Bed Auto Leveling feature

Check the Readme for instruction how to enable and configure the feature

Marlin/Configuration.h

@@ -292,13 +292,50 @@ const bool Z_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of
 
 #define min_software_endstops true // If true, axis won't move to coordinates less than HOME_POS.
 #define max_software_endstops true  // If true, axis won't move to coordinates greater than the defined lengths below.
+
+//============================= Bed Auto Leveling ===========================
+
+//#define ENABLE_AUTO_BED_LEVELING // Delete the comment to enable (remove // at the start of the line)
+
+#ifdef ENABLE_AUTO_BED_LEVELING
+
+  // these are the positions on the bed to do the probing
+  #define LEFT_PROBE_BED_POSITION 15
+  #define RIGHT_PROBE_BED_POSITION 170
+  #define BACK_PROBE_BED_POSITION 180
+  #define FRONT_PROBE_BED_POSITION 20
+
+  // these are the offsets to the prob relative to the extruder tip (Hotend - Probe)
+  #define X_PROBE_OFFSET_FROM_EXTRUDER -25
+  #define Y_PROBE_OFFSET_FROM_EXTRUDER -29
+  #define Z_PROBE_OFFSET_FROM_EXTRUDER -12.35
+
+  #define XY_TRAVEL_SPEED 8000         // X and Y axis travel speed between probes, in mm/min
+
+  #define Z_RAISE_BEFORE_PROBING 15    //How much the extruder will be raised before traveling to the first probing point.
+  #define Z_RAISE_BETWEEN_PROBINGS 5  //How much the extruder will be raised when traveling from between next probing points
+
+
+  //If defined, the Probe servo will be turned on only during movement and then turned off to avoid jerk
+  //The value is the delay to turn the servo off after powered on - depends on the servo speed; 300ms is good value, but you can try lower it.
+  // You MUST HAVE the SERVO_ENDSTOPS defined to use here a value higher than zero otherwise your code will not compile.
+
+//  #define PROBE_SERVO_DEACTIVATION_DELAY 300  
+
+#endif
+
 // Travel limits after homing
 #define X_MAX_POS 205
 #define X_MIN_POS 0
 #define Y_MAX_POS 205
 #define Y_MIN_POS 0
 #define Z_MAX_POS 200
+
+#ifndef ENABLE_AUTO_BED_LEVELING
 #define Z_MIN_POS 0
+#else
+#define Z_MIN_POS (-1*Z_PROBE_OFFSET_FROM_EXTRUDER)  //With Auto Bed Leveling, the Z_MIN MUST have the same distance as Z_PROBE
+#endif
 
 #define X_MAX_LENGTH (X_MAX_POS - X_MIN_POS)
 #define Y_MAX_LENGTH (Y_MAX_POS - Y_MIN_POS)

Marlin/Marlin.ino

@@ -0,0 +1,52 @@
+/* -*- c++ -*- */
+
+/*
+    Reprap firmware 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/>.
+ */
+
+/*
+ This firmware is a mashup between Sprinter and grbl.
+  (https://github.com/kliment/Sprinter)
+  (https://github.com/simen/grbl/tree)
+ 
+ It has preliminary support for Matthew Roberts advance algorithm 
+    http://reprap.org/pipermail/reprap-dev/2011-May/003323.html
+ */
+
+/* All the implementation is done in *.cpp files to get better compatibility with avr-gcc without the Arduino IDE */
+/* Use this file to help the Arduino IDE find which Arduino libraries are needed and to keep documentation on GCode */
+
+#include "Configuration.h"
+#include "pins.h"
+
+#ifdef ULTRA_LCD
+  #if defined(LCD_I2C_TYPE_PCF8575)
+    #include <Wire.h>
+    #include <LiquidCrystal_I2C.h>
+  #elif defined(LCD_I2C_TYPE_MCP23017) || defined(LCD_I2C_TYPE_MCP23008)
+    #include <Wire.h>
+    #include <LiquidTWI2.h>
+  #elif defined(DOGLCD)
+    #include <U8glib.h> // library for graphics LCD by Oli Kraus (https://code.google.com/p/u8glib/)
+  #else
+    #include <LiquidCrystal.h> // library for character LCD
+  #endif
+#endif
+
+#if defined(DIGIPOTSS_PIN) && DIGIPOTSS_PIN > -1
+#include <SPI.h>
+#endif