/**
* @brief Read magnetometer heading/direction data.
*
* This function obtains magnetometer data for all three axes of the Honeywell
* device. The data is read from six device registers using a multi-byte
* bus transfer. The 10-bit raw results are then assembled from the two
* register values for each axis, including extending the sign bit, to
* form a signed 32-bit value.
*
* Along with the actual sensor data, the LSB byte contains a "new" flag
* indicating if the data for this axis has been updated since the last
* time the axis data was read. Reading either LSB or MSB data will
* clear this flag.
*
* @param hal Address of an initialized sensor device descriptor.
* @param data The address of a vector storing sensor axis data.
* @return bool true if the call succeeds, else false is returned.
*/
static bool hmc5883l_get_heading(sensor_hal_t *hal, sensor_data_t *data)
{
/* Get magnetic field measurements & test for data overflow. */
vector3_t mag_data;
bool result = hmc5883l_get_data(hal, &mag_data);
if (result) {
/* Apply sensitivity adjustment to data */
hmc5883l_apply_sensitivity(&mag_data);
/* Apply measurement offsets to data */
hmc5883l_apply_offset(&mag_data);
/* Calculate direction, inclination, and field strength. */
scalar_t theta; /* direction angle (degrees) */
scalar_t delta; /* inclination angle (degrees) */
scalar_t strength; /* magnetic field intensity */
result = field_direction(&mag_data, &theta, &delta, &strength);
if (result) {
strength *= ((scalar_t)GAUSS_TO_MICRO_TESLA /
scale_table[dev_range]);
data->heading.direction = (int32_t)theta;
data->heading.inclination = (int32_t)delta;
data->heading.strength = (int32_t)strength;
}
}
return result;
}
/**
* @brief Read magnetometer heading/direction data.
*
* This function obtains magnetometer data for all three axes of the AKM
* device. The data is read from six device registers using a multi-byte
* bus transfer. The 10-bit raw results are then assembled from the two
* register values for each axis, including extending the sign bit, to
* form a signed 32-bit value.
*
* Along with the actual sensor data, the LSB byte contains a "new" flag
* indicating if the data for this axis has been updated since the last
* time the axis data was read. Reading either LSB or MSB data will
* clear this flag.
*
* @param hal Address of an initialized sensor hardware descriptor.
* @param data The address of a vector storing sensor axis data.
* @return bool true if the call succeeds, else false is returned.
*/
static bool ak8975_get_heading(sensor_hal_t *hal, sensor_data_t *data)
{
bool result = false;
/* Get magnetic field measurements & test for data overflow. */
vector3_t mag_data;
if (ak8975_get_data(hal, AK8975_SINGLE_MODE, &mag_data) &&
(!ak8975_check_overflow(&mag_data))) {
/* Apply stored measurement offsets to data. */
ak8975_apply_offset(&mag_data);
/* Calculate direction, inclination, and field strength. */
scalar_t theta; /* direction angle (degrees) */
scalar_t delta; /* inclination angle (degrees) */
scalar_t strength; /* magnetic field intensity */
result = field_direction(&mag_data, &theta, &delta, &strength);
if (result) {
strength *= (scalar_t)MICRO_TESLA_PER_COUNT;
data->heading.direction = (int32_t)theta;
data->heading.inclination = (int32_t)delta;
data->heading.strength = (int32_t)strength;
}
}
return result;
}
