Hackaday Prize Entry: Modular, Low Cost Braille Display

A lot of work with binary arithmetic was pioneered in the mid-1800s. Boolean algebra was developed by George Boole, but a less obvious binary invention was created at this time: the Braille writing system. Using a system of raised dots (essentially 1s and 0s), visually impaired people have been able to read using their sense of touch. In the modern age of fast information, however, it’s a little more difficult. A number of people have been working on refreshable Braille displays, including [Madaeon] who has created a modular refreshable Braille display.

The idea is to recreate the Braille cell with a set of tiny solenoids. The cell is a set of dots, each of which can be raised or lowered in a particular arrangement to represent a letter or other symbol. With a set of solenoids, this can be accomplished rather rapidly. [Madaeon] has already prototyped these miniscule controllable dots using the latest 3D printing and laser cutting methods and is about ready to put together his first full Braille character.

While this isn’t quite ready for a full-scale display yet, the fundamentals look like a solid foundation for building one. This is all hot on the heels of perhaps the most civilized patent disagreement in history regarding a Braille display that’s similar. Hopefully all the discussion and hacking of Braille displays will bring the cost down enough that anyone who needs one will easily be able to obtain and use one.

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Hackaday Prize Entry: Selfie Bot Let’s You Vlog Hands Free

[Sergey Mironov] sent in his SelfieBot project. His company, Endurance Robots, sells a commercial version of the bot, which leads us to believe that in a strange and maybe brilliant move he decided to just sell the prototype stage of the product development as a kit. Since he also gave away the firmware, STLs, BOM, and made a guide so anyone can build it, we’re not complaining.

The bot is simple enough. Nicely housed hobby servos in a 3D printed case take care of the pan and tilt of the camera. The base of the bot encloses the electronics, which are an Arduino nano, a Bluetooth module, and the support electronics for power and motor driving.

To perform the face tracking, the build assumes you have a second phone. This is silly, but isn’t so unreasonable. Most people who’ve had a smart phone for a few years have a spare one living in a drawer as back-up. One phone runs the face tracking software and points the bot, via Bluetooth, towards the user. The other phone records the video.

The bot is pretty jumpy in the example video, but this can be taken care of with better motors. For a proof-of-concept, it works. A video of it in action after the break.

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Hackaday Prize Entry: Shakelet

A person who is deaf can’t hear sound, but that doesn’t mean they can’t feel vibrations. For his Hackaday Prize entry, [Alex Hunt] is developing the Shakelet, a vibrating wristband for that notifies hearing impaired people about telephones, doorbells, and other sound alerts.

To tackle the difficulty of discriminating between the different sounds from different sources, [Alex’s] wants to attach little sound sensors directly to the sound emitting devices. The sensors wirelessly communicate with the wristband. If the wristband receives a trigger signal from one of the sensors, it alerts the wearer by vibrating. It also shows which device triggered the alert by flashing an RGB LED in a certain color. A first breadboard prototype of his idea confirmed the feasibility of the concept.

After solving a few minor problems with the sensitivity of the sensors, [Alex] now has a working prototype. The wristband features a pager motor and is controlled by an ATMEGA168. Two NRF24L01+ 2.4 GHz wireless transceiver modules take care of the communication. The sound sensors run on the smaller ATTiny85 and use a piezo disc as microphone. Check out the video below, where Alex demonstrates his build:

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Hackaday Prize Entry: Open Source FFT Spectrum Analyzer

Every machine has its own way of communicating with its operator. Some send status emails, some illuminate, but most of them vibrate and make noise. If it hums happily, that’s usually a good sign, but if it complains loudly, maintenance is overdue. [Ariel Quezada] wants to make sense of machine vibrations and draw conclusions about their overall mechanical condition from them. With his project, a 3-axis Open Source FFT Spectrum Analyzer he is not only entering the Hackaday Prize 2016 but also the highly contested field of acoustic defect recognition.

open_fft_machineFor the hardware side of the spectrum analyzer, [Ariel] equipped an Arduino Nano with an ADXL335 accelerometer, which is able to pick up vibrations within a frequency range of 0 to 1600 Hz on the X and Y axis. A film container, equipped with a strong magnet for easy installation, serves as an enclosure for the sensor. The firmware [Ariel] wrote is an efficient piece of code that samples the analog signals from the accelerometer in a free running loop at about 5000 Hz. It streams the digitized waveforms to a host computer over the serial port, where they are captured and stored by a Python script for further processing.

From there, another Python script filters the captured waveform, applies a window function, calculates the Fourier transform and plots the spectrum into a graph. With the analyzer up and running, [Ariel] went on testing the device on a large bearing of an arbitrary rotating machine he had access to. A series of tests that involved adding eccentric weights to the rotating shaft shows that the analyzer already makes it possible to discriminate between different grades of imbalance.

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Hackaday Prize Entry: Cheap, Open LiDAR

[adam] is a caver, meaning that he likes to explore caves and map their inner structure. This is still commonly done using traditional tools, such as notebooks (the paper ones), tape measure, compasses, and inclinometers. [adam] wanted to upgrade his equipment, but found that industrial LiDAR 3D scanners are quite expensive. His Hackaday Prize entry, the Open LIDAR, is an affordable alternative to the expensive industrial 3D scanning solutions out there.

The 3D scan of a small cave near Louisville (source: [caver.adam's] Sketchfab repository)
The 3D scan of a small cave near Louisville from [caver.adam’s] Sketchfab repository
LiDAR — Light Detection And Ranging —  is the technology that senses the distance between a sensor and an object by reflectively measuring the time of flight of a light beam between the two. By acquiring a two-dimensional array of multiple distance readings, this can be used for 3D scanning. Looking at how the industrial LiDAR scanners capture the environment using fast spinning mirrors, [adam] realized that he could basically achieve the same by using a cheap laser range finder strapped to a pan and tilt gimbal.

The gimbal he designed for this task uses stepper motors to aim an SF30-B laser rangefinder. An Arduino controls the movement and lets the eye of the sensor scan an object or an entire environment. By sampling the distance readings returned by the sensor, a point cloud is created which then can be converted into a 3D model. [adam] plans to drive the stepper motors in microstepping mode to increase the resolution of his scanner. We’re looking forwards to see the first renderings of 3D cave maps captured with the Open LIDAR.

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Hackaday Prize Entry: ESP Swiss Knife

The best equipment won’t help you if you don’t have it with you in the moment you need it. Knowledge, experience, and a thick skin may help you out there in the mud of the hardware battlegrounds, but they can’t replace a multimeter, an oscilloscope, a logic analyzer, a serial console or a WiFi access point. [Arcadia Labs] has taken on the challenge of combining most of these functions into a single device, developing the Hacker’s equivalent of a Swiss Army Knife: The ESP Swiss Knife.

esp_swiss_knife_enclosureJust like a Swiss Army Knife is first and foremost a knife, the EPS Swiss Knife is first and foremost an ESP8266. That means it is already a great platform for any kind of project, and [Arcadia Labs] supercharged the plain ESP-12E module by adding a couple of useful features commonly used in many projects. There’s an OLED display, four pushbuttons, a temperature sensor, and a Li-Ion cell with a charging module to power the device on the go. A universal “utility socket” breaks out the ESP8266’s leftover GPIOs and the supply voltage for attaching further peripherals.

With the hardware up and running, [Arcadia Labs] went on with building a couple of applications to provide the functionality that would make the device earn its name. Among them is a basic oscilloscope, a digital NTP based clock, a thermometer, a WiFi tester, a weather station and a 3D printer status monitor. More applications are planned, such as a chronometer, a timer, a DSLR intervalometer and more. A protective 3D printable enclosure is also in the works. [Arcadia Labs] has been joining the Hackaday Prize 2014 and 2015 before and we’re glad to see another great build coming into existence!

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Hackaday Prize Entry: Dtto Modular Robot

A robot to explore the unknown and automate tomorrow’s tasks and the ones after them needs to be extremely versatile. Ideally, it was capable of being any size, any shape, and any functionality, shapeless like water, flexible and smart. For his Hackaday Prize entry, [Alberto] is building such a modular, self-reconfiguring robot: Dtto.

ditto_family To achieve the highest possible reconfigurability, [Alberto’s] robot is designed to be the building block of a larger, mechanical organism. Inspired by the similar MTRAN III, individual robots feature two actuated hinges that give them flexibility and the ability to move on their own. A coupling mechanism on both ends of the robot allows the little crawlers to self-assemble in various configurations and carry out complex tasks together. They can chain together to form a snake, turn into a wheel and even become four (or more) legged walkers. With six coupling faces on each robot, that allow for connections in four orientations, virtually any topology is possible.

Each robot contains two strong servos for the hinges and three smaller ones for the coupling mechanism. Alignment magnets help the robots to index against each other before a latch locks them in place. The clever mechanism doubles as an ejector, so connections can be undone against the force of the alignment magnets. Most of the electronics, including an Arduino Nano, a Bluetooth and a NRF24L01+ module, are densely mounted inside one end of the robot, while the other end can be used to add additional features, such as a camera module, an accelerometer and more. The following video shows four Dtto robots in a snake configuration crawling through a tube.

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