From c4409b8f611f03e58178f15d34ca6f3d0af1d87b Mon Sep 17 00:00:00 2001
From: sarusani <62053849+sarusani@users.noreply.github.com>
Date: Tue, 25 Jul 2023 09:31:33 +0200
Subject: [PATCH] Delay Z-Axis on Autoload

Delay z-axis movement when the operators hand is close to the printhead.
---
 Firmware/Marlin_main.cpp | 11 +++++++----
 Firmware/ultralcd.cpp    |  3 ---
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/Firmware/Marlin_main.cpp b/Firmware/Marlin_main.cpp
index ad4ffa31c6..d7f3da7647 100644
--- a/Firmware/Marlin_main.cpp
+++ b/Firmware/Marlin_main.cpp
@@ -3596,7 +3596,7 @@ static void gcode_M600(const bool automatic, const float x_position, const float
     custom_message_type = CustomMsg::Status;
 }
 
-void gcode_M701(float fastLoadLength, uint8_t mmuSlotIndex){
+void gcode_M701(float fastLoadLength, uint8_t mmuSlotIndex, bool raise_z_axis = false){
     FSensorBlockRunout fsBlockRunout;
     
     prusa_statistics(22);
@@ -3612,6 +3612,10 @@ void gcode_M701(float fastLoadLength, uint8_t mmuSlotIndex){
         current_position[E_AXIS] += fastLoadLength;
         plan_buffer_line_curposXYZE(FILAMENTCHANGE_EFEED_FIRST); //fast sequence
 
+        if (raise_z_axis) { // backwards compatibility for 3.12 and older FW
+          raise_z_above(MIN_Z_FOR_LOAD);
+        }
+
         load_filament_final_feed(); // slow sequence
         st_synchronize();
 
@@ -8510,13 +8514,12 @@ SERIAL_PROTOCOLPGM("\n\n");
 
         // Z lift. For safety only allow positive values
         if (code_seen('Z')) z_target = fabs(code_value());
-        else raise_z_above(MIN_Z_FOR_LOAD); // backwards compatibility for 3.12 and older FW
-
+        
         // Raise the Z axis
         float delta = raise_z(z_target);
 
         // Load filament
-        gcode_M701(fastLoadLength, mmuSlotIndex);
+        gcode_M701(fastLoadLength, mmuSlotIndex, !code_seen('Z')); // if no z -> trigger MIN_Z_FOR_LOAD for backwards compatibility on 3.12 and older FW 
 
         // Restore Z axis
         raise_z(-delta);
diff --git a/Firmware/ultralcd.cpp b/Firmware/ultralcd.cpp
index 4f6d33e5c0..d599ffd4d5 100644
--- a/Firmware/ultralcd.cpp
+++ b/Firmware/ultralcd.cpp
@@ -1944,7 +1944,6 @@ void mFilamentItem(uint16_t nTemp, uint16_t nTempBed)
             // modified elsewhere and needs to be redrawn in full.
 
             // reset bFilamentWaitingFlag immediately to avoid re-entry from raise_z_above()!
-            bool once = !bFilamentWaitingFlag;
             bFilamentWaitingFlag = true;
 
             // also force-enable lcd_draw_update (might be 0 when called from outside a menu)
@@ -1961,12 +1960,10 @@ void mFilamentItem(uint16_t nTemp, uint16_t nTempBed)
             case FilamentAction::MmuLoad:
             case FilamentAction::MmuLoadingTest:
                 lcd_puts_P(_i("Preheating to load")); ////MSG_PREHEATING_TO_LOAD c=20
-                if (once) raise_z_above(MIN_Z_FOR_LOAD);
                 break;
             case FilamentAction::UnLoad:
             case FilamentAction::MmuUnLoad:
                 lcd_puts_P(_i("Preheating to unload")); ////MSG_PREHEATING_TO_UNLOAD c=20
-                if (once) raise_z_above(MIN_Z_FOR_UNLOAD);
                 break;
             case FilamentAction::MmuEject:
                 lcd_puts_P(_i("Preheating to eject")); ////MSG_PREHEATING_TO_EJECT c=20