain and are equally tired of evangelists of The Blockchain who claim it will cure all ills but can’t explain it in layman’s terms, then this relatively simple example is for you.

The wrong way to build a blockchain image: Jenny List. #FarmLife.