M166 Gradients, LCD Menu for 2-channel Mixer (Geeetech A10M/A20M) (#13022)

Marlin/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/default/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/3DFabXYZ/Migbot/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/AlephObjects/TAZ4/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/AliExpress/CL-260/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Anet/A2/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Anet/A2plus/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Anet/A6/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Anet/A8/Configuration.h

@@ -272,6 +272,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/AnyCubic/i3/Configuration.h

@@ -272,6 +272,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/ArmEd/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Azteeg/X5GT/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/BIBO/TouchX/default/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/BQ/Hephestos/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/BQ/Hephestos_2/Configuration.h

@@ -279,6 +279,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/BQ/WITBOX/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Cartesio/Configuration.h

@@ -272,6 +272,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Creality/CR-10/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Creality/CR-10S/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Creality/CR-10mini/Configuration.h

@@ -280,6 +280,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Creality/CR-8/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Creality/Ender-2/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Creality/Ender-3/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Creality/Ender-4/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Einstart-S/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Felix/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Felix/DUAL/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/FlashForge/CreatorPro/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/FolgerTech/i3-2020/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Formbot/Raptor/Configuration.h

@@ -312,6 +312,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Formbot/T_Rex_2+/Configuration.h

@@ -274,6 +274,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Formbot/T_Rex_3/Configuration.h

@@ -275,6 +275,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Geeetech/GT2560/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Geeetech/I3_Pro_X-GT2560/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Geeetech/MeCreator2/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Geeetech/Prusa i3 Pro B/bltouch/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Geeetech/Prusa i3 Pro B/noprobe/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Geeetech/Prusa i3 Pro C/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Geeetech/Prusa i3 Pro W/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Infitary/i3-M508/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/JGAurora/A5/Configuration.h

@@ -276,6 +276,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/MakerParts/Configuration.h

@@ -291,6 +291,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Malyan/M150/Configuration.h

@@ -276,6 +276,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Malyan/M200/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Micromake/C1/basic/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Micromake/C1/enhanced/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Mks/Robin/Configuration.h

@@ -272,6 +272,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Mks/Sbase/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/RapideLite/RL200/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/RepRapPro/Huxley/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/RepRapWorld/Megatronics/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/RigidBot/Configuration.h

@@ -274,6 +274,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/SCARA/Configuration.h

@@ -302,6 +302,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/STM32F10/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/STM32F4/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Sanguinololu/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/TheBorg/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/TinyBoy2/Configuration.h

@@ -293,6 +293,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Tronxy/X1/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Tronxy/X3A/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Tronxy/X5S/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Tronxy/XY100/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/UltiMachine/Archim1/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/UltiMachine/Archim2/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/VORONDesign/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Velleman/K8200/Configuration.h

@@ -291,6 +291,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Velleman/K8400/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Velleman/K8400/Dual-head/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/WASP/PowerWASP/Configuration.h

@@ -290,6 +290,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/adafruit/ST7565/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/Anycubic/Kossel/Configuration.h

@@ -286,6 +286,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/FLSUN/kossel/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/Geeetech/Rostock 301/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 3        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/Hatchbox_Alpha/Configuration.h

@@ -276,6 +276,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/MKS/SBASE/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/Tevo Little Monster/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/generic/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/kossel_mini/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/kossel_pro/Configuration.h

@@ -275,6 +275,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/delta/kossel_xl/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/gCreate/gMax1.5+/Configuration.h

@@ -276,6 +276,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/makibox/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/stm32f103ret6/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 3        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/tvrrug/Round2/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/config/examples/wt150/Configuration.h

@@ -271,6 +271,10 @@
   #define MIXING_STEPPERS 2        // Number of steppers in your mixing extruder
   #define MIXING_VIRTUAL_TOOLS 16  // Use the Virtual Tool method with M163 and M164
   //#define DIRECT_MIXING_IN_G1    // Allow ABCDHI mix factors in G1 movement commands
+  //#define GRADIENT_MIX           // Support for gradient mixing with M166 and LCD
+  #if ENABLED(GRADIENT_MIX)
+    //#define GRADIENT_VTOOL       // Add M166 T to use a V-tool index as a Gradient alias
+  #endif
 #endif
 
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).

Marlin/src/feature/mixing.cpp

@@ -35,14 +35,18 @@ Mixer mixer;
 #endif
 
 // Used up to Planner level
-uint_fast8_t Mixer::selected_vtool = 0;
-float        Mixer::collector[MIXING_STEPPERS]; // mix proportion. 0.0 = off, otherwise <= COLOR_A_MASK.
-mixer_comp_t Mixer::color[NR_MIXING_VIRTUAL_TOOLS][MIXING_STEPPERS];
+uint_fast8_t  Mixer::selected_vtool = 0;
+float         Mixer::collector[MIXING_STEPPERS]; // mix proportion. 0.0 = off, otherwise <= COLOR_A_MASK.
+mixer_comp_t  Mixer::color[NR_MIXING_VIRTUAL_TOOLS][MIXING_STEPPERS];
 
 // Used in Stepper
-int_fast8_t  Mixer::runner = 0;
-mixer_comp_t Mixer::s_color[MIXING_STEPPERS];
-mixer_accu_t Mixer::accu[MIXING_STEPPERS] = { 0 };
+int_fast8_t   Mixer::runner = 0;
+mixer_comp_t  Mixer::s_color[MIXING_STEPPERS];
+mixer_accu_t  Mixer::accu[MIXING_STEPPERS] = { 0 };
+
+#if DUAL_MIXING_EXTRUDER || ENABLED(GRADIENT_MIX)
+  mixer_perc_t Mixer::mix[MIXING_STEPPERS];
+#endif
 
 void Mixer::normalize(const uint8_t tool_index) {
   float cmax = 0;
@@ -66,9 +70,8 @@ void Mixer::normalize(const uint8_t tool_index) {
   #endif
 
   // Scale all values so their maximum is COLOR_A_MASK
-  const float inverse_max = RECIPROCAL(cmax);
-  MIXER_STEPPER_LOOP(i)
-    color[tool_index][i] = collector[i] * COLOR_A_MASK * inverse_max;
+  const float scale = float(COLOR_A_MASK) / cmax;
+  MIXER_STEPPER_LOOP(i) color[tool_index][i] = collector[i] * scale;
 
   #ifdef MIXER_NORMALIZER_DEBUG
     csum = 0;
@@ -86,6 +89,10 @@ void Mixer::normalize(const uint8_t tool_index) {
     }
     SERIAL_ECHOLNPGM("]");
   #endif
+
+  #if ENABLED(GRADIENT_MIX)
+    refresh_gradient();
+  #endif
 }
 
 void Mixer::reset_vtools() {
@@ -115,6 +122,79 @@ void Mixer::init() {
   #endif
 
   ZERO(collector);
+
+  #if DUAL_MIXING_EXTRUDER || ENABLED(GRADIENT_MIX)
+    update_mix_from_vtool();
+  #endif
+
+  #if ENABLED(GRADIENT_MIX)
+    update_gradient_for_planner_z();
+  #endif
 }
 
+void Mixer::refresh_collector(const float proportion/*=1.0*/, const uint8_t t/*=selected_vtool*/) {
+  float csum = 0, cmax = 0;
+  MIXER_STEPPER_LOOP(i) {
+    const float v = color[t][i];
+    cmax = MAX(cmax, v);
+    csum += v;
+  }
+  //SERIAL_ECHOPAIR("Mixer::refresh_collector(", proportion);
+  //SERIAL_ECHOPAIR(", ", int(t));
+  //SERIAL_ECHOPAIR(") cmax=", cmax);
+  //SERIAL_ECHOPAIR("  csum=", csum);
+  //SERIAL_ECHOPGM("  color");
+  const float inv_prop = proportion / csum;
+  MIXER_STEPPER_LOOP(i) {
+    collector[i] = color[t][i] * inv_prop;
+    //SERIAL_ECHOPAIR(" [", int(t));
+    //SERIAL_ECHOPAIR("][", int(i));
+    //SERIAL_ECHOPAIR("] = ", int(color[t][i]));
+    //SERIAL_ECHOPAIR(" (", collector[i]);
+    //SERIAL_ECHOPGM(")  ");
+  }
+  //SERIAL_EOL();
+}
+
+#if ENABLED(GRADIENT_MIX)
+
+  #include "../module/motion.h"
+  #include "../module/planner.h"
+
+  gradient_t Mixer::gradient = {
+    false,    // enabled
+    {0},      // color (array)
+    0, 0,     // start_z, end_z
+    0, 1,     // start_vtool, end_vtool
+    {0}, {0}  // start_mix[], end_mix[]
+    #if ENABLED(GRADIENT_VTOOL)
+      , -1    // vtool_index
+    #endif
+  };
+
+  float Mixer::prev_z; // = 0
+
+  void Mixer::update_gradient_for_z(const float z) {
+    if (z == prev_z) return;
+    prev_z = z;
+
+    const float slice = gradient.end_z - gradient.start_z;
+
+    float pct = (z - gradient.start_z) / slice;
+    NOLESS(pct, 0.0f); NOMORE(pct, 1.0f);
+
+    MIXER_STEPPER_LOOP(i) {
+      const mixer_perc_t sm = gradient.start_mix[i];
+      mix[i] = sm + (gradient.end_mix[i] - sm) * pct;
+    }
+
+    copy_mix_to_color(gradient.color);
+  }
+
+  void Mixer::update_gradient_for_planner_z() {
+    update_gradient_for_z(planner.get_axis_position_mm(Z_AXIS));
+  }
+
+#endif // GRADIENT_MIX
+
 #endif // MIXING_EXTRUDER

Marlin/src/feature/mixing.h

@@ -23,42 +23,70 @@
 
 #include "../inc/MarlinConfig.h"
 
-#ifdef __AVR__
+//#define MIXER_NORMALIZER_DEBUG
+
+#if !defined(__AVR__) // || DUAL_MIXING_EXTRUDER
+  // Use 16-bit (or fastest) data for the integer mix factors
+  typedef uint_fast16_t mixer_comp_t;
+  typedef uint_fast16_t mixer_accu_t;
+  #define COLOR_A_MASK 0x8000
+  #define COLOR_MASK 0x7FFF
+#else
+  // Use 8-bit data for the integer mix factors
+  // Exactness is sacrificed for speed
   #define MIXER_ACCU_SIGNED
   typedef uint8_t mixer_comp_t;
   typedef int8_t mixer_accu_t;
   #define COLOR_A_MASK 0x80
   #define COLOR_MASK 0x7F
-#else
-  typedef uint_fast16_t mixer_comp_t;
-  typedef uint_fast16_t mixer_accu_t;
-  #define COLOR_A_MASK 0x8000
-  #define COLOR_MASK 0x7FFF
 #endif
 
+typedef int8_t mixer_perc_t;
+
 #ifndef MIXING_VIRTUAL_TOOLS
   #define MIXING_VIRTUAL_TOOLS 1
 #endif
 
+enum MixTool {
+  FIRST_USER_VIRTUAL_TOOL = 0,
+  LAST_USER_VIRTUAL_TOOL = MIXING_VIRTUAL_TOOLS - 1,
+  NR_USER_VIRTUAL_TOOLS,
+  #ifdef RETRACT_SYNC_MIXING
+    MIXER_AUTORETRACT_TOOL = NR_USER_VIRTUAL_TOOLS,
+    NR_MIXING_VIRTUAL_TOOLS
+  #else
+    NR_MIXING_VIRTUAL_TOOLS = NR_USER_VIRTUAL_TOOLS
+  #endif
+};
+
 #ifdef RETRACT_SYNC_MIXING
-  #define NR_MIXING_VIRTUAL_TOOLS (MIXING_VIRTUAL_TOOLS + 1)
-  #define MIXER_AUTORETRACT_TOOL MIXING_VIRTUAL_TOOLS
-  #if NR_MIXING_VIRTUAL_TOOLS > 254
-    #error "MIXING_VIRTUAL_TOOLS must be <= 254!"
-  #endif
+  static_assert(NR_MIXING_VIRTUAL_TOOLS <= 254, "MIXING_VIRTUAL_TOOLS must be <= 254!");
 #else
-  #define NR_MIXING_VIRTUAL_TOOLS (MIXING_VIRTUAL_TOOLS)
-  #if NR_MIXING_VIRTUAL_TOOLS > 255
-    #error "MIXING_VIRTUAL_TOOLS must be <= 255!"
-  #endif
+  static_assert(NR_MIXING_VIRTUAL_TOOLS <= 255, "MIXING_VIRTUAL_TOOLS must be <= 255!");
 #endif
 
 #define MIXER_STEPPER_LOOP(VAR) \
   for (uint_fast8_t VAR = 0; VAR < MIXING_STEPPERS; VAR++)
 
-#define MIXER_BLOCK_FIELD      mixer_comp_t b_color[MIXING_STEPPERS]
-#define MIXER_POPULATE_BLOCK() mixer.populate_block(block->b_color)
-#define MIXER_STEPPER_SETUP()  mixer.stepper_setup(current_block->b_color)
+#define MIXER_BLOCK_FIELD       mixer_comp_t b_color[MIXING_STEPPERS]
+#define MIXER_POPULATE_BLOCK()  mixer.populate_block(block->b_color)
+#define MIXER_STEPPER_SETUP()   mixer.stepper_setup(current_block->b_color)
+
+#if ENABLED(GRADIENT_MIX)
+
+  typedef struct {
+    bool enabled;                         // This gradient is enabled
+    mixer_comp_t color[MIXING_STEPPERS];  // The current gradient color
+    float start_z, end_z;                 // Region for gradient
+    int8_t start_vtool, end_vtool;        // Start and end virtual tools
+    mixer_perc_t start_mix[MIXING_STEPPERS],   // Start and end mixes from those tools
+                 end_mix[MIXING_STEPPERS];
+    #if ENABLED(GRADIENT_VTOOL)
+      int8_t vtool_index;                 // Use this virtual tool number as index
+    #endif
+  } gradient_t;
+
+#endif
 
 /**
  * @brief Mixer class
@@ -67,27 +95,157 @@
 class Mixer {
   public:
 
-  static void init();
+  static float collector[MIXING_STEPPERS];    // M163 components, also editable from LCD
+
+  static void init(); // Populate colors at boot time
 
   static void reset_vtools();
+  static void refresh_collector(const float proportion=1.0, const uint8_t t=selected_vtool);
 
   // Used up to Planner level
+  FORCE_INLINE static void set_collector(const uint8_t c, const float f) { collector[c] = MAX(f, 0.0f); }
+
   static void normalize(const uint8_t tool_index);
+  FORCE_INLINE static void normalize() { normalize(selected_vtool); }
+
   FORCE_INLINE static uint8_t get_current_vtool() { return selected_vtool; }
-  FORCE_INLINE static void T(const uint_fast8_t c) { selected_vtool = c; }
-  FORCE_INLINE static void set_collector(const uint8_t c, const float f) { collector[c] = f; }
+
+  FORCE_INLINE static void T(const uint_fast8_t c) {
+    selected_vtool = c;
+    #if ENABLED(GRADIENT_VTOOL)
+      refresh_gradient();
+    #endif
+    #if DUAL_MIXING_EXTRUDER
+      update_mix_from_vtool();
+    #endif
+  }
 
   // Used when dealing with blocks
-  FORCE_INLINE static void populate_block(mixer_comp_t b_color[]) {
-    uint_fast8_t j = get_current_vtool();
-    MIXER_STEPPER_LOOP(i) b_color[i] = color[j][i];
+  FORCE_INLINE static void populate_block(mixer_comp_t b_color[MIXING_STEPPERS]) {
+    #if ENABLED(GRADIENT_MIX)
+      if (gradient.enabled) {
+        MIXER_STEPPER_LOOP(i) b_color[i] = gradient.color[i];
+        return;
+      }
+    #endif
+    MIXER_STEPPER_LOOP(i) b_color[i] = color[selected_vtool][i];
   }
-  FORCE_INLINE static void stepper_setup(mixer_comp_t b_color[]) { MIXER_STEPPER_LOOP(i) s_color[i] = b_color[i]; }
+
+  FORCE_INLINE static void stepper_setup(mixer_comp_t b_color[MIXING_STEPPERS]) {
+    MIXER_STEPPER_LOOP(i) s_color[i] = b_color[i];
+  }
+
+  #if DUAL_MIXING_EXTRUDER || ENABLED(GRADIENT_MIX)
+
+    static mixer_perc_t mix[MIXING_STEPPERS];  // Scratch array for the Mix in proportion to 100
+
+    static inline void copy_mix_to_color(mixer_comp_t (&tcolor)[MIXING_STEPPERS]) {
+      // Scale each component to the largest one in terms of COLOR_A_MASK
+      // So the largest component will be COLOR_A_MASK and the other will be in proportion to it
+      const float scale = (COLOR_A_MASK) * RECIPROCAL(float(MAX(mix[0], mix[1])));
+
+      // Scale all values so their maximum is COLOR_A_MASK
+      MIXER_STEPPER_LOOP(i) tcolor[i] = mix[i] * scale;
+
+      #ifdef MIXER_NORMALIZER_DEBUG
+        SERIAL_ECHOPAIR("Mix [", int(mix[0]));
+        SERIAL_ECHOPAIR(", ", int(mix[1]));
+        SERIAL_ECHOPAIR("] to Color [", int(tcolor[0]));
+        SERIAL_ECHOPAIR(", ", int(tcolor[1]));
+        SERIAL_ECHOLNPGM("]");
+      #endif
+    }
+
+    static inline void update_mix_from_vtool(const uint8_t j=selected_vtool) {
+      float ctot = 0;
+      MIXER_STEPPER_LOOP(i) ctot += color[j][i];
+      //MIXER_STEPPER_LOOP(i) mix[i] = 100.0f * color[j][i] / ctot;
+      mix[0] = mixer_perc_t(100.0f * color[j][0] / ctot);
+      mix[1] = 100 - mix[0];
+      #ifdef MIXER_NORMALIZER_DEBUG
+        SERIAL_ECHOPAIR("V-tool ", int(j));
+        SERIAL_ECHOPAIR(" [", int(color[j][0]));
+        SERIAL_ECHOPAIR(", ", int(color[j][1]));
+        SERIAL_ECHOPAIR("] to Mix [", int(mix[0]));
+        SERIAL_ECHOPAIR(", ", int(mix[1]));
+        SERIAL_ECHOLNPGM("]");
+      #endif
+    }
+
+  #endif // DUAL_MIXING_EXTRUDER || GRADIENT_MIX
+
+  #if DUAL_MIXING_EXTRUDER
+
+    // Update the virtual tool from an edited mix
+    static inline void update_vtool_from_mix() {
+      copy_mix_to_color(color[selected_vtool]);
+      #if ENABLED(GRADIENT_MIX)
+        refresh_gradient();
+      #endif
+      // MIXER_STEPPER_LOOP(i) collector[i] = mix[i];
+      // normalize();
+    }
+
+  #endif // DUAL_MIXING_EXTRUDER
+
+  #if ENABLED(GRADIENT_MIX)
+
+    static gradient_t gradient;
+    static float prev_z;
+
+    // Update the current mix from the gradient for a given Z
+    static void update_gradient_for_z(const float z);
+    static void update_gradient_for_planner_z();
+    static inline void gradient_control(const float z) {
+      if (gradient.enabled) {
+        if (z >= gradient.end_z)
+          T(gradient.end_vtool);
+        else
+          update_gradient_for_z(z);
+      }
+    }
+
+    static inline void update_mix_from_gradient() {
+      float ctot = 0;
+      MIXER_STEPPER_LOOP(i) ctot += gradient.color[i];
+      mix[0] = (mixer_perc_t)CEIL(100.0f * gradient.color[0] / ctot);
+      mix[1] = 100 - mix[0];
+      #ifdef MIXER_NORMALIZER_DEBUG
+        SERIAL_ECHOPAIR("Gradient [", int(gradient.color[0]));
+        SERIAL_ECHOPAIR(", ", int(gradient.color[1]));
+        SERIAL_ECHOPAIR("] to Mix [", int(mix[0]));
+        SERIAL_ECHOPAIR(", ", int(mix[1]));
+        SERIAL_ECHOLNPGM("]");
+      #endif
+    }
+
+    // Refresh the gradient after a change
+    static void refresh_gradient() {
+      #if ENABLED(GRADIENT_VTOOL)
+        const bool is_grd = (selected_vtool == gradient.vtool_index);
+      #else
+        constexpr bool is_grd = true;
+      #endif
+      gradient.enabled = is_grd && gradient.start_vtool != gradient.end_vtool && gradient.start_z < gradient.end_z;
+      if (gradient.enabled) {
+        mixer_perc_t mix_bak[MIXING_STEPPERS];
+        COPY(mix_bak, mix);
+        update_mix_from_vtool(gradient.start_vtool);
+        COPY(gradient.start_mix, mix);
+        update_mix_from_vtool(gradient.end_vtool);
+        COPY(gradient.end_mix, mix);
+        update_gradient_for_planner_z();
+        COPY(mix, mix_bak);
+        prev_z = -1;
+      }
+    }
+
+  #endif // GRADIENT_MIX
 
   // Used in Stepper
   FORCE_INLINE static uint8_t get_stepper() { return runner; }
   FORCE_INLINE static uint8_t get_next_stepper() {
-    do {
+    for (;;) {
       if (--runner < 0) runner = MIXING_STEPPERS - 1;
       accu[runner] += s_color[runner];
       if (
@@ -100,14 +258,13 @@ class Mixer {
         accu[runner] &= COLOR_MASK;
         return runner;
       }
-    } while( true );
+    }
   }
 
   private:
 
   // Used up to Planner level
   static uint_fast8_t selected_vtool;
-  static float        collector[MIXING_STEPPERS];
   static mixer_comp_t color[NR_MIXING_VIRTUAL_TOOLS][MIXING_STEPPERS];
 
   // Used in Stepper

Marlin/src/feature/power_loss_recovery.cpp

@@ -176,6 +176,10 @@ void PrintJobRecovery::save(const bool force/*=false*/, const bool save_queue/*=
       );
     #endif
 
+    #if ENABLED(GRADIENT_MIX)
+      memcpy(&info.gradient, &mixer.gradient, sizeof(info.gradient));
+    #endif
+
     #if ENABLED(FWRETRACT)
       COPY(info.retract, fwretract.current_retract);
       info.retract_hop = fwretract.current_hop;
@@ -305,6 +309,10 @@ void PrintJobRecovery::resume() {
     }
   #endif
 
+  #if ENABLED(GRADIENT_MIX)
+    memcpy(&mixer.gradient, &info.gradient, sizeof(info.gradient));
+  #endif
+
   // Restore Z (plus raise) and E positions with G92.0
   dtostrf(info.current_position[Z_AXIS] + RECOVERY_ZRAISE, 1, 3, str_1);
   dtostrf(info.current_position[E_AXIS]

Marlin/src/feature/power_loss_recovery.h

@@ -28,6 +28,10 @@
 #include "../sd/cardreader.h"
 #include "../inc/MarlinConfigPre.h"
 
+#if ENABLED(MIXING_EXTRUDER)
+  #include "../feature/mixing.h"
+#endif
+
 #define SAVE_INFO_INTERVAL_MS 0
 //#define SAVE_EACH_CMD_MODE
 //#define DEBUG_POWER_LOSS_RECOVERY
@@ -63,6 +67,15 @@ typedef struct {
     float retract[EXTRUDERS], retract_hop;
   #endif
 
+  // Mixing extruder and gradient
+  #if ENABLED(MIXING_EXTRUDER)
+    //uint_fast8_t selected_vtool;
+    //mixer_comp_t color[NR_MIXING_VIRTUAL_TOOLS][MIXING_STEPPERS];
+    #if ENABLED(GRADIENT_MIX)
+      gradient_t gradient;
+    #endif
+  #endif
+
   // Command queue
   uint8_t commands_in_queue, cmd_queue_index_r;
   char command_queue[BUFSIZE][MAX_CMD_SIZE];

Marlin/src/gcode/feature/mixing/M163-M165.cpp

@@ -38,7 +38,7 @@
 void GcodeSuite::M163() {
   const int mix_index = parser.intval('S');
   if (mix_index < MIXING_STEPPERS)
-    mixer.set_collector(mix_index, MAX(parser.floatval('P'), 0.0));
+    mixer.set_collector(mix_index, parser.floatval('P'));
 }
 
 /**
@@ -53,10 +53,12 @@ void GcodeSuite::M164() {
   #else
     constexpr int tool_index = 0;
   #endif
-  if (WITHIN(tool_index, 0, MIXING_VIRTUAL_TOOLS - 1))
-    mixer.normalize(tool_index);
+  if (tool_index >= 0) {
+    if (tool_index < MIXING_VIRTUAL_TOOLS)
+      mixer.normalize(tool_index);
+  }
   else
-    mixer.normalize(mixer.get_current_vtool());
+    mixer.normalize();
 }
 
 #if ENABLED(DIRECT_MIXING_IN_G1)
@@ -95,7 +97,7 @@ void GcodeSuite::M164() {
     MIXER_STEPPER_LOOP(i) {
       if (parser.seenval(mixing_codes[i])) {
         SBI(mix_bits, i);
-        mixer.set_collector(i, MAX(parser.value_float(), 0.0f));
+        mixer.set_collector(i, parser.value_float());
       }
     }
     // If any mixing factors were included, clear the rest
@@ -103,7 +105,7 @@ void GcodeSuite::M164() {
     if (mix_bits) {
       MIXER_STEPPER_LOOP(i)
         if (!TEST(mix_bits, i)) mixer.set_collector(i, 0.0f);
-      mixer.normalize(mixer.get_current_vtool());
+      mixer.normalize();
     }
   }
 

Marlin/src/gcode/feature/mixing/M166.cpp

@@ -0,0 +1,100 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "../../../inc/MarlinConfig.h"
+
+#if ENABLED(GRADIENT_MIX)
+
+#include "../../gcode.h"
+#include "../../../module/motion.h"
+#include "../../../module/planner.h"
+#include "../../../feature/mixing.h"
+
+inline void echo_mix() {
+  SERIAL_ECHOPAIR(" (", int(mixer.mix[0]));
+  SERIAL_ECHOPAIR("%|", int(mixer.mix[1]));
+  SERIAL_ECHOPGM("%)");
+}
+
+inline void echo_zt(const int t, const float &z) {
+  mixer.update_mix_from_vtool(t);
+  SERIAL_ECHOPAIR(" Z", z);
+  SERIAL_ECHOPAIR(" T", t);
+  echo_mix();
+}
+
+/**
+ * M166: Set a simple gradient mix for a two-component mixer
+ *       based on the Geeetech A10M implementation by Jone Liu.
+ *
+ *   S[bool]  - Enable / disable gradients
+ *   A[float] - Starting Z for the gradient
+ *   Z[float] - Ending Z for the gradient. (Must be greater than the starting Z.)
+ *   I[index] - V-Tool to use as the starting mix.
+ *   J[index] - V-Tool to use as the ending mix.
+ *
+ *   T[index] - A V-Tool index to use as an alias for the Gradient (Requires GRADIENT_VTOOL)
+ *              T with no index clears the setting. Note: This can match the I or J value.
+ *
+ * Example: M166 S1 A0 Z20 I0 J1
+ */
+void GcodeSuite::M166() {
+  if (parser.seenval('A')) mixer.gradient.start_z = parser.value_float();
+  if (parser.seenval('Z')) mixer.gradient.end_z = parser.value_float();
+  if (parser.seenval('I')) mixer.gradient.start_vtool = (uint8_t)constrain(parser.value_int(), 0, MIXING_VIRTUAL_TOOLS);
+  if (parser.seenval('J')) mixer.gradient.end_vtool = (uint8_t)constrain(parser.value_int(), 0, MIXING_VIRTUAL_TOOLS);
+
+  #if ENABLED(GRADIENT_VTOOL)
+    if (parser.seen('T')) mixer.gradient.vtool_index = parser.byteval('T', -1);
+  #endif
+
+  if (parser.seen('S')) mixer.gradient.enabled = parser.value_bool();
+
+  SERIAL_ECHOPGM("Gradient Mix ");
+  serialprint_onoff(mixer.gradient.enabled);
+
+  if (mixer.gradient.enabled) {
+
+    mixer.refresh_gradient();
+
+    #if ENABLED(GRADIENT_VTOOL)
+      if (mixer.gradient.vtool_index >= 0) {
+        SERIAL_ECHOPAIR(" (T", int(mixer.gradient.vtool_index));
+        SERIAL_CHAR(')');
+      }
+    #endif
+
+    SERIAL_ECHOPGM(" ; Start");
+    echo_zt(mixer.gradient.start_vtool, mixer.gradient.start_z);
+
+    SERIAL_ECHOPGM(" ; End");
+    echo_zt(mixer.gradient.end_vtool, mixer.gradient.end_z);
+
+    mixer.update_mix_from_gradient();
+    SERIAL_ECHOPAIR(" ; Current Z", planner.get_axis_position_mm(Z_AXIS));
+    echo_mix();
+  }
+
+  SERIAL_EOL();
+}
+
+#endif // GRADIENT_MIX

Marlin/src/gcode/gcode.cpp

@@ -443,6 +443,9 @@ void GcodeSuite::process_parsed_command(
         #if ENABLED(DIRECT_MIXING_IN_G1)
           case 165: M165(); break;                                // M165: Set multiple mix weights
         #endif
+        #if ENABLED(GRADIENT_MIX)
+          case 166: M166(); break;                                // M166: Set Gradient Mix
+        #endif
       #endif
 
       #if DISABLED(NO_VOLUMETRICS)