From 1cb094f12ea75f29384d6d1e968b6e2595fb3ac1 Mon Sep 17 00:00:00 2001
From: Tom Pittenger <magicrub@gmail.com>
Date: Fri, 29 Jan 2016 22:38:31 -0800
Subject: [PATCH] Plane: make throttle signed (pos and neg)

---
 ArduPlane/Attitude.cpp |  2 +-
 ArduPlane/Log.cpp      | 13 ++++++-------
 ArduPlane/Plane.h      |  2 +-
 ArduPlane/system.cpp   |  4 ++--
 4 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/ArduPlane/Attitude.cpp b/ArduPlane/Attitude.cpp
index 3ae1a6b1a3..417f5c1eaf 100644
--- a/ArduPlane/Attitude.cpp
+++ b/ArduPlane/Attitude.cpp
@@ -1110,7 +1110,7 @@ void Plane::demo_servos(uint8_t i)
  */
 void Plane::adjust_nav_pitch_throttle(void)
 {
-    uint8_t throttle = throttle_percentage();
+    int8_t throttle = throttle_percentage();
     if (throttle < aparm.throttle_cruise && flight_stage != AP_SpdHgtControl::FLIGHT_VTOL) {
         float p = (aparm.throttle_cruise - throttle) / (float)aparm.throttle_cruise;
         nav_pitch_cd -= g.stab_pitch_down * 100.0f * p;
diff --git a/ArduPlane/Log.cpp b/ArduPlane/Log.cpp
index c877b2a608..3dd27a43d5 100644
--- a/ArduPlane/Log.cpp
+++ b/ArduPlane/Log.cpp
@@ -242,13 +242,12 @@ struct PACKED log_Control_Tuning {
     int16_t pitch;
     int16_t throttle_out;
     int16_t rudder_out;
-    float   accel_y;
+    int16_t throttle_dem;
 };
 
 // Write a control tuning packet. Total length : 22 bytes
 void Plane::Log_Write_Control_Tuning()
 {
-    Vector3f accel = ins.get_accel();
     struct log_Control_Tuning pkt = {
         LOG_PACKET_HEADER_INIT(LOG_CTUN_MSG),
         time_us         : AP_HAL::micros64(),
@@ -258,7 +257,7 @@ void Plane::Log_Write_Control_Tuning()
         pitch           : (int16_t)ahrs.pitch_sensor,
         throttle_out    : (int16_t)channel_throttle->servo_out,
         rudder_out      : (int16_t)channel_rudder->servo_out,
-        accel_y         : accel.y
+        throttle_dem    : (int16_t)SpdHgt_Controller->get_throttle_demand()
     };
     DataFlash.WriteBlock(&pkt, sizeof(pkt));
 }
@@ -340,7 +339,7 @@ struct PACKED log_Sonar {
     float voltage;
     float baro_alt;
     float groundspeed;
-    uint8_t throttle;
+    int8_t throttle;
     uint8_t count;
     float correction;
 };
@@ -361,7 +360,7 @@ void Plane::Log_Write_Sonar()
         voltage     : rangefinder.voltage_mv()*0.001f,
         baro_alt    : barometer.get_altitude(),
         groundspeed : gps.ground_speed(),
-        throttle    : (uint8_t)(100 * channel_throttle->norm_output()),
+        throttle    : (int8_t)(100 * channel_throttle->norm_output()),
         count       : rangefinder_state.in_range_count,
         correction  : rangefinder_state.correction
     };
@@ -483,11 +482,11 @@ static const struct LogStructure log_structure[] = {
     { LOG_STARTUP_MSG, sizeof(log_Startup),         
       "STRT", "QBH",         "TimeUS,SType,CTot" },
     { LOG_CTUN_MSG, sizeof(log_Control_Tuning),     
-      "CTUN", "Qcccchhf",    "TimeUS,NavRoll,Roll,NavPitch,Pitch,ThrOut,RdrOut,AccY" },
+      "CTUN", "Qcccchhh",    "TimeUS,NavRoll,Roll,NavPitch,Pitch,ThrOut,RdrOut,ThrDem" },
     { LOG_NTUN_MSG, sizeof(log_Nav_Tuning),         
       "NTUN", "QCfccccfIf",  "TimeUS,Yaw,WpDist,TargBrg,NavBrg,AltErr,Arspd,Alt,GSpdCM,XT" },
     { LOG_SONAR_MSG, sizeof(log_Sonar),             
-      "SONR", "QHfffBBf",   "TimeUS,DistCM,Volt,BaroAlt,GSpd,Thr,Cnt,Corr" },
+      "SONR", "QHfffbBf",   "TimeUS,DistCM,Volt,BaroAlt,GSpd,Thr,Cnt,Corr" },
     { LOG_ARM_DISARM_MSG, sizeof(log_Arm_Disarm),
       "ARM", "QBH", "TimeUS,ArmState,ArmChecks" },
     { LOG_ATRP_MSG, sizeof(AP_AutoTune::log_ATRP),
diff --git a/ArduPlane/Plane.h b/ArduPlane/Plane.h
index eec3c35b89..ce53abb658 100644
--- a/ArduPlane/Plane.h
+++ b/ArduPlane/Plane.h
@@ -915,7 +915,7 @@ private:
     void servo_write(uint8_t ch, uint16_t pwm);
     bool should_log(uint32_t mask);
     void frsky_telemetry_send(void);
-    uint8_t throttle_percentage(void);
+    int8_t throttle_percentage(void);
     void change_arm_state(void);
     bool disarm_motors(void);
     bool arm_motors(AP_Arming::ArmingMethod method);
diff --git a/ArduPlane/system.cpp b/ArduPlane/system.cpp
index c23c8e37e5..b3cd6bf446 100644
--- a/ArduPlane/system.cpp
+++ b/ArduPlane/system.cpp
@@ -753,9 +753,9 @@ void Plane::frsky_telemetry_send(void)
 
 
 /*
-  return throttle percentage from 0 to 100
+  return throttle percentage from 0 to 100 for normal use and -100 to 100 when using reverse thrust
  */
-uint8_t Plane::throttle_percentage(void)
+int8_t Plane::throttle_percentage(void)
 {
     if (auto_state.vtol_mode) {
         return quadplane.throttle_percentage();