TradHeli - added throttle scaling and heli specific angle_boost function that takes into account that heli's main blades can have -ve pitch.

ArduCopter/ArduCopter.pde

@@ -1028,8 +1028,12 @@ void update_throttle_mode(void)
 
 		case THROTTLE_MANUAL:
 			if (g.rc_3.control_in > 0){
+			    #if FRAME_CONFIG == HELI_FRAME
+				    g.rc_3.servo_out = heli_get_angle_boost(heli_get_scaled_throttle(g.rc_3.control_in));
+				#else
 					angle_boost = get_angle_boost(g.rc_3.control_in);
 					g.rc_3.servo_out = g.rc_3.control_in + angle_boost;
+				#endif
 			}else{
 				g.pi_stabilize_roll.reset_I();
 				g.pi_stabilize_pitch.reset_I();
@@ -1058,8 +1062,12 @@ void update_throttle_mode(void)
 				// clear the new data flag
 				invalid_throttle = false;
 			}
+			#if FRAME_CONFIG == HELI_FRAME
+				g.rc_3.servo_out = heli_get_angle_boost(g.throttle_cruise + nav_throttle);
+			#else
 				angle_boost = get_angle_boost(g.throttle_cruise);
 				g.rc_3.servo_out = g.throttle_cruise + nav_throttle + angle_boost + manual_boost;
+			#endif
 			break;
 	}
 }

ArduCopter/heli.pde

@@ -6,6 +6,7 @@
 #define HELI_SERVO_AVERAGING_ANALOG  2  // 125Hz
 
 static int heli_manual_override = false;
+static float heli_throttle_scaler = 0;
 
 // heli_servo_averaging:
 //   0 or 1 = no averaging, 250hz
@@ -52,6 +53,9 @@ static void heli_init_swash()
 	g.heli_servo_3.radio_min = g.heli_coll_min - tilt_max[CH_3];
 	g.heli_servo_3.radio_max = g.heli_coll_max + tilt_max[CH_3];
 
+	// scaler for changing channel 3 radio input into collective range
+	heli_throttle_scaler = ((float)(g.heli_coll_max - g.heli_coll_min))/1000;
+	
 	// reset the servo averaging
 	for( i=0; i<=3; i++ )
 	    heli_servo_out[i] = 0;
@@ -193,4 +197,25 @@ static void output_motor_test()
 {
 }
 
+// heli_get_scaled_throttle - user's throttle scaled to collective range
+// input is expected to be in the range of 0~1000 (ie. pwm)
+// also does equivalent of angle_boost
+static int heli_get_scaled_throttle(int throttle)
+{
+    float scaled_throttle = (g.heli_coll_min - 1000) + throttle * heli_throttle_scaler;
+	return g.heli_coll_min - 1000 + (throttle * heli_throttle_scaler);
+}
+
+// heli_angle_boost - takes servo_out position
+// adds a boost depending on roll/pitch values
+// equivalent of quad's angle_boost function
+// pwm_out value should be 0 ~ 1000
+static int heli_get_angle_boost(int pwm_out)
+{
+    float angle_boost_factor = cos_pitch_x * cos_roll_x;
+	angle_boost_factor = 1.0 - constrain(angle_boost_factor, .5, 1.0);
+    int throttle_above_center = max(1000 + pwm_out - g.heli_coll_mid,0);
+	return pwm_out + throttle_above_center*angle_boost_factor;
+}
+
 #endif // HELI_FRAME

ArduCopter/radio.pde

@@ -18,7 +18,9 @@ static void init_rc_in()
 	g.rc_1.set_angle(4500);
 	g.rc_2.set_angle(4500);
 	g.rc_3.set_range(0,1000);
+    #if FRAME_CONFIG !=	HELI_FRAME
 	g.rc_3.scale_output = .9;
+	#endif
 	g.rc_4.set_angle(4500);
 
 	// reverse: CW = left

ArduCopter/system.pde

@@ -512,7 +512,11 @@ init_throttle_cruise()
 	// are we moving from manual throttle to auto_throttle?
 	if((old_control_mode <= STABILIZE) && (g.rc_3.control_in > MINIMUM_THROTTLE)){
 		g.pi_throttle.reset_I();
+		#if FRAME_CONFIG == HELI_FRAME
+		    g.throttle_cruise.set_and_save(heli_get_scaled_throttle(g.rc_3.control_in));
+		#else
 			g.throttle_cruise.set_and_save(g.rc_3.control_in);
+		#endif
 	}
 }