This Machine Teaches Sign Language

Sign language can like any language be difficult to learn if you’re not immersed in it, or at least learning from someone who is fluent. It’s not easy to know when you’re making minor mistakes or missing nuances. It’s a medium with its own unique issues when learning, so if you want to learn and don’t have access to someone who knows the language you might want to reach for the next best thing: a machine that can teach you.

This project comes from three of [Bruce Land]’s senior electrical and computer engineering students, [Alicia], [Raul], and [Kerry], as part of their final design class at Cornell University. Someone who wishes to learn the sign language alphabet slips on a glove outfitted with position sensors for each finger. A computer inside the device shows each letter’s proper sign on a screen, and then checks the sensors from the glove to ensure that the hand is in the proper position. Two letters include making a gesture as well, and the device is able to track this by use of a gyroscope and compass to ensure that the letter has been properly signed. It appears to only cover the alphabet and not a wider vocabulary, but as a proof of concept it is very effective.

The students show that it is entirely possible to learn the alphabet reliably using the machine as a teaching tool. This type of technology could be useful for other applications as well, such as gesture recognition for a human interface device. If you want to see more of these interesting and well-referenced senior design builds we’ve featured quite a few, from polygraph machines to a sonar system for a bicycle.

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RFID Doing More than ID

RFID is a workhorse in industrial, commercial, and consumer markets. Passive tags, like work badges and key fobs, need a base station but not the tags. Sensors are a big market and putting sensors in places that are hard to reach, hostile, or mobile is a costly proposition. That price could drop, and the sensors could be more approachable with help from MIT’s Auto-ID Lab who are experimenting with sensor feedback to RFID devices.

Let’s pretend you want to measure the temperature inside a vat of pressurized acid. You’d rather not drill a hole in it to insert a thermometer, but a temperature sensor sealed in Pyrex that wirelessly transmits the data and never runs out of power is a permanent and cheap solution. The researchers have their sights set on glucose sensing and that news come shortly after Alphabet gave up their RFID quest to measure glucose through contact lenses. Shown the top of this article is a prototype for a Battery Assisted Passive (BAP) RFID sensor that uses commodity glucose testing strips, sending data when the electrochemical reaction occurs. It uses six of these cells in parallel to achieve a high enough peak current to trigger the transmission. But the paper (10.1109/RFID.2018.8376201 behind paywall) mentions a few strategies to improve upon this. However, it does prove the concept that the current spike from the test strips determines the time the tag is active and that can be correlated to the blood glucose detected.

How many of our own projects would instantly upgrade with the addition of a few sensors that were previously unobtainable on a hacker budget? Would beer be brewed more effectively with more monitoring? How many wearables would be feasible with battery-free attachments? The sky is the figurative limit.

Thank you, [QES] for the tip [via TechXplore]

Organic Ornithopter Sensor Drone

Bees. The punchline to the title is bees carrying sensors like little baby bee backpacks. We would run out of fingers counting the robots which emulate naturally evolved creatures, but we believe there is a lot of merit to pirating natural designs, but researchers at the University of Washington cut out the middle-man and put their sensors right on living creatures. They measured how much a bee could lift, approximately 105 milligrams, then built a sensor array lighter than that. Naturally, batteries are holding back the design, and the rechargeable lithium-ion is more than half of the weight.

When you swap out brushless motors for organics, you gain and lose some things. You lose the real-time control, but you increase the runtime. You lose the noise, but you also lose the speed. You increase the range, but you probably wind up visiting the same field over and over. If your goal is to monitor the conditions of flowering crops, you may be ready to buy and install, but for the rest of us, dogs are great for carrying electronics. Oh yes. Cats are not so keen. Oh no.

Teardown: D50761 Aircraft Quick Access Recorder

Everyone’s heard of the “black box”. Officially known as the Flight Data Recorder (FDR), it’s a mandatory piece of equipment on commercial aircraft. The FDR is instrumental in investigating incidents or crashes, and is specifically designed to survive should the aircraft be destroyed. The search for the so-called “black box” often dominates the news cycle after the loss of a commercial aircraft; as finding it will almost certainly be necessary to determine the true cause of the accident. What you probably haven’t heard of is a Quick Access Recorder (QAR).

While it’s the best known, the FDR is not the only type of recording device used in aviation. The QAR could be thought of as the non-emergency alternative to the FDR. While retrieving data from the FDR usually means the worst has happened, the QAR is specifically designed to facilitate easy and regular access to flight data for research and maintenance purposes. Its data is stored on removable media and since the QAR is not expected to survive the loss of the aircraft it isn’t physically hardened. In fact, modern aircraft often use consumer-grade technology such as Compact Flash cards and USB flash drives as storage media in their QAR.

Through the wonders of eBay, I recently acquired a vintage Penny & Giles D50761 Quick Access Recorder. This was pulled out of an aircraft which had been in service with the now defunct airline, Air Toulouse International. Let’s crack open this relatively obscure piece of equipment and see just what goes into the hardware that airlines trust to help ensure their multi-million dollar aircraft are operating in peak condition.

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SENSEation Shows The Importance of Good Physical Design

Sensor network projects often focus primarily on electronic design elements, such as architecture and wireless transmission methods for sensors and gateways. Equally important, however, are physical and practical design elements such as installation, usability, and maintainability. The SENSEation project by [Mario Frei] is a sensor network intended for use indoors in a variety of buildings, and it showcases the deep importance of physical design elements in order to create hardware that is easy to install, easy to maintain, and effective. The project logs have an excellent overview of past versions and an analysis of what worked well, and where they fell short.

One example is the power supply for the sensor nodes. Past designs used wall adapters to provide constant and reliable power, but there are practical considerations around doing so. Not only do power adapters mean each sensor requires some amount of cable management, but one never really knows what one will find when installing a node somewhere in a building; a power outlet may not be nearby, or it may not have any unoccupied sockets. [Mario] found that installations could take up to 45 minutes per node as a result of these issues. The solution was to move to battery power for the sensor nodes. With careful power management, a node can operate for almost a year before needing a recharge, and removing any cable management or power adapter meant that installation time dropped to an average of only seven minutes.

That’s just one example of the practical issues discovered in the deployment of a sensor network in a real-world situation, and the positive impact of some thoughtful design changes in response. The GitHub repository for SENSEation has all the details needed to reproduce the modular design, so check it out.

‘SHE BON’ is an Artful, Wearable, Sensual, Sensing Platform

SHE BON (that’s the French bon, or “good”) is an ambitious project by [Sarah Petkus] that consists of a series of wearable electronic and mechanical elements which all come together as a system for a single purpose: to sense and indicate female arousal. As a proponent of increased discussion and openness around the topic of sexuality, [Sarah]’s goal is to take something hidden and turn it into something obvious and overt, while giving it a certain artful flair in the process.

The core of the system is a wearable backpack in the shape of a heart, from which all other sensors and feedback elements are connected. A lot of thought has gone into the design of the system, ensuring that the different modules have an artistic angle to their feedback while also being comfortable to actually wear, and [Sarah] seems to have a knack for slick design. Some of the elements are complete and some are still in progress, but the system is well documented with a clear vision for the whole. It’s an unusual and fascinating project, and was one of the finalists selected in the Human Computer Interface portion of the 2018 Hackaday Prize. Speaking of which, the Musical Instrument Challenge is underway, so be sure check it out!

Create Your Own ESP8266 Shields

The ESP8266 has become incredibly popular in a relatively short time, and it’s no wonder. Cheap as dirt, impressively powerful, Arduino-compatible, and best of all, includes Wi-Fi right out of the box. But for all its capability and popularity, it’s still lagging behind the Arduino in at least one respect. Namely, the vast collection of add-on “Shields” which plug into the Arduino to add everything from breadboards to GPS receivers.

Until such time as the free market decides to pick up the pace and start making standardized shields for the various ESP8266 development boards, it looks as if hackers are going to have to pick up the slack. [Rui Santos] has put together a very detailed step-by-step guide on the creation of a simple shield for the popular Wemos D1 Mini board, which should give you plenty of inspiration for spinning up your own custom add-on modules.

Presented as a written tutorial as well as a two part video, this guide covers everything from developing and testing your circuit on a breadboard to designing your PCB in KiCad and sending it off for fabrication. The end result is a professional looking PCB that matches the footprint of the stock D1 Mini and adds a DS18B20 temperature sensor, PIR motion detector, photoresistor, and some screw down terminals.

[Rui] goes on to show how you can utilize the new sensors shield via a web interface hosted on the ESP8266, and even wraps the whole thing up in a 3D printed enclosure. All worthwhile skills to check out if you’re looking to produce more cohesive finished products.

If you’re looking for a similar project for the ESP32, [Rui] has you covered there as well. You may also be interested in the series of ESP8266 tutorials we recently highlighted.

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