Gesture Sensing With A Temperature Sensor

January 4, 2019 by Inderpreet Singh 8 Comments

Good science fiction has sound scientific fact behind it and when Tony Stark first made his debut on the big screen with design tools that worked at the wave of a hand, makers and hackers were not far behind with DIY solutions. Over the years the ideas have become much more polished, as we can see with this Gesture Recognition with PIR sensors project.

The project uses the TPA81 8-pixel thermopile array which detects the change in heat levels from 8 adjacent points. An Arduino reads these temperature points over I2C and then a simple thresholding function is used to detect the movement of the fingers. These movements are then used to do a number of things including turn the volume up or down as shown in the image alongside.

The brilliant part is that the TPA81 8-Pixel sensor has been around for a number of years. It is a bit expensive though it has the ability to detect small thermal variations such as candle flames at up to 2 Meters. More recent parts such as the Panasonic AMG8834 that contain a grid of 8×8 such sensors are much more capable for your hacking/making pleasure, but come with an increased price tag.

This technique is not just limited to gestures, and can be used in Heat-Seeking Robots that can very well be trained to follow the cat around just to annoy it.

A Smartwatch You Can Easily Build Yourself

January 1, 2019 by Lewin Day 16 Comments

The concept of a smartwatch was thrown around for a long time before the technology truly came to fruition. Through the pursuit of miniaturisation, modern smartwatches are sleek, compact, and remarkably capable for their size. Companies such as Apple and Samsung throw serious money into research and development, but that doesn’t mean you can’t create something of your own. [Electronoobs] has done just that, with this Arduino-based smartwatch build.

The brain of the watch is that hacker staple, the venerable ATmega328, most well known for its use in the Arduino Uno and Nano platforms. An FTDI module is used for USB communication, making programming the board a snap. Bluetooth communication is handled by another pre-built module, and a smartphone app called Notiduino handles passing notifications over to the watch.

This is a build that doesn’t do anything crazy or difficult to understand, but simply combines useful parts in a very neat and tidy way. The watch is impressively thin and compact for a DIY build, and has a host of useful functions without going overboard.

We’ve seen other DIY builds in this space, too – such as this ESP8266-based smartwatch. Video after the break.

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Voice Controlled Camera For Journalist In Need

December 29, 2018 by Tom Nardi 13 Comments

Before going into the journalism program at Centennial College in Toronto, [Carolyn Pioro] was a trapeze performer. Unfortunately a mishap in 2005 ended her career as an aerialist when she severed her spinal cord, leaving her paralyzed from the shoulders down. There’s plenty of options in the realm of speech-to-text technology which enables her to write on the computer, but when she tried to find a commercial offering which would let her point and shoot a DSLR camera with her voice, she came up empty.

[Taras Slawnych] heard about [Carolyn’s] need for special camera equipment and figured he had the experience to do something about it. With an Arduino and a couple of servos to drive the pan-tilt mechanism, he came up with a small device which Carolyn can now use to control a Canon camera mounted to an arm on her wheelchair. There’s still some room for improvement (notably, the focus can’t be controlled via voice currently), but even in this early form the gadget has caught the attention of Canon’s Canadian division.

With a lavalier microphone on the operator’s shirt, simple voice commands like “right” and “left” are picked up and interpreted by the Arduino inside the device’s 3D printed case. The Arduino then moves the appropriate servo motor a set number of degrees. This doesn’t allow for particularly fine-tuned positioning, but when combined with movements of the wheelchair itself, gives the user an acceptable level of control. [Taras] says the whole setup is powered off of the electric wheelchair’s 24 VDC batteries, with a step-down converter to get it to a safe voltage for the Arduino and servos.

As we’ve seen over the years, assistive technology is one of those areas where hackers seem to have a knack for making serious contribution’s to the lives of others (and occasionally even themselves). The highly personalized nature of many physical disabilities, with specific issues and needs often unique to the individual, can make it difficult to develop devices like this commercially. But as long as hackers are willing to donate their time and knowledge to creating bespoke assistive hardware, there’s still hope.

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Machine Learning On Tiny Platforms Like Raspberry Pi And Arduino

December 25, 2018 by Bryan Cockfield 25 Comments

Machine learning is starting to come online in all kinds of arenas lately, and the trend is likely to continue for the forseeable future. What was once only available for operators of supercomputers has found use among anyone with a reasonably powerful desktop computer. The downsizing isn’t stopping there, though, as Microsoft is pushing development of machine learning for embedded systems now.

The Embedded Learning Library (ELL) is a set of tools for allowing Arduinos, Raspberry Pis, and the like to take advantage of machine learning algorithms despite their small size and reduced capability. Microsoft intended this library to be useful for anyone, and has examples available for things like computer vision, audio keyword recognition, and a small handful of other implementations. The library should be expandable to any application where machine learning would be beneficial for a small embedded system, though, so it’s not limited to these example applications.

There is one small speed bump to running a machine learning algorithm on your Raspberry Pi, though. The high processor load tends to cause small SoCs to overheat. But adding a heatsink and fan is something we’ve certainly seen before. Don’t let your lack of a supercomputer keep you from exploring machine learning if you see a benefit to it, and if you need more power than just one Raspberry Pi you can always build a cluster to get your task done just a little bit faster, too.

Thanks to [Baldpower] for the tip!

Arduino And Pi Share Boardspace

December 24, 2018 by Brian McEvoy 18 Comments

A Raspberry Pi Zero (W) and Arduino are very different animals, the prior has processing power and connectivity while the latter has some analog to digital converters (ADCs) and nearly real-time reactions. You can connect them to one another with a USB cable and for many projects that will happily wed the two. Beyond that, we can interface this odd couple entirely through serial, SPI, I2C, and logic-level signaling. How? Through a device by [cburgess] that is being called an Arduino shield that supports a Pi0 (W). Maybe it is a cape which interfaces with Arduino. The distinction may be moot since each board has a familiar footprint and both of them are found here.

Depending on how they are set up and programmed, one can take control over the other, or they could happily do their own thing and just exchange a little information. This board is like a marriage counselor between a Raspberry Pi and an Arduino. It provides the level-shifting so they don’t blow each other up and libraries so they can speak nicely to one another. If you want to dig a bit deeper into this one, design files and code examples are on available.

Perhaps we’ll report on this board at the heart of a pinball machine retrofit, a vintage vending machine restoration, or maybe a working prop replica from the retro bar in Back to the Future II.

Manual 3D Digitizer Works A Bit Like 3-Dimensional Measuring Tape

December 21, 2018 by Donald Papp 26 Comments

Digitizing an object usually means firing up a CAD program and keeping the calipers handy, or using a 3D scanner to create a point cloud representing an object’s surfaces. [Dzl] took an entirely different approach with his DIY manual 3D digitizer, a laser-cut and 3D printed assembly that uses rotary encoders to create a turntable with an articulated “probe arm” attached.

Each joint of the arm is also an encoder, and by reading the encoder values and applying a bit of trigonometry, the relative position of the arm’s tip can be known at all times. Manually moving the tip of the arm from point to point on an object therefore creates measurements of that object. [Dzl] successfully created a prototype to test the idea, and the project files are available on GitHub.

We remember the earlier version of this project and it’s great to see how it’s been updated with improvements like the addition of a turntable with an encoder. DIY 3D digitizing takes all kinds of approaches, and one example was this unit that used four Raspberry Pi Zeros and four cameras to generate high quality 3D scans.

A Star-Trek-Inspired Robot With Raspberry Pi And AI

December 21, 2018 by Al Williams 1 Comment

When [314Reactor] got a robot car kit, he knew he wanted to add some extra things to it. At about the same time he was watching a Star Trek episode that featured exocomps — robots that worked in dangerous areas. He decided to use those fictional devices to inspire his modifications to the car kit. Granted, the fictional robots were intelligent and had a replicator. So you know he won’t make an actual working replica. But then again, the ones on the TV show didn’t have all that either.

A Raspberry Pi runs Tensorflow using the standard camera. This lets it identify objects of interest (assuming it gets them right) and sends the image back to the operator along with some identifying information. The kit already had an Arduino onboard and the new robot talks to it via a serial port. You can see a video about the project, below.

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