IMU 32

IMU 32 is a project to simplify working with MPU9250 imu sensors and STM32 ARM M3 microprocessors.

MPU9250.h and MPU9250.c

MPU9250.h provides interface which uses the HAL functionality of STM32 and helps in developing applications to interact with imu data.

MPU9250 Abstraction Layer

MPU9250_Writebytes(I2C_HandleTypeDef* mpu_i2c_p, uint8_t reg, uint8_t data, uint8_t size)

Write size number of bytes to the register starting at reg.

MPU9250_Readbytes(I2C_HandleTypeDef* mpu_i2c_p, uint8_t reg, uint8_t* data, uint8_t size)

Read size number of bytes from the register starting at reg.

MPU9250_Writebit(I2C_HandleTypeDef* mpu_i2c_p, uint8_t reg, uint8_t data, uint8_t bit)

Write a bit to the register reg.

MPU9250_Readbit(I2C_HandleTypeDef* mpu_i2c_p, uint8_t reg, uint8_t* data, uint8_t bit)

Read a bit from the register reg.

MPU9250_SetGyroFullScale(I2C_HandleTypeDef* mpu_i2c_p, GYRO_FS_t gyro_fs)

Set Gyro Full Scale Range:
Available ranges (gyro_fs):
GYRO_FS_250dps: 250 deg/sec
GYRO_FS_500dps: 500 deg/sec
GYRO_FS_1000dps: 1000 deg/sec
GYRO_FS_2000dps: 2000 deg/sec

MPU9250_SetAccFullScale(I2C_HandleTypeDef* mpu_i2c_p, ACC_FS_t acc_fs)

Set Accelerometer Full Scale Range:
Available ranges (acc_fs):
ACC_FS_2g: 2 g ~ 20 m/s2
ACC_FS_4g: 4 g ~ 40 m/s2
ACC_FS_8g: 8 g ~ 80 m/s2
ACC_FS_16g: 16 g ~ 160 m/s2

MPU9250_SetGyroOffset(I2C_HandleTypeDef* mpu_i2c_p, int16_t* gyroOffsets)

Set gyro offsets to gyroOffsets[3].

MPU9250_SetAccOffset(I2C_HandleTypeDef* mpu_i2c_p, int16_t* accelOffsets)

Set accelrometer offsets to accelOffsets[3].

MPU9250_ConfigGyroDLPFilter(I2C_HandleTypeDef* mpu_i2c_p, GYRO_DLPF_t gyro_dlpf)

Configure Gyro Digital Low Pass Filter (DLPF).
Available options (gyro_dlpf):
GYRO_DLPF_BW_8800Hz: 8800 Hz bandwidth with 32 kHz of sampling frequency
GYRO_DLPF_BW_3600Hz_Fs_32kHz: 3600 Hz bandwidth with 32 kHz of sampling frequency
GYRO_DLPF_BW_250Hz: 250 Hz bandwidth with 8 kHz of sampling frequency
GYRO_DLPF_BW_184Hz: 184 Hz bandwidth with 1 kHz of sampling frequency
GYRO_DLPF_BW_92Hz: 92 Hz bandwidth with 1 kHz of sampling frequency
GYRO_DLPF_BW_41Hz: 41 Hz bandwidth with 1 kHz of sampling frequency
GYRO_DLPF_BW_20Hz: 20 Hz bandwidth with 1 kHz of sampling frequency
GYRO_DLPF_BW_10Hz: 10 Hz bandwidth with 1 kHz of sampling frequency
GYRO_DLPF_BW_5Hz: 5 Hz bandwidth with 1 kHz of sampling frequency
GYRO_DLPF_BW_3600Hz_Fs_8kHz: 3600 Hz bandwidth with 8 kHz of sampling frequency

MPU9250_ConfigAccelDLPFilter(I2C_HandleTypeDef* mpu_i2c_p, ACCEL_DLPF_t accel_dlpf)

Configure Accelerometer Digital Low Pass Filter (DLPF).
Available options (accel_dlpf):
ACCEL_DLPF_BW_1046Hz: 1046 Hz bandwidth
ACCEL_DLPF_BW_420Hz: 420 Hz bandwidth
ACCEL_DLPF_BW_218Hz: 218 Hz bandwidth
ACCEL_DLPF_BW_99Hz: 99 Hz bandwidth
ACCEL_DLPF_BW_44Hz: 44 Hz bandwidth
ACCEL_DLPF_BW_21Hz: 21 Hz bandwidth
ACCEL_DLPF_BW_10Hz: 10 Hz bandwidth
ACCEL_DLPF_BW_5Hz: 5 Hz bandwidth

EKF.h (TBD) and EKF.c (TBD)

EKF.h provides the interface to implement the Extended Kalman filter algorithm which enables estimation of the orientation of the sensor with extreme accuracy.