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drivers: sensor: lsm303dlhc_mag: Fix gain factor

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The magnetometer on the LSM303DLHC has a different gain conversion
factor for LSB to Gauss for the Z axis than it does for X, Y. This
commit takes into account the different conversion factors, and
adds the correct coefficients for each gain setting and axis.

Signed-off-by: Kevin Townsend <kevin.townsend@linaro.org>
This commit is contained in:
Kevin Townsend 2021-09-28 13:04:59 +02:00 • committed by Christopher Friedt
commit 21321fba1c
2 changed files with 30 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

25
drivers/sensor/lsm303dlhc_magn/lsm303dlhc_magn.c
View file

@ -52,11 +52,18 @@ static int lsm303dlhc_sample_fetch(const struct device *dev,
return 0;
}
static void lsm303dlhc_convert(struct sensor_value *val,
static void lsm303dlhc_convert_xy(struct sensor_value *val,
int64_t raw_val)
{
val->val1 = raw_val / LSM303DLHC_MAGN_LSB_GAUSS;
val->val2 = (1000000 * raw_val / LSM303DLHC_MAGN_LSB_GAUSS) % 1000000;
val->val1 = raw_val / LSM303DLHC_MAGN_LSB_GAUSS_XY;
val->val2 = (1000000 * raw_val / LSM303DLHC_MAGN_LSB_GAUSS_XY) % 1000000;
}
static void lsm303dlhc_convert_z(struct sensor_value *val,
int64_t raw_val)
{
val->val1 = raw_val / LSM303DLHC_MAGN_LSB_GAUSS_Z;
val->val2 = (1000000 * raw_val / LSM303DLHC_MAGN_LSB_GAUSS_Z) % 1000000;
}
static int lsm303dlhc_channel_get(const struct device *dev,
@ -67,18 +74,18 @@ static int lsm303dlhc_channel_get(const struct device *dev,
switch (chan) {
case SENSOR_CHAN_MAGN_X:
lsm303dlhc_convert(val, drv_data->magn_x);
lsm303dlhc_convert_xy(val, drv_data->magn_x);
break;
case SENSOR_CHAN_MAGN_Y:
lsm303dlhc_convert(val, drv_data->magn_y);
lsm303dlhc_convert_xy(val, drv_data->magn_y);
break;
case SENSOR_CHAN_MAGN_Z:
lsm303dlhc_convert(val, drv_data->magn_z);
lsm303dlhc_convert_z(val, drv_data->magn_z);
break;
case SENSOR_CHAN_MAGN_XYZ:
lsm303dlhc_convert(val, drv_data->magn_x);
lsm303dlhc_convert(val + 1, drv_data->magn_y);
lsm303dlhc_convert(val + 2, drv_data->magn_z);
lsm303dlhc_convert_xy(val, drv_data->magn_x);
lsm303dlhc_convert_xy(val + 1, drv_data->magn_y);
lsm303dlhc_convert_z(val + 2, drv_data->magn_z);
break;
default:
return -ENOTSUP;

21
drivers/sensor/lsm303dlhc_magn/lsm303dlhc_magn.h
View file

@ -37,19 +37,26 @@
LSM303DLHC_MAGN_ODR_SHIFT)
#if (CONFIG_LSM303DLHC_MAGN_RANGE == 1)
#define LSM303DLHC_MAGN_LSB_GAUSS 1100
#define LSM303DLHC_MAGN_LSB_GAUSS_XY 1100
#define LSM303DLHC_MAGN_LSB_GAUSS_Z 980
#elif (CONFIG_LSM303DLHC_MAGN_RANGE == 2)
#define LSM303DLHC_MAGN_LSB_GAUSS 760
#define LSM303DLHC_MAGN_LSB_GAUSS_XY 855
#define LSM303DLHC_MAGN_LSB_GAUSS_Z 760
#elif (CONFIG_LSM303DLHC_MAGN_RANGE == 3)
#define LSM303DLHC_MAGN_LSB_GAUSS 600
#define LSM303DLHC_MAGN_LSB_GAUSS_XY 670
#define LSM303DLHC_MAGN_LSB_GAUSS_Z 600
#elif (CONFIG_LSM303DLHC_MAGN_RANGE == 4)
#define LSM303DLHC_MAGN_LSB_GAUSS 400
#define LSM303DLHC_MAGN_LSB_GAUSS_XY 450
#define LSM303DLHC_MAGN_LSB_GAUSS_Z 400
#elif (CONFIG_LSM303DLHC_MAGN_RANGE == 5)
#define LSM303DLHC_MAGN_LSB_GAUSS 355
#define LSM303DLHC_MAGN_LSB_GAUSS_XY 400
#define LSM303DLHC_MAGN_LSB_GAUSS_Z 355
#elif (CONFIG_LSM303DLHC_MAGN_RANGE == 6)
#define LSM303DLHC_MAGN_LSB_GAUSS 295
#define LSM303DLHC_MAGN_LSB_GAUSS_XY 330
#define LSM303DLHC_MAGN_LSB_GAUSS_Z 295
#elif (CONFIG_LSM303DLHC_MAGN_RANGE == 7)
#define LSM303DLHC_MAGN_LSB_GAUSS 205
#define LSM303DLHC_MAGN_LSB_GAUSS_XY 230
#define LSM303DLHC_MAGN_LSB_GAUSS_Z 205
#endif
#define LSM303DLHC_MAGN_FS_SHIFT 5