AP_Tuning: Update OSD on 5 percent change

Author: Yury-MonZon

libraries/AP_Tuning/AP_Tuning.cpp

@@ -218,6 +218,7 @@ void AP_Tuning::check_input(uint8_t flightmode)
     last_channel_value = chan_value;
 
     float new_value;
+    static float old_value;
     if (chan_value > 0) {
         new_value = linear_interpolate(center_value, range*center_value, chan_value, 0, 1);
     } else {
@@ -227,11 +228,14 @@ void AP_Tuning::check_input(uint8_t flightmode)
     need_revert |= (1U << current_parm_index);
     set_value(current_parm, new_value);
 
-    GCS_SEND_TEXT(MAV_SEVERITY_INFO, 
-        "Tuning %s%s%0.5f", 
-        get_tuning_name(current_parm), 
-        ((chan_value < dead_zone) && (chan_value > -dead_zone)) ? "> " : ": ", 
-        (double)(new_value));
+    if ( fabs(new_value-old_value) > (0.05 * old_value) ) {
+        old_value = new_value;
+        GCS_SEND_TEXT(MAV_SEVERITY_INFO, 
+            "Tuning %s%s%0.4f", 
+            get_tuning_name(current_parm), 
+            ((chan_value < dead_zone) && (chan_value > -dead_zone)) ? "> " : ": ", 
+            (double)(new_value));
+    }
 
 #if HAL_LOGGING_ENABLED
     Log_Write_Parameter_Tuning(new_value);