Hi @NicolasGoualard ,
While reviewing the code you shared, we noticed that in the section you indicated, a fundamental step was missing. This step is described in the Application Manual AN5845.
int imu_start_acquisition(imu_recording_state_t wanted_state)
{
lsm6dsv16bx_pin_int_route_t pin1_int = {0};
lsm6dsv16bx_fifo_sflp_raw_t fifo_sflp = {0};
lsm6dsv16bx_filt_settling_mask_t filt_settling_mask = {0};
int ret;
sensor.state.recording_state = wanted_state;
/* Enable Block Data Update */
ret = lsm6dsv16bx_block_data_update_set(&sensor.dev_ctx, PROPERTY_ENABLE);
if (ret) {
LOG_ERR("lsm6dsv16bx_block_data_update_set (%i)", ret);
return ret;
}
/* 2. Configuration Init*/
ret = lsm6dsv16bx_sflp_configure(&sensor.dev_ctx);
if (ret) {
LOG_ERR("lsm6dsv16bx_sflp_configure (%i)", ret);
return ret;
}
/* Set full scale */
ret = lsm6dsv16bx_xl_full_scale_set(&sensor.dev_ctx, LSM6DSV16BX_8g);
if (ret) {
LOG_ERR("lsm6dsv16bx_xl_full_scale_set (%i)", ret);
return ret;
}
ret = lsm6dsv16bx_gy_full_scale_set(&sensor.dev_ctx, LSM6DSV16BX_2000dps);
if (ret) {
LOG_ERR("lsm6dsv16bx_gy_full_scale_set (%i)", ret);
return ret;
}
/*
* Set FIFO watermark (number of unread sensor data TAG + 6 bytes
* stored in FIFO) to CONFIG_LSM6DSV16BX_FIFO_WATERMARK samples
*/
ret = lsm6dsv16bx_fifo_watermark_set(&sensor.dev_ctx, 25);
if (ret) {
LOG_ERR("lsm6dsv16bx_fifo_watermark_set (%i)", ret);
return ret;
}
/* Set FIFO batch of sflp data */
fifo_sflp.game_rotation = wanted_state.sflp_state.game_rot_enabled; // true
fifo_sflp.gravity = wanted_state.sflp_state.gravity_enabled; // false
fifo_sflp.gbias = wanted_state.sflp_state.gbias_enabled; // false
ret = lsm6dsv16bx_fifo_sflp_batch_set(&sensor.dev_ctx, fifo_sflp);
if (ret) {
LOG_ERR("lsm6dsv16bx_fifo_sflp_batch_set (%i)", ret);
return ret;
}
/* Set FIFO mode to Stream mode (aka Continuous Mode) */
ret = lsm6dsv16bx_fifo_mode_set(&sensor.dev_ctx, LSM6DSV16BX_STREAM_MODE);
if (ret) {
LOG_ERR("lsm6dsv16bx_fifo_mode_set (%i)", ret);
return ret;
}
pin1_int.fifo_th = PROPERTY_ENABLE;
ret = lsm6dsv16bx_pin_int1_route_set(&sensor.dev_ctx, pin1_int);
if (ret) {
LOG_ERR("lsm6dsv16bx_pin_int1_route_set (%i)", ret);
return ret;
}
/* Set High Performance mode */
ret = lsm6dsv16bx_xl_mode_set(&sensor.dev_ctx, LSM6DSV16BX_XL_HIGH_PERFORMANCE_MD);
if (ret)
{
LOG_ERR("lsm6dsv16bx_xl_mode_set %i", ret);
return ret;
}
/* Set Output Data Rate */
ret = lsm6dsv16bx_xl_data_rate_set(&sensor.dev_ctx, LSM6DSV16BX_XL_ODR_AT_960Hz);
if (ret) {
LOG_ERR("lsm6dsv16bx_xl_data_rate_set (%i)", ret);
return ret;
}
/* Set High Performance mode */
ret = lsm6dsv16bx_gy_mode_set(&sensor.dev_ctx, LSM6DSV16BX_GY_HIGH_PERFORMANCE_MD);
if (ret)
{
LOG_ERR("lsm6dsv16bx_xl_mode_set %i", ret);
return ret;
}
/* Set Output Data Rate */
ret = lsm6dsv16bx_gy_data_rate_set(&sensor.dev_ctx, LSM6DSV16BX_GY_ODR_AT_960Hz);
if (ret) {
LOG_ERR("lsm6dsv16bx_gy_data_rate_set (%i)", ret);
return ret;
}
if (wanted_state.sflp_state.gbias_enabled || wanted_state.sflp_state.game_rot_enabled || wanted_state.sflp_state.gravity_enabled)
{
ret = lsm6dsv16bx_sflp_data_rate_set(&sensor.dev_ctx, LSM6DSV16BX_SFLP_120Hz);
if (ret) {
LOG_ERR("lsm6dsv16bx_sflp_data_rate_set (%i)", ret);
return ret;
}
}
if (wanted_state.sflp_state.game_rot_enabled || wanted_state.sflp_state.gravity_enabled || wanted_state.sflp_state.gbias_enabled)
{
ret = lsm6dsv16bx_sflp_game_rotation_set(&sensor.dev_ctx, PROPERTY_ENABLE);
if (ret) {
LOG_ERR("lsm6dsv16bx_sflp_game_rotation_set (%i)", ret);
return ret;
}
lsm6dsv16bx_sflp_gbias_t gbias;
gbias.gbias_x = 0.0f;
gbias.gbias_y = 0.0f;
gbias.gbias_z = 0.0f;
ret = lsm6dsv16bx_sflp_game_gbias_set(&sensor.dev_ctx, &gbias);
if (ret) {
LOG_ERR("lsm6dsv16bx_sflp_game_gbias_set (%i)", ret);
return ret;
}
}
/* Mask accelerometer and gyroscope data until the settling of the sensors filter is completed */
filt_settling_mask.drdy = PROPERTY_ENABLE;
filt_settling_mask.irq_xl = PROPERTY_ENABLE;
filt_settling_mask.irq_g = PROPERTY_ENABLE;
ret = lsm6dsv16bx_filt_settling_mask_set(&sensor.dev_ctx, filt_settling_mask);
if (ret) {
LOG_ERR("lsm6dsv16bx_filt_settling_mask_set (%i)", ret);
return ret;
}
return 0;
}
I took the liberty to modify some parts.
I noticed that you were saving accelerometer and gyroscope values as well as the timestamp into the FIFO. For an initial test, I removed these to simplify the results and avoid the risk of incorrect data.
Please try running the test again with these modifications, and the expected results should be obtained.
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