MetaHub max total frequency 20 Hz

levdikpavel

Hi!

I have an issue during data streaming with MetaHub (Android).

I am running MetaHub 1.1.4 on Samsung Galaxy S III GT-I9300 running Android 4.3.

My MetaMotion R have firmware 1.3.3.

I have a problem. I try to stream data and the max total stream frequency is 20 samples per second. Even if i set stream frequency 100 hz for accelerometer, Samsung stream only 20 Hz. 

levdikpavel

Here is the print screen of data example:

The filename tells us about 100 Hz frequency (as it was set), but in fact samples writes every 0.05 s - that is 20 Hz.

I also tried to turn on multiple sensors - Acc, Gyro, Mag, Pressure and total frequency was 20 Hz. 

So Samsung can only write 20 samples per second.

And the mystic is that on the other Android device - Xiaomi Mi Note 3 running Android 5.0.2 - there is no such problem (but it has other problem). 

Am I doing smth wrong? How does this depend on the device? 

I want to buy 8 smartphones to stream 8 Motion R and I want to be sure they will work OK, but now I don't know why one device can stream 100 Hz and the other can't.

Eric

Not all Android phones have the same BLE stack and radios, and BLE support was very shoddy on Android 4.3 compared to later releases.  In our experience, the Android devices with a good BLE implementation are Nexus devices (5, 6, 9) running Android M or later.  Any device newer than a Nexus 5 running Android 4.4 or later should also be a safe bet.

levdikpavel

Ok, thank you