Monthly Archives: August 2017

Horizontal Magnetic Levitation Experiments

via hardware – Hackaday

Levitating chairs from the Jetsons still have a few years of becoming a commercial product though they are fun to think about. One such curious inventor, [Conor Patrick], took a deep dive into the world of maglev and came up with a plan to create a clock with levitating hands. He shares the first part of his journey to horizontal levitational control.

[Conor Patrick] bought an off-the-shelf levitation product that was capable of horizontal levitation. Upon dissecting it he found a large magnet, four electromagnet coils, and a hall effect sensor. These parts collectively form a closed-loop control to hold an object at a specific distance. He soon discovered that in fact, there were just two coils energized by H-bridges. His first attempt at replicating the circuit, he employed a breadboard which worked fine for a single axis model. Unfortunately, it did not work as expected with multiple coils.

After a few iteration and experiments with the PID control loop, he was able to remove unwanted sensor feedback as well as overshoot in control current. He finally moved to a Teensy with a digital PD loop. The system works, but only marginally. [Conor Patrick] is seeking help from the control loop experts out there and that is the essence of the OSHW world. The best part of this project is that it is a journey that involves solving one problem at a time. We hope to see some unique results in the future.

We have covered Acoustic Levitation in the past and the Levitating Clock on a similar beat. We’re certain a more refined approach is on the horizon since many of us are now looking at making one to experiment with on our workbench.


Filed under: hardware, teardown

Over-engineered, Arduino-powered closet lights

via Arduino Blog

If you’re faced with a closet that doesn’t have any lights inside, you simply could go and find puck lights at most retail stores. But, if you’re Dillon Nichols, you buy a set of lights, and enhance them with a wired power supply and automatic Arduino control.

To accomplish this, Nichols decoded the infrared remote control signal to his puck lights using an Arduino Leonardo, then set up things up to sense the door’s opening via a physical switch and signal the lights accordingly. Now when he opens the closet, lights automatically shine down and fade out when it’s closed.

Nichols also added a timer, so that they turn off after 10 minutes automatically if he forgets to shut the door. Looking for an over-engineered, non-permanent solution for yourself? You can check out his detailed write-up here and find the code for his build on GitHub.

Project Aslan is a 3D-printed robotic sign language translator

via Arduino Blog

With the lack of people capable of turning written or spoken words into sign language in Belgium, University of Antwerp masters students Guy Fierens, Stijn Huys, and Jasper Slaets have decided to do something about it. They built a robot known as Aslan, or Antwerp’s Sign Language Actuating Node, that can translate text into finger-spelled letters and numbers.

Project Aslan–now in the form of a single robotic arm and hand–is made from 25 3D-printed parts and uses an Arduino Due, 16 servos, and three motor controllers. Because of its 3D-printed nature and the availability of other components used, the low-cost design will be able to be produced locally.

The robot works by receiving information from a local network, and checking for updated sign languages from all over the world. Users connected to the network can send messages, which then activate the hand, elbow, and finger joints to process the messages.

Although it is one arm now, work will continue with future masters students, focusing on expanding to a two-arm design, implementing a face, and even integrating a webcam into the system. For more info, you can visit the project’s website here as well as its write-up on 3D Hubs.

Hackaday Prize Entry: MappyDot, a Micro Smart LiDAR Sensor

via hardware – Hackaday

[Blecky]’s entry to the Hackaday Prize is MappyDot, a tiny board less than a square inch in size that holds a VL53L0X time-of-flight distance sensor and can measure distances of up to 2 meters.

MappyDot is more than just a breakout board; the ATMega328PB microcontroller on each PCB provides filtering, an easy to use  I2C interface, and automatically handles up to 112 boards connected in a bus. The idea is that one or a few MappyDots can be used by themselves, but managing a large number is just as easy. By dotting a device with multiple MappyDots pointing in different directions, a device could combine the readings to gain a LiDAR-like understanding of its physical environment. Its big numbers of MappyDots [Blecky] is going for, too: he just received a few panels of bare PCBs that he’ll soon be laboriously populating. The good news is, there aren’t that many components on each board.

It’s great to see open sourced projects and tools in which it is clear some thought has gone into making them flexible and easy to use. This means they are easier to incorporate into other work and helps make them a great contestant for the Hackaday Prize.


Filed under: hardware, The Hackaday Prize

Microcontroller action potential generator

via Dangerous Prototypes

pics-ap-generator-running-600

Scott Harden writes:

Here I demonstrate how to use a single microcontroller pin to generate action-potential-like waveforms. The output is similar my fully analog action potential generator circuit, but the waveform here is created in an entirely different way. A microcontroller is at the core of this project and determines when to fire action potentials. Taking advantage of the pseudo-random number generator (rand() in AVR-GCC’s stdlib.h), I am able to easily produce unevenly-spaced action potentials which more accurately reflect those observed in nature. This circuit has a potentiometer to adjust the action potential frequency (probability) and another to adjust the amount of overshoot (afterhyperpolarization, AHP). I created this project because I wanted to practice designing various types of action potential measurement circuits, so creating an action potential generating circuit was an obvious perquisite.

See the full post at SWHarden.com.

Check out the video after the break.

Hunting for life on Mars assisted by high-altitude balloons

via Raspberry Pi

Will bacteria-laden high-altitude balloons help us find life on Mars? Today’s eclipse should bring us closer to an answer.

NASA Bacteria Balloons Raspberry Pi HAB Life on Mars

image c/o NASA / Ames Research Center / Tristan Caro

The Eclipse Ballooning Project

Having learned of the Eclipse Ballooning Project set to take place today across the USA, a team at NASA couldn’t miss the opportunity to harness the high-flying project for their own experiments.

NASA Bacteria Balloons Raspberry Pi HAB Life on Mars

The Eclipse Ballooning Project invited students across the USA to aid in the launch of 50+ high-altitude balloons during today’s eclipse. Each balloon is equipped with its own Raspberry Pi and camera for data collection and live video-streaming.

High-altitude ballooning, or HAB as it’s often referred to, has become a popular activity within the Raspberry Pi community. The lightweight nature of the device allows for high ascent, and its Camera Module enables instant visual content collection.

Life on Mars

image c/o Montana State University

The Eclipse Ballooning Project team, headed by Angela Des Jardins of Montana State University, was contacted by Jim Green, Director of Planetary Science at NASA, who hoped to piggyback on the project to run tests on bacteria in the Mars-like conditions the balloons would encounter near space.

Into the stratosphere

At around -35 degrees Fahrenheit, with thinner air and harsher ultraviolet radiation, the conditions in the upper part of the earth’s stratosphere are comparable to those on the surface of Mars. And during the eclipse, the moon will block some UV rays, making the environment in our stratosphere even more similar to the martian oneideal for NASA’s experiment.

So the students taking part in the Eclipse Ballooning Project could help the scientists out, NASA sent them some small metal tags.

NASA Bacteria Balloons Raspberry Pi HAB Life on Mars

These tags contain samples of a kind of bacterium known as Paenibacillus xerothermodurans. Upon their return to ground, the bacteria will be tested to see whether and how the high-altitude conditions affected them.

Life on Mars

Paenibacillus xerothermodurans is one of the most resilient bacterial species we know. The team at NASA wants to discover how the bacteria react to their flight in order to learn more about whether life on Mars could possibly exist. If the low temperature, UV rays, and air conditions cause the bacteria to mutate or indeed die, we can be pretty sure that the existence of living organisms on the surface of Mars is very unlikely.

Life on Mars

What happens to the bacteria on the spacecraft and rovers we send to space? This experiment should provide some answers.

The eclipse

If you’re in the US, you might have a chance to witness the full solar eclipse today. And if you’re planning to watch, please make sure to take all precautionary measures. In a nutshell, don’t look directly at the sun. Not today, not ever.

If you’re in the UK, you can observe a partial eclipse, if the clouds decide to vanish. And again, take note of safety measures so you don’t damage your eyes.

Life on Mars

You can also watch a live-stream of the eclipse via the NASA website.

If you’ve created an eclipse-viewing Raspberry Pi project, make sure to share it with us. And while we’re talking about eclipses and balloons, check here for our coverage of the 2015 balloon launches coinciding with the UK’s partial eclipse.

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