Hi,
While trying to calibrate the magnetometer, upon successive failures, I noticed that the values that were read for the Y and Z axes are successively repeated until a different value is read (as can be seen below). It appears that there's some kind of great threshold for a new value to be stored in the register.
It's hard to debug this issue, especially since the documentation on the magnetometer of the LSM9DS1 is quite scarce (namely its functionality, as opposed to the accelerometer and gyroscope on the datasheet).
The configuration is as follows:
int32_t IMU_config(IMU_FW * imu){
/* Check device ID */
lsm9ds1_id_t whoamI;
lsm9ds1_dev_id_get(&imu->dev_ctx_mag, &imu->dev_ctx_imu, &whoamI);
if (whoamI.imu != LSM9DS1_IMU_ID || whoamI.mag != LSM9DS1_MAG_ID){
while(1){
return 0;
}
}
/* Restore default configuration */
uint8_t rst;
lsm9ds1_dev_reset_set(&imu->dev_ctx_mag, &imu->dev_ctx_imu, PROPERTY_ENABLE);
do {
lsm9ds1_dev_reset_get(&imu->dev_ctx_mag, &imu->dev_ctx_imu, &rst);
} while (rst);
/* Little-Endian Format Selection */
lsm9ds1_dev_data_format_set(&imu->dev_ctx_mag, &imu->dev_ctx_imu, LSM9DS1_LSB_LOW_ADDRESS);
/* Enable Block Data Update */
lsm9ds1_block_data_update_set(&imu->dev_ctx_mag, &imu->dev_ctx_imu, PROPERTY_DISABLE);
/* Set INT1 as Gyroscope Data Ready */
lsm9ds1_pin_int1_route_t val;
val.int1_drdy_xl = 0;
val.int1_drdy_g = 1;
val.int1_boot = 0;
val.int1_fth = 0;
val.int1_ovr = 0;
val.int1_fss5 = 0;
val.int1_ig_xl = 0;
val.int1_ig_g = 0;
lsm9ds1_pin_int1_route_set(&imu->dev_ctx_imu, val);
/* Set full scale */
lsm9ds1_xl_full_scale_set(&imu->dev_ctx_imu, LSM9DS1_4g);
lsm9ds1_gy_full_scale_set(&imu->dev_ctx_imu, LSM9DS1_2000dps);
lsm9ds1_mag_full_scale_set(&imu->dev_ctx_mag, LSM9DS1_16Ga);
/* Configure filtering chain - See datasheet for filtering chain details */
/* Accelerometer filtering chain */
lsm9ds1_xl_filter_aalias_bandwidth_set(&imu->dev_ctx_imu, LSM9DS1_AUTO);
lsm9ds1_xl_filter_lp_bandwidth_set(&imu->dev_ctx_imu, LSM9DS1_LP_ODR_DIV_50);
lsm9ds1_xl_filter_out_path_set(&imu->dev_ctx_imu, LSM9DS1_LP_OUT);
/* Gyroscope filtering chain */
lsm9ds1_gy_filter_lp_bandwidth_set(&imu->dev_ctx_imu, LSM9DS1_LP_STRONG);
lsm9ds1_gy_filter_hp_bandwidth_set(&imu->dev_ctx_imu, LSM9DS1_HP_MEDIUM);
lsm9ds1_gy_filter_out_path_set(&imu->dev_ctx_imu, LSM9DS1_LPF1_HPF_LPF2_OUT);
/* Set Output Data Rate / Power mode */
lsm9ds1_imu_data_rate_set(&imu->dev_ctx_imu, 0xA2);
lsm9ds1_mag_data_rate_set(&imu->dev_ctx_mag, 0x27);
//IMU_setInertialRate(imu, IMU_59Hz5);
//IMU_setMagnetometerRate(imu, MAG_80Hz);
/* Set SPI as communication interface */
lsm9ds1_sim_t random;
uint32_t ret = lsm9ds1_spi_mode_set(&imu->dev_ctx_mag, &imu->dev_ctx_imu,LSM9DS1_SPI_4_WIRE);
lsm9ds1_spi_mode_get(&imu->dev_ctx_mag, &imu->dev_ctx_imu,&random);
lsm9ds1_i2c_dis_t rand;
ret = lsm9ds1_i2c_interface_set(&imu->dev_ctx_mag,&imu->dev_ctx_imu,LSM9DS1_I2C_DISABLE);
ret = lsm9ds1_i2c_interface_get(&imu->dev_ctx_mag,&imu->dev_ctx_imu,&rand);
return 1;
}
I have attached a .csv file that serves as a datalog of the several readings while rotating the LSM9DS1 with the motion described in section 2.2.5 of the UM2192.
Any idea on what might be causing this issue?
Thanks in advance.
