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Rendered at 18:40:09 GMT+0000 (Coordinated Universal Time) with Vercel.
There's probably no reason why these kinetic switches can't also be used for detecting other events like doors opening/closing etc. I feel like a radio signal is a bit more reliable and easier to detect than high frequency sound.
I also think calling these a "sensor" is a bit of a stretch. They detect events but have no knowledge of the current state of the thing they're sensing. E.g. the can detect a door opening/closing, but have no idea if the door is open or closed at a given time
Sure you have to press it very slightly harder than a regular switch and the travel is a little more, but not by much.
I think the doorbell cost like £20 in 2020, actually lemme check Amazon...ah in fact it was 15.99£ (now it's £20.99 hmmm) "TECKNET self powered doorbell".
You're right that they're expensive and need a decent activation force. They also are quite large and make a quite loud clicking noise which might be annoying for a sensor application.
Indeed. At best, they're an "emitter", a "proxy", a "relay", a "transformer", or some combination thereof with "sense" or "marshall" that indicates the transformation of input to output a la "sense proxy emitter" or "marshalling sensor".
If any of those doors are important for security, then I'd want something an intruder can't easily jam or spoof.
They're good but relatively expensive and relatively large. So I can kind of see why this might make sense. On the other hand having to put ultrasonic microphones all through your house is clearly much worse than a radio receiver, so I'd say these are a bit of a gimmick still.
1) 93.75% success rate in controlled conditions, 92.1% in a somewhat-realistic deployment scenario - too low for reliability. I wouldn't use something like that to trigger smart home automations.
2) Range hardcapped at ~1m due to how ultrasound works, you can't centralize detection. Their answer is to give everyone in the household a wearable receiver, which is eeeeeeeh idk, doesn't look consumer-friendly to me.
3) Paper suggests a mix of durable and consumable parts for the transmitter. Their numbers show that the 3d-printed PLA cantilever needs to be replaced every 900 cycles or so. Should work fine, but...
4) ...every transmitter pair needs to be tuned per-setup, every time. Not a plug&play in the consumer sense.
> 2) Range hardcapped at ~1m due to how ultrasound works, you can't centralize detection. Their answer is to give everyone in the household a wearable receiver, which is eeeeeeeh idk, doesn't look consumer-friendly to me.
Sure yes if you could do this with an always-listening smartphone or smartwatch that would be workable, but even then it constrains it to an occupant-activity detector.
Fixing that would require in the best case prompting an app install when visitors arrive. And still it is deaf to any other changes such as a door closing in the wind.
All possible, but feels several technosocial cycles away. Interesting to think about anyway.
https://www.guinnessworldrecords.com/world-records/385428-fi...
My grandfather used to love to show off how he could jingle his keys to turn on his TV.
Also, without regulating the ultrasonic frequency space, I imagine this would be prone to interference from other devices already employing ultrasoud, today, like Google Home.
https://support.google.com/googlenest/answer/9509981?hl=en
"Why does Google flush all of my donors' smart toilets whenever I tap my champagne glass before a toast?"
Author probably has a specific use case in mind. Probably some application where EM emissions are undesirable or power is complicated that has thus far resisted automated industrial data entry. Investigating the use of something like ultrasound would align with constraints like that. Someone (department head? PR department?) said that was too niche and to make up some bullshit with mass market appeal.
inherently private
Zenith Space Command remote “clicker” remotes did not use batteries: they were mechanical.
Pressing a button struck a small aluminum rod inside the remote, producing an ultrasonic tone that the TV detected.
The 4 buttons were labelled: channel lower, volume mute, on off, channel higher. Or on an older version: ON OFF, LEFT, RIGHT, MUTE As per photos: https://www.theverge.com/23810061/zenith-space-command-remot...
https://www.theverge.com/23810061/zenith-space-command-remot...
I wonder how reliable they were?
My grandfather had one; he seemed to find it more entertaining to talk to people about it than to actual use it.
Personally, I would not find it useful as they seem relatively fragile and if the receiver is not bulletproof and VERY sensitive then it could miss state changes.
However, it would be interesting to see how it would work if you were able to have different ones on different frequencies with one main receiver. That would make a cost effective way to track cabinets, doors, etc in the same room.
Unfortunately... I see issues:
> Those frequencies are above 20 kilohertz, which is the upper limit of sounds humans can hear.
Yeah. Humans' range ends there, at least in adulthood. But what about pets? Wildlife? Children and toddlers? Or just people that take care of their hearing by not frying their ears with too much exposure to loudness? It's already an issue with "mosquito teenager repellant" devices.
It was an early TV remote that used spring loaded strikers controlled by buttons on the remote. The strikers hit tuned metal bars that rang out at ultrasonic frequencies the TV detected.
A links below but honestly it's the kind of topic that seems to never be covered well by a single resource. There are YouTube videos showing the inside of the controller and the striker.
[0] https://forums.atari.io/topic/10559-zenith-space-command-vin...
Now companies are desperately trying to figure out how to jack up the price to $10.00 each without us knowing they are ripping us off.
Ultrasonic is DOA, sorry, but that just won't do. It's already a nuisance to have all these switching supplies that mess up your hearing (and some can be surprisingly loud), using it for power delivery is really a non-starter.
There was a company that planned on using ultrasonic for power delivery to smart phones, every engineer with some ultrasonic experience said it wasn't going to work and they just kept going until they - predictably - went out of business.
https://en.wikipedia.org/wiki/SonicEnergy (formerly Ubeam).
Just wishing it exists does not mean it is possible or practical, that's right up there with Theranos (and I think Theranos actually had a better chance of working even though that chance was extremely slim).
There are interesting start-ups around the theme of energy scavenging though, that's a far more realistic but still extremely challenging proposition.
Since it's just a little signal, there's very little power in it, so while your pet might hear it, and maybe it'll cause your noise-canceling headphone to squawk, it's not going to have enough energy to hurt anything.
Most common one - kiddo smashes it 5 times which kicks it into pairing mode...
The linked Instagram video was really useful and understanding the applications. I highly recommend watching that too. In addition to reading the article.
Also I guess this might be annoying for pets that can hear well beyond 20 kHz.
People need smart devices to count their reps !?
If so, will it penetrate through walls?
See http://en.wikipedia.org/wiki/The_Thing_(listening_device)
Could work for drywalls
Just stand on the other side of a drywall and see how well high pitched normally audible sounds get through vs the much lower frequency sounds. It sounds decidedly muffled because all the high has been absorbed.
The flow is then Open door --> Signal triggers --> Signal caught by microphone --> Microphone device relays to server --> Server turns on smart lighting in that room.
There is a lot more that you can do, but this is just an example. The microphone to pick it up is a limitations, but the gain is:
- reduced power usage as the signal generators are not power-operated
- less waste as no empty batteries need to be discarded (if non-rechargeable batteries are used)
- improved security because the signal generators are not connected to the internet, reducing the attack surface.
Sensors must be using batteries, wear out in a month or so, tied to an oppressive cloud seevice, and regular up-sells of things that would be standard but we stratified types of paying users.
For a dotedu, this is perfectly fine. But this wouldn't pass muster as a real product. You can't do all the HorribleUsesAsAService like almost all IoT hardware is.
This isn't a smart home sensor.
[1] Because any AC-powered Zigbee device is a repeater, so just a bulb or a plug is enough
My biggest immediately question though and one I'm a little surprised not see addressed, even at the research stage, is any mention of other animals. There is a bunch there about the ultrasonic frequency being well above the human limit of ~20 kHz. But IIRC for example dogs can hear up to like 45-60 kHz, and cats all the way to 65-85 kHz. I assume lots and lots of other animals also can perceive sounds well beyond human senses. Noise pollution is already a somewhat unrecognized but big problem for all sorts of life around us (not that it's irrelevant to human health either), so if more use of ultrasonics made that worse that's a concern. And as a practical matter the product market is probably going to shrink pretty dramatically if it drives pets mad, a lot of people have pets nowadays they care about a great deal. For that matter even in public environments if it messed with service dogs that might have ADA or equivalent implications.
Still, good reminder of various side channels one doesn't always think about.
If it's 28 in perfectly ideal conditions, 23 is well within range
I feel so relieved.
Out of genuine curiosity, could you elaborate on this further, or share some sources I could read more on? I knew that was once the case, but my understanding was that significant improvements were made for the Maintain Power Signature (MPS) requirements with dual signature and PD standards in the 802.3bt update. According to [0], in the section on 145.3.9 PD MPS:
>"To further reduce minimum standby power consumption for PoE systems, Type 3 and Type 4 dual-signature PDs can make use of optimized MPS timings when connected to a Type 3 or Type 4 PSE, as shown in Figure 19. PDs assigned to Class 1 through 5 must draw a current of 10 mA for at least 7 ms with no more than 310 ms between pulses. This translates to an average power consumption of 12 mW per pairset, or about 1/10th (12 mW/ 124.6 mW ) of the Type 1 / Type 2 minimum pulse average power consumption."
So my assumption was that the spec had significantly improved on this front starting around 7 years ago? I mean, I'm aware that there can be a very, very great deal of lag time between specs and sufficiently cheap and developed new chipsets taking advantage, but I don't think that's the spec's fault either. In principle if the market was there (and yes, it isn't) the tech could meet it right? My extremely limited experience too is that typical wireless battery powered setups can be sensitive to heat as well in the few applications I've dealt with where it's significant, which makes me wonder if in practice in some cases it might be better to use an IR sensor aimed at a semi-closed or closed but air separated material with known (presumably as close to 1.00 as feasible?) thermal emissivity.
Still, there's lots of sensor use cases where it just doesn't matter, but it'd be nice to be able to hard wire+network on the cheap stuff that's very isolated from wireless signal and physically awkward to get at. I'm fully cognizant though that it's a dream unlikely to be realized, just a personal wish there was more PoE IOT stuff (and while we're at it with magical dream lands that it all had open fully local APIs and everyone worked on first class Home Assistant support and...).
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0: https://ethernetalliance.org/wp-content/uploads/2019/08/EA_P...
Also, supporting those tiny pulses requires large capacitors to hold a charge in between pulses. That plus the required magnetics make PoE sensors way more bulky and expensive to manufacture than old fashioned RS-485 sensors.
> And they don’t travel very far, so only nearby microphones would “hear” the tag. That makes the devices inherently private, Deng said, because other people wouldn’t detect any activity unless they were within a meter or so.
It would seem these things don't really produce loud noises, so probably not adding much to the noise pollution that already exists in our environments. At the same time it seems the statement kind of negates the "point" of this tech, that you don't need an active (energy consuming) device close to the source of the events that you want to detect. So not sure of how to interpret it.
I'd be unironically delighted if you could point me at some site helping me find what I've been missing like a goof, because it feels more like the question is "what isn't missing from the PoE sensor market?" It's pretty niche isn't it, with what little there is available also being at enormously increased prices? Take something as simple as "is there water where it shouldn't be", isn't there basically just the Aquo Proteus XE at $350 and, I think maybe one other I can't remember? Surely there are some "call us for a quote" industrial gear too but it's not exactly the common case vs z-wave/zigbee/wifi. Same with pretty much whatever else one might name. Like, what if you want a semi-permanent motion sensor (not a camera), are there any PoE options at all? I think I remember reading someone working on an mmWave one to get it work with HA but that's it. And yes 100% you can say that it's "overkill" or the like but looking at DigiKey's PoE controller pricing doesn't seem like it inherently has to be a huge premium, just isn't anything mass produced.
I mean, it is certainly very arguable that the entire IOT market is and always has been sort of a total mess more than not, and that PoE switches weren't the $50/8-port affairs you can get now either until pretty recently. I totally understand why it's not a thing, I want to be clear this is more of an idle wistful "that'd be a nicer world" along with all sorts of other areas of tech. And I know there are PoE splitters so sometimes you can get roughly the same effect if something has ethernet+power separately. Wireless is also certainly sometimes simply the most sensible option. Just would be nice to have more options when it counted is all. I've dealt with enough odd spaces where it's a pain to get any signal in and even if it's only once every few years it still sucks to have to have somebody work their way in there to replace a battery and sometimes things randomly fritz out, makes one long for good ol' hard wire with super easy ways to just power cycle the switch and eliminate lots of complicated stacks of networking. Ah well.
"Everything Presence Pro is our most advanced presence sensor ever, combining long-range static mmWave, tracking mmWave, PIR, PoE, Ethernet/WiFi connectivity, and optional CO₂ sensing (Sold separately) in a single, ultra-capable device"
USD$93.00
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https://apolloautomation.com/products/r-pro-1?_pos=1&_sid=f8...
Apollo Automation "R PRO-1 PoE dual mmWave Multisensor (LD2450 | additional LD2412 optional)"
- Dual mmWave Compatibility: LD2412 and LD2450 - TR390 for ambient lux and UV sensing - Optional SCD40 for high-accuracy NDIR CO₂ sensing (extra $20)
USD$69.99
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Also check out https://www.tindie.com/ - it's a site for small companies & individuals to sell tech-related stuff. A quick POE search turned up Radiation Dosimeters, Air quality meters, BLE gateways and more.
But most people are not like us. They're not interested in wires, and many have grown up in a very connected world where there aren't any wires.
Smart home sensors are already a pretty niche market. People who want smart home devices that use ethernet are a small subset of that niche. By the time we drill down to smarthome stuff that is powered with ethernet, we've lost almost everyone's attention.
...
That said, I've made dumber things than this work. A facility I've done work at has a physical access control system that is "wireless". It's not really wireless, of course; it's got a fuckton of wire, but the comms are at least wireless.
They wanted a pushbutton on their dispatch console's touch screen that could unlock the front door. Easy-enough, right? The console provides contact closures on the back end.
But the "wireless" access control system's only useful interface for this was a stupid key fob, like for a car. It uses a CR2032 battery. It was, again, stupid. I hated it, but I used it anyway.
I powered it with 12VDC that was stepped down with a fixed 3-volt linear regulator. I used some rather nice Japanese-made small-signal relays to "push" the buttons on the fob. Those little relays were, in-turn, controlled by the operation of the dispatch console's relays (which were located a couple of hundred hundred cable-feet away).
It took a couple of hours to put it together. They paid the bill. It's been working fine for years.