Support for Ortur 4.3 mainboard (#17790)

Marlin/src/core/boards.h

 #define BOARD_TANGO                   1148  // BIQU Tango V1
 #define BOARD_MKS_GEN_L_V2            1149  // MKS GEN L V2
 #define BOARD_COPYMASTER_3D           1150  // Copymaster 3D
+#define BOARD_ORTUR_4                 1151  // Ortur 4
 
 //
 // RAMBo and derivatives

Marlin/src/pins/pins.h

   #include "ramps/pins_MKS_GEN_L_V2.h"          // ATmega2560                             env:mega2560
 #elif MB(COPYMASTER_3D)
   #include "ramps/pins_COPYMASTER_3D.h"         // ATmega2560                             env:mega2560
+#elif MB(ORTUR_4)
+  #include "ramps/pins_ORTUR_4.h"               // ATmega2560                             env:mega2560
 
 //
 // RAMBo and derivatives

Marlin/src/pins/ramps/pins_ORTUR_4.h

+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 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/>.
+ *
+ */
+#pragma once
+
+/**
+ * Ortur 4 Arduino Mega based on RAMPS v1.4 pin assignments
+ */
+
+#define BOARD_INFO_NAME "Ortur 4.3"
+#define DEFAULT_MACHINE_NAME BOARD_INFO_NAME
+
+//
+// Servos
+//
+#define SERVO0_PIN                            29
+
+//
+// Limit Switches
+//
+#define X_MAX_PIN                             18
+#define Z_MIN_PIN                             63
+
+#define Z_MIN_PROBE_PIN                        2
+#define FIL_RUNOUT_PIN                        59
+
+//
+// Steppers
+//
+#define E0_CS_PIN                             44
+#define E1_CS_PIN                             42
+
+//
+// Temperature Sensors
+//
+#define TEMP_0_PIN                            15  // Analog Input
+#define TEMP_1_PIN                            13  // Analog Input
+
+//
+// Software serial
+//
+#define X_SERIAL_TX_PIN                       59
+#define X_SERIAL_RX_PIN                       63
+
+#define Y_SERIAL_TX_PIN                       64
+#define Y_SERIAL_RX_PIN                       40
+
+#define Z_SERIAL_TX_PIN                       44
+#define Z_SERIAL_RX_PIN                       42
+
+#define E0_SERIAL_TX_PIN                      66
+#define E0_SERIAL_RX_PIN                      65
+
+#include "pins_RAMPS.h"
+
+//
+// Steppers
+//
+#undef E0_STEP_PIN
+#undef E0_DIR_PIN
+#undef E0_ENABLE_PIN
+#define E0_STEP_PIN                           36
+#define E0_DIR_PIN                            34
+#define E0_ENABLE_PIN                         30
+
+#undef E1_STEP_PIN
+#undef E1_DIR_PIN
+#undef E1_ENABLE_PIN
+#define E1_STEP_PIN                           26
+#define E1_DIR_PIN                            28
+#define E1_ENABLE_PIN                         24
+
+//
+// LCD / Controller
+//
+#if ENABLED(REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER)
+  #undef BEEPER_PIN
+  #define BEEPER_PIN                          35
+
+  #undef LCD_PINS_RS
+  #undef LCD_PINS_ENABLE
+  #undef LCD_PINS_D4
+  #define LCD_PINS_RS                         27
+  #define LCD_PINS_ENABLE                     23
+  #define LCD_PINS_D4                         37
+
+  #undef LCD_SDSS
+  #undef SD_DETECT_PIN
+  #define LCD_SDSS                            53
+  #define SD_DETECT_PIN                       49
+
+  #undef BTN_EN1
+  #undef BTN_EN2
+  #undef BTN_ENC
+  #define BTN_EN1                             29
+  #define BTN_EN2                             25
+  #define BTN_ENC                             16
+#endif