Author: Zoe Skyforest

3720 Articles

Self-Glowing Ring Is Its Own Battery

April 4, 2020 by 19 Comments

LED jewelry has always been a popular part of the maker community. Oftentimes, coin cells are used as a compact source of power, or wires are run to discreet hidden battery packs. [OguzC3] went another route, however, creating a glowing ring which works as its own battery.

The design will be familiar to those who have done high-school experiments on basic batteries. An aluminium pipe forms the inner surface of the ring, which is then wrapped in a layer of newspaper. A copper outer ring is then placed outside. When soaked in a salt water solution, this forms a basic battery. The voltage output is only around 0.5 volts, so a joule thief circuit is built into the ring to step this up high enough to drive an LED. [OguzC3] reports that the ring lasts several hours at a time, and only needs a quick rinse in fresh salty water to recharge.

It’s a creative concept, and the final piece looks like a magical object from the world of fantasy. It would make a great addition to any cosplay, and we’re sure the technique could be adapted to other accoutrements, too. A similar experiment done in a more extreme way is this electric car charged via lemons. If you’ve got your own battery chemistry project cooking up at home, be sure to let us know!

A Touchless Handwashing Timer Comes In Handy

April 3, 2020 by 23 Comments

In 2020, it’s no longer enough to simply wash your hands. You’ve got to do it right. Proper process involves rubbing soap and water over every surface of your hands, and taking a full 20 seconds to do the job. While many recommend singing various popular songs to keep time, that can be more than a little embarassing in shared spaces. [Alex Glow] instead created this simple timer to help out.

The timer is built on the Adafruit Circuit Playground Express, a devboard that features 10 RGB LEDs already onboard, making the project a cinch. It also comes with a MEMS microphone and a light sensor all ready to go. Thus, with a bit of code, [Alex] was able to create a timer activated by a loud noise, such as clapping. Once detected, the timer starts, flashing its LEDs to indicate time remaining. There’s also a nightlight feature, which activates when light levels decrease, making it easier to navigate the bathroom in the dark.

It’s a useful little project for these troubled times, and one that makes great use of everything onboard the Circuit Playground Express. Having everything included certainly does make projects come together quickly. You can even program it from your phone! Video after the break.

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LED Heart Beats With The Beholder

April 3, 2020 by 9 Comments

Many a maker likes to use their craft to create gifts for loved ones. [Jiří Praus] was celebrating having been married for 5 years, and crafted this beautiful LED heart sculpture to commemorate the occasion.

The outer shell was created by first starting with a 3D printed heart shape. This was used as a form upon which the brass wire could be soldered together to form an attractive heart-shaped cage. Inside, an Arduino Nano is hooked up to a series of WS2812b LEDs. The LEDs are flashed in time with the heartbeat of the person holding the heart, thanks to a MAX30102 heartbeat sensor. There’s also a TP4056 charge module and a small lithium battery to provide power for the device.

Adding the heartbeat sensor really makes this project shine, forming a connection between the holder and the device itself. The tasteful craftsmanship of the brass design makes this an excellent gift, one we’re sure anyone would like to receive. We’ve seen [Jiří Praus] make the most of this artform before too, with projects like this stunning tulip or dead-bug Arduino. Video after the break.  Continue reading “LED Heart Beats With The Beholder” →

Charging Pad Flips For Solar Power

April 3, 2020 by 10 Comments

Charging pads are now a common, popular way to charge small devices. They have the benefit of reducing wear on connectors and being easier to use. [bcschmi6] decided to build a solar powered charging pad, which should come in handy when out and about.

The build uses a 3 W square solar panel, hooked up to an Adafruit solar charging board. This charges a pair of 18650 lithium batteries. The batteries only put out a maximum of 4.2 V, so they’re hooked up to a boost converter to get the output a little higher, up to 5.2 V. The output of the boost converter is then hooked up to a charging pad harvested from an Anker charger, and it’s all wrapped up in a tidy 3D printed frame.

We imagine the device would be great for camping. It could be left charging in the sun during the day, before being flipped over and used as a charging pad at night. It would be easy to build a bigger version for charging several phones at once, too. If you want to build your own charging coils, that’s a thing, too. And if you’ve got your own solar project cooking up as we head into summer, be sure to let us know!

Cellular Tracking Used During COVID-19 Pandemic

April 3, 2020 by 43 Comments

As most in the technology community know, nation states have a suite of powerful tools that can be used to trace and monitor mobile phones. By and large, this comes up in discussions of privacy and legislation now and then, before fading out of the public eye once more. In the face of a global pandemic, however, governments are now using these tools in the way many have long feared – for social control. Here’s what’s happening on the ground.

The Current Situation

With COVID-19 sweeping the globe, its high level of contagiousness and rate of hospitalizations has left authorities scrambling to contain the spread. Unprecedented lockdowns have been put in place in an attempt to flatten the curve of new cases to give medical systems the capacity to respond. A key part of this effort is making sure that confirmed cases respect quarantine rules, and isolate themselves to avoid spreading the disease. Rules have also been put in place in several countries where all overseas arrivals must quarantine, regardless of symptoms or status. Continue reading “Cellular Tracking Used During COVID-19 Pandemic” →

Particle Sniffer For Pollution Point Sources

April 2, 2020 by 13 Comments

When measuring air quality, particulate matter is an important metric to watch. The PM2.5 rating refers to particulate matter that has a diameter of less than 2.5 micrometers. While it’s often measured by authorities on a city-wide basis, [rabbitcreek] wanted a way to track down point sources indoors.

The tool [rabbitcreek] built is in a similar form factor to a typical infrared workshop thermometer. Inside, it packs a Honeywell HPMA115S0-TIR laser particle sensor, hooked up to an ESP32 which runs the show. The sensor chosen makes things easy, with the device already set up with a blower and inlet and outlet ports for taking accurate readings.. Results are displayed on an SSD1306 OLED screen. It’s all wrapped up in a 3D printed case with a trigger grip, and a dog nose on the front which hints at the devices true purpose.

In testing, the device proves capable of detecting point sources of atmospheric particulates like flowers and a toaster. It’s something we’re sure would prove handy to those working in HVAC and environmental assessment industries. We’ve seen other rigs for monitoring particulates before, too. Video after the break.

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A Digital Pitch Pipe Gets You In Tune

April 1, 2020 by 4 Comments

Some humans are blessed with perfect pitch, an ability that comes in handy when pursuing the musical arts. For many others though, a little help is often appreciated. A pitch pipe is a handy way to find the starting note of a performance, and [Isaac] decided to build his own in the digital realm.

The project is based on the Adafruit Circuit Playground express, which packs in all the peripherals needed right on board. The buttons are used to select the pitch required, with the LEDs used to display the selected note. Blue means flat, green means natural, and red means sharp. A 3D printed outer ring is clipped on to the board to denote the pitches for the user. To play the note, the user simply blows on the pitch pipe. The onboard MEMS microphone detects this and plays the note on the onboard speaker.

It’s a tidy little project that is a great way to get one’s feet wet with embedded programming and working with audio. We’ve seen the Circuit Express pop up before too, such as in this pizza-box DJ mixer. Video after the break.
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