> However on android the sampling rate of the acceleration sensor is limited to 50/s. At least if you install through the official app store.

My understanding is that it’s the same even on iOS (or at least on my iPhone SE 2020). More specifically, the output only measures till 50hz (but the sensor sampling rate is actually 100hz - Nquist, you need double the measured frequency as sampling frequency, yada yada.)

I get 100/s on an iPhone SE2. 50/s on a Samsung Galaxy A16 which was released in 2024 or 2025, but that is due to an API restriction. You can export from phyphox (.xslx or .cvs). You get timestamps in the first column. Phyphox refers to the raw data rate, not Nyquist freq.

The sensors have analog lowpass filters that can be adjusted in order to avoid aliasing.

In general, with more bandwidth you can do more intrusive things. But if you want to tell wether two people ride in the same car, 50 Hz should be sufficient anyways.

Phyphox has a smartphone sensor database:

https://phyphox.org/sensordb/

By the way, it’s important to note that measuring vibrating things can permanently damage the OIS VCs in the camera. (See: Apple’s warning against motorcycle mounts.) my iPhone already had a broken OIS so I didn’t mind as much.

Does the version on f-droid not have that limitation?

That is a possibility, didn’t check

Huh? I get 500 Hz here on a Samsung from 2019 and make use of it regularly. Sensor frequency is one of the things I check before buying a new phone, surely newer Android versions haven't killed that with new api restrictions?!

Edit: no, it can't have. Then the phone sensor database would show that since it is built from submissions within Phyphox: https://phyphox.org/sensordb/

I'm not sure what problem you're running into (perhaps a very unusual phone that has only a 50 Hz accelerometer) but Android/Phyphox can do way more than 50 Hz

It is a Samsung a16 and it is just an observation I made, not a problem at all. If it was, I would try another installation source or even switch to a degoogled OS first to get more control over the hardware. Only thing I tried to get more samples was fiddling with the App restrictions. But it really doesn’t matter at all.

The A16 gets 250~500 Hz according to Phyphox' database (depending on which A16 model you've got)

But I see Google indeed introduced another permission for this: https://developer.android.google.cn/develop/sensors-and-loca...

Curious that the database shows good rates but you're not seeing it in your instance. The device is from 2024 so it'll have shipped with this new restriction; the database submissions can't be from an older android version. Phyphox must declare that permission or else it shouldn't be in the database like that, but then you should also see higher rates in the app. So I don't get it but Android still can do more it seems, if an app is granted the new permission

Thanks for researching. Maybe I failed to give microphone access to phyphox which in my understanding of the source you pointed to limits sensor update rate. Sounds like me because I never grant access for anything I don’t plan to use.