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Batteries Not Included, or Required, for These Smart Home Sensors

coe.gatech.edu

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Re: Batteries Not Included, or Required, for These Smart Home Sensors

#31

Post by nine_k »

anVlad11 wrote: post #17

It's research, not a product. Even with that, framing it as a smart home sensor in the press release is a stretch. 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 gi…

Could be more interesting for hard-to-reach underwater sensors. Water attenuates RF quite severely, but is good at conducting ultrasound. The response would have to be in ultrasound, too, of course.

Re: Batteries Not Included, or Required, for These Smart Home Sensors

#33

Post by alnwlsn »

buescher wrote: post #14
cyberax wrote: post #8

Trivia time! The first practical wireless remote control for TVs also used ultrasound: https://www.youtube.com/watch?v=MLPk1Us62xQ

Right, and they were superseded by battery-powered infrared remotes for good reasons. I would recommend revisiting those reasons before proposing this sort of technology for wireless sensors.

Mostly it was that electronics got cheap enough that you didn't need to keep building the bulky and expensive mechanical version. The first wireless remotes that used batteries were still ultrasonic, they just generated the tone electronically instead of by striking a metal bar. Plus, you could have way more buttons with an electric version; you would need a bar per function for the mechanical way.

Re: Batteries Not Included, or Required, for These Smart Home Sensors

#34

Post by Zigurd »

My father was an engineer at Zenith when they were developing the Space Command TV remote control. This was a couple years before I was born, so by the time I got interested in hacking, Zenith TVs with this remote were commonplace. When visiting my friends homes I would prank them by jangling my keys and making the TV louder or quieter and randomly change channels. This presents new opportunities.

Re: Batteries Not Included, or Required, for These Smart Home Sensors

#35

Post by IshKebab »

harg wrote: post #13

There already exists "kinetic" switches for lights etc whose switch contains some passive electronics that when actuated produces enough energy to emit a radio signal that can be read by a relay module. They're pretty handy as you can basically place the switch anywhere you want without the need for the wires to be there. The relay can live in the light fitting or somewhere else convenient. There's probably no reason…

I use these kinetic switches all the time (the Quinetic brand is great and reliable; I've tried a Chinese one once and it died after a few months).

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.

Re: Batteries Not Included, or Required, for These Smart Home Sensors

#36

Post by IshKebab »

buescher wrote: post #15
harg wrote: post #13

There already exists "kinetic" switches for lights etc whose switch contains some passive electronics that when actuated produces enough energy to emit a radio signal that can be read by a relay module. They're pretty handy as you can basically place the switch anywhere you want without the need for the wires to be there. The relay can live in the light fitting or somewhere else convenient. There's probably no reason…

Piezo harvesting switches and similar (I think there’s a flywheel design out there too) are quite expensive, not terribly reliable or consistent, and require substantial activation force. Conventional switches and batteries that can last for years in remote push buttons and sensors are extremely inexpensive in volume.

The Quinetic switches I use are extremely reliable and consistent. I've been mentally making a note of when the switch does not trigger the light, and it actually hasn't happened once yet and I've been using them for about 10 years.

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.

Re: Batteries Not Included, or Required, for These Smart Home Sensors

#37

Post by taco_emoji »

buescher wrote: post #15
harg wrote: post #13

There already exists "kinetic" switches for lights etc whose switch contains some passive electronics that when actuated produces enough energy to emit a radio signal that can be read by a relay module. They're pretty handy as you can basically place the switch anywhere you want without the need for the wires to be there. The relay can live in the light fitting or somewhere else convenient. There's probably no reason…

Piezo harvesting switches and similar (I think there’s a flywheel design out there too) are quite expensive, not terribly reliable or consistent, and require substantial activation force. Conventional switches and batteries that can last for years in remote push buttons and sensors are extremely inexpensive in volume.

The ones I have in my house [0] were not that expensive and have been quite reliable for years now.

[0] https://www.amazon.com/dp/B09MHL8QTC

Re: Batteries Not Included, or Required, for These Smart Home Sensors

#38

Post by ZaoLahma »

xoa wrote: post #24

For a brief, beautiful moment from the headline I thought "oh good, more PoE sensors finally happening!" doho. But no not just about battery but any power at all, and an interesting approach for further research. Of course to actually get data from still requires powered devices but in a lot of cases it'd be much easier to have that be a single or small number of more easily placed central units vs every single senso…

From the article:

> 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.

Re: Batteries Not Included, or Required, for These Smart Home Sensors

#40

Post by svnt »

anVlad11 wrote: post #17

It's research, not a product. Even with that, framing it as a smart home sensor in the press release is a stretch. 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 gi…

This is the big constraint:

> 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.

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