Custom Calculator Rolls D20 So You Don’t Have To

There are a number of sticking points that can keep new players away from complex tabletop games such as Dungeons & Dragons. Some people are intimidated by the math involved, and of course others just can’t find enough friends who are willing to sit down and play D&D with them in 2019. While this gadget created by [Caleb Everett] won’t help you get more open minded friends, it will take some of the mental gymnastics out of adding up dice rolls.

In its current form the device saves you from the hassle of not only having to roll various combinations of physical dice, but adding up all the faces after the fact as well. In the future [Caleb] plans on adding more advanced software features which will allow for tricks not possible with real dice, such as increasing the likelihood of rolling numbers which haven’t been seen in awhile. Now that the hardware is put together, he’s free to dig into the software side of things and really get creative.

Inside the 3D printed case of his calculator there’s a Adafruit Feather M0 Express, a 128 x 32 OLED display, and a 2200 mAh lithium ion battery that lets him go mobile. The keys, which are Cherry MX clones, are wired directly to the digital pins of the Feather board as [Caleb] found that easier to wrap his head around than doing a matrix. This ended up working out as he had enough pins, but does stifle future expansion a bit.

Even if you aren’t into the sort of tabletop gaming which would benefit from an automatic dice roller and tabulator, we think [Caleb] has come up with a very neat form factor for similar pocket sized gadgets. It reminds us of the Handlink from Quantum Leap; before the prop department swapped it out for a jumble of gummy bears later on in the series, anyway. Since he’s shared the link to the OnShape project, you can even tweak the design a bit without having to suffer through modifying the STLs.

Many of the electronic dice we’ve seen in the past have tried to emulate the size and appearance of traditional dice, so it’s interesting to see this approach which goes in the opposite direction entirely. Critics might say that at some point you’d be better off just using a software application for your smartphone, but we’re not in the business of complaining when people produce interesting pieces of hardware.

FabricKeyboard Is Piano, Theremin And More

Two researchers of Responsive Environments, MIT Media Lab, have put to together a device that is an amazing array of musical instruments squeezed into one flexible package. Made using seven layers of fabrics with different electrical properties, the result can be played using touch, proximity, pressure, stretch, or with combinations of them. Using a fabric-based keyboard, ribbon-controller, and trackpad, it can be played as a one-octave keyboard, a theremin, and in ways that have no words, such as stretching while pressing keys. It can also be folded up and stuffed into a case along with your laptop, and care has even been taken to make it washable.

The FabricKeyboard layers
The FabricKeyboard layers

Layer one, the top layer, is a conductive fabric for detecting proximity and touch. The twelve keys can work independently with a MPR121 proximity touch controller or the controller can treat them all as one, extending the distance the hand can be and have it still work. Layer two is just a knit fabric but layers three to six detect pressure, consisting to two conductive layers with a mesh fabric and a piezo-resistive fabric in between. The piezo-resistive fabric is LTT-SPLA from eeonyx, a knit fabric coated with the conductive polymer, polypyrrole (PPy). Layer seven consists of two strips of knitted spandex fabric, also coated with PPy, and detects stretching. Two strips of this are sewn on the bottom, one horizontal and one vertical. You can see and hear the amazing sound this all produces in the video below.

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A Beacon Suitable For Tracking Santa’s Sleigh?

High-altitude ballooning is becoming a popular activity for many universities, schools and hacker spaces. The balloons, which can climb up to 40 km in the stratosphere, usually have recovery parachutes to help get the payload, with its precious data, back to solid ground safely. But when you live in areas where the balloon is likely to be flying over the sea most of the time, recovery of the payload becomes tricky business. [Paul Clark] and his team from Durham University’s Centre for Advanced Instrumentation are working on building a small, autonomous glider – essentially a flying hard drive – to navigate from 30 km up in the stratosphere to a drop zone somewhere near a major road. An important element of such a system is the locator beacon to help find it. They have now shared their design for an “Iridium 9603 Beacon” — a small Arduino-compatible unit which can transmit its location and other data from anywhere via the Iridium satellite network.

The beacon uses the Short Burst Data service which sends email to a designated mail box with its date, time, location, altitude, speed, heading, temperature, pressure and battery voltage. To do all of this, it incorporates a SAMD21G18 M0 processor; FGPMMOPA6H GPS module; MPL3115A2 altitude sensor; Iridium 9603 Short Burst Data module + antenna and an LTC3225 supercapacitor charger. Including the batteries and antenna, the whole thing weighs in at 72.6 g, making it perfectly suited for high altitude ballooning. The whole package is powered by three ‘AAA’ Energizer Ultimate Lithium batteries which ought to be able to withstand the -56° C encountered during the flight. The supercapacitors are required to provide the high current needed when the beacon transmits data.

The team have tested individual components up to 35 km on a balloon flight from NASA’s Columbia Scientific Balloon Facility and the first production unit will be flown on a much smaller balloon, launched from the UK around Christmas. The GitHub repository contains detailed information about the project along with the EagleCAD hardware files and the Arduino code. Now, if only Santa carried this on his Sleigh, it would be easy for NORAD to track his progress in real time.