range of barely 3 meters, doesn't mesh, purely unidirectional, only applicable as a sensor for collision detection, still needs a powered microphone on the receiving side, most likely wears out.
This isn't a smart home sensor.
Batteries Not Included, or Required, for These Smart Home Sensors
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Re: Batteries Not Included, or Required, for These Smart Home Sensors
#82Same for EnOcean (energy harvesting ones). But most of them are too expensive for wide adoption (€50 for a temperature+humidity sensor is bit too much).
Re: Batteries Not Included, or Required, for These Smart Home Sensors
#83Get an SDR, tune into the frequency, and troll the home automation system! Given that it’s not of a high frequency, the attack can be done from a distance with proper antenna, and the frequencies use a hardcoded algorithm. Hell, I wouldn’t be surprised to see flipper zero addon to that (hardware through GPIO and software) for portability.
SDR can't ultrasound
Yes it does, my LimeSDR can go to 100khz. If you need less, just get a piezoelectric transducer paired with signal generator like arduino or esp32, might add drive circuit/gate driver to improve it. It’s very doable, and you can programmatically troll the system knowing the algo, and I am saying “troll” but obviously you can have serious use of that.
Re: Batteries Not Included, or Required, for These Smart Home Sensors
#84Earlier quoted context omitted.
Out of curiosity what do you find missing from the PoE sensor market?
> Out of curiosity what do you find missing from the PoE sensor market? 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…
I like PoE, too -- ethernet in general is something that I think is pretty swell.
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.
Re: Batteries Not Included, or Required, for These Smart Home Sensors
#85What a brilliant concept, useful for so many applications!
The linked Instagram video was really useful and understanding the applications. I highly recommend watching that too. In addition to reading the article.
Re: Batteries Not Included, or Required, for These Smart Home Sensors
#86Earlier quoted context omitted.
Not very reliable. The remote only had four buttons (volume up/down, channel up/down) and various sounds like kitchen appliances, flushing toilets, and jingling keys would be interpreted as remote control actions by the TV. My grandfather had one; he seemed to find it more entertaining to talk to people about it than to actual use it.
Blaupunkt (in the early 80s) had a similar system which was a lot more reliable also based on ultrasound, they used an encoding that was a bit less likely to show up in normal environmental sounds.
Doesn't / didn't Blaupunkt make hi-fidelity audio equipment? I would think the range of sounds output by its speakers would make finding distinct sounds difficult. Maybe their audio expertise came in handy.
Re: Batteries Not Included, or Required, for These Smart Home Sensors
#87Earlier quoted context omitted.
Out of curiosity what do you find missing from the PoE sensor market?
> Out of curiosity what do you find missing from the PoE sensor market? 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…
https://shop.everythingsmart.io/products/everything-presence...
"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
---
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
---
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.
Re: Batteries Not Included, or Required, for These Smart Home Sensors
#88Earlier quoted context omitted.
Blaupunkt (in the early 80s) had a similar system which was a lot more reliable also based on ultrasound, they used an encoding that was a bit less likely to show up in normal environmental sounds.
Doesn't / didn't Blaupunkt make hi-fidelity audio equipment? I would think the range of sounds output by its speakers would make finding distinct sounds difficult. Maybe their audio expertise came in handy.
Yes, they did, but this was on a TV set, a - for the time - large color TV. It was a pretty weird little box, I have been searching but can't find an image for it.
Re: Batteries Not Included, or Required, for These Smart Home Sensors
#89Earlier quoted context omitted.
PoE is lousy for sensors. The switch will cut the power if you draw less than 10mA (480 mW), so regardless of PHY efficiency (which is terrible compared to most RS-485, CAN, or even radio ICs), you are REQUIRED by the spec to generate heat that will mess up your sensor measurements.
> The switch will cut the power if you draw less than 10mA (480 mW), so regardless of PHY efficiency [...] you are REQUIRED by the spec to generate heat that will mess up your sensor measurements. 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 Pow…
Good luck finding reasonably priced switches and low power PD ICs that support type 3 or type 4 PoE.
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.
Re: Batteries Not Included, or Required, for These Smart Home Sensors
#90Earlier quoted context omitted.
Children too. My own hearing extended to about 23 kHz until I was in my early 20s, and I don't think I was exceptional. There was a jewelry store in my town that I couldn't go in to because the "ultrasonic" motion detector was so painfully loud. But I doubt these devices would be a problem for children or pets because the pulse is so short.
I mean, TV. Kids were definitely a market for it, throughout its history, but until the flat panel era nobody cared that the flyback transformer in most CRTs made a deafening whine in the 20khz range. I could walk into a house and hear a soundless TV three rooms away, and I know I wasn’t alone in that.
Yeah I could too(not know though...). Trying to sleep, and knowing your parents are watching TV in the living room few doors away isn't the best experience.