Copter: add logging for CH6 parameter tuning

Logs CH6 tuning values to a new PTUN log struct, specific to
APM::Copter at this point

ArduCopter/Log.pde

@@ -597,6 +597,31 @@ static void Log_Write_Baro(void)
     DataFlash.Log_Write_Baro(barometer);
 }
 
+struct PACKED log_ParameterTuning {
+    LOG_PACKET_HEADER;
+    uint32_t time_ms;
+    uint8_t  parameter;     // parameter we are tuning, e.g. 39 is CH6_CIRCLE_RATE
+    float    tuning_value;  // normalized value used inside tuning() function
+    int16_t  control_in;    // raw tune input value
+    int16_t  tuning_low;    // tuning low end value
+    int16_t  tuning_high;   // tuning high end value
+};
+
+static void Log_Write_Parameter_Tuning(uint8_t param, float tuning_val, int16_t control_in, int16_t tune_low, int16_t tune_high)
+{
+    struct log_ParameterTuning pkt_tune = {
+        LOG_PACKET_HEADER_INIT(LOG_PARAMTUNE_MSG),
+        time_ms        : hal.scheduler->millis(),
+        parameter      : param,
+        tuning_value   : tuning_val,
+        control_in     : control_in,
+        tuning_low     : tune_low,
+        tuning_high    : tune_high
+    };
+
+    DataFlash.WriteBlock(&pkt_tune, sizeof(pkt_tune));
+}
+
 static const struct LogStructure log_structure[] PROGMEM = {
     LOG_COMMON_STRUCTURES,
 #if AUTOTUNE_ENABLED == ENABLED
@@ -605,6 +630,8 @@ static const struct LogStructure log_structure[] PROGMEM = {
     { LOG_AUTOTUNEDETAILS_MSG, sizeof(log_AutoTuneDetails),
       "ATDE", "Iff",          "TimeMS,Angle,Rate" },
 #endif
+    { LOG_PARAMTUNE_MSG, sizeof(log_ParameterTuning),
+      "PTUN", "IBfHHH",          "TimeMS,Param,TunVal,CtrlIn,TunLo,TunHi" },  
     { LOG_OPTFLOW_MSG, sizeof(log_Optflow),       
       "OF",   "IBffff",   "TimeMS,Qual,flowX,flowY,bodyX,bodyY" },
     { LOG_NAV_TUNING_MSG, sizeof(log_Nav_Tuning),       

ArduCopter/defines.h

@@ -243,6 +243,7 @@ enum FlipState {
 #define LOG_AUTOTUNEDETAILS_MSG         0x1A
 #define LOG_RATE_MSG                    0x1D
 #define LOG_MOTBATT_MSG                 0x1E
+#define LOG_PARAMTUNE_MSG               0x1F
 
 #define MASK_LOG_ATTITUDE_FAST          (1<<0)
 #define MASK_LOG_ATTITUDE_MED           (1<<1)

ArduCopter/tuning.pde

@@ -17,6 +17,8 @@ static void tuning() {
     float tuning_value = (float)g.rc_6.control_in / 1000.0f;
     g.rc_6.set_range(g.radio_tuning_low,g.radio_tuning_high);
 
+    Log_Write_Parameter_Tuning(g.radio_tuning, tuning_value, g.rc_6.control_in, g.radio_tuning_low, g.radio_tuning_high);
+
     switch(g.radio_tuning) {
 
     // Roll, Pitch tuning