MotionFX Library frequency : can work correctly with variable frequency or less than 100Hz ?

[malarab]

Hi,

I am using MotionFX Library on stm32wl55 (CM4 without FPU). run at 48MHz (max frequency)

it is impossible to run MotionFX_CM4F_wc32_ot.a

so i use :MotionFX_CM3_wc32_ot.a and it is work.

 

by debugging, the MotionFX_manager_run function take different execution time in different cycles?. in general, it tack 1 or 2 ms for 3 or 4 cycles, than 10 to 15 ms for the 5th cycle ! (trying Oz and Ofast optimisation)

it is normal ?

in attachment a screenshot for fusion execution real time record.

 

 

the lowest recommended frequency on the UM2220 is 100Hz.

in my case it is just impossible to do faster !

so is the library can work correctly if i set a lower frequency ?

the third argument in MotionFX_manager_run(pdata_in, pdata_out, MOTION_FX_ENGINE_DELTATIME) can be a variable (set the real delta time between two execution)? because in ST examples it is always set to a fix value.

if you have other recommendation to reduce the time of execution, pleas tel me :)

 

Thank you,

Sincerely.

 

 

 

[malarab]

When MotionFX_manager_run takes more time, it is due to the MotionFX_update call.

It is possible to reduce the number of calls by increasing DECIMATION.

To process all data correctly and obtain the correct output from the sensor fusion algorithm, I read the data from the IMU when an interrupt occurs (INT1 is set when data is available), i save the data in a FreeRTOS queue, then it is processed later by a specific task