Remove active_extruder completely

we only use 1 extruder + saves ~800B

Firmware/Marlin.h

@@ -316,8 +316,9 @@ extern bool fan_state[2];
 extern int fan_edge_counter[2];
 extern int fan_speed[2];
 
-// Handling multiple extruders pins
-extern uint8_t active_extruder;
+// Active extruder becomes a #define to make the whole firmware compilable.
+// We may even remove the references to it wherever possible in the future
+#define active_extruder 0
 
 //Long pause
 extern unsigned long pause_time;

Firmware/Marlin_main.cpp

@@ -244,7 +244,6 @@ float extruder_offset[NUM_EXTRUDER_OFFSETS][EXTRUDERS] = {
 };
 #endif
 
-uint8_t active_extruder = 0;
 int fanSpeed=0;
 uint8_t newFanSpeed = 0;
 
@@ -362,9 +361,7 @@ uint8_t saved_printing_type = PRINTING_TYPE_SD;
 static float saved_pos[4] = { X_COORD_INVALID, 0, 0, 0 };
 static uint16_t saved_feedrate2 = 0; //!< Default feedrate (truncated from float)
 static int saved_feedmultiply2 = 0;
-static uint8_t saved_active_extruder = 0;
-float saved_extruder_temperature = 0.0; //!< Active extruder temperature
-float saved_bed_temperature = 0.0; //!< Bed temperature
+static float saved_extruder_temperature = 0.0; //!< Active extruder temperature
 static bool saved_extruder_relative_mode = false;
 int saved_fan_speed = 0; //!< Print fan speed
 //! @}
@@ -11122,7 +11119,6 @@ void stop_and_save_print_to_ram(float z_move, float e_move)
     if (pos_invalid) saved_pos[X_AXIS] = X_COORD_INVALID;
 
     saved_feedmultiply2 = feedmultiply; //save feedmultiply
-	saved_active_extruder = active_extruder; //save active_extruder
 	saved_extruder_temperature = degTargetHotend(active_extruder);
 	saved_bed_temperature = degTargetBed();
 	saved_extruder_relative_mode = axis_relative_modes & E_AXIS_MASK;
@@ -11171,11 +11167,11 @@ void stop_and_save_print_to_ram(float z_move, float e_move)
 }
 
 void restore_extruder_temperature_from_ram() {
-    if (degTargetHotend(saved_active_extruder) != saved_extruder_temperature)
+    if (degTargetHotend(active_extruder) != saved_extruder_temperature)
     {
-        setTargetHotendSafe(saved_extruder_temperature, saved_active_extruder);
+        setTargetHotendSafe(saved_extruder_temperature, active_extruder);
         heating_status = HeatingStatus::EXTRUDER_HEATING;
-        wait_for_heater(_millis(), saved_active_extruder);
+        wait_for_heater(_millis(), active_extruder);
         heating_status = HeatingStatus::EXTRUDER_HEATING_COMPLETE;
     }
 }
@@ -11202,11 +11198,8 @@ void restore_print_from_ram_and_continue(float e_move)
     // restore bed temperature (bed can be disabled during a thermal warning)
     if (degBed() != saved_bed_temperature)
         setTargetBed(saved_bed_temperature);
-
-	// restore active_extruder
-	active_extruder = saved_active_extruder;
 	fanSpeed = saved_fan_speed;
-	restore_extruder_temperture_from_ram();
+	restore_extruder_temperature_from_ram();
 	axis_relative_modes ^= (-saved_extruder_relative_mode ^ axis_relative_modes) & E_AXIS_MASK;
 	float e = saved_pos[E_AXIS] - e_move;
 	plan_set_e_position(e);

Firmware/mmu2.cpp

@@ -16,6 +16,10 @@
 #include "ultralcd.h"
 #include "cardreader.h" // for IS_SD_PRINTING
 
+// As of FW 3.12 we only support building the FW with only one extruder, all the multi-extruder infrastructure will be removed.
+// Saves at least 800B of code size
+static_assert(EXTRUDERS==1);
+
 // Settings for filament load / unload from the LCD menu.
 // This is for Prusa MK3-style extruders. Customize for your hardware.
 #define MMU2_FILAMENTCHANGE_EJECT_FEED 80.0
@@ -281,7 +285,6 @@ bool MMU2::tool_change(uint8_t index) {
 
         extruder = index; //filament change is finished
         previous_extruder = extruder;
-        SetActiveExtruder(0);
 
         // @@TODO really report onto the serial? May be for the Octoprint? Not important now
         //        SERIAL_ECHO_START();
@@ -315,7 +318,6 @@ bool MMU2::tool_change(char code, uint8_t slot) {
         manage_response(false, false);
         extruder = slot;
         previous_extruder = extruder;
-        SetActiveExtruder(0);
         set_extrude_min_temp(EXTRUDE_MINTEMP);
     } break;
 
@@ -467,7 +469,6 @@ bool MMU2::load_filament_to_nozzle(uint8_t index) {
 
         extruder = index;
         previous_extruder = extruder;
-        SetActiveExtruder(0);
 
         Sound_MakeSound(e_SOUND_TYPE_StandardConfirm);
     }
@@ -515,7 +516,7 @@ bool MMU2::eject_filament(uint8_t index, bool recover) {
 }
 
 void MMU2::Button(uint8_t index){
-    SERIAL_ECHOLNPGM("Button");
+    LogEchoEvent_P(PSTR("Button"));
     logic.Button(index);
 }
 
@@ -525,7 +526,7 @@ void MMU2::Home(uint8_t mode){
 
 void MMU2::SaveAndPark(bool move_axes, bool turn_off_nozzle) {
     if (mmu_print_saved == SavedState::None) { // First occurrence. Save current position, park print head, disable nozzle heater.
-        LogEchoEvent("Saving and parking");
+        LogEchoEvent_P(PSTR("Saving and parking"));
         st_synchronize();
       
         resume_hotend_temp = degTargetHotend(active_extruder);
@@ -553,7 +554,7 @@ void MMU2::SaveAndPark(bool move_axes, bool turn_off_nozzle) {
 
         if (turn_off_nozzle){
             mmu_print_saved |= SavedState::CooldownPending;
-            LogEchoEvent("Heater cooldown pending");
+            LogEchoEvent_P(PSTR("Heater cooldown pending"));
             // This just sets the flag that we should timeout and shut off the nozzle in 30 minutes...
             //setAllTargetHotends(0);
         }
@@ -568,10 +569,10 @@ void MMU2::ResumeHotendTemp() {
     {
         // Clear the "pending" flag if we haven't cooled yet.
         mmu_print_saved &= ~(SavedState::CooldownPending);
-        LogEchoEvent("Cooldown flag cleared");
+        LogEchoEvent_P(PSTR("Cooldown flag cleared"));
     }
     if ((mmu_print_saved & SavedState::Cooldown) && resume_hotend_temp) {
-        LogEchoEvent("Resuming Temp");
+        LogEchoEvent_P(PSTR("Resuming Temp"));
         MMU2_ECHO_MSG("Restoring hotend temperature ");
         SERIAL_ECHOLN(resume_hotend_temp);
         mmu_print_saved &= ~(SavedState::Cooldown);
@@ -583,15 +584,14 @@ void MMU2::ResumeHotendTemp() {
             manage_inactivity(true);
         });
         lcd_update_enable(true); // temporary hack to stop this locking the printer...
-        LogEchoEvent("Hotend temperature reached");
+        LogEchoEvent_P(PSTR("Hotend temperature reached"));
         lcd_clear();
     }
 }
 
-void MMU2::ResumeUnpark()
-{
+void MMU2::ResumeUnpark(){
     if (mmu_print_saved & SavedState::ParkExtruder) {
-        LogEchoEvent("Resuming XYZ");
+        LogEchoEvent_P(PSTR("Resuming XYZ"));
 
         current_position[X_AXIS] = resume_position.xyz[X_AXIS];
         current_position[Y_AXIS] = resume_position.xyz[Y_AXIS];
@@ -609,11 +609,11 @@ void MMU2::CheckUserInput(){
     auto btn = ButtonPressed((uint16_t)lastErrorCode);
 
     // Was a button pressed on the MMU itself instead of the LCD?
-    if (btn == Buttons::NoButton && lastButton != Buttons::NoButton)
-    {
+    if (btn == Buttons::NoButton && lastButton != Buttons::NoButton){
         btn = lastButton;
         lastButton = Buttons::NoButton; // Clear it. 
     }
+
     switch (btn) {
     case Left:
     case Middle:
@@ -662,25 +662,19 @@ void MMU2::manage_response(const bool move_axes, const bool turn_off_nozzle) {
         manage_inactivity(true); // calls LogicStep() and remembers its return status
         lcd_update(0);
 
-        if (mmu_print_saved & SavedState::CooldownPending)
-        {
-            if (!nozzleTimeout.running())
-            {
+        if (mmu_print_saved & SavedState::CooldownPending){
+            if (!nozzleTimeout.running()){
                 nozzleTimeout.start();
-                LogEchoEvent("Cooling Timeout started");
-            } 
-            else if (nozzleTimeout.expired(DEFAULT_SAFETYTIMER_TIME_MINS*60*1000ul)) // mins->msec. TODO: do we use the global or have our own independent timeout
-            {
+                LogEchoEvent_P(PSTR("Cooling Timeout started"));
+            } else if (nozzleTimeout.expired(DEFAULT_SAFETYTIMER_TIME_MINS*60*1000ul)){ // mins->msec. TODO: do we use the global or have our own independent timeout
                 mmu_print_saved &= ~(SavedState::CooldownPending);
                 mmu_print_saved |= SavedState::Cooldown;
                 setAllTargetHotends(0);
-                LogEchoEvent("Heater cooldown");
+                LogEchoEvent_P(PSTR("Heater cooldown"));
             }
-        }
-        else if (nozzleTimeout.running())
-        {
+        } else if (nozzleTimeout.running()) {
             nozzleTimeout.stop();
-            LogEchoEvent("Cooling timer stopped");
+            LogEchoEvent_P(PSTR("Cooling timer stopped"));
         }
 
         switch (logicStepLastStatus) {
@@ -696,11 +690,10 @@ void MMU2::manage_response(const bool move_axes, const bool turn_off_nozzle) {
             return;
         case CommandError:
             // Don't proceed to the park/save if we are doing an autoretry.
-            if (inAutoRetry)
-            {
+            if (inAutoRetry){
                 continue;
             }
-            /* FALLTHRU */
+            [[fallthrough]];
         case CommunicationTimeout:
         case ProtocolError:
             SaveAndPark(move_axes, turn_off_nozzle); // and wait for the user to resolve the problem
@@ -743,7 +736,7 @@ StepStatus MMU2::LogicStep() {
         break;
     case ButtonPushed:
         lastButton = logic.Button();
-        LogEchoEvent("MMU Button pushed");
+        LogEchoEvent_P(PSTR("MMU Button pushed"));
         CheckUserInput(); // Process the button immediately
         break;
     default:
@@ -767,16 +760,10 @@ void MMU2::execute_extruder_sequence(const E_Step *sequence, uint8_t steps) {
         current_position[E_AXIS] += pgm_read_float(&(step->extrude));
         plan_buffer_line_curposXYZE(pgm_read_float(&(step->feedRate)));
         st_synchronize();
-//        SERIAL_ECHOPGM("EES:");
-//        SERIAL_ECHOLN(position[E_AXIS]);
         step++;
     }
 }
 
-void MMU2::SetActiveExtruder(uint8_t ex){ 
-    active_extruder = ex; 
-}
-
 void MMU2::ReportError(ErrorCode ec, uint8_t res) {
     // Due to a potential lossy error reporting layers linked to this hook
     // we'd better report everything to make sure especially the error states
@@ -791,8 +778,7 @@ void MMU2::ReportError(ErrorCode ec, uint8_t res) {
     // Right now the filtering of MMU_NOT_RESPONDING is done in ReportErrorHook() as it is not a problem if mmu2.cpp
 
     // Depending on the Progress code, we may want to do some action when an error occurs
-    switch (logic.Progress())
-    {
+    switch (logic.Progress()){
     case ProgressCode::UnloadingToFinda:
         unloadFilamentStarted = false;
         break;
@@ -808,8 +794,7 @@ void MMU2::ReportError(ErrorCode ec, uint8_t res) {
 
     if( ec != lastErrorCode ){ // deduplicate: only report changes in error codes into the log
         lastErrorCode = ec;
-        SERIAL_ECHO_START;
-        SERIAL_ECHOLNRPGM( _T(PrusaErrorTitle(PrusaErrorCodeIndex((uint16_t)ec))) );
+        LogErrorEvent_P( _T(PrusaErrorTitle(PrusaErrorCodeIndex((uint16_t)ec))) );
     }
 
     static_assert(mmu2Magic[0] == 'M' 
@@ -824,103 +809,89 @@ void MMU2::ReportError(ErrorCode ec, uint8_t res) {
 
 void MMU2::ReportProgress(ProgressCode pc) {
     ReportProgressHook((CommandInProgress)logic.CommandInProgress(), (uint16_t)pc);
-
-    SERIAL_ECHO_START;
-    SERIAL_ECHOLNRPGM( _T(ProgressCodeToText((uint16_t)pc)) );
+    LogEchoEvent_P( _T(ProgressCodeToText((uint16_t)pc)) );
 }
 
 void MMU2::OnMMUProgressMsg(ProgressCode pc){
     if (pc != lastProgressCode) {
-        ReportProgress(pc);
-        lastProgressCode = pc;
-
-        // Act accordingly - one-time handling
-        switch (pc) {
-        case ProgressCode::UnloadingToFinda:
-            if ((CommandInProgress)logic.CommandInProgress() == CommandInProgress::UnloadFilament
-            || ((CommandInProgress)logic.CommandInProgress() == CommandInProgress::ToolChange))
-            {
-                // If MK3S sent U0 command, ramming sequence takes care of releasing the filament.
-                // If Toolchange is done while printing, PrusaSlicer takes care of releasing the filament
-                // If printing is not in progress, ToolChange will issue a U0 command.
-                break;
-            }
-            else
-            {
-                // We're likely recovering from an MMU error
-                st_synchronize();
-                unloadFilamentStarted = true;
-                current_position[E_AXIS] -= MMU2_RETRY_UNLOAD_TO_FINDA_LENGTH;
-                plan_buffer_line_curposXYZE(MMU2_RETRY_UNLOAD_TO_FINDA_FEED_RATE);
-            }
+        OnMMUProgressMsgChanged(pc);
+    } else {
+        OnMMUProgressMsgSame(pc);
+    }
+}
+
+void MMU2::OnMMUProgressMsgChanged(ProgressCode pc){
+    ReportProgress(pc);
+    lastProgressCode = pc;
+    switch (pc) {
+    case ProgressCode::UnloadingToFinda:
+        if ((CommandInProgress)logic.CommandInProgress() == CommandInProgress::UnloadFilament
+        || ((CommandInProgress)logic.CommandInProgress() == CommandInProgress::ToolChange))
+        {
+            // If MK3S sent U0 command, ramming sequence takes care of releasing the filament.
+            // If Toolchange is done while printing, PrusaSlicer takes care of releasing the filament
+            // If printing is not in progress, ToolChange will issue a U0 command.
             break;
-        case ProgressCode::FeedingToFSensor:
-            // prepare for the movement of the E-motor
+        } else {
+            // We're likely recovering from an MMU error
             st_synchronize();
-            loadFilamentStarted = true;
-            break;
-        default:
-            // do nothing yet
-            break;
+            unloadFilamentStarted = true;
+            current_position[E_AXIS] -= MMU2_RETRY_UNLOAD_TO_FINDA_LENGTH;
+            plan_buffer_line_curposXYZE(MMU2_RETRY_UNLOAD_TO_FINDA_FEED_RATE);
         }
-    } else {
-        // Act accordingly - every status change (even the same state)
-        switch (pc) {
-        case ProgressCode::UnloadingToFinda:
-            if (unloadFilamentStarted && !blocks_queued()) { // Only plan a move if there is no move ongoing
-                if (fsensor.getFilamentPresent() == 1)
-                {
-                    current_position[E_AXIS] -= MMU2_RETRY_UNLOAD_TO_FINDA_LENGTH;
-                    plan_buffer_line_curposXYZE(MMU2_RETRY_UNLOAD_TO_FINDA_FEED_RATE);
-                } else {
-                    unloadFilamentStarted = false;
-                }
+        break;
+    case ProgressCode::FeedingToFSensor:
+        // prepare for the movement of the E-motor
+        st_synchronize();
+        loadFilamentStarted = true;
+        break;
+    default:
+        // do nothing yet
+        break;
+    }
+}
+
+void MMU2::OnMMUProgressMsgSame(ProgressCode pc){
+    switch (pc) {
+    case ProgressCode::UnloadingToFinda:
+        if (unloadFilamentStarted && !blocks_queued()) { // Only plan a move if there is no move ongoing
+            if (fsensor.getFilamentPresent()) {
+                current_position[E_AXIS] -= MMU2_RETRY_UNLOAD_TO_FINDA_LENGTH;
+                plan_buffer_line_curposXYZE(MMU2_RETRY_UNLOAD_TO_FINDA_FEED_RATE);
+            } else {
+                unloadFilamentStarted = false;
             }
-            break;
-        case ProgressCode::FeedingToFSensor:
-            if (loadFilamentStarted) {
-                switch (WhereIsFilament()) {
-                case FilamentState::AT_FSENSOR:
-                    // fsensor triggered, finish FeedingToBondtech state
-                    loadFilamentStarted = false;
-                    // After the MMU knows the FSENSOR is triggered it will:
-                    // 1. Push the filament by additional 30mm (see fsensorToNozzle)
-                    // 2. Disengage the idler and push another 5mm.
-//                    SERIAL_ECHOPGM("ATF1=");
-//                    SERIAL_ECHO(current_position[E_AXIS]);
-                    current_position[E_AXIS] += 30.0f + 2.0f;
+        }
+        break;
+    case ProgressCode::FeedingToFSensor:
+        if (loadFilamentStarted) {
+            switch (WhereIsFilament()) {
+            case FilamentState::AT_FSENSOR:
+                // fsensor triggered, finish FeedingToBondtech state
+                loadFilamentStarted = false;
+                // After the MMU knows the FSENSOR is triggered it will:
+                // 1. Push the filament by additional 30mm (see fsensorToNozzle)
+                // 2. Disengage the idler and push another 5mm.
+                current_position[E_AXIS] += 30.0f + 2.0f;
+                plan_buffer_line_curposXYZE(MMU2_LOAD_TO_NOZZLE_FEED_RATE);
+                break;
+            case FilamentState::NOT_PRESENT:
+                // fsensor not triggered, continue moving extruder
+                if (!blocks_queued()) { // Only plan a move if there is no move ongoing
+                    current_position[E_AXIS] += 2.0f;
                     plan_buffer_line_curposXYZE(MMU2_LOAD_TO_NOZZLE_FEED_RATE);
-//                    SERIAL_ECHOPGM("ATF2=");
-//                    SERIAL_ECHOLN(current_position[E_AXIS]);
-                    break;
-                case FilamentState::NOT_PRESENT:
-                    // fsensor not triggered, continue moving extruder
-                    if (!blocks_queued()) { // Only plan a move if there is no move ongoing
-                        current_position[E_AXIS] += 2.0f;
-                        plan_buffer_line_curposXYZE(MMU2_LOAD_TO_NOZZLE_FEED_RATE);
-                    }
-                    break;
-                default:
-                    // Abort here?
-                    break;
                 }
+                break;
+            default:
+                // Abort here?
+                break;
             }
-            break;
-        default:
-            // do nothing yet
-            break;
         }
+        break;
+    default:
+        // do nothing yet
+        break;
     }
 }
 
-void MMU2::LogErrorEvent(const char *msg){
-    MMU2_ERROR_MSG(msg);
-    SERIAL_ECHOLN();
-}
-
-void MMU2::LogEchoEvent(const char *msg){
-    MMU2_ECHO_MSG(msg);
-    SERIAL_ECHOLN();
-}
-
 } // namespace MMU2

Firmware/mmu2.h

@@ -201,7 +201,6 @@ private:
     
     void filament_ramming();
     void execute_extruder_sequence(const E_Step *sequence, uint8_t steps);
-    void SetActiveExtruder(uint8_t ex);
 
     /// Reports an error into attached ExtUIs
     /// @param ec error code, see ErrorCode
@@ -215,13 +214,11 @@ private:
     /// Responds to a change of MMU's progress
     /// - plans additional steps, e.g. starts the E-motor after fsensor trigger
     void OnMMUProgressMsg(ProgressCode pc);
+    /// Progress code changed - act accordingly
+    void OnMMUProgressMsgChanged(ProgressCode pc);
+    /// Repeated calls when progress code remains the same
+    void OnMMUProgressMsgSame(ProgressCode pc);
     
-    /// Report the msg into the general logging subsystem (through Marlin's SERIAL_ECHO stuff)
-    void LogErrorEvent(const char *msg);
-    
-    /// Report the msg into the general logging subsystem (through Marlin's SERIAL_ECHO stuff)
-    void LogEchoEvent(const char *msg);
-
     /// Save print and park the print head
     void SaveAndPark(bool move_axes, bool turn_off_nozzle);
 

Firmware/mmu2_log.cpp

@@ -0,0 +1,17 @@
+#include "mmu2_log.h"
+
+namespace MMU2 {
+
+void LogErrorEvent_P(const char *msg){
+    SERIAL_ERROR_START;
+    SERIAL_MMU2();
+    SERIAL_ECHOLNRPGM(msg);
+}
+
+void LogEchoEvent_P(const char *msg){
+    SERIAL_ECHO_START;
+    SERIAL_MMU2();
+    SERIAL_ECHOLNRPGM(msg);
+}
+
+} // namespace MMU2

Firmware/mmu2_log.h

@@ -8,6 +8,18 @@
 // and MMU2::ReportError + MMU2::ReportProgress
 static constexpr char mmu2Magic[] PROGMEM = "MMU2:";
 
+namespace MMU2 {
+
+/// Report the msg into the general logging subsystem (through Marlin's SERIAL_ECHO stuff)
+/// @param msg pointer to a string in PROGMEM
+void LogErrorEvent_P(const char *msg);
+
+/// Report the msg into the general logging subsystem (through Marlin's SERIAL_ECHO stuff)
+/// @param msg pointer to a string in PROGMEM
+void LogEchoEvent_P(const char *msg);
+
+} // namespace
+
 #define SERIAL_MMU2() { serialprintPGM(mmu2Magic); }
 
 #define MMU2_ECHO_MSG(S) do{ SERIAL_ECHO_START; SERIAL_MMU2(); SERIAL_ECHO(S); }while(0)

Firmware/planner.cpp

@@ -911,8 +911,6 @@ block->steps_y.wide = labs((target[X_AXIS]-position[X_AXIS]) - (target[Y_AXIS]-p
     block->direction_bits |= (1<<E_AXIS); 
   }
 
-  block->active_extruder = extruder;
-
   //enable active axes
   #ifdef COREXY
   if((block->steps_x.wide != 0) || (block->steps_y.wide != 0))

Firmware/planner.h

@@ -75,7 +75,6 @@ typedef struct {
   dda_usteps_t step_event_count;            // The number of step events required to complete this block
   uint32_t acceleration_rate;               // The acceleration rate used for acceleration calculation
   unsigned char direction_bits;             // The direction bit set for this block (refers to *_DIRECTION_BIT in config.h)
-  unsigned char active_extruder;            // Selects the active extruder
   // accelerate_until and decelerate_after are set by calculate_trapezoid_for_block() and they need to be synchronized with the stepper interrupt controller.
   uint32_t accelerate_until;                // The index of the step event on which to stop acceleration
   uint32_t decelerate_after;                // The index of the step event on which to start decelerating