LSM6DSV16X accelerometer settings for low noise readout for small movements

[Stefan3]

I want to recognise small movements with small acceleration.

Which mode is best suited?

Is it better to have a high sampling rate or a lower one?

which filters?

where do the large peaks (incorrect values) come from?

But I can already recognise the acceleration and braking

[Federica Bossi]

Hi @Stefan3 ,

A smaller FS range (e.g., ±2g) will provide higher sensitivity and better resolution for detecting small accelerations.

A higher sampling rate can capture more data points and provide a more detailed representation of the movement. This is useful for detecting small and rapid changes in acceleration. However, it will also increase power consumption and the amount of data to process.

I suggest you to use High-accuracy ODR (HAODR) mode. This mode typically offers better precision and lower noise.

About the incorrect values, did you enable the BDU bit?

[Stefan3]

Hi Federica

±2g is set.

I haven't done anything yet
except set CTRL1(10h) to 960Hz and read with 10mSec (100Hz) with the I2C bus (1MHz).

I have enough power available but reading faster than 100Hz is not so easy.

Should I choose low-power mode3 (8mean)? Or a high performance mode?

Should I enable the BDU bit anyway?

 

[Federica Bossi]

Hi @Stefan3 ,

Yes, it is always suggested to enable the BDU bit.

In addition, high performance mode is suggested for this kind of application :)

[Stefan3]

Hi Federica

I can select different frequencies on the LSM6DSV16X

samplerate 15,30,60,120,240,480,960,1920,3840,7680 in Hz

can i also sample these at slightly higher frequencies?

960=>1000

1920=>2000

3840=>4000

7680=>8000

[Federica Bossi]

Hi @Stefan3 ,

Unfortunately, you cannot directly set the LSM6DSV16X to sample at frequencies slightly higher than these predefined rates. The ODRs are determined by the internal clock and configuration of the sensor, and they are fixed to the values specified in the datasheet.

[Andrea VITALI]

You can sample at 1000, 2000, 4000, 8000Hz.

As mentioned above: enable HA-ODR mode (high-accuracy ODR more) - see AN5763 section 3.1 page 18, table 11. You have 3 sets of ODR available: multiples of 15Hz, multiples of 15.625Hz, and multiples of 12.5Hz. 

The option in the middle is what you need: as you see in table 11!