Better Security, Harry Potter Style

We all know we shouldn’t use 1234 as our password. But we often don’t do the absolute best practice when it comes to passwords. After all, you should have some obscure strange password that is unique for every site. But we all have lots of passwords, so most of us use $pock2020 or something like that. If you know I’m a Star Trek fan, that wouldn’t be super hard to guess. [Phani] writes about a technique called Horcruxing — a term taken from the literary realm of Harry Potter that allowed Voldemort to preserve life by splitting it into multiple parts, all of which were required to bring an end to his villany. [Phani’s] process promises to offer better security than using a single password, without the problems associated with having hundreds of random passwords.

Most people these days use some form of password manager. That’s great because the manager can create 48 character passwords of random words or symbols and even you don’t know the password. Of course, you do know the master password or, at least, you better. So if anyone ever compromised that password, they’d have all your passwords at their fingers. Horcruxing makes sure that the password manager doesn’t know the entire password, just the hard parts of it.

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Do You Know Where Your Children Are? Check The Weasley Clock

What’s the coolest thing you could build for a Harry Potter fan, aside from a working magic wand or Quidditch broomstick? We would have to say a Weasley clock that shows the whereabouts of everyone in the family is pretty high on the list, especially if that fan is a wife and mother.

Here’s how it works: they’ve set up geofences to define the boundaries of home, each person’s school or workplace, and so on. The family’s locations are tracked through their phones’ GPS using Home Assistant, which is hosted on a Raspberry Pi. Whenever someone’s location changes, the Pi alerts the clock over MQTT, and it moves the 3D-printed hands with servos.

The clock has some interesting granularity to it as well. As someone gets closer to home, their pointer’s distance reflects that in its proximity to the Home slice. And Home itself is divided into the main house and the shop and reflected by the pointer’s position.

We particularly like the attention to detail here, like the art poster used for the clock’s face that includes all the Weasley’s whereabouts in the background. It’s built into a thrift store grandmother clock, which is smaller than a grandfather clock but no less majestic. In the future there are plans to implement the clock’s chimes to announce that someone is back home.

No matter what you’re into, the whereabouts clock idea can probably fit that universe. For instance, here’s one that uses LEGO mini-fig heads to locate roommates.

Harry Potter Wand Hack Makes Magic Real

Any sufficiently advanced hack is indistinguishable from magic, a wise man once observed. That’s true with this cool build from [Jasmeet Singh] that magically opens a box when you wave a Harry Potter magic wand in the right way. Is it magic? No, it’s a neat hack that uses computer vision to track the wand and recognize when you make the magic gesture.

The trick is based on the same technique that Universal Studios use in their Harry Potter theme park, as detailed in a patent with the snappy title of “System and method for tracking a passive wand and actuating an effect based on a detected wand path“. The basic idea is that a retroreflective dot on the end of the wand reflects light from a set of infra-red LEDs around the camera. An infra-red sensitive camera detects this reflected light as a bright dot. This camera is tied into a computer vision system that tracks the path of the dot, then triggers the action if it follows a certain pattern.

The version that [Jasmeet] built uses a Raspberry Pi NoIR camera, and a Raspberry Pi 3 running OpenCV. This feeds into a machine learning graph that detects the letters of the alphabet. If the detected letter is an A (for Alomahora, the Harry Potter open spell), then the box opens. If it is a C, the box closes. This is all tied together using Python.

It’s a neat build that ties together a number of interesting techniques, and which could keep the kids amused for a while. You could also expand it further, such as adding a death ray that triggers if you trace an S for Sectumsempra. That’ll teach them not to mess with the dark arts.

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Lighting Up Your Spectrespecs

In the ever-popular world of Harry Potter, a pair of Spectrespecs are useful if you’re hunting for wrackspurts and nargles. While we’ve never spotted either of these creatures ourselves, if you’d like to go out on a hunt, [Laveréna]’s build might be for you.

To start with, you’ll need the frames for the Spectrespecs. [Laveréna] elected to source hers commercially, but you can 3D print them or even craft them by hand if you so desire. Then, a TinyLily microcontroller board is installed, with its small size allowing it to be tucked neatly out of sight in the top of the sunglasses. Two NeoPixels are then installed, with the TinyLily programmed to flash the LEDs in the requisite blue and red colors for easy identification of supernatural creatures.

Tools such as cheap microcontrollers designed for wearables and low-cost addressable LEDs are making advanced cosplay designs easier than ever. Whipping up custom blinkables no longer requires knowledge of advanced multiplexing techniques and how to properly drive high-power LEDs. Of course, LED wearables do still get properly advanced – like this skin-based 7-segment display. If you’ve got a glowable project of your own that you’re dying to share, be sure to let us know!

Play Chess Like Harry Potter

If you are a Harry Potter fan, you might remember that one of the movies showed an Isle of Lewis chess set whose pieces moved in response to a player’s voice commands. This feat has been oft replicated by hackers and [amoyag00] has a version that brings together a Raspberry Pi, Arduino, Android, and the Stockfish chess engine in case you want to play by yourself. You can see a video of the game, below.

Interestingly, the system uses Marlin — the 3D printing software — to handle motion using the Arduino. We suppose moving chess pieces over a path isn’t much different than moving a print head. It is certainly a novel use of GCode.

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Magic Wand Learns Spells Through Machine Learning And An IMU

Jennifer Wang likes to dress up for cosplay and she’s a Harry Potter fan. Her wizarding skills are technological rather than magical but to the casual observer she’s managed to blur those lines. Having a lot of experience with different sensors, she decided to fuse all of this together to make a magic wand. The wand contains an inertial measurement unit (IMU) so it can detect gestures. Instead of hardcoding everything [Jennifer] used machine learning and presented her results at the Hackaday Superconference. Didn’t make it to Supercon? No worries, you can watch her talk on building IMU-based gesture recognition below, and grab the code from GitHub.

Naturally, we enjoyed seeing the technology parts of her project, and this is a great primer on applying machine learning to sensor data. But what we thought was really insightful was the discussions about the entire design lifecycle. Asking questions to scope the design space such as how much money can you spend, who will use the device, and where you will use it are often things we subconsciously answer but don’t make explicit. Failing to answer these questions at all increases the risk your project will fail or, at least, not be as successful as it could have been.

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Mad Eye For The WiFi

In the Harry Potter universe, Professor Moody was, perhaps unfairly, given the nickname Mad Eye for the prosthetic eye he wore. His eye remains a challenge for technically-minded cosplayers aiming to recreate the look and feel of this unique piece of headgear. [cyborgworkshop] had already mastered the basic eye, but wanted to take things further.

The original build relied on a sub-micro servo to move the eyeball. This was done at random as an attempt to simulate the eye’s behaviour in the books and films. However, wanting more, [cyborgworkshop] decided to make the eye more reactive to its surrounding environment. Using the Adafruit Huzzah, a breakout board for the ESP8266, code was whipped up to detect the number of WiFi access points in the area. The more access points, the more frequent and erratic the movement of the eye. Occasional slower periods of movement are coded in before the eye resumes its wild darting once more, depending on just how saturated the local WiFi environment is.

It’s a great twist on the project, and [cyborgworkshop] has provided more details on the initial build, too. If you think you’re having déja vu, check out this build using recycled parts.