Added back the AUX channel tuning

Very useful feature in development.

src/main/flight/mixer_tricopter.c

@@ -59,6 +59,7 @@
 #include "fc/runtime_config.h"
 #include "fc/rc_controls.h"
 
+#define USE_AUX_CHANNEL_TUNING                  (0)
 #define TRI_TAIL_SERVO_ANGLE_MID                (900)
 #define TRI_YAW_FORCE_CURVE_SIZE                (100)
 #define TRI_TAIL_SERVO_MAX_ANGLE                (500)
@@ -105,6 +106,9 @@ static void predictGyroOnDeceleration(void);
 static float scalePIDBasedOnTailMotorSpeed(float scaledPidOutput, float pidSumLimit);
 static void tailMotorStep(int16_t setpoint, float dT);
 static int8_t triGetServoDirection(void);
+#if USE_AUX_CHANNEL_TUNING
+static int16_t scaleAUXChannel(u8 channel, int16_t scale);
+#endif
 
 void triInitMixer(servoParam_t *pTailServoConfig, int16_t *pTailServoOutput)
 {
@@ -770,3 +774,13 @@ static int8_t triGetServoDirection(void)
 
     return direction;
 }
+
+#if USE_AUX_CHANNEL_TUNING
+static int16_t scaleAUXChannel(u8 channel, int16_t scale)
+{
+    int16_t constrained = constrain(rcData[channel], 1000, 2000);
+    constrained -= 1000;
+
+    return constrained * scale / 1000;
+}
+#endif