how can i detect the ultrasound data use some tools in my google nest hub (generation 2nd)

[gkmbw]

current i have a device google nest hub with ultrasound detect, when set timer i can see it enlarge the text when person leave, when close it, it will change to small. while i am curious, how it works, how can i capture the ultrasound info that the nest hub emmit

[Juni]

Hi gkmbw.
 

Thanks for posting here in the Google Nest Community.
 

Good question. Let me help you. When you set a timer and Nest display detects that you’re nearby, it will automatically show your touch controls so you can easily control your timer. If you’re across the room, your timer will be displayed in a larger font to help you view it more easily. 
 

The Ultrasound sensing feature is performed on your device and is used to adjust your display to make it more glanceable and easier to control based on your proximity to the device. No motion, proximity, or presence sensor data is sent to the cloud. 
 

You can check this link for more information.

Hope this helps.
 

Regards,

Juni

[gkmbw]

Hi Juni.
thanks for your explanation. i know the scenario for ultrasound used in google
hub nest. and i have check the link you share to me, it have some useful information. while in my side i prefer to know how can i capture the ultrasound data.
as i know the ultrasound frequency is above 20khz. i use frequecy generator app send 20khz
ultrasound in one mobile phone, and then in another mobile phone open audio recorder app with 48khz sample rate to capture the audio data. view the capture wav file in audio tools(acoustic spectrum analyser), can see the obvious freqency is 20khz, so means have capture the ultrasound data successfully.
while when use audio recorder app in mobile phone with 48khz sample rate to catch the ultrasound data emmit by goole nest hub, put the phone together with nest hub(after set timer and person close to and away from the nest hub, the displayed time change to bigger and smaller for several times). after check the spectrum graph, can't see the ultrasound related frequency wave.
do you know how should i do to capture the ultrasound data that google nest hub emmit.

thanks

[Juni]

Hi there,

Thanks for the details you provided. We don't have the means of capturing  the ultrasound data that Google Nest Hub emmit.  We appreciate people who are keen on sharing their thoughts with us. We're always looking for ways to improve. I'd suggest you submit feedback about it, here's how.

Let us know if you have other questions and concerns otherwise, we will be locking this thread after 24 hours. 

Thanks,

Juni