LSM6DS3 - How to avoid Acceleration steps when temperature changes?

Ronald Niederhagen · ‎2023-03-07

I'm observing steps in acceleration values (X, Y, and Z likewise) when chip temperature changes (as read through OUT_TEMP_L (20h), OUT_TEMP(21h)). A graph is appended below. It shows the temperature converted to Celsius in dark blue, scale on the right Y axis, and the acceleration values in Units, in light blue. I would expect noisy acceleration values, maybe drifting with temperature, but NO steps!

Acceleration full scale: 4G

Acceleration sample rate: 416Hz

FIFO sample rate: 100Hz

The relevant register settings is here:

Reg 0x6 = 0x0 = 0000 0000

Reg 0x7 = 0x0 = 0000 0000

Reg 0x8 = 0x9 = 0000 1001

Reg 0x9 = 0x0 = 0000 0000

Reg 0xa = 0x26 = 0010 0110

Reg 0x10 = 0x6b = 0110 1011

Reg 0x11 = 0x60 = 0110 0000

Reg 0x12 = 0x44 = 0100 0100

Reg 0x13 = 0x84 = 1000 0100

Reg 0x14 = 0x0 = 0000 0000

Reg 0x15 = 0x0 = 0000 0000

Reg 0x16 = 0x40 = 0100 0000

Reg 0x17 = 0x0 = 0000 0000

Reg 0x18 = 0x38 = 0011 1000

Reg 0x19 = 0x38 = 0011 1000

Ronald Niederhagen · ‎2023-09-28

I'm led to believe this is a systemic bug in the LSM6DS3. I've seen it now in many individual devices of that type. It might be a bug in the internal temperature compensation. But I'm only speculating

I'd be very interested to hear from official side at ST what they say about this issue.