BMM150 functional test and calibration for production testing

[davidlr]

Hi, We are using a BMM150 along with ST LSM6DSL for a product. This product is ready to manufacture, and we are designing some functional tests (real measurements) for the assembling factory doing the SMT works. I am aware of the BMM150 self test, but the factory wants to check with real data that the BMM150 outputs and can verify is in a given spread of values. Could you provide some hints or support on the easiest way to get it done? I have searched for application notes on this but found nothing about soft iron/hard iron cal and real functional tests. Danke schön. Mit freundlichen Grüßen, David

[kgoveas · Accepted solution]

Hi davidlr,

The values read from the BMM150 solely depend on the environment it is in. Typically, it will be a sum of the Earth's magnetic field and the other Soft and Hard iron components in your system, like speakers, magnetic locks, screws etc. in short, the magnetometer's environment and orientation. Modeling this can be done by reading a stream of values from multiple devices you know to be working at the point of test and creating a spread so as to not detect a working device as faulty. This will have to be replicated for each production line.

If I hear about how most of our customer's tackle the same issue, I will post the solution here.

Grüße,

kgoveas