3-D printed plastic objects that can communicate with WiFi devices
washington.edu
washington.edu
Why. Why why why do all IoT-related articles always use awful consumer goods examples like this. Nobody, or next-to-nobody, would want to have that. There are so many good ideas and existing uses of IoT tech outside of the consumer goods sector, and pretty much every application in the consumer goods sector is hot garbage, and consumers know it.
Could you give some examples? I've yet to hear a single IoT thing I'd be willing to pay money for.
Before we had to navigate our way to the other side of a open plan room in the dark to find a light switch, now the motion sensor triggers the Hue bulb.
Plus we have a dimmer without needing an electrician to install one, and can set other colors of light for the mood or to improve the atmosphere of a movie.
You can get started with Philip's Hue for $50 (on Black Friday) and at that price point it is well worth it for a lot of benefits/circumstances.
For one example imagine if you're away on holiday but want to give the impression somebody is home, you'll need to invest in a timer, with Hue you've already got that.
You mean, pay $5? Plus it works for other stuff besides lights (we turned on a radio too).
That's not a matter of trying them, it's whether you live in a house with a crappy installation. A switch on every entrance is a basic requirement. I agree that if you're renting, fixing those problems yourself for $50 can be useful, though.
This would be easier to determine if I lived alone. When someone comes in, someone else could be sleeping, watching something in the dark, etc. There's a decision tree for which lights to turn on and how bright.
What I would expect the lights to do is more complex than I would want to spend the time perfecting. I like tinkering, but not with things that I actually rely on. That's why I haven't tried it. Well, that, and because I'm not willing to give an appliance an internet uplink.
You can get an ESP8266 individually for $5, and its only a few more dollars for a relay or a couple of MOSFETS depending on what you want to control. You can use the Homie for ESP8266 framework to take care of the boilerplate, and build functional device that communicates over MQTT in less than an hour.
Most open source home automation software supports MQTT and you can use habridge to emulate Phillips Hue devices if you want to integrate it with an Echo or other commercial device.
The problem is that you're renting so you can't do any cool home automation stuff.
I made a web interface so that I can control it with my phone when I'm not at home.
It is based off an ESP8266 placed in the boiler which controls a relay to tell the boiler whether to heat or not, and an ESP8266 in my office that has a temperature probe and a rudimentary user interface, and runs a web server to allow remote temperature inputs, and controls the ESP8266-relay over WiFi.
The 3d-printed enclosure is rather coarse, but does the job: https://img.jes.xxx/1585
EDIT: Failure of the system could result in you freezing, but that's true of anything that controls your heating, and at least this is a device you understand are in control of, and it doesn't rely on anything outside your house. If it fails and you're freezing, just short the terminals of the relay while you debug it.
An easy way to insure against such failure is to put your homemade thermostat in parallel with an old fashioned thermostat which is set to a constant low temperature.
This is one thing that's constantly on my mind when toying with long-lived electronics projects. Do we know of an actual precedent here?
[1] I work for Honeywell
When I go on vacation for a week there is no way to say "go to max energy savings while saving my pipes mode until just before I get back." I can reprogram the entire week, but then I lose what is the correct programming for normal until I reprogram it. Worse my house is uncomfortable when I get back - usually when I'm tired and want to jump into bed asap (if I know I'll get home about noon I'll look for a tourist thing to kill some time long before I get home).
I don't always have the same schedule. When I'm home sick I don't want to reprogram it. Some weekends I'm at home all day, some I'm out all day - which program is right? IoT thermostats also through privacy and reliability concerns in. The old fashioned mercury thermostats from the 1950s still work as good as new. While your IoT thermostat work next year - some do not.
All the above is made even harder because my house is headed by an air source heat pump: if I'm returning at 9pm it might or might not be better to start heating my house at 11am when the day is warmest. The algorithm depends on the weather which is best predicted the day of.
I've got a Honeywell model [1] I can set from anywhere via an app. It also has scheduling it falls back to if I haven't overridden it via the app or faceplate. My winter weekday schedule: 66 at 6am, 62 at 9am, 65 at 4pm, 62 at 10pm.
1) https://www.amazon.com/Honeywell-Programmable-Thermostat-RTH...
https://nest.com/thermostats/nest-learning-thermostat/overvi...
Similarly tagging stuff that you bring yourself to any group event (let's say you are an event organizer and you hand out things and you want to easily account for them).
Sole pressure monitors in shoes would be great to detect problems with stance/gait/load, etc.
Rather than "IoT" tags, I'm of the opinion that we should use dirt-cheap (a few ¢ each, rather than $10+ for a full "IoT tag") RFID tags, and have a reader that can be accessed by a phone over Bluetooth (or have a few permanently installed around the house). Just need to drive the cost of the readers down.
I'm a bit astonished how it still costs 15 EUR for a BLE thingie. :o
My HP printer can reorder ink when it runs out.
Sadly, that all got balled up almost immediately. The offer came with a mailer for exhausted cartridges. I put them in the mailer, put the mailer in the box (rural route). My spouse mistook it for incoming mail, ripped it open, said "Why is HP sending us empty printer cartridges?"
Fortunately HP had a button to click on the web site to get another mailer mailed to me. I clicked, got the mailer (which was entirely different from the one that came with the offer) and sent the cartridges off.
That was weeks ago. No new ink. My credit card continues to be debited monthly, but the printer is defunct and now what?
These things are so, so prone to getting in a wad and leaving you frustrated. More work than actually buying new cartridges as needed.
I was always running out of black ink, or, because of infrequent usage, my inkjet cartridge/head would be clogged. I was so sick of it. I just wanted to hit "print", and have the printer spit out the page - like I could at my employer.
What did my employer use?
A laser printer. So I started looking into it. The last time I had, such printers were still expensive, but they had come down in price. But even better, because of this, businesses and others were getting rid of their "old and slow" b/w laser printers and upgrading to faster color ones. I eventually found my first laser printer at a computer surplus outlet.
It was an HP Laserjet 6M - I paid $100.00 for it, but it didn't have a cartridge. It was a gamble, but I asked the place if I could return it if it didn't work, they said "sure".
I went to a local ink cartridge and printer ribbon store I knew about (they were an old-time fixture here, they even sold typewriter ribbons! Sadly, they no longer exist), and told them my dilemma - I needed a cartridge to test with, I didn't know if the printer worked. They gave me a mostly used cartridge from their refill pile, and told me to bring it back and they'd refill it for me if it worked! Grateful, I took it home and plugged it in.
It worked perfectly! I ran the self-test, and the printer only had about a 25000 page count - a baby! These old LaserJets are tanks, and that was a very low page count. I took the cartridge back, and got it refilled. Total score!
Some time went by, eventually I upgraded the memory to the max (8 MB using common SIMMs) and got the PostScript board for it (so now it is technically a 6MP). It still chugs away, prints when I want it to, I just have to keep feeding it paper - which is rare, because I don't print much.
I'm also only on my third cartridge; I can get them fairly cheap from multiple places, and still a lot of business use these tanks because they are so damn reliable. It isn't a fast printer, but I don't need this thing to spit out a book a minute, just a page here and there; I can wait.
One of the best computing purchases I ever made.
Years later I found a 5P at a Goodwill with the cartridge. I fired it up in the store, and it too had a very low page count (around 15K). Bought it for $25.00 and stuck it in my shop - I also bought the postscript board for it as well. My original intention was to use it for printing toner transfer PCB art, but costs for PCB fabbing have dropped low enough that it isn't really worth it. So I just keep it if and when my 6MP dies...
I figure I'll pass away long before these workhorses do.
If that is what you mean by IoT as just a rebranding of things that have been around for a long time?
That's given rise to the term IIoT (industrial IoT), but it's still troublesome since some discussions of IoT refer to both kinds and some don't, and because the exact same piece of hardware can be IoT or not IoT depending on whether it is installed in a home or a business.
Surely discussions of IoT security should refer to both industrial and consumer products!
> Maybe some people have decided to take IoT literally and redefine it to include existing technologies
I'm pretty sure it's normal to take new descriptive terms and group preexisting things into them where applicable. For example, just because the terms "car" and "motor car" came into use circa 1895 doesn't mean that nothing prior to that date can be considered a car.
Whether the definition actually works for the devices mentioned is still a valid question though.
> that definitely wasn’t the original intention of the word.
That's an odd thing to argue. We aren't talking about people who compute things when we talk about computers, are we? The original meanings of words are fairly inconsequential if over time the accepted meaning is something else.
See here: https://www.pcmag.com/article/344336/the-best-smart-locks
--
And speaking of smart locks - in the current IoT - that is, cloud-connected - version, they are just idiotic. Such things shouldn't be vendor-locked and their core functionality should be available over LAN. Even that PCMag article doesn't seem to recognize it, as they don't have an "works without Internet" row in their table.
Although you might just have it monitor your housemates smartphone location and lock your doors if all phones have left the house. If you don't want it to lock, it will just push message you the lock state.
Hi, I'm your nobody. I'm constantly running out of soap and shampoo and other trivial home goods because I always forget that I need them until the moment I get back home. Why wouldn't I want a feature like that?
Not techy enough for ya? Think of it as preserving state and passing it across time from "the you who knows" (senses a need) to "the you who does" (is at the store). Or as asynchronous communication with yourself.
I mean, seriously, I know what soap I want to buy when I'm shopping. It might be a different one every week. And I definitely don't want my automated solutions to vendor-lock me.
But if its just making a list, then what's the point? I can write on the slip of paper on the fridge anyway.
Also, why not just have this automated instead?
A backup bottle means you never are out - if you remember any time during the 2-month period it takes to use up a bottle. Or have an automated system.
Or hell, when you are at 50/25/10%, order another.
And if you are uncomfortable with it ordering it for you, it could just add it to a shopping list for you.
This requires developing two habits: 1) adding a thing to the shopping list when you fetch the backup item, and 2) actually using a shopping list.
Now I sympathize with the fact that different people have problems with different habits, so if it really doesn't work for you, then I guess you need something else :). But the benefit of this trick (or "life hack") is that it's free to use, doesn't require any purchase to set up, and doesn't tie you to any vendor.
I have noticed that we pay more over the longer term however as we miss sales/discounts/etc that you'd get by ordering in singles. Don't love that.
I could also know what I needed to buy for cooking meals that week. It would be super efficient.
But when there is a technology that can make things better for us, allowing us to have to remember less and do less, why not?
I buy a specific brand of cat litter, laundry detergent, paper towels, and toilet paper. And all of them I often forget I'm low on until it's too late, and I need to run to the store for a single thing.
You can give me all the "solutions" in the world and i've probably tried them, this has happened my whole life.
But then a technology comes along and takes care of this for me, and people are upset that it exists!?
Yeah, the retailer the automation buys from could jack up the prices, if they do that I'll stop using it. Yeah, it could end up costing me slightly more for the convenience, i'm okay with that. Yeah, there are other solutions that work well for other people, they don't for me.
And besides, there are tons of other uses for this kind of thing. The software doesn't need to automatically order it if you don't want to, it could just make a list for you if you'd prefer.
That said, I think people - myself included - complain about this example usage because of all the uses one can come up in 30 seconds, this one is the least generally useful, and most ridiculous one, and this is the one that the authors decided to run their story with. For me, frankly, it's a bit pathetic.
It strongly reminds me of another example - BLE beacons. There are plenty of useful applications that are also obvious when you understand what it is, but what was that the companies (I won't name a particularly well-known brand from my area[0]) decided to run with? Pushing ads into peoples' phones when they're shopping.
It's as if people are purposefully trying to not use technology for good, and instead focus on the worst parts of our culture - greed, consumerism and exploiting others.
--
[0] - There is also another, lesser-known BLE beacon brand in my area, which started their copy with industrial and medical uses. Well, after the success of the retail-oriented brand, they too decided to go with retail instead.
If this ever gets to the point where I can buy filament for it and print stuff myself, the first thing I'll be doing with it is hacking something together to order stuff as it runs out.
Just look at it from my perspective. To me it's like people saying they can use BLE for medical and industrial purposes, and everyone is shouting about how useless and anti-consumer it is...
"Convince Me Why Washer Must Talk to Grill" https://www.eetimes.com/author.asp?section_id=36&doc_id=1323...
The other reason you only see this stuff in the consumer sector is that non-consumer use of IoT is a hot garbage fire. Mesh networks used for industrial sensor tracking at scale are shit, no matter what high or low level protocols you use, and nobody has developed standards ubiquitous and unencumbered enough for everyone to adopt. And everyone already has connectivity for the devices and sensors that need them.
until it malfunctions and buys me a few hundred dollars worth at once. Or gets hacked and buys someone else a few hundred dollars worth at once.
Your attention is one of the most valuable products in the world. Sub-dividing and parceling off that attention in as fine-grained a manner possible is extremely profitable.
I'm really concerned about this. It's not ads I'm worried about but the long term potential for truly unethical misuse of this technology. Combined with AI this stuff could be used to build psychological models on every human. The potential for misuse by everyone from governments to criminals is just insane.
We are building the infrastructure for a hellish dystopia just to get people to click ads.
I'm not really sure what the point of that would be?
Maybe my wife and I are in the minority, but we purchase exactly one brand of detergent, and we haven't switched in a very long time (that said, we switched to this detergent because it was less irritating to our skin than the other brand product we had been using).
We are pretty much the same with other products we buy on a regular basis; we don't brand hop unless there's a very good reason to, and sometimes we'll go out of our way to stick with a particular brand if we have to and can. We certainly don't do so because of advertisements (we don't watch television, and throw away the various adverts we get in the mail, and I only listen to NPR).
Maybe other people brand hop all the time because of a commercial they see. I'm not sure what to think about that, if that's the case
It's about selling to advertisers. It doesn't matter so much whether or not it would actually work, just that it offers ad vendors a new "blue crystals" feature to sell. Micro-targeting segments the market more finely, allowing higher prices to be charged overall while giving advertisers the illusion that prices are lower.
I wouldn't say that. I think that everyone would want it if it didn't add more work, cost or mental overhead than it would remove. And to do that it would have to be ridiculously reliable and simple and be integrated into the products rather than work as an add-on. That won't happen for many years for many of those products.
That said, the usual caveats to this idea apply: it's too easy to have the device order stuff when you don't need it or don't order stuff when you need it, and I definitely don't want to tie myself to a particular retailer.
$4.99 is an 'expensive piece of electronics'?
And putting it on at home is foolish - more work than just reordering detergent myself when it runs out.
It's great because I never remember to do that before its "too late", and its still MY CHOICE to press the button. Nobody wants individual toilet paper packages stuck with their own tracking devices, at least not now.
It's weird that articles like to push that idea, rather than more simple examples people might use.
The very few people I know with them have 5 or more. That adds up. Especially considering you could just modify one to handle any number of products.
You are describing the end-user price of a device that includes batteries, a circuit board, a WiFi transciever, a switch, and an enclosure. If the BOM and assembly costs can be brought down to $4.99, that's a miraculous feat of engineering and modern civilization's economies of scale; if it can end up on your doorstop for that price it must be subsidized.
How else could that device cost less than the gallon of industrial chemistry that you order with it?
$2.72 for a single programmable WiFi device, delivered for free. All you need after that is a cheap battery, button, and enclosure. The existence of the ESP8266 is changing the way I think about electronics.
which is subsidized by the USPS and Chinese government using mail reciprocity agreements to ship for pennies.
https://www.washingtonpost.com/news/storyline/wp/2014/09/12/...
This way you will have months or even years in autonomy instead of weeks.
Anyway, here's a teardown I found:
https://mpetroff.net/2015/05/amazon-dash-button-teardown/
Now a surprising thing that I didn't know before - this thing has a microphone on board. Yes. Yet another Internet-connected microphone. Apparently used only to configure the button via ultrasound, but I wonder how hard would be to repurpose it...
Actually it does. It manipulates the WiFi signal.
> it cannot work reliably across variable environmental conditions
Nope nor can my tablet, notebook or streaming stick but 99% of the time. It does work almost all the time though. I really think this is possibly the best scientific measurement tool idea I have seen in a while. Minimal of parts should keep this working for years and no electronics sounds like there will be many different applications.
> Actually it does. It manipulates the WiFi signal.
Actually, it doesn't. It scatters back some radio frequencies, including 2.4GHz, which happens to be used by Wi-Fi... and Bluetooth, and Zigbee, and other stuff that people might have in their homes. You still need at least a dedicated radio driver, which has absolutely nothing to do with Wi-Fi protocol, to actually read the data those devices send.
Your comment is a good example of exactly why the way this article (and the original paper) uses the word "Wi-Fi" and "connection" is a big problem. See also: https://news.ycombinator.com/item?id=15861392.
The main point of the article was : "University of Washington researchers are the first to make this a reality by 3-D printing plastic objects and sensors that can collect useful data and communicate with other WiFi-connected devices entirely on their own."
Um I don't understand if you look at the flow chart this paper is narrowly speaking about wifi that it is
Wifi TX --> 3D Printed Object --> Wifi RX
I am talking about how this is 100% wifi communication and sure the Wifi RX is where the success of this relays. Sure it will work with other protocols but this is about them specifically using it as a way for Wifi RX
> > Actually it does. It manipulates the WiFi signal.
> Actually, it doesn't.
"backscatter" the Wifi signal isn't manipulation?
If you follow the "Backscatter" link in the article they actually state the following:
"This new “interscatter communication” works by converting Bluetooth signals into Wi-Fi transmissions over the air." http://www.washington.edu/news/2016/08/17/interscatter-commu...
So they can convert signals from bluetooth to Wifi isn't manipulation?
Your statement of
> It scatters back some radio frequencies, including 2.4GHz, which happens to be used by Wi-Fi...
Seems off to their own "backscatter" definition. This is not simple reflections of radio signals these technically are new signals physically manipulated by the non-electronic devices.
From the paper
"We 3D print a cup anemometer as shown in Fig. 2 to measure wind speeds. The entire setup is sufficiently light that even wind speeds as low as 2.3 m/s will cause it to spin. The hub of the anemometer is attached to backscatter gear that encodes an alternating sequence of zero one bits. When the hub spins, the backscatter gear pushes against the spring switch. The switch makes contact with the antenna and generates the backscatter signal. Wind speed can be inferred from the rate at which bit transitions occur."
See https://youtu.be/4tmatoD0I1o?t=3m48s
They could do it with a radio signal of a clean sine wave and through the 3D object they could convert the sine wave into wifi. Just like they could take a bluetooth wave and make a wifi signal. The big advantage to this is they can just take a Wifi and use it to do the same thing. No need for new hardware.
They are both "backscatter" in that they change an existing signal and thus require less energy than if they generated it themselves, but that's about it when it comes to similarities.
I thought maybe I am missing something, but I see that the objects are encoded with bit and transmits.
Printed Wifi Paper
"PRINTED MAGLINK At a high level, by varying the magnetic properties of the material used within a single print job, we can embed multiple sequences of bits across the object. We consider the 3D printed object that modulates the magnetic field as the transmitter and the smartphone as the receiver.
Maybe it is the word modulates that is the issue?
Modulate Definition - In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted. Most radio systems in the 20th century used frequency modulation (FM) or amplitude modulation (AM) to make the carrier carry the radio broadcast. https://en.wikipedia.org/wiki/Modulation
I think you're confusing three or four different projects at this point, whose only common property is that they operate on the energy of an incoming 2.4GHz signal (the "backscatter" thing).
The project that is the topic of discussion in this whole HN thread is the one that uses a 3D-printed plastic mechanism that changes the way an antenna (incidentally, 3D-printed too, out of a filament that mixes copper and plastic) reflects an incoming signal. There is a binary pattern, but it's encoded in the cog-like thing in the mechanism.
It's pretty much like sending light signals with a mirror, except it's reflecting radio waves. The way they use technical terms in this article (and the original paper) is problematic, and I believe your confusion in this subthread is a perfect example of why the abuse of "Wi-Fi" references is a problem.
No, it's:
Wifi TX --> 3D Printed Object --> general 2.4GHz RX through a specialized device or driver for an existing 2.4GHz device
They're not magically encoding new Wi-Fi packets; they're changing the amplitude of Wi-Fi packets - and everything else that's on 2.4GHz - seen by the receiver. Contrast with the interscatter you mention, which uses an electronic device to encode new Wi-Fi packets.
Interscatter is not what's happening here.
"In this backscatter system, an antenna embedded in a 3-D printed object (middle) reflects radio signals emitted by a WiFi router (left) to encode information that is “read” by the WiFi receiver in a phone, computer or other device (right).University of Washington"
Screenshot: https://i.imgur.com/rzX4RXX.png
> They're not magically encoding new Wi-Fi packets
Yes, these are NEW signals powered by the radio signals that specifically in this article is wifi since it is so widely used.
"The chip uses a technique called long-range backscatter to communicate with other devices. Instead of creating signals from scratch, it is able to selectively reflect radio waves that are already passing through space to create a new signal." https://www.technologyreview.com/the-download/608869/a-new-m...
Just because they are using residual radio signals (They could use TV, Wifi or FM signals) doesn't mean the new singals aren't new. They are just using the energy in the signal itself doesn't make them magic. Instead of using electricity from a battery or a cord they are using the power of the radio wave. They can even power themselves off of the Gollakota’s radio frequency power scavenging technology. You could light up a led without any on board electricity and communicate between two devices https://www.youtube.com/watch?v=gX9cbxLSOkE
Here is a speech about HitchHike: Practical Backscatter Using Commodity WiFi at (SenSys 2016) https://youtu.be/4tmatoD0I1o?t=3m48s
> At a high level, a Wi-Fi transmitter sends a sequence of Wi-Fi packets and the Wi-Fi receiver uses the changes to the amplitude of the Wi-Fi packets, caused due to the backscatter operation, to extract the backscatter information
> So we decode the backscatter information from the amplitude variations in the received Wi-Fi signal across packets.
Your other links again are about totally different projects, doing different things (they involve chips for instance, not just 3D printed components. "Of course" chips can actually send/manipulate data at the speed necessary to generate packets, nobody is arguing against that)
"To 3-D print objects that can communicate with commercial WiFi receivers, the team employed backscatter techniques that allow devices to exchange information. In this case, the team replaced some functions normally performed by electrical components with mechanical motion activated by springs, gears, switches and other parts that can be 3-D printed — borrowing from principles that allow battery-free watches to keep time."
...
"Information — in the form of 1s and 0s — is encoded by the presence or absence of the tooth on a gear. Energy from a coiled spring drives the gear system, and the width and pattern of gear teeth control how long the backscatter switch makes contact with the antenna, creating patterns of reflected signals that can be decoded by a WiFi receiver."
A Wifi packet is a few milliseconds long at best, it should be obvious why a 3D printed mechanical thing can not be fast enough to change bits in there to actually generate a new packet.
Please note that I'm not claiming that it's not using backscatter techniques, that it isn't novel or that it isn't interesting. Backscatter is a generic enough term to cover all these things, despite them being quite different.
I'm claiming that it does not generate Wifi packets. It merely changes their physical characteristics in a way that can be detected, without changing anything about the packet contents.
How does the Wifi transmit how much laundry soap or any measurement if it wasn't new packets???? Maybe if you can just look at this for 2 minutes you'll understand how this is new packets? https://youtu.be/4tmatoD0I1o?t=14m5s
It has to be received and transmit data. Your assuming a reflection is what's happening. Than a mirror could also do the same thing?
This is your laptop or Smartphone able to receive a signal from a 3D device with no new hardware using only the power of a Wifi transition signal that a Wifi receive will read.
The project discussed in this article is exactly like a mirror, but for RF. If you'd attach a mirror to a spring and had it rotated back and forth with a cog-like thing, you'd have built the exact same thing they're presenting here, except for light. You wouldn't want to call it "Li-Fi communication" just because the mirror can reflect the same frequencies Li-Fi devices use, though. Which is why calling this project a "Wi-Fi device" is wrong.
They are called in the published paper "printed Wifi devices, Wi-Fi input widgets, 3D Printed Wi-Fi Smart Objects." If your smarter and see how stupid or misleading these Phds are and MIT for publishing these finding then do it. Otherwise you are basing your whole argument on incorrect presuppositions and you didn't do any due diligence to see your missing knowledge how these actually work. How in the world would you send measurements to a Wifi receiver in your laptop? You would send a measurement of test tubes to a laptop without any electronics and no dc power.
Read how this is done for measuring wind speed:
"We 3D print a cup anemometer as shown in Fig. 2 to measure wind speeds. The entire setup is sufficiently light that even wind speeds as low as 2.3 m/s will cause it to spin. The hub of the anemometer is attached to backscatter gear that encodes an alternating sequence of zero.
I understand your missing the similarities in the projects but they are all related by the same principles. The 3D printed Wifi devices (plastic adn metal, are doing what is normally requiring circuitry.
http://printedwifi.cs.washington.edu/printedwifi.pdf
Achieving data communication using push buttons requires us to address two unique challenges: 1) we need a mechanism to identify the beginning of a packet, and 2) since users can push buttons at different speeds, we need an algorithm for symbol synchronization.
> In our case, the backscatter signal is a narrowband transmission embedded on top of the ambient Wi-Fi signals, since the printed Wi-Fi objects send data at a low data rate.
Even your quoted text doesn't say that it sends packets IMO.
My explanation:
The 3D printed Wifi device uses plastic and metal to connect to any Wifi receiver (normal laptop or smartphone) using any commercially available Wifi transmitter. 3D device uses it's antenna to send new data. The data is sent uses reflection and absorption of the Wifi signal to create new data of 1s and 0s though at a slower rate of speed. This is all done without the need for batteries or other electronics. There is no special hardware or software besides the 3D device to connect and send data. The device can toggle an electronic switch to either absorb or reflect an ambient signal to convey a sequence of 0 and 1 bits using reflective and non-reflective states. This is accomplished by leverages present Wifi backscatter technology but for the first time instead of using electronic components these 3D devices use non-electronic and printable analogues.
> "embedded on top of the ambient Wi-Fi signals,"
That is how backscatter works and how they connect to wifi and send specific 1s and 0s. It absorbs and reflex a wifi signal out of those absorption and reflections.
It can't work without some signal to carry on top of it and could work with a single 2.4 sine wave. But backscatter absolutely sends measurements to a normal Wifi rx aka a phone or laptop through the Wifi transmitter.
because consumer goods manufacturers have the big bucks to throw at research like this
I think you substantially underestimate the apathy of the broader consumer market...
- Recurring revenue - Frictionless transactions - Vendor lock in
To a business, this stuff is irresistible. Of course consumers would hate this. But consumers also hated DRM, and they managed to shove that down our throats.
To be fair, this 3D trick also replaces remembering, driving, buying, restocking.
How so? You can already order online. All this devices replaces is the clicks it takes to do that.
A cellphone means you don't have to choose between receiving calls or going out. It's incomparable in its utility.
Just because people call it progress doesn’t mean the world is a better place.
That said, we're now on the verge of switching most of ICE uses into electricity, which can be made more renewable than horses. We'll be good, if we can make the transition.
> In this case, the antenna is contained in a 3-D printed object made of conductive printing filament that mixes plastic with copper.
So this appears to be some sort of copper-plastic alloy that prints well and is conductive after printing. This part seems more revolutionary than the commercial aspect.
I try to not nitpick too often, but things like this really irk me. And before someone says that it's a simplification for non-specialists - this is exactly the problem. Such stupid "simplifications" only serve to confuse people, instead of educating them. They promote fairy tales (easy to exploit later) instead of building an accurate model of reality.
Writing things like that is wrong, and hurtful to the readers. Writing things like that intentionally is simply malicious.
It would be great if they actually gave details. I want to know:
1. What device is receiving the signals. Is it commodity hardware (like a phone or laptop) or do they have to build a custom RF receive chain?
2. What software is used? What signal processing do they have to do? How does the software differentiate between one device and another one?
The interesting, ground breaking stuff is all in the electronics and software. The 3D printing stuff is fluff - it's just taking 100 year old technology and adding "3D printed" to it to make it seem modern.
> We note that prior electronic-based designs use both Wi-Fi signal variations (RSSI) as well as channel state information (CSI) variations [Kellogg et al.2014] to extract backscatter data. The backscattered signal from our 3D printed objects can be extracted using either of these procedures. Our implementation uses the MAX2829 802.11a/b/g transceiver that gives us access to the received 802.11g baseband signal.
Based on my time in grad school, I'm guessing they custom built a microcontroller for the task, and used that chip. There's a wealth of papers online dealing with backscatter, including the Kellogg paper cited above. Among their proposed setups is this fairly passive one:
> Finally, we check the feasibility of using only the periodic beacon messages from the AP. We use an Intel Wi-Fi Link 5300 card configured as the AP and an Intel Wi-Fi Link 5300 card as a Wi-Fi reader. The reader does not generate any traffic on the network and passively listens to the beacon messages periodically transmitted by the access point. No other device is associated with the access point, but it operates on channel 6, which is the same frequency as our organization’s Wi-Fi network.
Your other questions may be similar answered by following citations =)
- uses MAX2829 802.11a/b/g transceiver - if WiFi preamble is detected, pass it further up the stack - otherwise normalise the signal and apply apply a 10th order 100 Hz low pass filter. - bitrate is 45bps :)
EDIT: Here are some diagrams of how it works:
11 previous submissions: https://hn.algolia.com/?query=listening%20thing&sort=byPopul...
Yes, the nitpicks are correct. But wouldn't it be more inspiring to talk about how it could be used?
That said, to invent uses for a technology, one needs to understand what it does, and what it does not. Hence the nitpicking. This technology is functionally worse than regular RFIDs, but it's potentially dirt-cheap to manufacture. Saying it has anything to do with "Wi-Fi" or "connecting" is so deeply wrong that it heavily distorts one's understanding of its pros and cons.
Unfortunately, AFAIK the technology doesn't have a searchable name, so I can't find anything about it now.
Of course, being able to listen for an arbitrary audio signal would be even more useful.
(side view)
+-------------+
+---+ BUTTON +--------------------------------+
| | | |
| +-------------+ |
-+ <-- valve |
| +-------- -------------------------------------+
| | flute x x x x x x x x x x <-- sounds comes
| +-----------------------------------------------+ out here
+--------------------------------------------------+
x - a hole with an externally accessible
lever that can be used to open or close it
Pros:
- No electricity needed.
- Fully configurable, open source.
- 3D-printable maybe? Still, can be entirely plastic, so even more dirt-cheap to manufacture than the backscatter thingie.
- Less chance of interference - it's easier to keep the sound contained within your apartment than it is to keep radio waves.
I think what you are aiming for is more on the order of a disk siren. The rotation speed could be adjusted to produce a different base frequency, and one siren disk can support tone production from several air streams, each aimed at a different radius of the disk. Blocking off or opening the individual air streams can produce different chords based on the base tone.
If you have twelve speeds and six air streams, you can make 767 different chords. The same rotor can turn the siren disk and a fan to move the air. You press the button, the disk spins, and a pre-programmed chord plays.
Still, based on your explanation, I feel that a fully-mechanical device that has hundreds of configurable tones and is operated through pressing a button should be feasible for easy mass-production and/or even 3D-printing.
I used to do the same thing with DTMF tones back in the 90's. The SSI202 was the hot DTMF to binary decoder chip.
> In 1956, Robert Adler developed "Zenith Space Command", a wireless remote. It was mechanical and used ultrasound to change the channel and volume. When the user pushed a button on the remote control, it clicked and struck a bar, hence the term "clicker". Each bar emitted a different frequency and circuits in the television detected this sound. The invention of the transistor made possible cheaper electronic remotes that contained a piezoelectric crystal that was fed by an oscillating electric current at a frequency near or above the upper threshold of human hearing, though still audible to dogs. The receiver contained a microphone attached to a circuit that was tuned to the same frequency. Some problems with this method were that the receiver could be triggered accidentally by naturally occurring noises, and some people could hear the piercing ultrasonic signals.
[1] https://en.wikipedia.org/wiki/Remote_control#Television_remo...
How is my WiFi network supposed to know that the interference in the signal came from my detergent bottle - not my neighbor's, and not from some other random object passing by? Do I have to do some sort of pairing every time I buy a new detergent brand to teach my network about it?
This is a really interesting idea for IOT. I'm really excited by the possibilities it could open up.
I imagine this would be really good for things like weather sensors or even security systems... but I have serious doubts of the efficacy of what they are doing.
On reading the paper rather than the article: it's even simpler than I thought. No custom hardware necessary.
With machine learning someone could probably train models that know what you are doing in your home.
The level of security you seek is unattainable in practice.
...or by building an otherwise identical object that manipulates flaws in how the Wi-fi reads the signals and then replacing the original object with the malicious one.
This development will probably lead to a new combination of something like RFID, WiFi and electromagnetic power delivery (AM radio).
More details here. http://iotwifi.cs.washington.edu/
No.
Or malware could just say "Hey Alexa [insert other name here]" and order detergent (This has happened accidentally in commercials).
it was just an example. If arbitrary, easy to replicate signals without an authentication start to represent meaningful device input, then that means anything that can generate these signals (such as maybe your phone, or maybe someone with a transmitter sitting in your driveway) can spoof your intent. It's like if someone could come into your house and start typing on keyboards.
and yes the example of speaking arbitrary voice commands to wake up alexas and google devices is a real problem too.
You renamed it, but it is still does not indicate that the thing does 0 actual wifi protocol communication.