Add clogging prevention if previous filament had higher temp on unload than filament on load

Author: Bjoern Kerler

src/marlin_stubs/pause/M701_2.cpp

@@ -38,7 +38,10 @@ using namespace filament_gcodes;
 bool filament_gcodes::load_unload([[maybe_unused]] LoadUnloadMode type, filament_gcodes::Func f_load_unload, pause::Settings &rSettings) {
     float disp_temp = marlin_vars()->active_hotend().display_nozzle;
     float targ_temp = Temperature::degTargetHotend(rSettings.GetExtruder());
-
+    float previous_filament_temp = filament::get_description(config_store().get_previous_filament_type(rSettings.GetExtruder())).nozzle;
+    if (previous_filament_temp > disp_temp) {
+        targ_temp = previous_filament_temp;
+    }
     if (disp_temp > targ_temp) {
         thermalManager.setTargetHotend(disp_temp, rSettings.GetExtruder());
     }
@@ -169,6 +172,7 @@ void filament_gcodes::M70X_process_user_response(PreheatStatus::Result res, uint
     switch (res) {
     case PreheatStatus::Result::DoneHasFilament: {
         auto filament = config_store().get_filament_type(target_extruder);
+        config_store().set_previous_filament_type(target_extruder, filament);
         auto preheat_temp = filament::get_description(filament).nozzle_preheat;
         thermalManager.setTargetHotend(preheat_temp, 0);
         break;

src/persistent_stores/store_instances/config_store/store_definition.cpp

@@ -526,6 +526,62 @@ void CurrentStore::set_filament_type([[maybe_unused]] uint8_t index, filament::T
 #endif
 }
 
+filament::Type CurrentStore::get_previous_filament_type([[maybe_unused]] uint8_t index) {
+#if EXTRUDERS <= 1
+    assert(index == 0);
+    return filament_prev_type_0.get();
+#else
+    switch (index) {
+    case 0:
+        return filament_prev_type_0.get();
+    case 1:
+        return filament_prev_type_1.get();
+    case 2:
+        return filament_prev_type_2.get();
+    case 3:
+        return filament_prev_type_3.get();
+    case 4:
+        return filament_prev_type_4.get();
+    case 5:
+        return filament_prev_type_5.get();
+    default:
+        assert(false && "invalid index");
+        return {};
+    }
+#endif
+}
+
+void CurrentStore::set_previous_filament_type([[maybe_unused]] uint8_t index, filament::Type value) {
+#if EXTRUDERS <= 1
+    assert(index == 0);
+    filament_type_0.set(value);
+#else
+    switch (index) {
+    case 0:
+        filament_prev_type_0.set(value);
+        break;
+    case 1:
+        filament_prev_type_1.set(value);
+        break;
+    case 2:
+        filament_prev_type_2.set(value);
+        break;
+    case 3:
+        filament_prev_type_3.set(value);
+        break;
+    case 4:
+        filament_prev_type_4.set(value);
+        break;
+    case 5:
+        filament_prev_type_5.set(value);
+        break;
+    default:
+        assert(false && "invalid index");
+        return;
+    }
+#endif
+}
+
 float CurrentStore::get_nozzle_diameter([[maybe_unused]] uint8_t index) {
 #if HOTENDS <= 1
     assert(index == 0);

src/persistent_stores/store_instances/config_store/store_definition.hpp

@@ -261,8 +261,19 @@ struct CurrentStore : public journal::CurrentStoreConfig<journal::Backend, backe
     StoreItem<filament::Type, defaults::filament_type, journal::hash("Filament Type 5")> filament_type_5;
 #endif
 
+    StoreItem<filament::Type, defaults::filament_type, journal::hash("Filament Previous Type 0")> filament_prev_type_0;
+#if EXTRUDERS > 1 // for now only doing one ifdef for simplicity
+    StoreItem<filament::Type, defaults::filament_type, journal::hash("Filament Previous Type 1")> filament_prev_type_1;
+    StoreItem<filament::Type, defaults::filament_type, journal::hash("Filament Previous Type 2")> filament_prev_type_2;
+    StoreItem<filament::Type, defaults::filament_type, journal::hash("Filament Previous Type 3")> filament_prev_type_3;
+    StoreItem<filament::Type, defaults::filament_type, journal::hash("Filament Previous Type 4")> filament_prev_type_4;
+    StoreItem<filament::Type, defaults::filament_type, journal::hash("Filament Previous Type 5")> filament_prev_type_5;
+#endif
+
     filament::Type get_filament_type(uint8_t index);
     void set_filament_type(uint8_t index, filament::Type value);
+    filament::Type get_previous_filament_type(uint8_t index);
+    void set_previous_filament_type(uint8_t index, filament::Type value);
 
     StoreItem<bool, defaults::bool_false, journal::hash("Heatup Bed")> heatup_bed;