[ahrs] use weak functions for things that don't need to be implemented by each algorithm

sw/airborne/subsystems/ahrs.c

@@ -29,3 +29,13 @@
 
 struct Ahrs ahrs;
 
+#define WEAK __attribute__((weak))
+// weak functions, used if not explicitly provided by implementation
+
+void WEAK ahrs_propagate(void) {}
+
+void WEAK ahrs_update_accel(void) {}
+
+void WEAK ahrs_update_mag(void) {}
+
+void WEAK ahrs_update_gps(void) {}

sw/airborne/subsystems/ahrs.h

@@ -61,25 +61,25 @@ 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.
+ *  Does nothing if not implemented by specific 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.
+ *  Does nothing if not implemented by specific 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.
+ *  Does nothing if not implemented by specific AHRS algorithm.
  */
 extern void ahrs_update_mag(void);
 
 /** Update AHRS state with GPS measurements.
  *  Reads the global #gps data struct.
- *  Needs to be implemented by each AHRS algorithm.
+ *  Does nothing if not implemented by specific AHRS algorithm.
  */
 extern void ahrs_update_gps(void);
 

sw/airborne/subsystems/ahrs/ahrs_ardrone2.c

@@ -195,22 +195,8 @@ void ahrs_propagate(void) {
   }
 }
 
-void ahrs_update_accel(void) {
-
-}
-
-void ahrs_update_mag(void) {
-
-}
-
-void ahrs_update_gps(void) {
-
-}
-
 void ahrs_aligner_init(void) {
-
 }
 
 void ahrs_aligner_run(void) {
-
 }

sw/airborne/subsystems/ahrs/ahrs_float_mlkf.c

@@ -125,9 +125,6 @@ void ahrs_propagate(void) {
   set_body_state_from_quat();
 }
 
-void ahrs_update_gps(void) {
-}
-
 void ahrs_update_accel(void) {
   struct FloatVect3 imu_g;
   ACCELS_FLOAT_OF_BFP(imu_g, imu.accel);

sw/airborne/subsystems/ahrs/ahrs_gx3.c

@@ -347,14 +347,3 @@ void ahrs_aligner_run(void) {
 void ahrs_aligner_init(void) {
 }
 
-void ahrs_propagate(void) {
-}
-
-void ahrs_update_accel(void) {
-}
-
-void ahrs_update_mag(void) {
-}
-
-void ahrs_update_gps(void) {
-}

sw/airborne/subsystems/ahrs/ahrs_infrared.c

@@ -87,11 +87,6 @@ void ahrs_propagate(void) {
   stateSetBodyRates_f(&body_rate);
 }
 
-void ahrs_update_accel(void) {
-}
-
-void ahrs_update_mag(void) {
-}
 
 void ahrs_update_gps(void) {
 

sw/airborne/subsystems/ahrs/ahrs_int_cmpl_euler.c

@@ -278,10 +278,6 @@ void ahrs_update_mag(void) {
 
 }
 
-void ahrs_update_gps(void) {
-
-}
-
 /* measures phi and theta assuming no dynamic acceleration ?!! */
 __attribute__ ((always_inline)) static inline void get_phi_theta_measurement_fom_accel(int32_t* phi_meas, int32_t* theta_meas, struct Int32Vect3 accel) {
 

sw/airborne/subsystems/ahrs/ahrs_sim.c

@@ -94,13 +94,3 @@ void ahrs_propagate(void) {
   }
 }
 
-void ahrs_update_accel(void) {
-}
-
-void ahrs_update_mag(void) {
-}
-
-void ahrs_update_gps(void) {
-
-}
-