Guaranteed specs on the ISM330DHCX specially accelerometer part

[IMaru.1]

Hello support team,

We are decided to use your ISM330DHCX for our next products. So we are ongoing to describing the FW requirement to the FW team in our organization.

However, I’m not sure we should use the USER OFFSET registers in device for the offset calibration. I think some of specs as described in the d/s (ie: LA_So, LA_Cx) are assumed with use the USER OFFSET registers. Is it correct? Or, even not use the USER OFFSET registers but the specs are guaranteed? I think for the offset calibration, the USER OFFSET registers should be used but some colleagues believe no use the USER OFFSET registers should be ok and the offset value can store in the memory in the MCU and use for the calibration by the MCU at each time as to decide the angles.

Please give us your advice.

Best regards,

Izumi Maruyama

[Eleon BORLINI · Accepted solution]

Hi Izumi @IMaru.1​ ,

basically, the USER OFFSET allows the user to fine-tune the residual offset at application level, that could be the result of soldering stresses, mounting effects, etc... So these are empty registers (referring to each axis) that can be filled by the user after he/she has characterized the zero g-level or zero rate level with the device mounted on the application board.

This means that the ISM330DHCX is calibrated "per-se" at production level (and they are stored at flash level in the "reserved" registers, so they are uploaded after the device booting), but it might suffer from little deviation from the zero calibration independent from the production test. This last value can be written in volatile memory by the user firmware / software and the register content will be automatically subtracted by the internal ASIC during the data acquisition process, without need of p

post-processing compensation.

-Eleon

[IMaru.1]

Thanks Eleon,

I’m now clear.

Best regards,

Izumi Maruyama