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

tetris11 wrote: post #2

Im not sure I got it. It generates acoustic signals and a microphone server picks them up. If so, will it penetrate through walls?

The microphone is on a smart watch the user is wearing.

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

#5

Post by croes » Wed, May 06, 2026, 9:04 AM UTC

tetris11 wrote: post #2

Im not sure I got it. It generates acoustic signals and a microphone server picks them up. If so, will it penetrate through walls?

Unlikely because it’s ultrasonic sound, at least if you have brick walls.

Could work for drywalls

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

#6

Post by croes » Wed, May 06, 2026, 9:05 AM UTC

fragmede wrote: post #4

tetris11 wrote: post #2

Im not sure I got it. It generates acoustic signals and a microphone server picks them up. If so, will it penetrate through walls?

The microphone is on a smart watch the user is wearing.

Do you need a signal that tells you the window is open if you are in the same room?

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

#7

Post by hilti » Wed, May 06, 2026, 9:08 AM UTC

croes wrote: post #6

fragmede wrote: post #4

Earlier quoted context omitted.

The microphone is on a smart watch the user is wearing.

Do you need a signal that tells you the window is open if you are in the same room?

If you are constantly looking at your smartphone and ignore the real world ... yes ;-)

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

#8

Post by cyberax » Wed, May 06, 2026, 9:11 AM UTC

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

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

#9

Post by combocosmo » Wed, May 06, 2026, 9:12 AM UTC

It's a unique idea that I could see being useful in select situations. The reliance on wearable microphones sounds like a downside.

Also I guess this might be annoying for pets that can hear well beyond 20 kHz.

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

#10

Post by ogig » Wed, May 06, 2026, 9:24 AM UTC

I can see some uses, but calling this system batteries free seems a stretch. A sensor is worth nothing if it can't be read, and to read this you need a powered microphone and computing. Some already common magnetic door systems do the same; door plate and magnet movement is enough to create a detectable current, (using no external power), then that signal is read and computed by an electronic/digital system (using power).