SRV_Channel: added set_trim_to_servo_out_for()

this will be used for new TRIM_AUTO functionality in plane

libraries/SRV_Channel/SRV_Channel.h

@@ -288,9 +288,9 @@ public:
     // set output for all channels matching the given function type, allow radio_trim to center servo
     static void set_output_pwm_trimmed(SRV_Channel::Aux_servo_function_t function, int16_t value);
 
-    // set and save the trim for a function channel to radio_in on matching input channel
-    static void set_trim_to_radio_in_for(SRV_Channel::Aux_servo_function_t function);
-
+    // set and save the trim for a function channel to the output value
+    static void set_trim_to_servo_out_for(SRV_Channel::Aux_servo_function_t function);
+    
     // set the trim for a function channel to min of the channel
     static void set_trim_to_min_for(SRV_Channel::Aux_servo_function_t function);
 

libraries/SRV_Channel/SRV_Channel_aux.cpp

@@ -211,22 +211,18 @@ SRV_Channels::set_output_pwm_trimmed(SRV_Channel::Aux_servo_function_t function,
 }
 
 /*
-  set and save the trim value to radio_in for all channels matching
+  set and save the trim value to current output for all channels matching
   the given function type
  */
 void
-SRV_Channels::set_trim_to_radio_in_for(SRV_Channel::Aux_servo_function_t function)
+SRV_Channels::set_trim_to_servo_out_for(SRV_Channel::Aux_servo_function_t function)
 {
     if (!function_assigned(function)) {
         return;
     }
     for (uint8_t i = 0; i < NUM_SERVO_CHANNELS; i++) {
         if (channels[i].function.get() == function) {
-            RC_Channel *rc = RC_Channels::rc_channel(channels[i].ch_num);
-            if (rc && rc->get_radio_in() != 0) {
-                rc->set_radio_trim(rc->get_radio_in());
-                rc->save_radio_trim();
-            }
+            channels[i].servo_trim.set_and_save_ifchanged(channels[i].output_pwm);
         }
     }
 }