These Dice Know If You’re Cheating

October 9, 2019 by Sharon Lin 13 Comments

Fans of D&D are surely aware of the significance of a good pair of dice. What if your dice were not only stylish, but smart? For anyone who’s ever had to deal with playing board games with less than reputable siblings or friends, the electric die just might be your savior.

The dice are configured via Bluetooth, tracking rolls and stats over the course of gameplay captured by an accelerometer.

The PCB had to have a flexible surface – specifically in the shape of an unfolded icosahedron – in order to form the shape of the die which constrains the design to two layers. Each face contains an LED facing outwards to light up the number on that side. The LEDs are directly powered by a rechargeable battery, which uses a small coil for wireless inductive charging. Rather than opting for a Qi charger chipset, which regulates the maximum amount of power transmitted if the efficiency falls below a threshold, [Jean Simonet] uses a simpler charger setup using a full bridge rectifier, capacitors, and a linear regulator to create a stable 5V supply for the receiving end.

While the initial design for the die required an injection molded plastic shell, an easier solution was to simply cast the designs in resin. The electronics are placed into a dice mold and cast just as a regular die would be.

This luckily also solved the issue of needing to fit the components inside a screw-on container with a removable lid, which presented a hassle in terms of finding a battery that would fit the dimensions. The LEDs – purchased for cheap on Alibaba – are daisy chained to reduce the complexity of the routing.

One issue with the LEDs, however, is that the internal PWMs modulating the intensity remain on even at an intensity of 0, constantly drawing 21 mA (for the 21 LEDs on the die). This causes the battery to die after 2-3 hours. The solution [Simonet] used was to add a transistor to cut off power to the LEDs and to have the MCU toggle the transistor when the LEDs are turned off. Even this solution didn’t solve the entire problem since the LEDs still drain current from the data and clock lines, so those lines had to be low before going to sleep.

There were some stability issues with using a small buck converter to bring the LiPo voltage down to 3.3V, so the power regulation was done directly by the MCU instead. Switching the die off is controlled by a magnetic switch connected to a power buck converter that turns off logic when a magnet is present. This initially caused the LED control lines to become floating when power was turned off, turning the LEDs to arbitrary colors. The solution was to wire the output of the magnetic sensor to the MCU and to allow the software to handle the LEDs as well.

Maybe it’s because creator [Simonet] happens to be a game developer as well, but the early development stages of the electronic die (CAD, circuit schematics, prototyping, hand soldering components) were streamed on Twitch, adding some interactivity to even the build phase. The end result may be small, but these dice certainly have large brains!

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Making Music From Cardboard

October 8, 2019 by Sharon Lin No comments

Fans of MaKey MaKey may find this project similar, but there’s a lot more to the Mini Automat than making music from fruit.

The idea for the Mini Automat (which is an off-shoot of the original Automat project by [Dada Machines]) is to make music accessible to anyone. The device functions as a plug and play MIDI-controller that connects to a computer, MIDI workstation (keyboards and sequencers), or DAW for input and triggers actuators on the output to create music.

The modifications make the originally Automat more hackable by making the board compatible with Arduino and Circuit Python, as well as adding in digital and analog pins for connecting to sensors, buttons, or light systems.

The team has released all schematics, firmware, and software, with only the board layouts unreleased to the public. From solenoids that push, pull, jiggle, smash, and bash at drums to surfaces that vibrate screws and beads, there’s a huge variety of household objects that can be used to make complex layered musical compositions, even for a one-person musician.

The Berlin-based team works on open source music tech hardware with the hopes of bringing environmentally and financially sustainable ideas to market.

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Dry Your Clothes In One Minute Or Less

October 7, 2019 by Sharon Lin 39 Comments

If you’re like most people, then washing clothes is probably a huge pain for you. Figuring out the odd number of minutes necessary to run a wash and dry cycle, trying desperately not to end up with clothes that are still wet, and worst of all having to wait so long for your clothes to be clean can be a real hassle.

One team of inventors decided to build Eleven, a dryer that dries and sanitizes clothes in a minute or less. As explained in their demo video, clothes are placed around the center tube and dried by the airflow initiated by Eleven. Fragrance and ozone is injected to prevent bacteria from causing bad smells.

The team experimented with ultrasonics and microwave-vacuum system, and ultimately decided to use a method that controls the flow of air within the fabric. A steam generator sprays the clothes with a disinfectant while a filter quarantines the chemicals to a receptacle within the device.

They also installed sensors to monitor the performance of the machine remotely, allowing users to track their clothes and the health of the machine even when they aren’t home. Something we’ve previously seen done in the DIY space.

It might not be the futuristic heat-free clothes dryer we were promised, but Eleven certainly looks like a step in the right direction.

Soldering Your Own Soldering Iron

October 6, 2019 by Sharon Lin 14 Comments

A device that even DIY enthusiasts don’t usually think to DIY is the humble soldering iron. Yet, that’s exactly what one Hackaday.io user did by building a USB-powered soldering pen with better performance than a $5 Chinese soldering pen.

The project draws inspiration from another Weller RT tip-based soldering pen by [vlk], although this project has a simpler display than an OLED. Slovakia-based maker [bobricius] was inspired by the DiXi ATSAMD11C14-based development board. The project uses the same 32-bit ATMEL ARM microcontroller with a USB bootloader, which makes updating the firmware a lot easier.

Two buttons control the heat (+/-) and the jack for the Weller RT soldering tip controls the power out with PWM. For the display, 20 Charlieplexed 3014 LEDs are used to show the temperature from 0-399. The last missing LED is left out since 5 GPIO pins can only drive 20 LEDs.

Assuming that the main heating controls stay the same as [vlk]’s project, the pen uses a current sensor and heating controller for PID control of a heating module, which connects to the SMT connector for the Weller RT soldering iron tip. The temperature sensor uses a an op-amp for amplification of the signal from a type K thermocouple.

While there aren’t currently GERBER files for the PCB yet, the project is based on the open-source OLED display soldering pen project by [vlk], whose schematic for the device is published.

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Building A Wind Power Generator In Your Backyard

October 5, 2019 by Sharon Lin 53 Comments

For many environmental enthusiasts, horizontal-axis wind turbines (HAWTs) — the kind that look like windmills slowly spinning in the distance — are a pretty familiar sight. Unfortunately, there are quite a few caveats that make them harder to adopt despite the fact that harvesting renewable energy sources is more sustainable than relying on natural gas and fuels that can be depleted. Since they face in one axis, they need to be able to track the wind, or else trade off the ability to maximize energy output. In turbulent and gusty conditions, as well, HAWTs face accelerated fatigue when harvesting.

The development of the vertical-axis wind turbine (VAWT) solves several of these issues. In addition, the turbines are typically closer to the ground and the gearbox replacement is simpler and more efficient. Maintenance is more accessible due to the size of the turbines, so no heavy machinery is typically necessary to access crucial components on-site. In addition, the gearbox by nature of its operation takes on less fatigue and is able to function in turbulent winds, which reduces the rate of failure.

For a simple version of a VAWT that you can build yourself, [BlueFlower] has published several mechanical drawings that detail the layout of the design. The wind power generator uses 24 magnets, copper wire fashioned into coils, and a metal plate for the main generator. The coils are arranged in a circular formation on a static plate, while the magnets are equally spaced on a moving circular plate. As the magnets pass over coils, the flux induces a current, which increases as the plates spin faster.

The blades of the generator are made from blue foam with a metal bar running through it for structure. Three of the blades are attached with triangular bars to a central rod, which also holds the spinning magnetic plate.

In [BlueFlower]’s initial trials using the VAWT for charging a battery they were able to generate a max power of 15W on boost mode and 30-70W when charging in PWM mode. Not bad for a home-made wind power generator!

There aren’t only pros to the design, however. While VAWTs may be cheaper, more mobile, and more resistant to wear and tear, there are some design features that prevent the generators from functioning as well as HAWTs at harvesting energy. The blades don’t produce torque at the same time, with some blades simply being pushed along. This produces more drag on the blades when they rotate, limiting the efficiency of the entire system. In addition, higher wind speeds are typically found at higher altitudes, so the VAWTs will perform better if installed on a towering structure. Vibration forces close to the ground can also wear out the bearings, resulting in more maintenance and costs.

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This Biofuel Cell Harvests Energy From Your Sweat

October 4, 2019 by Sharon Lin 14 Comments

Researchers from l’Université Grenoble Alpes and the University of San Diego recently developed and patented a flexible device that’s able to produce electrical energy from human sweat. The lactate/O2 biofuel cell has been demonstrated to light an LED, leading to further development in the area of harvesting energy through wearables.

The research was published in Advanced Functional Materials on September 25, 2019. The potential use cases for this type of biofuel cell within the wearables space include medical and athletic monitoring. By using biofuels present in human fluids, the devices can rely on an efficient energy source that easily integrated with the human body.

Scientists have developed a flexible conductive material made up of carbon nanotubes, cross-linked polymers, and enzymes connected to each and printed through screen-printing. This type of composite is known as a buckypaper, and uses the carbon nanotubes as the electrode material.

The lactate oxidase works as the anode and the bilirubin oxidase (from the yellowish compound found in blood) as the cathode. Given the theoretical high power density of lactate, this technology has the potential to produce even more power than its current power generation of 450 µW.

The cell follows deformations in the skin and produces electrical energy through oxygen reduction and oxidation of the lactate in perspiration. A boost converter is used to increase the voltage to continuously power an LED. The biofuel cells currently delivered 0.74V of open circuit voltage. As measurements for power generation had to be taken with the biofuel cell against human skin, the device has shown to be productive even when stretched and compressed.

At the moment, the biggest cost for production is the price of the enzymes that transform the compounds in sweat. Beyond cost considerations, the researchers also need to look at ways to increase the voltage in order to power larger portable devices.

With all the exciting research surrounding wearable technology right now, hopefully we’ll be hearing about further developments and applications from this research group soon!

[Thanks to Qes for the tip!]

Indonesian Jungle Vespas

October 4, 2019 by Sharon Lin 10 Comments

Typically, we associate Vespas with Italians, riding their posh scooters midday under the heat of the Mediterranean sun. In one community, however, the riders and vehicles are pretty different – and by that we mean a whole lot different. Think Mad Max: Fury Road meets The Jungle Book.

The first Vespa arrived in Indonesia in the 1960s when the vehicles were rewarded to Indonesian peacekeepers returning from a mission in Africa. While many of the Vespas on the archipelago maintain the same classic style, some riders have modified theirs into entirely new conceptions.

Indonesian photographer [Muhammad Fadli] captures these riders on their Vespa sampah (“garbage Vespa”) and Vespa gembel (“Vespa drifter”), as they are known by locals. The unique design of the riders is partially attributed to their emergence in the early 2000s coinciding with the fall of the Soeharto authoritarian regime. The newfound freedom and self expression, as well as the relaxed law enforcement, contributed to the development of new types of modified vehicles on the road.

While the scooters are widespread, there isn’t any known count of extreme Vespas in the country. Most of the Vespas are not meant for riding, but rather to show off their physical form. While some are made from cheap steel frames and tires, others are adorned with road scraps and symbols. Anything from buffalo skeletons to machine gun rounds are used to accentuate the design of the scooters, many of which have a punk or metal vibe.

Within the community, there are annual extreme Vespa gatherings, which can draw thousands of riders from all over Indonesia. From frames made of bamboo to frames made of garbage, stalls that collect recyclables to add to their vehicles, and riders from all walks of life, there’s no apparent limit to the builders’ creativity.