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.

Continue reading “This Machine Teaches Sign Language”

Super Simple Sensor Makes DSLR Camera Motion Sensitive

Do you have a need to photographically document the doings of warm-blooded animals? If so, a game camera from the nearest hunting supplier is probably your best bet. But if you don’t need the value-added features such as a weather-resistant housing that can be chained to a tree, this DIY motion trigger for a DSLR is a quick and easy build, and probably loads more fun.

The BOM on [Jeremy S Cook]’s build is extremely short – just a PIR sensor and an optoisolator, with a battery, a plug for the camera’s remote jack, and a 3D-printed bracket. The PIR sensor is housed in a shroud to limit its wide field of view; [Jeremy] added a second shroud when an even narrower field is needed. No microcontroller is needed because all it does is trigger the camera when motion is sensed, but one could be added to support more complicated use cases, like an intervalometer or constraining the motion sensing to certain times of the day. The video below shows the build and some quick tests.

Speaking of intervalometers, we’ve seen quite a few of those over the years. From the tiny to the tinier to the electromechanical, people seem to have a thing for taking snapshots at regular intervals.

Continue reading “Super Simple Sensor Makes DSLR Camera Motion Sensitive”

Green Hacking: Overclocking Photosynthesis

We think of hacking as bending technology to our will. But some systems are biological,  and we’re also starting to see more hacking in that area. This should excite science fiction fans used to with reading about cultures that work with biological tech, so maybe we’ll get there in the real world too.  Hacking farm crops and animals goes back centuries, although we are definitely getting better at it. A case in point: scientists have found a way to make photosynthesis better and this should lead to more productive crops.

We learned in school that plants use carbon dioxide and sunlight to create energy and produce oxygen. But no one explained to us exactly how that happened. It seems a protein called rubisco is what causes this to happen, but unfortunately it isn’t very picky. In addition to converting carbon (from carbon dioxide) into sugar, it also converts oxygen into toxic compounds called ROS (reactive oxygen species) that most plants then have to spend energy eliminating. Scientists estimate that if you could recover the calories lost in this process, you could feed an additional 200 million people worldwide at current production levels.

Continue reading “Green Hacking: Overclocking Photosynthesis”

Sugar As A Bed Adhesive For 3D Printing

3D printers, like most CNC machines, reward careful thought and trial and error. It’s important to use the correct machine settings and to prepare the build environment properly in order to get good results. Fused Filament Fabrication printers rely on melting plastic just so in the production of parts, and have their own set of variables to play with. [Mysimplefix] has been exploring various solutions to bed adhesion and found something that seems to work perfectly, right in the pantry.

That’s right, this solution to the problem of bed adhesion is more commonly stirred into your coffee every morning – it’s sugar. [Mysimplefix] shares their preferred process, consisting of first mixing up a sugar/water solution in the microwave, before applying it to the bed with a paper towel and allowing the water to evaporate off.

Several test prints are then shown, with major overhangs, to show the adhesive capabilities of the sugar. The results are impressive, with parts sticking well while the bed is hot, while being easy to remove once cool. The video deals with PLA, but we’d be interested to see the performance with other materials as well.

It’s a tidy solution, and we’d love to know your thoughts and experiences in the comments. We’ve had a good long think about adhesives ourselves, too.

Continue reading “Sugar As A Bed Adhesive For 3D Printing”

Tech Tattoos Trace Two Dimensions

Flexible circuit boards bend as you might expect from a playing card, while skin stretches more like knit fabric. The rules for making circuit boards and temporary tattoos therefore need to be different. Not just temporary tattoos, there are also circuits that reside on the skin so no unregulated heat traces, please. In addition to flexing and stretching, these tattoos can be applied to uneven surfaces and remain intact. Circuits could be added to the outside of projects or use the structure as the board to reduce weight and size. Both are possible with the research from Carnegie Mellon’s Soft Machines Lab and the Institute of Systems and Robotics at the University of Coimbra.

These circuits are an improvement over the existing method which relies on cropping away metal foil with a magnifying glass, tweezers and a steady hand. Instead, silver particles are printed with an inkjet printer before the traces are coated in eutectic gallium indium which is liquid metal at room temperature. If we were to oversimplify, we might describe it as similar to a non-toxic equivalent of mercury that we have also seen used in DIY OLEDs. This is a development likely to be interesting in a range of fields from medicine to cosplay.

Continue reading “Tech Tattoos Trace Two Dimensions”

Build A Home Automation Hub For $20

With so many WiFi home automation devices on the market, you might want to take advantage of these low cost products without having to send your data to third-party servers. This can be accomplished by running your own home automation hub on your home network.

If you don’t want to use a full computer for this purpose, [Albert] has you covered. He recently wrote a guide on running Domoticz on the $20 GL-MT300Nv2 pocket router.

The setup is rather simple: just perform a firmware update on your router using the provided image and a full home automation stack is installed. Domoticz provides a web interface for configuring your devices, setting up rules, and viewing sensor data.

The pocket router is also supported by OpenWrt and provides a USB host port, making it a low-cost option for any WiFi hack you might have in mind. We’ve seen quite a few OpenWrt based hacks over the years.

One More Weekend To Sculpt Your Circuits!

Drop what you’re doing and get thee to thy workshop. This is the last weekend of the Hackaday Circuit Sculpture Contest, the perfect chance for you to exercise the creative hacker within by building something artistic using stuff you already have on hand.

The concept is simple: build a sculpture where the electronic circuit is the sculpture. Wire the components up in a way that shows off that wiring, and uses it as the structure of the art piece. Seven top finishers will win prizes, but really we want to see everyone give this a try because the results are so cool! Need proof? Check out all the entries, then ooh and ah over a few we’ve picked out below. You have until this Tuesday at noon Pacific time to get in the game.

These are just three awesome examples of the different styles we’ve seen so far in the contest. Who needs a circuit board for a retro computer? Most people… but apparently not [Matseng] as this Z80 computer is freformed yet still interactive.

Really there can’t be many things more horrifying than the thought of spider robots, but somehow [Sunny] has taken away all of our fears. The 555 spider project takes “dead bug” to a whole new level. We love the angles in the legs, and the four SMD LEDs as spider eyes really finish the look of the tiny beast.

Finally, the 3D design of [Emily Valesco’s] RGB Atari Punk Console is spectacular. It’s a build that sounds great, and looks as though it will hold up to regular use. But visually, this earns a place on your desk long after the punky appeal wears off. We also like it that she added a color-coded photograph to match up the structure to the schematic, very cool!

What are you waiting for, whether it’s a mess of wires or a carefully structured electron ballet, we want to see your Circuit Sculpture!