Creality v4.3.1 (Ender 6) board (#20512)

Marlin/src/core/boards.h

 #define BOARD_CHITU3D_V6              4036  // Chitu3D TronXY X5SA V5 Board
 #define BOARD_CREALITY_V4             4037  // Creality v4.x (STM32F103RE)
 #define BOARD_CREALITY_V427           4038  // Creality v4.2.7 (STM32F103RE)
-#define BOARD_CREALITY_V452           4039  // Creality v4.5.2 (STM32F103RE)
-#define BOARD_CREALITY_V453           4040  // Creality v4.5.3 (STM32F103RE)
-#define BOARD_TRIGORILLA_PRO          4041  // Trigorilla Pro (STM32F103ZET6)
-#define BOARD_FLY_MINI                4042  // FLY MINI (STM32F103RCT6)
-#define BOARD_FLSUN_HISPEED           4043  // FLSUN HiSpeedV1 (STM32F103VET6)
-#define BOARD_BEAST                   4044  // STM32F103RET6 Libmaple-based controller
-#define BOARD_BTT_SKR_CR6             4045  // BigTreeTech SKR CR6 v1.0 (STM32F103RE)
+#define BOARD_CREALITY_V431           4039  // Creality v4.3.1 (STM32F103RE)
+#define BOARD_CREALITY_V452           4040  // Creality v4.5.2 (STM32F103RE)
+#define BOARD_CREALITY_V453           4041  // Creality v4.5.3 (STM32F103RE)
+#define BOARD_TRIGORILLA_PRO          4042  // Trigorilla Pro (STM32F103ZET6)
+#define BOARD_FLY_MINI                4043  // FLY MINI (STM32F103RCT6)
+#define BOARD_FLSUN_HISPEED           4044  // FLSUN HiSpeedV1 (STM32F103VET6)
+#define BOARD_BEAST                   4045  // STM32F103RET6 Libmaple-based controller
+#define BOARD_BTT_SKR_CR6             4046  // BigTreeTech SKR CR6 v1.0 (STM32F103RE)
 
 //
 // ARM Cortex-M4F

Marlin/src/pins/pins.h

   #include "stm32f1/pins_CREALITY_V4.h"         // STM32F1                                env:STM32F103RET6_creality
 #elif MB(CREALITY_V427)
   #include "stm32f1/pins_CREALITY_V427.h"       // STM32F1                                env:STM32F103RET6_creality
+#elif MB(CREALITY_V431)
+  #include "stm32f1/pins_CREALITY_V431.h"       // STM32F1                                env:STM32F103RET6_creality
 #elif MB(CREALITY_V452)
   #include "stm32f1/pins_CREALITY_V452.h"       // STM32F1                                env:STM32F103RET6_creality
 #elif MB(CREALITY_V453)

Marlin/src/pins/stm32f1/pins_CREALITY_V427.h

  * CREALITY v4.2.7 (STM32F103) board pin assignments
  */
 
-#if NOT_TARGET(__STM32F1__)
-  #error "Oops! Select an STM32F1 board in 'Tools > Board.'"
-#endif
-
 #define BOARD_INFO_NAME      "Creality v4.2.7"
 #define DEFAULT_MACHINE_NAME "Creality3D"
 

Marlin/src/pins/stm32f1/pins_CREALITY_V431.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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * CREALITY v4.3.1 (STM32F103) board pin assignments
+ */
+
+#define BOARD_INFO_NAME      "Creality v4.3.1"
+#define DEFAULT_MACHINE_NAME "Creality3D"
+
+//
+// Steppers
+//
+#define X_STEP_PIN                        PB8
+#define X_DIR_PIN                         PB7
+
+#define Y_STEP_PIN                        PC2
+#define Y_DIR_PIN                         PB9
+
+#include "pins_CREALITY_V4.h"