some more doxygen comments

sw/airborne/subsystems/ahrs.h

@@ -19,6 +19,10 @@
  * Boston, MA 02111-1307, USA.
  */
 
+/** \file ahrs.h
+ * \brief Attitude and Heading Reference System interface
+ */
+
 #ifndef AHRS_H
 #define AHRS_H
 
@@ -34,41 +38,44 @@
 #include AHRS_TYPE_H
 #endif
 
-
+/** Attitude and Heading Reference System state (fixed point version) */
 struct Ahrs {
 
-    struct Int32Quat   ltp_to_imu_quat;
-    struct Int32Eulers ltp_to_imu_euler;
-    struct Int32RMat   ltp_to_imu_rmat;
-    struct Int32Rates  imu_rate;
+  struct Int32Quat   ltp_to_imu_quat;  ///< Rotation from LocalTangentPlane to IMU frame as unit quaternion
+  struct Int32Eulers ltp_to_imu_euler; ///< Rotation from LocalTangentPlane to IMU frame as Euler angles
+  struct Int32RMat   ltp_to_imu_rmat;  ///< Rotation from LocalTangentPlane to IMU frame as Rotation Matrix
+  struct Int32Rates  imu_rate;         ///< Rotational velocity in IMU frame
 
-    struct Int32Quat   ltp_to_body_quat;
-    struct Int32Eulers ltp_to_body_euler;
-    struct Int32RMat   ltp_to_body_rmat;
-    struct Int32Rates  body_rate;
+  struct Int32Quat   ltp_to_body_quat;  ///< Rotation from LocalTangentPlane to body frame as unit quaternion
+  struct Int32Eulers ltp_to_body_euler; ///< Rotation from LocalTangentPlane to body frame as Euler angles
+  struct Int32RMat   ltp_to_body_rmat;  ///< Rotation from LocalTangentPlane to body frame as Rotation Matrix
+  struct Int32Rates  body_rate;         ///< Rotational velocity in body frame
 
-    uint8_t status;
+  uint8_t status; ///< status of the AHRS, AHRS_UNINIT or AHRS_RUNNING
 };
 
+/** Attitude and Heading Reference System state (floating point version) */
 struct AhrsFloat {
-  struct FloatQuat   ltp_to_imu_quat;
-  struct FloatEulers ltp_to_imu_euler;
-  struct FloatRMat   ltp_to_imu_rmat;
-  struct FloatRates  imu_rate;
+  struct FloatQuat   ltp_to_imu_quat;  ///< Rotation from LocalTangentPlane to IMU frame as unit quaternion
+  struct FloatEulers ltp_to_imu_euler; ///< Rotation from LocalTangentPlane to IMU frame as Euler angles
+  struct FloatRMat   ltp_to_imu_rmat;  ///< Rotation from LocalTangentPlane to IMU frame as Rotation Matrix
+  struct FloatRates  imu_rate;         ///< Rotational velocity in IMU frame
   struct FloatRates  imu_rate_previous;
   struct FloatRates  imu_rate_d;
 
-  struct FloatQuat   ltp_to_body_quat;
-  struct FloatEulers ltp_to_body_euler;
-  struct FloatRMat   ltp_to_body_rmat;
-  struct FloatRates  body_rate;
+  struct FloatQuat   ltp_to_body_quat;  ///< Rotation from LocalTangentPlane to body frame as unit quaternion
+  struct FloatEulers ltp_to_body_euler; ///< Rotation from LocalTangentPlane to body frame as Euler angles
+  struct FloatRMat   ltp_to_body_rmat;  ///< Rotation from LocalTangentPlane to body frame as Rotation Matrix
+  struct FloatRates  body_rate;         ///< Rotational velocity in body frame
   struct FloatRates  body_rate_d;
 
   // always use status from fixed point ahrs struct for now
   //uint8_t status;
 };
 
+/** global AHRS state (fixed point version) */
 extern struct Ahrs ahrs;
+/** global AHRS state (floating point version) */
 extern struct AhrsFloat ahrs_float;
 
 extern float ahrs_mag_offset;
@@ -86,10 +93,33 @@ extern float ahrs_mag_offset;
     RATES_BFP_OF_REAL(ahrs.body_rate, ahrs_float.body_rate);                   \
   }
 
+/** AHRS initialization. Called at startup.
+ *  Needs to be implemented by each AHRS algorithm.
+ */
 extern void ahrs_init(void);
+
+/** Aligns the AHRS. Called after ahrs_aligner has run to set initial attitude and biases.
+ *  Must set the ahrs status to AHRS_RUNNING.
+ *  Needs to be implemented by each AHRS algorithm.
+ */
 extern void ahrs_align(void);
+
+/** Propagation. Usually integrates the gyro rates to angles.
+ *  Reads the global #imu data struct.
+ *  Needs to be implemented by each AHRS algorithm.
+ */
 extern void ahrs_propagate(void);
+
+/** Update AHRS state with accerleration measurements.
+ *  Reads the global #imu data struct.
+ *  Needs to be implemented by each AHRS algorithm.
+ */
 extern void ahrs_update_accel(void);
+
+/** Update AHRS state with magnetometer measurements.
+ *  Reads the global #imu data struct.
+ *  Needs to be implemented by each AHRS algorithm.
+ */
 extern void ahrs_update_mag(void);
 
 #endif /* AHRS_H */

sw/airborne/subsystems/gps.c

@@ -19,6 +19,11 @@
  * Boston, MA 02111-1307, USA.
  */
 
+/** @file gps.c
+ *  @brief Device independent GPS code
+ *
+ */
+
 #include "subsystems/gps.h"
 
 #include "led.h"

sw/airborne/subsystems/gps.h

@@ -20,7 +20,7 @@
  */
 
 /** @file gps.h
- *  @brief Device independent GPS code
+ *  @brief Device independent GPS code (interface)
  *
  */
 
@@ -48,16 +48,17 @@
 #define GPS_NB_CHANNELS 1
 #endif
 
-/** Space Vehicle Information */
+/** data structure for Space Vehicle Information of a single satellite */
 struct SVinfo {
-  uint8_t svid;
-  uint8_t flags;
-  uint8_t qi;
-  uint8_t cno;
-  int8_t elev;  ///< deg
-  int16_t azim; ///< deg
+  uint8_t svid;  ///< Satellite ID
+  uint8_t flags; ///< bitfield with GPS receiver specific flags
+  uint8_t qi;    ///< quality bitfield (GPS receiver specific)
+  uint8_t cno;   ///< Carrier to Noise Ratio (Signal Strength) in dbHz
+  int8_t elev;   ///< elevation in deg
+  int16_t azim;  ///< azimuth in deg
 };
 
+/** data structure for GPS information */
 struct GpsState {
   struct EcefCoor_i ecef_pos;    ///< position in ECEF in cm
   struct LlaCoor_i lla_pos;      ///< position in LLA (lat,lon: rad*1e7; alt: mm over ellipsoid)
@@ -77,7 +78,7 @@ struct GpsState {
   uint32_t tow;                  ///< time of week in ms
 
   uint8_t nb_channels;           ///< Number of scanned satellites
-  struct SVinfo svinfos[GPS_NB_CHANNELS];
+  struct SVinfo svinfos[GPS_NB_CHANNELS]; ///< holds information from the Space Vehicles (Satellites)
 
   uint32_t last_fix_ticks;       ///< cpu time in ticks at last valid fix
   uint16_t last_fix_time;        ///< cpu time in sec at last valid fix
@@ -90,6 +91,7 @@ struct GpsTimeSync {
   uint32_t t0;          ///< for time sync: hw clock ticks when GPS message is received
 };
 
+/** global GPS state */
 extern struct GpsState gps;
 
 

sw/airborne/subsystems/imu.c

@@ -21,6 +21,10 @@
  * Boston, MA 02111-1307, USA.
  */
 
+/** \file imu.c
+ * \brief Inertial Measurement Unit interface
+ */
+
 #include "subsystems/imu.h"
 
 struct Imu imu;

sw/airborne/subsystems/imu.h

@@ -20,6 +20,9 @@
  * the Free Software Foundation, 59 Temple Place - Suite 330,
  * Boston, MA 02111-1307, USA.
  */
+/** \file imu.h
+ * \brief Inertial Measurement Unit interface
+ */
 
 #ifndef IMU_H
 #define IMU_H
@@ -32,23 +35,24 @@
 extern void imu_impl_init(void);
 extern void imu_periodic(void);
 
+/** abstract IMU interface providing fixed point interface  */
 struct Imu {
-  struct Int32Rates gyro;
-  struct Int32Vect3 accel;
-  struct Int32Vect3 mag;
-  struct Int32Rates gyro_prev;
-  struct Int32Vect3 accel_prev;
-  struct Int32Rates gyro_neutral;
-  struct Int32Vect3 accel_neutral;
-  struct Int32Vect3 mag_neutral;
-  struct Int32Rates gyro_unscaled;
-  struct Int32Vect3 accel_unscaled;
-  struct Int32Vect3 mag_unscaled;
-  struct Int32Quat  body_to_imu_quat;
-  struct Int32RMat  body_to_imu_rmat;
+  struct Int32Rates gyro;             ///< gyroscope measurements
+  struct Int32Vect3 accel;            ///< accelerometer measurements
+  struct Int32Vect3 mag;              ///< magnetometer measurements
+  struct Int32Rates gyro_prev;        ///< previous gyroscope measurements
+  struct Int32Vect3 accel_prev;       ///< previous accelerometer measurements
+  struct Int32Rates gyro_neutral;     ///< gyroscope bias
+  struct Int32Vect3 accel_neutral;    ///< accelerometer bias
+  struct Int32Vect3 mag_neutral;      ///< magnetometer neutral readings (bias)
+  struct Int32Rates gyro_unscaled;    ///< unscaled gyroscope measurements
+  struct Int32Vect3 accel_unscaled;   ///< unscaled accelerometer measurements
+  struct Int32Vect3 mag_unscaled;     ///< unscaled magnetometer measurements
+  struct Int32Quat  body_to_imu_quat; ///< rotation from body to imu frame as a unit quaternion
+  struct Int32RMat  body_to_imu_rmat; ///< rotation from body to imu frame as a rotation matrix
 };
 
-/* abstract IMU interface providing floating point interface  */
+/** abstract IMU interface providing floating point interface  */
 struct ImuFloat {
   struct FloatRates   gyro;
   struct FloatVect3   accel;
@@ -61,6 +65,8 @@ struct ImuFloat {
 };
 
 extern void imu_float_init(struct ImuFloat* imuf);
+
+/** global IMU state */
 extern struct Imu imu;
 
 /* underlying hardware */