Change the semantics of load filament

Load filament performs feed to FINDA and retract:
- engage idler
- feed normal to FINDA with config::feedToFinda distance until FINDA triggers
- retract normal and as soon FINDA un-triggers move back to PTFE config::cuttingEdgeToFindaMidpoint
- disengage the idler

That implied introducing another substate machine - RetractFromFinda, which does the opposite
of FeedToFinda while also checking for the FINDA switching off while retracting filament.

Still, ToolChange and CutFilament need fixing with this change

src/logic/CMakeLists.txt

@@ -7,6 +7,7 @@ target_sources(
           feed_to_finda.cpp
           load_filament.cpp
           no_command.cpp
+          retract_from_finda.cpp
           set_mode.cpp
           tool_change.cpp
           unload_filament.cpp

src/logic/feed_to_finda.cpp

@@ -32,29 +32,14 @@ bool FeedToFinda::Step() {
         if (mf::finda.Pressed() || (feedPhaseLimited && mui::userInput.AnyEvent())) { // @@TODO probably also a command from the printer
             mm::motion.AbortPlannedMoves(); // stop pushing filament
             // FINDA triggered - that means it works and detected the filament tip
-            state = UnloadBackToPTFE;
+            state = OK;
-            mm::motion.PlanMove<mm::Pulley>(-config::cuttingEdgeToFindaMidpoint, config::pulleyFeedrate);
         } else if (mm::motion.QueueEmpty()) { // all moves have been finished and FINDA didn't switch on
             state = Failed;
-            // @@TODO - shall we disengage the idler?
             ml::leds.SetMode(mg::globals.ActiveSlot(), ml::green, ml::off);
             ml::leds.SetMode(mg::globals.ActiveSlot(), ml::red, ml::blink0);
         }
     }
         return false;
-    case UnloadBackToPTFE:
-        if (mm::motion.QueueEmpty()) { // all moves have been finished
-            state = DisengagingIdler;
-            mi::idler.Disengage();
-        }
-        return false;
-    case DisengagingIdler:
-        if (!mi::idler.Engaged()) {
-            state = OK;
-            ml::leds.SetMode(mg::globals.ActiveSlot(), ml::green, ml::off);
-        }
-        // @@TODO FINDA must be reported as OFF again as we are pulling the filament from it - is this correct?
-        return false;
     case OK:
     case Failed:
     default:

src/logic/load_filament.cpp

@@ -51,20 +51,22 @@ bool LoadFilament::StepInner() {
                 ml::leds.SetMode(mg::globals.ActiveSlot(), ml::green, ml::off);
                 ml::leds.SetMode(mg::globals.ActiveSlot(), ml::red, ml::blink0); // signal loading error
             } else {
-                state = ProgressCode::FeedingToBondtech;
+                state = ProgressCode::RetractingFromFinda;
-                james.Reset(config::feedToBondtechMaxRetries);
+                retract.Reset();
             }
         }
         break;
-    case ProgressCode::FeedingToBondtech:
+    case ProgressCode::RetractingFromFinda:
-        if (james.Step()) { // No, Mr. Bond, I expect you to FEED
+        if (retract.Step()) {
-            switch (james.State()) {
+            if (retract.State() == RetractFromFinda::Failed) {
-            case FeedToBondtech::Failed:
+                state = ProgressCode::ERRDisengagingIdler;
-
+                error = ErrorCode::FINDA_DIDNT_SWITCH_OFF;
-            case FeedToBondtech::OK:
-                mm::motion.Disable(mm::Pulley);
                 mi::idler.Disengage();
+                ml::leds.SetMode(mg::globals.ActiveSlot(), ml::green, ml::off);
+                ml::leds.SetMode(mg::globals.ActiveSlot(), ml::red, ml::blink0); // signal loading error
+            } else {
                 state = ProgressCode::DisengagingIdler;
+                mi::idler.Disengage();
             }
         }
         break;

src/logic/load_filament.h

@@ -2,7 +2,7 @@
 #include <stdint.h>
 #include "command_base.h"
 #include "feed_to_finda.h"
-#include "feed_to_bondtech.h"
+#include "retract_from_finda.h"
 
 namespace logic {
 
@@ -21,7 +21,7 @@ public:
 
 private:
     FeedToFinda feed;
-    FeedToBondtech james; // bond ;)
+    RetractFromFinda retract;
 };
 
 /// The one and only instance of LoadFilament state machine in the FW

src/logic/progress_codes.h

@@ -33,4 +33,5 @@ enum class ProgressCode : uint_fast8_t {
     ReturningSelector, // P21
     ParkingSelector, // P22
     EjectingFilament, // P23
+    RetractingFromFinda, // P24
 };

src/logic/retract_from_finda.cpp

@@ -0,0 +1,42 @@
+#include "retract_from_finda.h"
+#include "../modules/finda.h"
+#include "../modules/globals.h"
+#include "../modules/idler.h"
+#include "../modules/leds.h"
+#include "../modules/motion.h"
+
+namespace logic {
+
+void RetractFromFinda::Reset() {
+    state = EngagingIdler;
+    ml::leds.SetMode(mg::globals.ActiveSlot(), ml::green, ml::blink0);
+    mi::idler.Engage(mg::globals.ActiveSlot());
+}
+
+bool RetractFromFinda::Step() {
+    switch (state) {
+    case EngagingIdler:
+        if (mi::idler.Engaged()) {
+            state = UnloadBackToPTFE;
+            mm::motion.PlanMove<mm::Pulley>(-config::cuttingEdgeToFindaMidpoint, config::pulleyFeedrate);
+        }
+        return false;
+    case UnloadBackToPTFE:
+        if (mm::motion.QueueEmpty()) { // all moves have been finished
+            if (!mf::finda.Pressed()) { // FINDA switched off correctly
+                state = OK;
+            } else { // FINDA didn't switch off
+                state = Failed;
+                ml::leds.SetMode(mg::globals.ActiveSlot(), ml::green, ml::off);
+                ml::leds.SetMode(mg::globals.ActiveSlot(), ml::red, ml::blink0);
+            }
+        }
+        return false;
+    case OK:
+    case Failed:
+    default:
+        return true;
+    }
+}
+
+} // namespace logic

src/logic/retract_from_finda.h

@@ -0,0 +1,36 @@
+#pragma once
+#include <stdint.h>
+
+namespace logic {
+
+/// @brief Retract filament from FINDA to PTFE
+///
+/// Continuously pull filament by a fixed length (originally 600 steps) + verify FINDA is switched OFF
+struct RetractFromFinda {
+    /// internal states of the state machine
+    enum {
+        EngagingIdler,
+        UnloadBackToPTFE,
+        OK,
+        Failed
+    };
+
+    inline RetractFromFinda()
+        : state(OK) {}
+
+    /// Restart the automaton
+    void Reset();
+
+    /// @returns true if the state machine finished its job, false otherwise
+    bool Step();
+
+    /// This method may be used to check the result of the automaton
+    /// @returns OK if everything went OK and FINDA triggered
+    /// @returns Failed if the FINDA didn't trigger
+    inline uint8_t State() const { return state; }
+
+private:
+    uint8_t state;
+};
+
+} // namespace logic

tests/unit/logic/feed_to_finda/test_feed_to_finda.cpp

@@ -63,26 +63,26 @@ TEST_CASE("feed_to_finda::feed_phase_unlimited", "[feed_to_finda]") {
         1500));
     // From now on the FINDA is reported as ON
 
-    // unloading back to PTFE
+    //    // unloading back to PTFE
-    REQUIRE(ff.State() == FeedToFinda::UnloadBackToPTFE);
+    //    REQUIRE(ff.State() == FeedToFinda::UnloadBackToPTFE);
-    REQUIRE(WhileCondition(
+    //    REQUIRE(WhileCondition(
-        ff,
+    //        ff,
-        [&](int) { return ff.State() == FeedToFinda::UnloadBackToPTFE; },
+    //        [&](int) { return ff.State() == FeedToFinda::UnloadBackToPTFE; },
-        5000));
+    //        5000));
 
-    // disengaging idler
+    //    // disengaging idler
-    REQUIRE(ff.State() == FeedToFinda::DisengagingIdler);
+    //    REQUIRE(ff.State() == FeedToFinda::DisengagingIdler);
-    REQUIRE(WhileCondition(
+    //    REQUIRE(WhileCondition(
-        ff,
+    //        ff,
-        [&](int) { return mi::idler.Engaged(); },
+    //        [&](int) { return mi::idler.Engaged(); },
-        5000));
+    //        5000));
 
-    CHECK(mm::axes[mm::Idler].pos == mi::Idler::SlotPosition(5).v); // @@TODO constants
+    //    CHECK(mm::axes[mm::Idler].pos == mi::Idler::SlotPosition(5).v); // @@TODO constants
     CHECK(mm::axes[mm::Selector].pos == ms::Selector::SlotPosition(0).v);
 
-    // state machine finished ok, the green LED should be on
+    // state machine finished ok, the green LED should be blinking
     REQUIRE(ff.State() == FeedToFinda::OK);
-    REQUIRE(ml::leds.Mode(mg::globals.ActiveSlot(), ml::green) == ml::off);
+    REQUIRE(ml::leds.Mode(mg::globals.ActiveSlot(), ml::green) == ml::blink0);
 
     REQUIRE(ff.Step() == true); // the automaton finished its work, any consecutive calls to Step must return true
 }

tests/unit/logic/load_filament/CMakeLists.txt

@@ -5,6 +5,7 @@ add_executable(
   ${CMAKE_SOURCE_DIR}/src/logic/feed_to_bondtech.cpp
   ${CMAKE_SOURCE_DIR}/src/logic/feed_to_finda.cpp
   ${CMAKE_SOURCE_DIR}/src/logic/load_filament.cpp
+  ${CMAKE_SOURCE_DIR}/src/logic/retract_from_finda.cpp
   ${CMAKE_SOURCE_DIR}/src/modules/buttons.cpp
   ${CMAKE_SOURCE_DIR}/src/modules/debouncer.cpp
   ${CMAKE_SOURCE_DIR}/src/modules/finda.cpp

tests/unit/logic/load_filament/test_load_filament.cpp

@@ -57,23 +57,23 @@ void LoadFilamentSuccessful(uint8_t slot, logic::LoadFilament &lf) {
         }
         return lf.TopLevelState() == ProgressCode::FeedingToFinda; },
         5000));
-    REQUIRE(VerifyState(lf, false, slot, slot, true, ml::blink0, ml::off, ErrorCode::RUNNING, ProgressCode::FeedingToBondtech));
+    REQUIRE(VerifyState(lf, false, slot, slot, true, ml::blink0, ml::off, ErrorCode::RUNNING, ProgressCode::RetractingFromFinda));
 
-    // Stage 3 - feeding to bondtech
+    // Stage 3 - retracting from finda
-    // we'll make a fsensor switch during the process
+    // we'll assume the finda is working correctly here
     REQUIRE(WhileCondition(
         lf,
         [&](int step) -> bool {
-        if(step == 100){ // on 100th step make fsensor trigger
+        if(step == 50){ // on 50th step make FINDA trigger
-            mfs::fsensor.ProcessMessage(true);
+            hal::gpio::WritePin(FINDA_PIN, hal::gpio::Level::low);
         }
-        return lf.TopLevelState() == ProgressCode::FeedingToBondtech; },
+        return lf.TopLevelState() == ProgressCode::RetractingFromFinda; },
         5000));
-    REQUIRE(VerifyState(lf, false, slot, slot, true, ml::blink0, ml::off, ErrorCode::RUNNING, ProgressCode::DisengagingIdler));
+    REQUIRE(VerifyState(lf, false, slot, slot, false, ml::blink0, ml::off, ErrorCode::RUNNING, ProgressCode::DisengagingIdler));
 
     // Stage 4 - disengaging idler
     REQUIRE(WhileTopState(lf, ProgressCode::DisengagingIdler, idlerEngageDisengageMaxSteps));
-    REQUIRE(VerifyState(lf, true, mi::Idler::IdleSlotIndex(), slot, true, ml::off, ml::off, ErrorCode::OK, ProgressCode::OK));
+    REQUIRE(VerifyState(lf, true, mi::Idler::IdleSlotIndex(), slot, false, ml::on, ml::off, ErrorCode::OK, ProgressCode::OK));
 }
 
 TEST_CASE("load_filament::regular_load_to_slot_0-4", "[load_filament]") {

tests/unit/logic/tool_change/CMakeLists.txt

@@ -5,6 +5,7 @@ add_executable(
   ${CMAKE_SOURCE_DIR}/src/logic/feed_to_bondtech.cpp
   ${CMAKE_SOURCE_DIR}/src/logic/feed_to_finda.cpp
   ${CMAKE_SOURCE_DIR}/src/logic/load_filament.cpp
+  ${CMAKE_SOURCE_DIR}/src/logic/retract_from_finda.cpp
   ${CMAKE_SOURCE_DIR}/src/logic/tool_change.cpp
   ${CMAKE_SOURCE_DIR}/src/logic/unload_filament.cpp
   ${CMAKE_SOURCE_DIR}/src/logic/unload_to_finda.cpp