Lighting The Way For The Visually Impaired

September 28, 2019 by Sharon Lin 8 Comments

The latest creation from Bengali roboticist [nabilphysics] might sound familiar. His laser-augmented glove gives users the ability to detect objects horizontally in front of them, much like a cane or pole is used by the visually impaired to navigate through a physical space.

As a stand in for the physical cane, he uses the VL53L0X time-of-flight (TOF) sensor which detects the time taken for a laser source to bounce back to the sensor. Theses are much more accurate than IR distance sensors and have a much finer focus than ultrasonic sensors for excellent directionality.

While the sensors can succumb to interferences from background light or other time-of-flight sensors, the main advantages are speed of calculation (it relies on a single shot to compute the distances within a scene) and an efficient distance algorithm that simplifies the measurement of distance data. In contrast to stereo vision, which requires complex correlation algorithms, the process for extracting information for a time-of-flight sensor is entirely direct, requiring a small amount of processing power.

The glove delivers haptic feedback to the user to determine if an object is in their way. The feedback is controlled through an Arduino Pro Mini, powered remotely by a LiPo battery. The code is uploaded to the Arduino from an FTDI adapter, and works by taking continuous readings from the time-of-flight sensor and determining if the object in front is within 450 millimeters of the glove, at which point it triggers the vibration motor to alert the user of the object’s presence.

Since the glove used for the project is a bicycle glove, the form factor is straightforward — the Arduino, motor, battery, and switch are all located inside a plastic box on the top of the glove, while the time-of-flight sensor sticks out to make continuous measurements when the glove is switched on.

In general, the setup is fairly simple, but the idea of using a time-of-flight sensor rather than an IR or sonar sensor is interesting. In the broader usage of sensors, LIDARs are already the de facto sensor used for autonomous vehicles and robotic components that rely on distance sensing. This three-dimensional data wouldn’t be much use here and this sensor works without mechanical moving parts since it doesn’t rely on the point-by-point scan from a laser beam that LIDAR systems use.

Barcode Guitar Plays More Than Beep-Bop

September 26, 2019 by Kristina Panos 5 Comments

One of our favorite things about the rise of hobbyist development ecosystems such as the Arduino is that it’s now possible to make a MIDI controller out of almost anything, as long as you have the the shields and the dedication. We’re glad that [James Bruton] takes the occasional break from making robots to detour into instrument making, because his latest creation turns it up to 11.

This awesome guitar uses a barcode scanner to play notes, and various arcade controls to manipulate those notes. The barcodes themselves scan as ASCII values, and their equivalent integers are sent to an external MIDI device. This futuristic axe is built on an Arduino Mega, with a USB shield for the barcode scanner, and a MIDI shield on top that [James] connects to various synths in the video after the break.

In between shooting barcodes, the right hand also controls octave shifting and changing MIDI channels with the joystick, and doing pitch-bends with the rotary encoder. The array of arcade buttons on the bottom neck let him switch between single player for monophonic synths, and multiplayer for polys. The other three buttons are press-and-scan programmable single-note sounders that assist in chord-making and noodling.

We particularly dig the construction, which is a combination of 20/20 and 3D printed boxes. [James] found some angled PVC to serve as fretboards for the four necks, and a nice backgrounds for bar codes.The only thing we would change is the native beep of the barcode scanner — either silence it forever or make it mutable, because it doesn’t jive with every note. It might be nice to get the gun to scan continuously so [James] doesn’t get trigger finger. Or better yet, build the scanner into a glove.

Want to do something more useful with that barcode scanner in your parts bin? Use it to manage your household inventory. But first, reacquaint yourself with the history of the humble barcode as presented by [Adam Fabio].

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Review: OSEPP STEM Kit 1, A Beginner’s All-in-One Board Found In The Discount Aisle

September 26, 2019 by Al Williams 11 Comments

As the name implies, the OSEP STEM board is an embedded project board primarily aimed at education. You use jumper wires to connect components and a visual block coding language to make it go.

I have fond memories of kits from companies like Radio Shack that had dozens of parts on a board, with spring terminals to connect them with jumper wires. Advertised with clickbait titles like “200 in 1”, you’d get a book showing how to wire the parts to make a radio, or an alarm, or a light blinker, or whatever.

The STEM Kit 1 is sort of a modern arduino-powered version of these kits. The board hosts a stand-alone Arduino UNO clone (included with the kit) and also has a host of things you might want to hook to it. Things like the speakers and stepper motors have drivers on board so you can easily drive them from the arduino. You get a bunch of jumper wires to make the connections, too. Most things that need to be connected to something permanently (like ground) are prewired on the PCB. The other connections use a single pin. You can see this arrangement with the three rotary pots which have a single pin next to the label (“POT1”, etc.).

I’m a sucker for a sale, so when I saw a local store had OSEPP’s STEM board for about $30, I had to pick one up. The suggested price for these boards is $150, but most of the time I see them listed for about $100. At the deeply discounted price I couldn’t resist checking it out.

So does an embedded many-in-one project kit like this one live up to that legacy? I spent some time with the board. Bottom line, if you can find a deal on the price I think it’s worth it. At full price, perhaps not. Join me after the break as I walk through what the OSEPP has to offer.

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Tinker Pilot Project Cranks Cockpit Immersion To 11

September 25, 2019 by Donald Papp 1 Comment

One of the more interesting ideas being experimented with in VR is 1:1 mapping of virtual and real-world objects, so that virtual representations can have physically interaction in a normal way. Tinker Pilot is a VR spaceship simulator project by [LLUÍS and JAVI] that takes this idea and runs with it, aiming for the ability to map a cockpit’s joysticks, switches, and other hardware to real-world representations. What does that mean? It means a virtual cockpit with flight sticks, levers, and switches that have working physical versions that actually exist exactly where they appear to be.

A few things about the project design caught our eye. One is the serial communications protocol intended to interface easily with microcontrollers, allowing for feedback between the program and any custom peripherals. (By the way, this is the same approach Kerbal Space Program took with KSPSerialIO, which enables custom mission control hardware at whatever level of complexity a user may wish to implement.)

The possibilities are demonstrated starting around 1:09 in the teaser trailer (embedded below) in which a custom controller is drawn up in CAD, then 3D-printed and attached to an Arduino, and finally the 3D model is imported into the cockpit as a 1:1 representation of the actual working unit, with visual positional feedback.

Unlike this chair experiment we saw which attached a Vive Tracker to a chair, there is no indication of needing positional trackers on individual controls in Tinker Pilot. In a cockpit layout, controls can be reasonably expected to remain in fixed positions relative to the cockpit, meaning that they can be set up as 1:1 representations of a physical layout and otherwise left alone. The kind of experimentation that is available today even to individual developers or small teams is remarkable, and it’s fascinating to see the ideas being given some experimentation.

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Smart Map Puts On A Show Thanks To Arduinos And DMX

September 24, 2019 by Lewin Day 9 Comments

Maps can be a great way to get a message across when the data you’re dealing with affects people on a country’s population scale. [jwolin] works for a non-profit organization, and wanted a way to help people visualize the extent of their operations and the causes they deal with. To do that, he created a nifty smart map wall display.

The display consists of a world map cut out of MDF, and affixed to a brick wall. There’s also two 4K Samsung monitors included as part of the system. The top monitor displays headings to contextualise the data, while the bottom screen displays related full motion video. A series of DMX-controlled lights then shine on the world map in various configurations to highlight the area of interest.

The system requires delicate coordination to operate cleanly and smoothly. There are three Windows 10 computers in the system, one for each monitor and another for the world map. An AutoHotkey script runs on the first computer, which selects a random video, and then sends out a command over serial to an Arduino Nano. This Arduino nano then communicates with two others, which make sure the second screen and DMX lighting rig then play the correct matching sequences, in time with the main video. Special care is taken to ensure that transitions are as smooth as possible, with no gaps in between each sequence. The entire installation is simple to update just by uploading additional content to a Dropbox folder, a crucial touch to future proof the project.

It’s an eye-catching system that helps educate visitors as to the mission of the organisation. We’ve seen other innovative world-map displays, like this clock that highlights night and day around the world. Video after the break.

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Getting The Heat On With A Thermal Camera

September 22, 2019 by Sharon Lin 13 Comments

Need a quick way to tell your temperature before work tomorrow? Student maker [The Marpe] recently fashioned a sleek home-use thermal camera that even looks like a point and shoot. It works as an Android hardware add-on by integrating the readings from a MLX90640 far-infrared (FIR) thermal sensor with a STM32F042F6Px microcontroller. All this connects to an Android application via USB (MicroUSB or Type C).

On the app, users are able to view, take photos, and display the resulting thermal images from the open thermal camera. The code for the open Android application is also available on his GitHub.

The FIR sensors contain a small array of IR pixels, integrated to measure the ambient temperature of the internal chip, and supply sensor to measure the VDD. Each pixel on the sensor array responds to the IR energy focused on it to produce an electronic signal, which is processed by the camera processor to create a map of the apparent temperature of the object. The outputs of the sensors and VDD are stored in an internal RAM and are accessible through 3.3V I2C. They’re not only low-cost and fairly high resolution, but also available by order on Digi-Key.

The microcontroller is based on the STM32 platform, with 32-bit performance, low-power operation (at 2V to 3.6V and 48 MHz) and is fairly low-cost. The custom-designed PCBs are fitted inside a 3D-printed casing with M2.5 inserts to ease assembly. [The Marpe] used an Esra soldering iron to create a heat insert tool for easier assembly and more consistent results with the heat inserts, which made for a nicer overall finish.

The project has since been presented at the Ljublana Mini Maker Faire in Slovenia and the Trieste Mini Maker Faire in Italy. Here, the open thermal camera is being tested out on a faulty PCB with a shorted component, showing the location of the short on the Android application’s thermal camera display.

Other uses for the camera could be home insulation inspection, water leakage detection, wildlife observation, or even figuring out if your soldering iron is hot enough to use. We’ll say it’s a pretty useful DIY project!

A Hard Rocking Arduino Visualization Shield

September 22, 2019 by Tom Nardi 7 Comments

Over the summer [ElectroSmash] put the finishing touches on the Arduino Audio Meter, a shield for the Arduino Uno that visualizes various aspects of an incoming audio signal on a set of four 8×8 LED dot matrices. Obsentisibly it’s for use on a guitar pedalboard, but thanks to the incredible documentation and collection of example code provided by the team, the project promises to be an excellent platform for all sorts of audio experimentation.

Incoming audio is amplified with an MCP6002 and fed into the Uno’s Analog to Digital Converter, where it’s processed via whatever Sketch the user has uploaded. User input is provided by a digital encoder with push-button. A set of four MAX7219 chips control the entire 256-pixel matrix with just three pins on the Arduino. The resolution of the display allows the Arduino Audio Meter to show more than just a simple VU meter, it can even do text and basic graphics.

[ElectroSmash] provides various Sketches for use with the Arduino Audio Meter that provide the expected repertoire of audio visualizations, but they also provide a number of interesting Sketches to expand the capabilities of the device in unexpected ways. Some of them could be useful for a stage musician, such a tool to tune your guitar, whereas others are fun uses of the hardware such as a game of “Snake”.

With the entire project released as open source, users are free to run wild with the Arduino Audio Meter. Writing your own custom software is an obvious first step to making the project your own, but adding additional hardware features and functions certainly aren’t out of the question either.

Our very own [Lewin Day] once walked us through the effort involved in building boutique guitar pedals, and while the Audio Audio Meter’s capabilities are somewhat limited as it doesn’t have the ability to change the audio going through it, we’re still interested in seeing what the community will come up with once they have an easy way to bring their ideas to life.

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