AP_Mount: add support for non-spring-loaded joysticks

libraries/AP_Mount/AP_Mount.cpp

@@ -144,10 +144,20 @@ void AP_Mount::update_mount_position()
 		// RC radio manual angle control, but with stabilization from the AHRS
 		case MAV_MOUNT_MODE_RC_TARGETING:
 		{
+//#define MNT_SPRING_LOADED_JOYSTICK
+#ifdef MNT_SPRING_LOADED_JOYSTICK
 			// rc_input() takes degrees * 100 units
 			G_RC_AUX(k_mount_roll)->rc_input(&_roll_control_angle, _roll_angle*100);
 			G_RC_AUX(k_mount_pitch)->rc_input(&_pitch_control_angle, _pitch_angle*100);
 			G_RC_AUX(k_mount_yaw)->rc_input(&_yaw_control_angle, _yaw_angle*100);
+#else
+			if (g_rc_function[RC_Channel_aux::k_mount_roll])
+				_roll_control_angle  = g_rc_function[RC_Channel_aux::k_mount_roll]->angle_input_rad();
+			if (g_rc_function[RC_Channel_aux::k_mount_pitch])
+				_pitch_control_angle = g_rc_function[RC_Channel_aux::k_mount_pitch]->angle_input_rad();
+			if (g_rc_function[RC_Channel_aux::k_mount_yaw])
+				_yaw_control_angle   = g_rc_function[RC_Channel_aux::k_mount_yaw]->angle_input_rad();
+#endif
 			stabilize();
 			break;
 		}

libraries/RC_Channel/RC_Channel_aux.cpp

@@ -84,6 +84,20 @@ RC_Channel_aux::rc_input(float *control_angle, int16_t angle)
 	}
 }
 
+/// returns the angle (degrees*100) that the RC_Channel input is receiving
+long
+RC_Channel_aux::angle_input()
+{
+	return (get_reverse()?-1:1) * ((long)radio_in - (long)radio_min) * ((long)angle_max - (long)angle_min) / ((long)radio_max - (long)radio_min) + (get_reverse()?angle_max:angle_min);
+}
+
+/// returns the angle (radians) that the RC_Channel input is receiving
+float
+RC_Channel_aux::angle_input_rad()
+{
+	return radians(angle_input()*0.01);
+}
+
 /// map a function to a servo channel and output it
 void
 RC_Channel_aux::output_ch(unsigned char ch_nr)

libraries/RC_Channel/RC_Channel_aux.h

@@ -55,6 +55,10 @@ public:
 
 	void rc_input(float *control_angle, int16_t angle);
 
+	long angle_input();
+
+	float angle_input_rad();
+
 	void output_ch(unsigned char ch_nr);
 
 	static const struct AP_Param::GroupInfo var_info[];