[Mikhail] sent us a teaser video for a hack he’d done (embedded below). He takes a Bluetooth LE fitness tracker dongle and reflashes it spit out the raw accelerometer data and trigger events. He then wrote a phone app that receives the data and uses the device as an alarm, an on/off switch, a data-logging device, and more.
We thought it was cool enough that we asked [Mikhail] for more detail, and he delivered in spades! Inside the device is a Nordic NRF51822, their ARM Cortex + Bluetooth chip, an accelerometer, and a bunch of LEDs. [Mikhail] mapped out the programming headers, erased the old flash, and re-filled it with his own code. He even added over-the-air DFU re-flashing capability so that he wouldn’t have to open up the case again.
Continue reading “Custom Firmware Unlocks Fitness Tracker”
What does your gait look like to your foot? During which part of your gait is the ball of your feet experiencing the most pressure? Is there something wrong with it? Can you fix it by adding or removing material from a custom insole? All these answers can be had with an expensive system and a visit to a podiatrist, but if [Charles Fried] succeeds you can build a similar system at home.
The device works by having an array of pressure sensors on a flat insole inside of a shoe. When the patient walks, the device streams the data to a computer which logs it. The computer then produces a heat map of the person’s step. The computer also produces a very useful visualization called a gait line. This enables the orthotist to specify or make the correct orthotic.
[Charles]’s version of this has another advantage over the professional versions. His will be able to stream wirelessly to a data logger. This means you can wear the sensor around for a while and get a much more realistic picture of your gait. Like flossing right before the dentist, many people consciously think about their gait while at the foot doctor; this affects the result.
He currently has a prototype working. He’s not sure how long his pressure sensors will last in the current construction, and he’s put wireless logging on hold for now. However, the project is interesting and we can’t wait to see if [Charles] can meet all his design goals.
Looking for a quick DIY project to separate yourself from the crowd at your next business function or maker expo? Take a leaf out of [Pete Prodoehl’s] book and make your own name tag complete with blinking LED!
Minimalist, yet flashy (sorry!), this quick project can be completed inside a few hours with few resources, and is a great way to display your DIY handiwork. Continue reading “Bright Idea for a Name Tag”
[Harris Shallcross] decided to build a pair of smart glasses and recently completed a first prototype of his project ‘Ochi’ – an STM32 based, BLE-connected, OLED eyeglass display. There are of course several homebrew smart glasses projects out there; many are more polished-looking and nearly all of them also display information from a smartphone over Bluetooth. This one is interesting partly because it highlights many of the design challenges that smart glasses and other near-eye displays face. It also demonstrates the iterative development process: begin by getting something working to learn what does and doesn’t cut it at a basic level, and don’t optimize prematurely; let the process bring problems to the surface.
For his project, [Harris Shallcross] used a small 0.95″ diagonal 96×64 color OLED as the display. The lens is from a knockoff Google Cardboard headset, and is held in a 3D printed piece that slides along a wire rail to adjust focus. The display uses a custom font and is driven by an STM32 microcontroller on a small custom PCB, with an HM11 BLE module to receive data wirelessly. Power is provided by a rechargeable lithium-ion battery with a boost converter. An Android app handles sending small packets of data over Bluetooth for display. The prototype software handles display of time and date, calendar, BBC news feed, or weather information.
Devices like these have a lot to deal with. Weight and distribution of that weight is a concern, the size and comfort of the optics is important, and displaying data on a small OLED is only part of the battle – choosing what information to display and when are vital to the device being actually useful in any way, otherwise it’s just a tech demo.
This project set out to show whether it was possible to use the parts listed to make a glasses mounted smart display that was at least somewhat functional, and the software to support it. Clearly, [Harris Shallcross] succeeded at that, but what really showcases the development process is his list of improvements – what he decided needs to go into a second version, and why. One of those goals is to improve the optics; perhaps there’s something to learn from The $60 Bluetooth Head Mounted Display project, which used a similar OLED and a prism to locate the display off to the side instead of in front.
[Rafael] made a sweet little retro watch that’s a fantastic introduction to hardware DIY. If you’ve programmed an Arduino before, but you’ve never had a board made, and you are up for some SMD soldering, this might be for you. It’s got some small components, so ease off the coffee before soldering, but it’s nothing that you won’t be able to do. In the end, you’ll have something awesome.
Aesthetically, the centerpiece is the bubble display, which reminds us of the old HP calculator that our parents kept in the junk drawer, long after it had ceased to be relevant. It would return 3.9999999 for the square-root of 16, but we loved to play with it anyway. This watch will let you vicariously reclaim our childhood.
But that’s not all! It’s also an Arduino and RTC clock. Functions that are already implemented include clock, calendar, stopwatch, and “temperature”. (Temperature is from the AVR’s internal thermometer, which isn’t super-accurate and is probably just going to tell you how hot your wrist is anyway…) It’s got buttons, and tons of free flash space left over. It’s begging to be customized. You know what to do.
It’s not a smart watch, but it’s a great project. “The nostalgic retro bubble display is certain to flatter any hacker’s outfit.” Or something. OK, but we want one.
[via OSHpark’s Hackaday.io feed]
It’s a really tough problem that has been solved to an amazing level. How do you capture and contain urine from a floppy, curved, and moving human infant? Ah, but the problem is a bit harder than that. You also want to keep that liquid away from the soft skin of the newborn and keep the exterior of your overall system dry too. From an R&D point of view the nice thing is that the customer base is huge — everyone needs some type of diapers. And what we have achieved thus far is a huge accomplishment of material science. [Bill Hammack], The Engineer Guy, takes on the engineering of baby diapers in his latest video.
A diaper uses three inner layers to sweep urine away from baby’s skin. The first layer actually repels water — being injected between skin and this layer, liquid passes through the holes in the material. But the moisture repellent property prevents it from moving in the opposite direction because of the next two layers encountered. The second layer uses capillary action to pull the moisture toward the third (and to act as a one-way moisture valve). The third layer contains a super-absorbent polymer. That layer starts off very thin and swells with absorption.
Bill explores just a bit about how these materials are actually manufactured. The layers are non-woven to form the necessary structures. The absorption layer uses cotton fibers to ensure moisture doesn’t form a dam between polymers. Whether you have a little one in your own household or not, the science behind this solved problem is fascinating and well worth the six minutes you’ll spend on the video below.
Continue reading “Disposable Diapers Are A Tribute To Material Science”
Intel made an appearance at the recent summer X Games in Austin, TX with the Curie, a gadget for sensing the motion and position of skateboarders and BMXers. The Curie, attached to the bikes or helmets, measured the dynamics of the tricks performed by the participants.
An Intel 32 bit Quark SE system on a chip sent the telemetry data in real-time using Bluetooth. The module contains an accelerometer and gyroscope to capture all the twists, turns, and tumbles of the athletes. An analysis of the data was presented as part of the on-screen graphic displays of the events.
Continue reading “Does Intel Measure Up at the Austin X Games?”