Hi Everyone,
I'm currently migrating from LSM6DSM to LSM6DSO in my application and facing some issues with accelerometer accuracy in stable conditions.
System Overview:
MCU: STM32L4
Sensor Interface: SPI (3-wire)
Purpose: Reading raw accelerometer and gyroscope data, converting to physical units, and estimating roll/pitch/yaw using MotionFX.
Configuration Details:
Parameter Value
| Acc/Gyro ODR | 1.6 kHz |
| FIFO Output Rate | 400 Hz |
| Main Loop Rate | 100 Hz |
| Averaging | 4 samples/frame |
What’s Working:
I can successfully communicate with LSM6DSO via 3-wire SPI.
I’m able to read raw data from the accelerometer and gyroscope.
Sensor fusion (MotionFX) works and outputs roll, pitch, and yaw.
- With LSM6DSM, I was getting clean and accurate data as expected.
Problem:
I'm trying to measure raw linear acceleration (after converting to g).
The requirement is that the noise level (in a static, stable condition) should be less than ±0.005g in all directions.
With LSM6DSO, the data seems noisier and less accurate, even though I'm using the same processing and averaging method.
The Register Configuration of LSM6DSM and LSM6DSO -
The flow to read the data from LSM6DSO is
typedef struct
{
int16_t acc[3];
}AccRawData_t;
AccRawData_t read_lsm6dso_data;
if((Mems_ID & MEMS_ID_LSM6DSO_ID) == MEMS_ID_LSM6DSO_ID)
{
number_of_words_available = Mems_get_available_samples();
number_of_samples_available = number_of_words_available;
Test_noOfwordsAvailable = number_of_samples_available;
for (int j = 0; j < number_of_samples_available; j++)
{
Mems_get_data_type(&pattern);
Mems_get_dso_raw_data(read_lsm6dso_data.acc);
switch(pattern)
{
case LSM6DSO_GYRO_DATA_TYPE:
gyro_raw_data[acc_raw_buffer_index].gyro[0] = read_lsm6dso_data.acc[0];
gyro_raw_data[acc_raw_buffer_index].gyro[1] = read_lsm6dso_data.acc[1];
gyro_raw_data[acc_raw_buffer_index].gyro[2] = read_lsm6dso_data.acc[2];
break;
case LSM6DSO_ACC_DATA_TYPE:
acc_raw_buffer[acc_raw_buffer_index].acc[0] = read_lsm6dso_data.acc[0];
acc_raw_buffer[acc_raw_buffer_index].acc[1] = read_lsm6dso_data.acc[1];
acc_raw_buffer[acc_raw_buffer_index].acc[2] = read_lsm6dso_data.acc[2];
break;
default:
dso_fail_count++;
break;
}
acc_avg[0] += acc_raw_buffer[acc_raw_buffer_index].acc[0];
acc_avg[1] += acc_raw_buffer[acc_raw_buffer_index].acc[1];
acc_avg[2] += acc_raw_buffer[acc_raw_buffer_index].acc[2];
gyro_avg[0] += gyro_raw_data[acc_raw_buffer_index].gyro[0];
gyro_avg[1] += gyro_raw_data[acc_raw_buffer_index].gyro[1];
gyro_avg[2] += gyro_raw_data[acc_raw_buffer_index].gyro[2];
}
Kindly help me to fix the acceleration data to get it's Noise level low.
