Hackaday Prize Entry: HaptiVision Creates a Net of Vibration Motors

HaptiVision is a haptic feedback system for the blind that builds on a wide array of vibration belts and haptic vests. It’s a smart concept, giving the wearer a warning when an obstruction comes into sensor view.

The earliest research into haptic feedback wearables used ultrasonic sensors, and more recent developments used a Kinect. The project team for HaptiVision chose the Intel RealSense camera because of its svelte form factor. Part of the goal was to make the HaptiVision as discreet as possible, so fitting the whole rig under a shirt was part of the plan.

In addition to a RealSense camera, the team used an Intel Up board for the brains, mostly because it natively controlled the RealSense camera. It takes a 640×480 IR snapshot and selectively triggers the 128 vibration motors to tell you what’s close. The motors are controlled by 8 PCA9685-based PWM expander boards.

The project is based on David Antón Sánchez’s OpenVNAVI project, which also featured a 128-motor array. HaptiVision aims to create an easy to replicate haptic system. Everything is Open Source, and all of the wiring clips and motor mounts are 3D-printable.

Hackaday Prize Entry: Post Stroke Spasticity Rehab Helper

A stroke is caused when poor blood flow to the brain causes cell damage, causing that part of the brain to stop functioning. Common causes are either blood vessel blockage or internal bleeding, and effects depend on the part of the brain that is affected. In most cases, spasticity (muscle contraction), poor motor control and the inability to move and feel are common after effects. Recovery is often a long, slow process and involves re-learning the affected lost skills. This is where physical therapy using assistive technologies becomes important. Rehabilitation must start as early as possible since the first few weeks are critical for good recovery. [Sergei V. Bogdanov] is building a cheap and simple Post-Stroke Spasticity Rehab Helper to address this problem.

He’s using ten hobby micro servos connected to an Arduino Nano, all mounted on a kitchen chopping board, with a few other bits thrown in to round out the build. There’s one pair of servos for each finger. A five bar linkage converts the servo rotations to two-dimensional motion. The end of the linkage has a swiveling metallic disk. Patient fingers are attached to these discs via magnetic metal pads that are attached to the end of the fingers using adhesive plaster tape. Two push buttons cycle through a large number of exercise modes and two potentiometer’s help adjust the speed and smoothness (the number of points calculated for the desired motion). Two 7-segment LED display modules connected to the Arduino provides a visual interface showing program modes, speed, number of cycles and other relevant information. Replicating the project ought to be very straightforward since the device uses off-the-shelf parts which are easy to put together using the detailed build instructions, photos and code posted on [Sergei]’s project page. Check out the videos below to see the rehab helper in action.

Continue reading “Hackaday Prize Entry: Post Stroke Spasticity Rehab Helper”

Hackaday Prize Entry: MOLBED Braille Display

Electromechanical braille displays, where little pins pop up or drop down to represent various characters, can cost upwards of a thousand dollars. That’s where the Modular Low-cost Braille Electro Display, aka MOLBED, steps up. The project’s creator, [Madaeon] aims to create a DIY-friendly, 3D-printable,  and simple braille system. He’s working on a single character’s display, with the idea it could be expanded to cover a whole row or even offer multiple rows.

[Madeon]’s design involves using Flexinol actuator wire to control whether a pin sticks or not. He designed a “rocker” system consisting of a series of 6 pins that form the Braille display. Each pin is actuated by two Flexinol wires, one with current applied to it and one without, popping the pin up about a millimeter. Swap polarity and the pin pops down to be flush with the surface.

This project is actually [Madeon]’s second revision of the MOLBED system. The first version, an entry to the Hackaday Prize last year, used very small solenoids with two very small magnets at either end of the pole to hold the pin in place. The new system, while slightly more complex mechanically, should be easier to produce in a low-cost version, and has a much higher chance of bringing this technology to people who need it. It’s a great project, and a great entry to the Hackaday Prize.

Hackaday Prize Entry: The $50 Raspberry Pi Smartphone

The Hackaday Prize is a challenge to create hardware, and the ZeroPhone is quite possibly the most popular project entered in the Hackaday Prize. What is it? It’s a mobile phone built around the Raspberry Pi Zero that can be assembled for about $50 in parts. Already, it’s a finalist in the Hackaday Prize best product competition, a finalist for the grand prize of $50,000, and one of the most popular projects on Hackaday.io of all time.

We took a look at the ZeroPhone early this year, and while there have been significant advances in this project, the philosophy is still pretty much the same. This is a mobile phone with a numeric keypad and a 128 x 64 pixel OLED display — basically the same user interface as a Nokia brick. The brain of the phone is a Raspberry Pi Zero wrapped in a PCB sandwich, with options for WiFi, Bluetooth, HDMI and audio outputs, a USB port, battery charging, and a ton of GPIOs that include ISM band radios, infrared receivers and transmitters, more flash storage, and anything else you can imagine. Basically, we’re looking at one of those modular, reconfigurable smartphone ideas, using a Raspberry Pi as the brains. Tech journos should be creaming themselves over this. We’re looking forward to [Arsenijs]’ cover story in Wired.

As with any Open Source / DIY cell phone, the big question surrounding the ZeroPhone is the cellular radio. 2G radios are cheap and plentiful, but the infrastructure is either coming down shortly, or already is down. A 3G radio is a must for a minimum viable product, and [Arsenijs] says there are provisions for replacing the 2G radio with a 3G module. Of course, 3G modules aren’t as capital-‘O’-Open as their technological predecessors, but that’s a discussion for another time.

Already the ZeroPhone is a huge success. There’s an actual team working on this project, the ZeroPhone subreddit is bigger than the Hackaday subreddit, there are newsletters, a wiki, and there will be a crowdfunding campaign ‘shortly’. This is one to look out for, and a very worthy project in the running for the 2017 Hackaday Prize.

Hackaday Prize Entry: A PCB To Emulate Coin Cells

The Coin Cell Emulator CR2016/CR2032 by [bobricius] homes in on a problem some hardware developers don’t realize they have: when working on hardware powered by the near-ubiquitous CR2016 or CR2032 format 3V coin cells, power can be a bit troublesome. Either the device is kept fed with coin cells as needed during development, or the developer installs some breakout wires to provide power from a more convenient source.

[bobricius]’s solution to all this is a small PCB designed to be inserted into most coin cell holders just like the cell itself. It integrates a micro USB connector with a 3V regulator for using USB as an external power source. The board also provides points for attaching alligator clips, should one wish to conveniently measure current consumption. It’s a tool with a purpose, and cleverly uses the physical shape of the PCB itself as an integral part of the function, much like another of [bobricius]’s projects: the Charlieplexed 7-segment LED display.

Hackaday Prize Entry: You Can Tune A Guitar, But Can You Reference REO Speedwagon?

Just for a second, let’s perform a little engineering-based thought experiment. Let’s design a guitar tuner. First up, you’ll need a 1/4″ input, and some op-amps to get that signal into a microcontroller. In the microcontroller, you’re going to be doing some FFT. If you’re really fancy, you’ll have some lookup tables and an interface to switch between A440, maybe A430, and if you’re a huge nerd, C256. The interface is simple enough — just use a seven-segment display and a few LEDs to tell the user what note they’re on and how on-pitch they are. All in all, the design isn’t that hard.

Now let’s design a tuner for blind musicians. This makes things a bit more interesting. That LED interface isn’t going to work, and you’ve got to figure out a better way of telling the musician they’re on-pitch. This is the idea of [Pepijn]’s Accessible Guitar Tuner. It’s a finalist in The Hackaday Prize Assistive Technology round, and a really interesting problem to solve.

Most of [Pepijn]’s tuner is what you would expect — microcontrollers and FFT. The microcontroller is an ATMega, which is sufficient enough for a simple guitar tuner. The real trick here is the interface. [Pepijn] modulating the input from the guitar against a reference frequency. The difference between the guitar and this reference frequency is then turned into clicks and played through headphones. Fewer clicks mean the guitar is closer to being in tune.

This is one of those projects that’s a perfect fit for the Hackaday Prize Assistive Technology round. It’s an extremely simple problem to define, somewhat easy to build, and very useful. That doesn’t mean [Pepijn] isn’t having problems — he’s having a lot of trouble with the signal levels from a guitar. He’s looking for some help, so if you have some insights in reading signals that range from tiny piezos to active humbuckers, give him a few words of advice.

Hackaday Prize Entry: SoleSense for Balance Therapy

Rehabilitating brain injuries where a patient’s sense of balance has been compromised is no easy task. Current solutions only trigger when the patient reaches a threshold and by then, it may already be too late for a graceful recovery. [Simon Merrett]’s SoleSense is being designed to give continuous feedback like a stock humans innate sense of balance. Therapists hope this will aid recovery by more closely imitating what most of us grew up with.

SoleSense relies on capacitive sensors arranged under the feet to know where the patients are placing their weight. [OSHPark] is providing the first round of flexible PCBs so some lucky sole is going to get purple inserts.

Outside of recovery, devices like this can teach better posture or possibly enhance a fully functioning sense of balance. That could improve physical performance. Who knows, we are finding new ways of perceiving the world all the time.

Remapping senses is a popular assistive technology and sound is ideal for the SoleSense to piggyback because brain injuries are less likely to affect hearing than other senses. Of course, senses can be remapped or even created. You could gain a sense of magnetic north or expand the range of light you can perceive.