There are truisms about dice that you’ve probably already heard: if you have just one of them it’s called a “die”, opposite faces of each die always add up to seven, and those dots that you’re adding together are known as “pips”. But what about the infrared properties of those pips? It turns out they reflect less IR than the white body of the die and that trait can be used to build an automatic die reader.
Great projects have a way of bubbling to the surface. The proof of concept comes from way back in 2009, and while the source blog is now defunct, it’s thankfully been preserved by the Internet Archive. In recreating the project based on that barebones description, [Calvin] reached for a set of five IR transmitter/receiver pairs. Take a close look and you’ll see each transmitter is hidden under its partnered receiver. The light shines up through the receiver and the presence of the pip is detected by measuring how much of it bounces back.
This board is only the sensor portion of the design. A 595 shift register provides the ability to control which IR pair is powered, plus five more signals heading out to the analog pins of an Arduino Uno to monitor how much light is being detected by the receivers. Hey, that’s another interesting fact about dice, you only need to read five different pips to establish the value shown!
We wish there were a demo video showing this in action, but alas we couldn’t find one. We were amused to hear [Calvin] mentioned this was a sorting assignment at University and the team didn’t want to build yet another candy sorter. Look, we love an epic M&M sorter just as much as the next electronic geek, but it’s pretty hard to one-up this dice-based random number generator which rolls 1.3 million times each day.
People take their tabletop games very, very seriously. [Andrew Lauritzen], though, has gone far above and beyond in pursuit of a fair game. The game in question is Star War: X-Wing, a strategy wargame where miniature pieces are moved according to rolls of the dice. [Andrew] suspected that commercially available dice were skewing the game, and the automated machine-vision dice tester shown in the video after the break was the result.
The rig is a very clever design that maximizes the data set with as little motion as possible. The test chamber is a box with clear ends that can be flipped end-for-end by a motor; walls separate the chamber into four channels to test multiple dice on each throw, and baffles within the channels assure randomization. A webcam is positioned below the chamber to take a snapshot of each “throw”, which is then analyzed in OpenCV. This scheme has the unfortunate effect of looking at the dice from the table’s perspective, but [Andrew] dealt with that in true hacker fashion: he ignored it since it didn’t impact the statistics he was interested in.
And speaking of statistics, he generated a LOT of them. The 62-page report of results from his study is an impressive piece of work, which basically concludes that the dice aren’t fair due to manufacturing variability, and that players could use this fact to cheat. He recommends pooled sets of dice to eliminate advantages during competitive play.
This isn’t the first automated dice roller we’ve seen around these parts. There was the tweeting dice-bot, the Dice-O-Matic, and all manner of electronic dice throwers. This one goes the extra mile to keep things fair, and we appreciate that.
Continue reading “Automated Dice Tester Uses Machine Vision To Ensure A Fair Game”
In the electronic battlefield that is 2019, the realm of password security is fraught with dangers. Websites from companies big and small leak like sieves, storing user data in completely unsecure ways. Just about the worst thing you can do is use the same password across several services, meaning that an attack on one gives entry to multiple accounts. The challenge is to generate a unique and secure password for each and every application, and [Ilia]’s way of doing that is called HashDice.
No, it’s not a password manager, or an app – it’s a simple method that can be readily applied by anyone with the right tools. A simple dice is used to create random numbers, which are used to select words from a list to form the basic secret phrase. This is then combined with the name of the service or application to be accessed, the date, and a salt, before hashing using the SHA256 algorithm. The final hash is then truncated to create the password. You can do it all on a device that’s airgapped from the world, ensuring your core secret is never exposed, thus maintaining security.
There are some pitfalls to this method, of course. Many websites make things harder by requiring special characters or enforcing length limits on passwords. [Ilia] helpfully suggests several workarounds for this, but admits that no system is perfect in the face of these obstacles.
If you’re now wondering if your current password is safe, there are ways to investigate that, too.
We salute hackers who make technology useful for people in emerging markets. Leigh Johnson joined that select group when she accepted the challenge to build portable machine vision units that work offline and can be deployed for under $100 each. For hardware, a Raspberry Pi with camera plus screen can fit under that cost ceiling, and the software to give it sight is the focus of her 2018 Hackaday Superconference presentation. (Video also embedded below.)
The talk is a very concise 13 minutes, so Leigh flies through definitions of basic terms, before quickly naming TensorFlow and Keras as the tools she used. The time she saved here was spent on explaining what convolutional neural networks are and how they work, just enough to prepare the audience. But all of that is really just background, the meat of the talk is self-contained examples that Leigh has put together and made available online. I love to see that since it means you go beyond just watching and try it out for yourself. Continue reading “Leigh Johnson’s Guide To Machine Vision On Raspberry Pi”
There are applications you can download for your smartphone that can “roll” an arbitrary number of dice with whatever number of sides you could possibly want. It’s faster and easier than throwing physical dice around, and you don’t have to worry about any of them rolling under the couch. No matter how you look at it, it’s really a task better performed by software than hardware. All that being said, there’s something undeniably appealing about the physical aspect of die rolling when playing a game.
Luckily, [Paul Klinger] thinks he has the solution to the problem. His design combines the flexibility of software number generation with the small form factor of a physical die. The end result is a tiny gadget that can emulate anything from a 2 to 64 sided die with just 6 LEDs while remaining as easy to operate as possible. No need to tap on your smartphone screen with Cheetos-stained hands when you’ve got to make an intelligence check, just squeeze the Universal Electronic Die and off you go. Granted you’ll need to do some binary math in your head, but if you’re the kind of person playing D&D with DIY electronic dice, we think you’ll probably be able to manage.
The 3D printed case that [Paul] came up with for his digital die is very clever, though it did take him awhile to nail it down. As shown in the video after the break, it took seven iterations before he got the various features such as the integrated button “flaps” right. There’s also a printed knob to go on the central potentiometer, to make it easier to select how many sides your virtual die will have.
In terms of the electronics, the design is actually quite simple. All that lives on the custom PCB is a ATtiny1614 microcontroller, the aforementioned LEDs, and a couple of passive components. A CR2032 coin cell powers the whole operation, and it should provide enough juice for plenty of games as it’s only turned on when the user is actively “rolling”.
We’ve seen a number of very impressive electronic dice projects over the years, and it doesn’t look like the trend is slowing down anytime soon. Of course, if you absolutely must hear those physical dice rolling, we can help you with that too.
These days, it’s easy to get high-quality custom PCBs made and shipped to your door for under $50. It’s something that was unfathomable only a decade ago, but now it’s commonplace. However, it doesn’t mean that the techniques of home PCB production are now completely obsolete. Maybe you live somewhere a little off the beaten track (Australia, even!) and need to iterate quickly on a project, or perhaps you’d like to tinker with the chemical processes involved. For your learning pleasure, [Emiliano] decided to share some tips on making SMD-ready PCBs with the TinyDice project.
The actual project is to create a small electronic dice, and [Emiliano] touches on the various necessary considerations such as how to decrease power consumption, and how to source good quality, organic random numbers from your local microcontroller. Though its far from an exhaustive discussion on either topic, it shows an understanding of the deeper factors at play here.
However, the real meat of the write-up is the PCB production process. The guide goes through several stages of etching to not only prepare the PCB but also to add solder mask and produce a solder paste stencil as well using an aluminum can. This gives the boards that colored finish we’re all used to and lets the boards be reflowed for easy SMD assembly.
It’s a tidy guide as to how to approach producing your own boards to be used with SMD components, and it’s complete with clear photos and instructions throughout. If you want to take your designs up another notch, why not consider putting your components inside the circuit board?
There’s no shortage of projects that replace your regular board game dice with an electronic version of them, bringing digital features into the real world. [Jean] however goes the other way around and brings the real world into the digital one with his Bluetooth equipped electronic dice.
These dice are built around a Simblee module that houses the Bluetooth LE stack and antenna along with an ARM Cortex-M0 on a single chip. Adding an accelerometer for side detection and a bunch of LEDs to indicate the detected side, [Jean] put it all on a flex PCB wrapped around the battery, and into a 3D printed case that is just slightly bigger than your standard die.
While they’ll work as simple LED lighted replacement for your regular dice as-is, their biggest value is obviously the added Bluetooth functionality. In his project introduction video placed after the break, [Jean] shows a proof-of-concept game of Yahtzee displaying the thrown dice values on his mobile phone. Taking it further, he also demonstrates scenarios to map special purposes and custom behavior to selected dice and talks about his additional ideas for the future.
After seeing the inside of the die, it seems evident that getting a Bluetooth powered D20 will unfortunately remain a dream for another while — unless, of course, you take this giant one as inspiration for the dimensions.
Continue reading “Spice Up Your Dice With Bluetooth”