Question
Sparse LIS331 Datasheet(s)
Posted on July 12, 2018 at 08:16
Dear all - especially STM developers,
I recently integrated an LIS331HH sensor. It seams to be very nice sensor! But anyway while reading LIS331 Datasheet, I found that information required for proper MCU driver implementation (especially interrupt-related information) missing.
Even though some information become clear during repeated reading of Datasheet, something remains unclear. Even though I was able to find proper settings experimentally, it took some time...
Some points:
- The two's complement output (OUT_X_L, OUT_X_H, ...) range is not explicitely given (it is clear after repeated Datasheet reading, but implicitly hidden) - is it full range (16bit two's complement used? or there are limits? e.g. -4096 to 4096?) - I found, that full range is used for LIS331HH, but other family members are be different (I have no experience, but I saw code here:
https://github.com/szotsaki/LIS331/blob/master/src/LIS331.cpp
) - missing explicite range declaration in Datasheet causes confusion - meaning of threshold and other interrupt-related settings is foggy:
- it is unclear how to set-up threshold value (INT1_THS/INT2_THS) - depends on range ...
- for XLIE interrupt: 'value lower than preset threshold' is ambiguous (same for other interrupts): means 'abs(INT1_THS) > abs(accel)' or '- INT1_THS > accel', thus signaling 'crossing threshold back to defined range' or 'crossing threshold out of range'
- self-test function is described poorly (missing use-case?)
Please, could you clarify here or extend the datasheet?
Thank you!
Jan