Report Selector refused to move as FINDA_DIDNT_SWITCH_OFF

MMU-176

src/logic/feed_to_finda.cpp

@@ -12,7 +12,7 @@
 #include "../debug.h"
 namespace logic {
 
-void FeedToFinda::Reset(bool feedPhaseLimited, bool haltAtEnd) {
+bool FeedToFinda::Reset(bool feedPhaseLimited, bool haltAtEnd) {
     dbg_logic_P(PSTR("\nFeed to FINDA\n\n"));
     state = EngagingIdler;
     this->feedPhaseLimited = feedPhaseLimited;
@@ -20,12 +20,15 @@ void FeedToFinda::Reset(bool feedPhaseLimited, bool haltAtEnd) {
     ml::leds.SetPairButOffOthers(mg::globals.ActiveSlot(), ml::blink0, ml::off);
     mi::idler.Engage(mg::globals.ActiveSlot());
     // We can't get any FINDA readings if the selector is at the wrong spot - move it accordingly if necessary
-    ms::selector.MoveToSlot(mg::globals.ActiveSlot());
+    return ms::selector.MoveToSlot(mg::globals.ActiveSlot()) == ms::Selector::OperationResult::Accepted;
 }
 
 bool FeedToFinda::Step() {
     switch (state) {
     case EngagingIdler:
+        // A serious deadlock may occur at this spot in case of flickering FINDA.
+        // Therefore FeedToFinda::Reset returns false in case of Selector refusing to move.
+        // We don't have to check the FINDA state while the move is in progress.
         if (mi::idler.Engaged() && ms::selector.Slot() == mg::globals.ActiveSlot()) {
             dbg_logic_P(PSTR("Feed to Finda --> Idler engaged"));
             dbg_logic_fP(PSTR("Pulley start steps %u"), mpu::pulley.CurrentPosition_mm());

src/logic/feed_to_finda.h

@@ -33,7 +33,10 @@ struct FeedToFinda {
     ///  * false feed phase is unlimited, can be interrupted by any button press after blanking time
     ///  Beware: the function returns immediately without actually doing anything if the FINDA is "pressed", i.e. the filament is already at the FINDA
     /// @param haltAtEnd true if the Pulley's motion shall be brought into a halt (which is what LoadFilament wants, but not ToolChange)
-    void Reset(bool feedPhaseLimited, bool haltAtEnd);
+    /// @returns
+    ///  * true if the operation has been successfully started.
+    ///  * false if the selector refused to move to the desired spot (which can be caused by pressed FINDA)
+    bool Reset(bool feedPhaseLimited, bool haltAtEnd);
 
     /// @returns true if the state machine finished its job, false otherwise
     bool Step();

src/logic/tool_change.cpp

@@ -41,11 +41,15 @@ bool ToolChange::Reset(uint8_t param) {
         state = ProgressCode::UnloadingFilament;
         unl.Reset(mg::globals.ActiveSlot());
     } else {
-        state = ProgressCode::FeedingToFinda;
+        if (feed.Reset(true, false)) {
-        error = ErrorCode::RUNNING;
+            state = ProgressCode::FeedingToFinda;
-        dbg_logic_P(PSTR("Filament is not loaded --> load"));
+            error = ErrorCode::RUNNING;
-        mg::globals.SetFilamentLoaded(plannedSlot, mg::FilamentLoadState::InSelector);
+            //        mg::globals.SetFilamentLoaded(plannedSlot, mg::FilamentLoadState::InSelector); // this is set in feed @@TODO
-        feed.Reset(true, false);
+            dbg_logic_P(PSTR("Filament is not loaded --> load"));
+        } else {
+            // selector refused to move - FINDA problem suspected
+            GoToErrDisengagingIdler(ErrorCode::FINDA_DIDNT_SWITCH_OFF);
+        }
     }
     return true;
 }

src/logic/unload_filament.cpp

@@ -46,9 +46,12 @@ void UnloadFilament::GoToRetractingFromFinda() {
 }
 
 void UnloadFilament::GoToRecheckFilamentAgainstFINDA() {
-    state = ProgressCode::FeedingToFinda;
+    if (feed.Reset(true, true)) {
-    error = ErrorCode::RUNNING;
+        state = ProgressCode::FeedingToFinda;
-    feed.Reset(true, true);
+        error = ErrorCode::RUNNING;
+    } else {
+        GoToErrDisengagingIdler(ErrorCode::FINDA_DIDNT_SWITCH_OFF);
+    }
 }
 
 bool UnloadFilament::StepInner() {