Add bowden length runtime detection and tuning

Still, unit tests must check this thoroughly as this code
is extremely hard to test on the real HW.

src/config/config.h

@@ -18,7 +18,10 @@
 /// Wrangler for assorted compile-time configuration and constants.
 namespace config {
 
-static constexpr const uint8_t toolCount = 5U; ///< Max number of extruders/tools/slots
+/// Max number of extruders/tools/slots
+/// Beware - if you change this, the EEPROM structure will become invalid and no migration procedures have been implemented.
+/// So if you really have to change this, erase your EEPROM content then.
+static constexpr const uint8_t toolCount = 5U;
 static_assert(toolCount < 15, "Up to 14 valid slots (+1 parking) is supported in EEPROM storage");
 
 // Printer's filament sensor setup
@@ -84,9 +87,9 @@ static constexpr U_mm couplerToBowden = 3.5_mm; /// 3.5_mm /// FINDA Coupler scr
 // just another piece of PLA (probably having more resistance in the tubes)
 // and we are at least 40mm off! It looks like this really depends on the exact position
 // We'll probably need to check for stallguard while pushing the filament to avoid ginding the filament
-static constexpr U_mm defaultBowdenLength = 427.0_mm; ///< ~427.0_mm - Default Bowden length. @TODO Should be stored in EEPROM. 392 a 784
-static constexpr U_mm minimumBowdenLength = 341.0_mm; ///< ~341.0_mm - Minimum bowden length. @TODO Should be stored in EEPROM.
-static constexpr U_mm maximumBowdenLength = 792.0_mm; ///< ~792.0_mm - Maximum bowden length. @TODO Should be stored in EEPROM.
+static constexpr U_mm defaultBowdenLength = 427.0_mm; /// ~427.0_mm /// Default Bowden length.
+static constexpr U_mm minimumBowdenLength = 341.0_mm; /// ~341.0_mm /// Minimum bowden length.
+static constexpr U_mm maximumBowdenLength = 792.0_mm; /// ~792.0_mm /// Maximum bowden length.
 static constexpr U_mm feedToFinda = cuttingEdgeToFindaMidpoint + filamentMinLoadedToMMU;
 static constexpr U_mm maximumFeedToFinda = feedToFinda + 20.0_mm; ///< allow for some safety margin to load to FINDA
 static constexpr U_mm pulleyHelperMove = 10.0_mm; ///< Helper move for Load/Unload error states - when the MMU should slowly move the filament a bit

src/hal/avr/eeprom.cpp

@@ -15,5 +15,13 @@ void EEPROM::UpdateByte(EEPROM::addr_t addr, uint8_t value) {
     eeprom_update_byte((uint8_t *)addr, value);
 }
 
+uint16_t EEPROM::ReadWord(EEPROM::addr_t addr) {
+    return eeprom_read_word((const uint16_t *)addr);
+}
+
+void EEPROM::UpdateWord(EEPROM::addr_t addr, uint16_t value) {
+    eeprom_update_word((uint16_t *)addr, value);
+}
+
 } // namespace eeprom
 } // namespace hal

src/logic/feed_to_bondtech.cpp

@@ -28,6 +28,31 @@ void logic::FeedToBondtech::GoToPushToNozzle() {
     state = PushingFilamentIntoNozzle;
 }
 
+void FeedToBondtech::UpdateBowdenLength(int32_t feedEnd_mm) {
+    int32_t measuredBowdenLength = abs(feedEnd_mm - feedStart_mm);
+    if (measuredBowdenLength < config::maximumBowdenLength.v) { // is the measured length any valid/acceptable?
+        static_assert(config::maximumBowdenLength.v <= 65535, "Max bowden length too long");
+        int16_t mbl = (int16_t)measuredBowdenLength;
+        int16_t difference = abs(mbl - mps::BowdenLength::Get(mg::globals.ActiveSlot()));
+        if (difference > 5) { // @@TODO 5_mm is it good enough?
+            mps::BowdenLength::Set(mg::globals.ActiveSlot(), mbl);
+        }
+    }
+}
+
+bool FeedToBondtech::PushingFilament() {
+    if (mfs::fsensor.Pressed()) {
+        mm::motion.AbortPlannedMoves(); // stop pushing filament
+        GoToPushToNozzle();
+    } else if (mm::motion.StallGuard(mm::Pulley)) {
+        // stall guard occurred during movement - the filament got stuck
+        state = Failed; // @@TODO may be even report why it failed
+    } else if (mm::motion.QueueEmpty()) {
+        return false;
+    }
+    return true;
+}
+
 bool FeedToBondtech::Step() {
     switch (state) {
     case EngagingIdler:
@@ -67,6 +92,30 @@ bool FeedToBondtech::Step() {
             //            // stall guard occurred during movement - the filament got stuck
             //            state = PulleyStalled;
         } else if (mm::motion.QueueEmpty()) { // all moves have been finished and the fsensor didn't switch on
+/*=======
+            dbg_logic_fP(PSTR("Pulley start steps %u"), mm::motion.CurPosition(mm::Pulley));
+            state = PushingFilamentToFSensorFast;
+            mm::motion.InitAxis(mm::Pulley);
+            feedStart_mm = mm::stepsToUnit<mm::P_pos_t>(mm::P_pos_t({ mm::motion.CurPosition(mm::Pulley) }));
+            // fast feed in millimeters - if the EEPROM value is incorrect, we'll get the default length
+            mm::motion.PlanMove<mm::Pulley>(
+                { (long double)mps::BowdenLength::Get(mg::globals.ActiveSlot()) },
+                config::pulleyFeedrate, config::pulleySlowFeedrate);
+        }
+        return false;
+    case PushingFilamentToFSensorFast:
+        if (!PushingFilament()) { // ran out of stored bowden length, continue slowly
+            state = PushingFilamentToFSensorSlow;
+            // do the remaining move up to maximum bowden length slowly
+            mm::motion.PlanMove<mm::Pulley>(
+                { (long double)abs(config::maximumBowdenLength.v - mps::BowdenLength::Get(mg::globals.ActiveSlot())) }, // fast feed in millimeters - if the EEPROM value is incorrect, we'll
+                config::pulleySlowFeedrate, config::pulleySlowFeedrate);
+        }
+        return false;
+    case PushingFilamentToFSensorSlow:
+        if (!PushingFilament()) { // all moves have been finished and the fsensor didn't switch on
+>>>>>>> Add bowden length runtime detection and tuning
+*/
             state = Failed;
         }
         return false;
@@ -92,6 +141,9 @@ bool FeedToBondtech::Step() {
             dbg_logic_P(PSTR("Feed to Bondtech --> Idler disengaged"));
             dbg_logic_fP(PSTR("Pulley end steps %u"), mpu::pulley.CurrentPosition_mm());
             state = OK;
+            mpu::pulley.Disable();
+            UpdateBowdenLength(mm::stepsToUnit<mm::P_pos_t>(mm::P_pos_t({ mm::motion.CurPosition(mm::Pulley) })));
+            mm::motion.Disable(mm::Pulley);
             ml::leds.SetMode(mg::globals.ActiveSlot(), ml::green, ml::on);
         }
         return false;

src/logic/feed_to_bondtech.h

@@ -1,6 +1,7 @@
 /// @file feed_to_bondtech.h
 #pragma once
 #include <stdint.h>
+#include "../modules/axisunit.h"
 
 namespace logic {
 
@@ -10,6 +11,10 @@ namespace logic {
 /// Then it feeds a bit more very gently to push the filament into the nozzle
 /// Disengages the Idler after finishing the feed.
 /// Disables the Pulley axis after disengaging the idler.
+///
+/// If filament has been successfully fed into the fsensor,
+/// records/updates PTFE length for the active slot.
+/// To prevent constant EEPROM updates only significant changes are recorded.
 struct FeedToBondtech {
     /// internal states of the state machine
     enum {
@@ -46,8 +51,15 @@ struct FeedToBondtech {
     void GoToPushToNozzle();
 
 private:
+    /// Update bowden length if changed significantly
+    void UpdateBowdenLength(int32_t feedEnd_mm);
+
+    /// Common processing of pushing filament into fsensor (reused by multiple states)
+    bool PushingFilament();
+
     uint8_t state;
     uint8_t maxRetries;
+    int32_t feedStart_mm; // intentionally trying to avoid using U_mm because it is a float (reps. long double)
 };
 
 } // namespace logic

src/modules/axisunit.h

@@ -145,6 +145,13 @@ static constexpr typename AU::type_t unitToSteps(U v) {
     return unitToAxisUnit<AU>(v).v;
 }
 
+/// Convert a steps type (pos_t or steps_t) to a unit::Unit.
+/// Extract the raw step count from an AxisUnit with type checking.
+template <typename U, typename AU>
+static constexpr typename U::type_t stepsToUnit(AU pos) {
+    return axisUnitToUnit<U, AU>(pos);
+}
+
 // Pulley
 typedef AxisUnit<pos_t, Pulley, Lenght> P_pos_t; ///< Pulley position type (steps)
 typedef AxisUnit<steps_t, Pulley, Speed> P_speed_t; ///< Pulley speed type (steps/s)

src/modules/permanent_storage.cpp

@@ -3,6 +3,7 @@
 #include "../hal/eeprom.h"
 #include "globals.h"
 #include "../config/config.h"
+#include "axisunit.h"
 
 #include <stddef.h>
 
@@ -43,10 +44,14 @@ static const uint8_t layoutVersion = 0xff;
 // ideally, this would have been a nice constexpr (since it is a compile time constant), but the C++ standard prohibits reinterpret_casts in constexpr
 static eeprom_t *const eepromBase = reinterpret_cast<eeprom_t *>(0); ///< First EEPROM address
 constexpr const uint16_t eepromEmpty = 0xffffU; ///< EEPROM content when erased
-constexpr const uint16_t eepromLengthCorrectionBase = 7900U; ///< legacy bowden length correction base (~391mm)
-constexpr const uint16_t eepromBowdenLenDefault = 8900U; ///< Default bowden length (~427 mm)
-constexpr const uint16_t eepromBowdenLenMinimum = 6900U; ///< Minimum bowden length (~341 mm)
-constexpr const uint16_t eepromBowdenLenMaximum = 16000U; ///< Maximum bowden length (~792 mm)
+
+namespace mm = modules::motion;
+constexpr const uint16_t eepromLengthCorrectionBase = config::defaultBowdenLength.v;
+constexpr const uint16_t eepromBowdenLenDefault = config::defaultBowdenLength.v; ///< Default bowden length (~427 mm)
+constexpr const uint16_t eepromBowdenLenMinimum = config::minimumBowdenLength.v; ///< Minimum bowden length (~341 mm)
+constexpr const uint16_t eepromBowdenLenMaximum = config::maximumBowdenLength.v; ///< Maximum bowden length (~792 mm)
+
+// static_assert (mm::unitToSteps<mm::P_pos_t>(config::maximumBowdenLength) < 65535U, "");
 
 namespace ee = hal::eeprom;
 
@@ -88,11 +93,10 @@ static bool validBowdenLen(const uint16_t BowdenLength) {
 ///
 /// Returns stored value, doesn't return actual value when it is edited by increase() / decrease() unless it is stored.
 /// @return stored bowden length
-uint16_t BowdenLength::get() {
-    uint8_t filament = mg::globals.ActiveSlot();
-    if (validFilament(filament)) {
+uint16_t BowdenLength::Get(uint8_t slot) {
+    if (validFilament(slot)) {
         // @@TODO these reinterpret_cast expressions look horrible but I'm keeping them almost intact to respect the original code from MM_control_01
-        uint16_t bowdenLength = ee::EEPROM::ReadByte(reinterpret_cast<size_t>(&(eepromBase->eepromBowdenLen[filament])));
+        uint16_t bowdenLength = ee::EEPROM::ReadByte(reinterpret_cast<size_t>(&(eepromBase->eepromBowdenLen[slot])));
 
         if (eepromEmpty == bowdenLength) {
             const uint8_t LengthCorrectionLegacy = ee::EEPROM::ReadByte(reinterpret_cast<size_t>(&(eepromBase->eepromLengthCorrection)));
@@ -107,46 +111,10 @@ uint16_t BowdenLength::get() {
     return eepromBowdenLenDefault;
 }
 
-/// @brief Construct BowdenLength object which allows bowden length manipulation
-///
-/// To be created on stack, new value is permanently stored when object goes out of scope.
-/// Active filament and associated bowden length is stored in member variables.
-BowdenLength::BowdenLength()
-    : filament(mg::globals.ActiveSlot()) // @@TODO - verify correct initialization order
-    , length(BowdenLength::get()) // @@TODO
-{
+void BowdenLength::Set(uint8_t slot, uint16_t steps) {
+    if (validFilament(slot)) {
+        ee::EEPROM::UpdateWord(EEOFFSET(eepromBase->eepromBowdenLen[slot]), steps);
     }
-
-/// @brief Increase bowden length
-///
-/// New value is not stored immediately. See ~BowdenLength() for storing permanently.
-/// @retval true passed
-/// @retval false failed, it is not possible to increase, new bowden length would be out of range
-bool BowdenLength::increase() {
-    if (validBowdenLen(length + stepSize)) {
-        length += stepSize;
-        return true;
-    }
-    return false;
-}
-
-/// @brief Decrease bowden length
-///
-/// New value is not stored immediately. See ~BowdenLength() for storing permanently.
-/// @retval true passed
-/// @retval false failed, it is not possible to decrease, new bowden length would be out of range
-bool BowdenLength::decrease() {
-    if (validBowdenLen(length - stepSize)) {
-        length -= stepSize;
-        return true;
-    }
-    return false;
-}
-
-/// @brief Store bowden length permanently.
-BowdenLength::~BowdenLength() {
-    if (validFilament(filament))
-        ee::EEPROM::UpdateWord(EEOFFSET(eepromBase->eepromBowdenLen[filament]), length);
 }
 
 /// @brief Get filament storage status

src/modules/permanent_storage.h

@@ -16,22 +16,17 @@ void Init();
 /// Erase the whole EEPROM
 void EraseAll();
 
-/// @brief Read manipulate and store bowden length
+/// @brief Read and store bowden length
 ///
 /// Value is stored independently for each filament.
 /// Active filament is deduced from active_extruder global variable.
 class BowdenLength {
 public:
-    static uint16_t get();
-    static const uint8_t stepSize = 10u; ///< increase()/decrease() bowden length step size
-    BowdenLength();
-    bool increase();
-    bool decrease();
-    ~BowdenLength();
+    /// @returns bowden length for selected slot
+    static uint16_t Get(uint8_t slot);
 
-private:
-    uint8_t filament; ///< Selected filament
-    uint16_t length; ///< Selected filament bowden length
+    /// Sets
+    static void Set(uint8_t slot, uint16_t steps);
 };
 
 /// @brief Read and store last filament loaded to nozzle

tests/unit/logic/feed_to_bondtech/test_feed_to_bondtech.cpp

@@ -71,7 +71,7 @@ TEST_CASE("feed_to_bondtech::feed_phase_unlimited", "[feed_to_bondtech]") {
         if( step == 100 ){
             mfs::fsensor.ProcessMessage(true);
         }
-        return fb.State() == FeedToBondtech::PushingFilamentToFSensor; },
+        return fb.State() == FeedToBondtech::PushingFilamentToFSensorFast; },
         1500));
 
     REQUIRE(mfs::fsensor.Pressed());