diff --git a/libraries/RC_Channel/RC_Channel.cpp b/libraries/RC_Channel/RC_Channel.cpp
index c297224e14..ce94b57e96 100644
--- a/libraries/RC_Channel/RC_Channel.cpp
+++ b/libraries/RC_Channel/RC_Channel.cpp
@@ -475,22 +475,25 @@ void RC_Channel::init_aux_function(const aux_func_t ch_option, const aux_switch_
     }
 }
 
-void RC_Channel::read_aux()
+/*
+  read an aux channel. Return true if a switch has changed
+ */
+bool RC_Channel::read_aux()
 {
     const aux_func_t _option = (aux_func_t)option.get();
     if (_option == AUX_FUNC::DO_NOTHING) {
         // may wish to add special cases for other "AUXSW" things
         // here e.g. RCMAP_ROLL etc once they become options
-        return;
+        return false;
     }
     aux_switch_pos_t new_position;
     if (!read_3pos_switch(new_position)) {
-        return;
+        return false;
     }
     const aux_switch_pos_t old_position = old_switch_position();
     if (new_position == old_position) {
         debounce.count = 0;
-        return;
+        return false;
     }
     if (debounce.new_position != new_position) {
         debounce.new_position = new_position;
@@ -499,12 +502,13 @@ void RC_Channel::read_aux()
     // a value of 2 means we need 3 values in a row with the same
     // value to activate
     if (debounce.count++ < 2) {
-        return;
+        return false;
     }
 
     // debounced; undertake the action:
     do_aux_function(_option, new_position);
     set_old_switch_position(new_position);
+    return true;
 }
 
 
diff --git a/libraries/RC_Channel/RC_Channel.h b/libraries/RC_Channel/RC_Channel.h
index d23d596c1f..9f60ec7ebf 100644
--- a/libraries/RC_Channel/RC_Channel.h
+++ b/libraries/RC_Channel/RC_Channel.h
@@ -97,7 +97,7 @@ public:
 
     // auxillary switch support:
     void init_aux();
-    void read_aux();
+    bool read_aux();
 
     // Aux Switch enumeration
     enum class AUX_FUNC {
diff --git a/libraries/RC_Channel/RC_Channels.cpp b/libraries/RC_Channel/RC_Channels.cpp
index 4e1656a704..2bbc210977 100644
--- a/libraries/RC_Channel/RC_Channels.cpp
+++ b/libraries/RC_Channel/RC_Channels.cpp
@@ -25,6 +25,7 @@
 extern const AP_HAL::HAL& hal;
 
 #include <AP_Math/AP_Math.h>
+#include <AP_Logger/AP_Logger.h>
 
 #include "RC_Channel.h"
 
@@ -136,13 +137,18 @@ void RC_Channels::read_aux_all()
         // exit immediately when no RC input
         return;
     }
+    bool need_log = false;
 
     for (uint8_t i=0; i<NUM_RC_CHANNELS; i++) {
         RC_Channel *c = channel(i);
         if (c == nullptr) {
             continue;
         }
-        c->read_aux();
+        need_log |= c->read_aux();
+    }
+    if (need_log) {
+        // guarantee that we log when a switch changes
+        AP::logger().Write_RCIN();
     }
 }