Merge pull request #383 from dob71/jeff

Hotend offset handling for multi-extruder machines

Marlin/Configuration.h

 #define DEFAULT_ACCELERATION          3000    // X, Y, Z and E max acceleration in mm/s^2 for printing moves 
 #define DEFAULT_RETRACT_ACCELERATION  3000   // X, Y, Z and E max acceleration in mm/s^2 for r retracts
 
-// 
+// Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
+// The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
+// For the other hotends it is their distance from the extruder 0 hotend.
+// #define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+// #define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+
+// The speed change that does not require acceleration (i.e. the software might assume it can be done instanteneously)
 #define DEFAULT_XYJERK                20.0    // (mm/sec)
 #define DEFAULT_ZJERK                 0.4     // (mm/sec)
 #define DEFAULT_EJERK                 5.0    // (mm/sec)

Marlin/Marlin_main.cpp

 // M207 - set retract length S[positive mm] F[feedrate mm/sec] Z[additional zlift/hop]
 // M208 - set recover=unretract length S[positive mm surplus to the M207 S*] F[feedrate mm/sec]
 // M209 - S<1=true/0=false> enable automatic retract detect if the slicer did not support G10/11: every normal extrude-only move will be classified as retract depending on the direction.
+// M218 - set hotend offset (in mm): T<extruder_number> X<offset_on_X> Y<offset_on_Y>
 // M220 S<factor in percent>- set speed factor override percentage
 // M221 S<factor in percent>- set extrude factor override percentage
 // M240 - Trigger a camera to take a photograph
 // M500 - stores paramters in EEPROM
 // M501 - reads parameters from EEPROM (if you need reset them after you changed them temporarily).  
 // M502 - reverts to the default "factory settings".  You still need to store them in EEPROM afterwards if you want to.
-// M503 - print the current settings (from memory not from eeprom)
+// M503 - print the current settings (from memory not from eeprom)
 // M540 - Use S[0|1] to enable or disable the stop SD card print on endstop hit (requires ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED)
 // M600 - Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
 // M907 - Set digital trimpot motor current using axis codes.
 float add_homeing[3]={0,0,0};
 float min_pos[3] = { X_MIN_POS, Y_MIN_POS, Z_MIN_POS };
 float max_pos[3] = { X_MAX_POS, Y_MAX_POS, Z_MAX_POS };
+// Extruder offset, only in XY plane
+float extruder_offset[2][EXTRUDERS] = { 
+#if defined(EXTRUDER_OFFSET_X) && defined(EXTRUDER_OFFSET_Y)
+  EXTRUDER_OFFSET_X, EXTRUDER_OFFSET_Y 
+#endif
+}; 
 uint8_t active_extruder = 0;
 int fanSpeed=0;
 
         retract_recover_feedrate = code_value() ;
       }
     }break;
-    
     case 209: // M209 - S<1=true/0=false> enable automatic retract detect if the slicer did not support G10/11: every normal extrude-only move will be classified as retract depending on the direction.
     {
       if(code_seen('S')) 
       }
       
     }break;
-    #endif
+    #endif // FWRETRACT
+    case 218: // M218 - set hotend offset (in mm), T<extruder_number> X<offset_on_X> Y<offset_on_Y>
+    {
+      if(setTargetedHotend(218)){
+        break;
+      }
+      if(code_seen('X')) 
+      {
+        extruder_offset[X_AXIS][tmp_extruder] = code_value();
+      }
+      if(code_seen('Y'))
+      {
+        extruder_offset[Y_AXIS][tmp_extruder] = code_value();
+      }
+      SERIAL_ECHO_START;
+      SERIAL_ECHOPGM(MSG_HOTEND_OFFSET);
+      for(tmp_extruder = 0; tmp_extruder < EXTRUDERS; tmp_extruder++) 
+      {
+         SERIAL_ECHO(" ");
+         SERIAL_ECHO(extruder_offset[X_AXIS][tmp_extruder]);
+         SERIAL_ECHO(",");
+         SERIAL_ECHO(extruder_offset[Y_AXIS][tmp_extruder]);
+      }
+      SERIAL_ECHOLN("");
+    }break;
     case 220: // M220 S<factor in percent>- set speed factor override percentage
     {
       if(code_seen('S')) 
     {
         Config_PrintSettings();
     }
-    break;
-    #ifdef ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED
-    case 540:
-    {
-        if(code_seen('S')) abort_on_endstop_hit = code_value() > 0;
-    }
-    break;
+    break;
+    #ifdef ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED
+    case 540:
+    {
+        if(code_seen('S')) abort_on_endstop_hit = code_value() > 0;
+    }
+    break;
     #endif
     #ifdef FILAMENTCHANGEENABLE
     case 600: //Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
       SERIAL_ECHOLN(MSG_INVALID_EXTRUDER);
     }
     else {
-      active_extruder = tmp_extruder;
+      boolean make_move = false;
+      if(code_seen('F')) {
+        make_move = true;
+        next_feedrate = code_value();
+        if(next_feedrate > 0.0) {
+          feedrate = next_feedrate;
+        }
+      }
+      if(tmp_extruder != active_extruder) {
+        // Save current position to return to after applying extruder offset
+        memcpy(destination, current_position, sizeof(destination));
+        // Offset extruder (only by XY)
+        int i;
+        for(i = 0; i < 2; i++) {
+           current_position[i] = current_position[i] - 
+                                 extruder_offset[i][active_extruder] +
+                                 extruder_offset[i][tmp_extruder];
+        }
+        // Set the new active extruder and position
+        active_extruder = tmp_extruder;
+        plan_set_position(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS]);
+        // Move to the old position if 'F' was in the parameters
+        if(make_move && Stopped == false) {
+           prepare_move();
+        }
+      }
       SERIAL_ECHO_START;
       SERIAL_ECHO(MSG_ACTIVE_EXTRUDER);
       SERIAL_PROTOCOLLN((int)active_extruder);
         case 109:
           SERIAL_ECHO(MSG_M109_INVALID_EXTRUDER);
           break;
+        case 218:
+          SERIAL_ECHO(MSG_M218_INVALID_EXTRUDER);
+          break;
       }
       SERIAL_ECHOLN(tmp_extruder);
       return true;

Marlin/thermistortables.h

    {970*OVERSAMPLENR, 25},
    {978*OVERSAMPLENR, 22},
    {1008*OVERSAMPLENR, 3},
-   {1023*OVERSAMPLENR, 0}  //to allow internal 0C
+   {1023*OVERSAMPLENR, 0}  //to allow internal 0 degrees C
 };
 #endif
 
    {994*OVERSAMPLENR, 15},
    {1001*OVERSAMPLENR, 10},
    {1005*OVERSAMPLENR, 5},
-   {1023*OVERSAMPLENR, 0}  //to allow internal 0C
+   {1023*OVERSAMPLENR, 0}  //to allow internal 0 degrees C
 };
 #endif
 #if (THERMISTORHEATER_0 == 8) || (THERMISTORHEATER_1 == 8) || (THERMISTORHEATER_2 == 8) || (THERMISTORBED == 8)