Tag Archives: hardware

Body Cardio Weighing Scale Teardown

via hardware – Hackaday

If you weigh yourself by standing on a bathroom scale, not liking the result, then balancing towards one corner to knock a few pounds off the dial, you are stuck in a previous century. Modern bathroom scales have not only moved from the mechanical to the electronic, they also gather body composition measurements and pack significant computing power.

Yet they’re a piece of domestic electronics that sits in our bathroom and rarely comes under scrutiny. How do they work, and what do they contain? The team at November Five tore down a top-of-the-range Withings Body Cardio scale to find out.

After a struggle with double-sided sticky pads, the scale revealed its secrets: a simple yet accomplished device. There are four load cells and the electrodes for the body measurement, and the PCB. On the board is a 120 MHz ARM Cortex M4 microcontroller, a wireless chipset, battery management, and the analogue measurement chipset. This last is particularly interesting, a Texas Instruments AFE4300, a specialised analogue front-end for this application. It’s a chip most of us will never use, but as always an obscure datasheet is worth a read.

The rather pretty fractal antenna.
The rather pretty fractal antenna.

Finally, the wireless antenna is not the normal simple angular trace you’ll be used to from the likes of ESP8266 boards, but an organic squiggle. It’s a fractal antenna, presumably designed to present a carefully calculated bandwidth to the chipset. A nice touch, though one the consumer will never be aware of.

We’ve shown you quite a few bathroom scales over the years. There was this wisecracking Raspberry Pi scale, this scale reverse engineered to gather weight data, and this one laid bare for use as a controller.


Filed under: ARM, hardware

Do You Miss The Sound Of Your Model M?

via hardware – Hackaday

There is one aspect of desktop computing in which there has been surprisingly little progress over the years. The keyboard you type on today will not be significantly different to the one in front of your predecessor from the 1970s. It may weigh less, its controller may be less power-hungry, and its interface will be different, but the typing experience is substantially identical. Or at least, in theory it will be identical. In fact it might be worse than the older peripheral, because its switches are likely to be more cheaply made.

The famous buckled springs in operation. Shaddim [CC BY-SA 3.0], via Wikimedia Commons.
The famous buckled spring in operation. Shaddim [CC BY-SA 3.0], via Wikimedia Commons.
Thus among keyboard aficionados the prized possessions are not necessarily the latest and greatest, but can often be the input devices of yesteryear. And one of the more famous of these old keyboards is the IBM Model M, a 1984 introduction from the computer behemoth that remains in production to this day. Its famous buckled-spring switches have a very positive action and a unique sound that once heard can never be forgotten.

So if you are a Model M enthusiast and you miss the characteristic clack of high-speed buckled-spring typing on your modern-day laptop, what’s to be done? Fortunately [Ico Doornekamp] has the answer, in the form of bucklespring, an IBM Model M sound emulator. Install it on your Linux box, your Mac, or your WIndows PC, and relive the classic sound of the 1980s as you type!

Yes, it’s gloriously silly, we’ll grant you that. And all your colleagues will hate you for it. But we know some of you won’t be able to help it, and will spend the next few days gleefully clacking away from your MacBook Airs until you get bored with it. After all, if using your computer no longer has the power to entertain, what’s the point?

If the Model M is too new for you, it’s not the only desirable IBM keyboard of yore, how about a Model F? Or give up on these newfangled electronics, and just use a typewriter.

Via Hacker News.

Header Model M image: Raymangold22 (Own work) [CC0], via Wikimedia Commons.


Filed under: classic hacks, hardware, peripherals hacks

Abacus Drive is a Speed-to-Torque Game-Changer

via hardware – Hackaday

Apart from the harmonic drive, the engineering community hasn’t really come up with any clever mechanisms for speed-to-torque conversion in the last few decades. However, recently a few folks at SRI have given us one more transmission to drool over: the Abacus Drive.

The Abacus Drive takes the standard concepts of a cycloidal drive, but takes the eccentric gear tooth pattern that we’re familiar with and converts it to two grooves in which an array of rolling spacers will ride. The benefit with this design is two-fold: it’s both constructed from entirely rigid components (unlike the harmonic drive), and it has a low-backdriving torque, enabling the application to more easily detect changes in load.

Achieving an affordable low-speed, high-torque transmission has been a holy grail among roboticists, where every motor-driven manipulator joint becomes an engineering design headache where the designers fight their application’s backlash, torque, and price constraints to get a functional robot arm. This problem stems from the fact that motors just don’t perform efficiently at low-speeds, where the near-stall conditions cause them to draw vastly larger amounts of torque compared to their full-speed conditions. While the Abacus Drive isn’t hitting the market anytime soon, we’ll let this idea stew in the community and hope to see some budget variants pop up in the near future.

[via IEEE Spectrum]


Filed under: hardware

Flip Dot Displays Appear with Modernized Drivers

via hardware – Hackaday

Admit it, you’ve always wanted to have your own flip-dot display to play with. Along with split-flap displays, flip-dots have an addictive look and sound that hearkens back half a century but still feels like modern technology. They use a magnetic coil to actuate each pixel — physical discs painted contrasting colors on either side. It means that you really only need electricity when changing the pixel, and that each pixel makes a satisfyingly unobtrusive click when flipped. The only problem with the displays is that they’re notoriously difficult to get your hands on.

flipdotBreakfast, a Brooklyn-based hardware firm known for creative marketing installations, unveiled their Flip-Disc Display System this morning. Used displays have come up on the usual sites from time to time, but often without a controller. Traditional flip-dot manufacturers haven’t sought out the individual hacker or hackerspace, and a click-to-buy option has been difficult if not impossible to find.

Breakfast’s offering modernizes the driver used to manage all of those electro-mechanical pixels. Whether this will make the displays more accessible is a question that still needs to be answered.

Breakfast has designed their own driver circuit for each panel of 28×28 pixels which includes a Cortex-M microcontroller. The easily daisy-chainable panels (using cat5 + power) pump up the maximum data propagation across a display by at least two orders of magnitude over traditional drivers. The demo video below shows 30 FPS being controlled by a time-of-flight camera (an ASUS Xtion in this case but that could change for production). Each panel draws about 300 mW at rest and typical full-motion operation is 25-50 W per panel but the system does have intelligent power design to cap total power draw.

Can you own one? Probably not — but that’s just because of your pocketbook. Breakfast wouldn’t give an exact price, but they did oblige when we asked for an approximation in terms of Honda Fits. Minimum order is 15 panels (140×84 pixels or about 7’x4.25′) and will run you about 6.25 Honda Fits.

Your workbench would look fantastic with one of these panels on it, right?
Your workbench would look fantastic with one of these panels on it, right?

Despite your not having low-six-figures lying around to spend on this, it is a notable development. The modernization of the driver, addition of an app and programming API, and a push to sell to a wider customer base should reinvigorate the occurrence of flip-dot displays which have been all but extinct this century. If there is a surge in purchases it will be many years before the secondary market benefits, but hopefully a groundswell of interest will encourage them to make the hacker-edition of their display available for a more… flippant… price.

We’ve seen a lot of work come out of Breakfast, notably this 6,400 pixel colored-thread display which is a mechanical engineering playground. When it comes to flip-dots, nothing beats what we saw at CES in 2015.


Filed under: hardware

Build Your Own YouTube Play Button

via hardware – Hackaday

The only thing that matters in this world is the likes you get on social media platforms. To that end, YouTube has been sending out silver and gold play buttons to their most valuable creators. [Sean] hasn’t screamed into a microphone while playing Minecraft long enough to earn one of these play buttons, so he decided to build his own.

This play button isn’t just a bit of pot metal ensconced in a frame brought to you by Audible dot com; this YouTube play button actually does something useful. It’s a PCB with 144 LEDs working together as a display. There’s an Atmel SAMD21 microcontroller on board to drive the LEDs, and an ESP8266 to pull data down from the Internet. What data is worthy enough to go on an Arduinofied YouTube play button? The subscriber count for [Sean]’s channel, of course. Go subscribe, it might crash his Play button.

Admittedly, there were a few problems with this Play button PCB. Firstly, the ESP8266 can’t directly communicate with the YouTube API to pull down the subscriber count. That problem was fixed with a Raspberry Pi that could connect to the API, and programming the ESP to pull the data from the Pi. Second, this was [Sean]’s first experiment with double-sided SMD boards reflowed in a toaster oven. The first side to be assembled was easy, but to get the second side on, [Sean] turned to low-temp bismuth solder paste. Except for a small error in assembling the board, everything worked as planned.

It’s a great project, and if you want to check out what the better parts of YouTube look like, check out [Sean]’s video below. Don’t forget to rate, comment, like, unlike, or subscribe.


Filed under: hardware

This Quick Hack Will Keep You Online During Your Next Power Outage

via hardware – Hackaday

The modern human’s worst nightmare: a power outage. Left without cat memes, Netflix, and — of course — Hackaday, there’s little to do except participate in the temporary anarchy that occurs when left without internet access. Lamenting over expensive and bulky uninterruptible power supplies, Youtube user [Gadget Addict] hacked together a UPS power bank that might just stave off the collapse of order in your household.

This simple and functional hack really amounts to snipping the end off of a USB  power cable. The cable is then attached to a screw terminal to barrel connector adapter and plugged it into a pass-through power USB power bank. No, really — that’s all there is to it. [Gadget Addict] notes that while most modems and routers are designed to run off a 12V power supply, they still operate at 5V. He goes on to connect several router and router/modem combination units to the power bank. In each case the system appears to boot up and perform normally.

The particular UPS unit [Gadget Addict] was  using has a lead acid battery that was prone to failure on an almost annual basis — which defeats the purpose of a backup power supply for even a non-critical system. This quick hack could be the ounce of prevention that offsets the potentially hours of internet-less boredom that strikes with your next power outage. An accompanying solar-powered 3D printer should also keep you plenty occupied.

[Thanks for the submission, Gadget Addict!]


Filed under: hardware, internet hacks