✨ BTT SKR Mini E3 V3.0.1 (#24722)

Marlin/src/core/boards.h

@@ -329,45 +329,46 @@
 #define BOARD_BTT_SKR_MINI_E3_V1_2    4025  // BigTreeTech SKR Mini E3 V1.2 (STM32F103RC)
 #define BOARD_BTT_SKR_MINI_E3_V2_0    4026  // BigTreeTech SKR Mini E3 V2.0 (STM32F103RC / STM32F103RE)
 #define BOARD_BTT_SKR_MINI_E3_V3_0    4027  // BigTreeTech SKR Mini E3 V3.0 (STM32G0B1RE)
-#define BOARD_BTT_SKR_MINI_MZ_V1_0    4028  // BigTreeTech SKR Mini MZ V1.0 (STM32F103RC)
-#define BOARD_BTT_SKR_E3_DIP          4029  // BigTreeTech SKR E3 DIP V1.0 (STM32F103RC / STM32F103RE)
-#define BOARD_BTT_SKR_CR6             4030  // BigTreeTech SKR CR6 v1.0 (STM32F103RE)
-#define BOARD_JGAURORA_A5S_A1         4031  // JGAurora A5S A1 (STM32F103ZE)
-#define BOARD_FYSETC_AIO_II           4032  // FYSETC AIO_II (STM32F103RC)
-#define BOARD_FYSETC_CHEETAH          4033  // FYSETC Cheetah (STM32F103RC)
-#define BOARD_FYSETC_CHEETAH_V12      4034  // FYSETC Cheetah V1.2 (STM32F103RC)
-#define BOARD_LONGER3D_LK             4035  // Longer3D LK1/2 - Alfawise U20/U20+/U30 (STM32F103VE)
-#define BOARD_CCROBOT_MEEB_3DP        4036  // ccrobot-online.com MEEB_3DP (STM32F103RC)
-#define BOARD_CHITU3D_V5              4037  // Chitu3D TronXY X5SA V5 Board (STM32F103ZE)
-#define BOARD_CHITU3D_V6              4038  // Chitu3D TronXY X5SA V6 Board (STM32F103ZE)
-#define BOARD_CHITU3D_V9              4039  // Chitu3D TronXY X5SA V9 Board (STM32F103ZE)
-#define BOARD_CREALITY_V4             4040  // Creality v4.x (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V422           4041  // Creality v4.2.2 (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V423           4042  // Creality v4.2.3 (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V425           4043  // Creality v4.2.5 (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V427           4044  // Creality v4.2.7 (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V4210          4045  // Creality v4.2.10 (STM32F103RC / STM32F103RE) as found in the CR-30
-#define BOARD_CREALITY_V431           4046  // Creality v4.3.1 (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V431_A         4047  // Creality v4.3.1a (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V431_B         4048  // Creality v4.3.1b (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V431_C         4049  // Creality v4.3.1c (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V431_D         4050  // Creality v4.3.1d (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V452           4051  // Creality v4.5.2 (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V453           4052  // Creality v4.5.3 (STM32F103RC / STM32F103RE)
-#define BOARD_CREALITY_V24S1          4053  // Creality v2.4.S1 (STM32F103RC / STM32F103RE) v101 as found in the Ender-7
-#define BOARD_CREALITY_V24S1_301      4054  // Creality v2.4.S1_301 (STM32F103RC / STM32F103RE) v301 as found in the Ender-3 S1
-#define BOARD_CREALITY_V25S1          4055  // Creality v2.5.S1 (STM32F103RE) as found in the CR-10 Smart Pro
-#define BOARD_TRIGORILLA_PRO          4056  // Trigorilla Pro (STM32F103ZE)
-#define BOARD_FLY_MINI                4057  // FLYmaker FLY MINI (STM32F103RC)
-#define BOARD_FLSUN_HISPEED           4058  // FLSUN HiSpeedV1 (STM32F103VE)
-#define BOARD_BEAST                   4059  // STM32F103RE Libmaple-based controller
-#define BOARD_MINGDA_MPX_ARM_MINI     4060  // STM32F103ZE Mingda MD-16
-#define BOARD_GTM32_PRO_VD            4061  // STM32F103VE controller
-#define BOARD_ZONESTAR_ZM3E2          4062  // Zonestar ZM3E2    (STM32F103RC)
-#define BOARD_ZONESTAR_ZM3E4          4063  // Zonestar ZM3E4 V1 (STM32F103VC)
-#define BOARD_ZONESTAR_ZM3E4V2        4064  // Zonestar ZM3E4 V2 (STM32F103VC)
-#define BOARD_ERYONE_ERY32_MINI       4065  // Eryone Ery32 mini (STM32F103VE)
-#define BOARD_PANDA_PI_V29            4066  // Panda Pi V2.9 - Standalone (STM32F103RC)
+#define BOARD_BTT_SKR_MINI_E3_V3_0_1  4028  // BigTreeTech SKR Mini E3 V3.0.1 (STM32F401RC)
+#define BOARD_BTT_SKR_MINI_MZ_V1_0    4029  // BigTreeTech SKR Mini MZ V1.0 (STM32F103RC)
+#define BOARD_BTT_SKR_E3_DIP          4030  // BigTreeTech SKR E3 DIP V1.0 (STM32F103RC / STM32F103RE)
+#define BOARD_BTT_SKR_CR6             4031  // BigTreeTech SKR CR6 v1.0 (STM32F103RE)
+#define BOARD_JGAURORA_A5S_A1         4032  // JGAurora A5S A1 (STM32F103ZE)
+#define BOARD_FYSETC_AIO_II           4033  // FYSETC AIO_II (STM32F103RC)
+#define BOARD_FYSETC_CHEETAH          4034  // FYSETC Cheetah (STM32F103RC)
+#define BOARD_FYSETC_CHEETAH_V12      4035  // FYSETC Cheetah V1.2 (STM32F103RC)
+#define BOARD_LONGER3D_LK             4036  // Longer3D LK1/2 - Alfawise U20/U20+/U30 (STM32F103VE)
+#define BOARD_CCROBOT_MEEB_3DP        4037  // ccrobot-online.com MEEB_3DP (STM32F103RC)
+#define BOARD_CHITU3D_V5              4038  // Chitu3D TronXY X5SA V5 Board (STM32F103ZE)
+#define BOARD_CHITU3D_V6              4039  // Chitu3D TronXY X5SA V6 Board (STM32F103ZE)
+#define BOARD_CHITU3D_V9              4040  // Chitu3D TronXY X5SA V9 Board (STM32F103ZE)
+#define BOARD_CREALITY_V4             4041  // Creality v4.x (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V422           4042  // Creality v4.2.2 (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V423           4043  // Creality v4.2.3 (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V425           4044  // Creality v4.2.5 (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V427           4045  // Creality v4.2.7 (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V4210          4046  // Creality v4.2.10 (STM32F103RC / STM32F103RE) as found in the CR-30
+#define BOARD_CREALITY_V431           4047  // Creality v4.3.1 (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V431_A         4048  // Creality v4.3.1a (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V431_B         4049  // Creality v4.3.1b (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V431_C         4050  // Creality v4.3.1c (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V431_D         4051  // Creality v4.3.1d (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V452           4052  // Creality v4.5.2 (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V453           4053  // Creality v4.5.3 (STM32F103RC / STM32F103RE)
+#define BOARD_CREALITY_V24S1          4054  // Creality v2.4.S1 (STM32F103RC / STM32F103RE) v101 as found in the Ender-7
+#define BOARD_CREALITY_V24S1_301      4055  // Creality v2.4.S1_301 (STM32F103RC / STM32F103RE) v301 as found in the Ender-3 S1
+#define BOARD_CREALITY_V25S1          4056  // Creality v2.5.S1 (STM32F103RE) as found in the CR-10 Smart Pro
+#define BOARD_TRIGORILLA_PRO          4057  // Trigorilla Pro (STM32F103ZE)
+#define BOARD_FLY_MINI                4058  // FLYmaker FLY MINI (STM32F103RC)
+#define BOARD_FLSUN_HISPEED           4059  // FLSUN HiSpeedV1 (STM32F103VE)
+#define BOARD_BEAST                   4060  // STM32F103RE Libmaple-based controller
+#define BOARD_MINGDA_MPX_ARM_MINI     4061  // STM32F103ZE Mingda MD-16
+#define BOARD_GTM32_PRO_VD            4062  // STM32F103VE controller
+#define BOARD_ZONESTAR_ZM3E2          4063  // Zonestar ZM3E2    (STM32F103RC)
+#define BOARD_ZONESTAR_ZM3E4          4064  // Zonestar ZM3E4 V1 (STM32F103VC)
+#define BOARD_ZONESTAR_ZM3E4V2        4065  // Zonestar ZM3E4 V2 (STM32F103VC)
+#define BOARD_ERYONE_ERY32_MINI       4066  // Eryone Ery32 mini (STM32F103VE)
+#define BOARD_PANDA_PI_V29            4067  // Panda Pi V2.9 - Standalone (STM32F103RC)
 
 //
 // ARM Cortex-M4F

Marlin/src/pins/pins.h

@@ -541,6 +541,8 @@
   #include "stm32f1/pins_BTT_SKR_MINI_E3_V2_0.h"  // STM32F1                              env:STM32F103RC_btt env:STM32F103RC_btt_USB env:STM32F103RE_btt env:STM32F103RE_btt_USB env:STM32F103RC_btt_maple env:STM32F103RC_btt_USB_maple env:STM32F103RE_btt_maple env:STM32F103RE_btt_USB_maple
 #elif MB(BTT_SKR_MINI_E3_V3_0)
   #include "stm32g0/pins_BTT_SKR_MINI_E3_V3_0.h"  // STM32G0                              env:STM32G0B1RE_btt env:STM32G0B1RE_btt_xfer
+#elif MB(BTT_SKR_MINI_E3_V3_0_1)
+  #include "stm32f4/pins_BTT_SKR_MINI_E3_V3_0_1.h"// STM32F4                              env:STM32F401RC_btt
 #elif MB(BTT_SKR_MINI_MZ_V1_0)
   #include "stm32f1/pins_BTT_SKR_MINI_MZ_V1_0.h"  // STM32F1                              env:STM32F103RC_btt env:STM32F103RC_btt_USB env:STM32F103RC_btt_maple env:STM32F103RC_btt_USB_maple
 #elif MB(BTT_SKR_E3_DIP)

Marlin/src/pins/stm32f1/pins_BTT_SKR_MINI_E3_common.h

@@ -135,6 +135,12 @@
   #define EXP1_02_PIN                       PB6
   #define EXP1_08_PIN                       PB7
 #endif
+#define EXP1_01_PIN                         PB5
+#define EXP1_03_PIN                         PA9
+#define EXP1_04_PIN                         -1    // RESET
+#define EXP1_05_PIN                         PA10
+#define EXP1_06_PIN                         PB9
+#define EXP1_07_PIN                         PB8
 
 #if HAS_DWIN_E3V2 || IS_DWIN_MARLINUI
   /**
@@ -156,22 +162,22 @@
 
   #define BEEPER_PIN                 EXP1_02_PIN
   #define BTN_EN1                    EXP1_08_PIN
-  #define BTN_EN2                           PB8
-  #define BTN_ENC                           PB5
+  #define BTN_EN2                    EXP1_07_PIN
+  #define BTN_ENC                    EXP1_01_PIN
 
 #elif HAS_WIRED_LCD
 
   #if ENABLED(CR10_STOCKDISPLAY)
 
-    #define BEEPER_PIN                      PB5
+    #define BEEPER_PIN               EXP1_01_PIN
     #define BTN_ENC                  EXP1_02_PIN
 
-    #define BTN_EN1                         PA9
-    #define BTN_EN2                         PA10
+    #define BTN_EN1                  EXP1_03_PIN
+    #define BTN_EN2                  EXP1_05_PIN
 
-    #define LCD_PINS_RS                     PB8
+    #define LCD_PINS_RS              EXP1_07_PIN
     #define LCD_PINS_ENABLE          EXP1_08_PIN
-    #define LCD_PINS_D4                     PB9
+    #define LCD_PINS_D4              EXP1_06_PIN
 
   #elif ENABLED(ZONESTAR_LCD)                     // ANET A8 LCD Controller - Must convert to 3.3V - CONNECTING TO 5V WILL DAMAGE THE BOARD!
 
@@ -179,23 +185,23 @@
       #error "CAUTION! ZONESTAR_LCD requires wiring modifications. See 'pins_BTT_SKR_MINI_E3_common.h' for details. (Define NO_CONTROLLER_CUSTOM_WIRING_WARNING to suppress this warning.)"
     #endif
 
-    #define LCD_PINS_RS                     PB9
+    #define LCD_PINS_RS              EXP1_06_PIN
     #define LCD_PINS_ENABLE          EXP1_02_PIN
-    #define LCD_PINS_D4                     PB8
-    #define LCD_PINS_D5                     PA10
-    #define LCD_PINS_D6                     PA9
-    #define LCD_PINS_D7                     PB5
+    #define LCD_PINS_D4              EXP1_07_PIN
+    #define LCD_PINS_D5              EXP1_05_PIN
+    #define LCD_PINS_D6              EXP1_03_PIN
+    #define LCD_PINS_D7              EXP1_01_PIN
     #define ADC_KEYPAD_PIN                  PA1   // Repurpose servo pin for ADC - CONNECTING TO 5V WILL DAMAGE THE BOARD!
 
   #elif EITHER(MKS_MINI_12864, ENDER2_STOCKDISPLAY)
 
     #define BTN_ENC                  EXP1_02_PIN
-    #define BTN_EN1                         PA9
-    #define BTN_EN2                         PA10
+    #define BTN_EN1                  EXP1_03_PIN
+    #define BTN_EN2                  EXP1_05_PIN
 
-    #define DOGLCD_CS                       PB8
-    #define DOGLCD_A0                       PB9
-    #define DOGLCD_SCK                      PB5
+    #define DOGLCD_CS                EXP1_07_PIN
+    #define DOGLCD_A0                EXP1_06_PIN
+    #define DOGLCD_SCK               EXP1_01_PIN
     #define DOGLCD_MOSI              EXP1_08_PIN
 
     #define FORCE_SOFT_SPI
@@ -238,7 +244,7 @@
        *   EXP1-1 ----------- EXP1-7   SD_DET
        */
 
-      #define TFTGLCD_CS                    PA9
+      #define TFTGLCD_CS             EXP1_03_PIN
 
     #endif
 
@@ -291,20 +297,20 @@
      * for backlight configuration see steps 2 (V2.1) and 3 in https://wiki.fysetc.com/Mini12864_Panel/
      */
 
-    #define LCD_PINS_RS                     PA9     // CS
+    #define LCD_PINS_RS              EXP1_03_PIN    // CS
     #define LCD_PINS_ENABLE                 PA3     // MOSI
     #define LCD_BACKLIGHT_PIN               -1
-    #define NEOPIXEL_PIN                    PB8
+    #define NEOPIXEL_PIN             EXP1_07_PIN
     #define LCD_CONTRAST                    255
-    #define LCD_RESET_PIN                   PA10
+    #define LCD_RESET_PIN            EXP1_05_PIN
 
-    #define DOGLCD_CS                       PA9
-    #define DOGLCD_A0                       PB5
+    #define DOGLCD_CS                EXP1_03_PIN
+    #define DOGLCD_A0                EXP1_01_PIN
     #define DOGLCD_SCK                      PA2
     #define DOGLCD_MOSI                     PA3
 
     #define BTN_ENC                         PA15
-    #define BTN_EN1                         PB9
+    #define BTN_EN1                  EXP1_06_PIN
     #define BTN_EN2                         PB15
 
     #define FORCE_SOFT_SPI
@@ -354,8 +360,8 @@
 
   #define BEEPER_PIN                 EXP1_02_PIN
 
-  #define CLCD_MOD_RESET                    PA9
-  #define CLCD_SPI_CS                       PB8
+  #define CLCD_MOD_RESET             EXP1_03_PIN
+  #define CLCD_SPI_CS                EXP1_07_PIN
 
 #endif // TOUCH_UI_FTDI_EVE && LCD_FYSETC_TFT81050
 
@@ -370,8 +376,8 @@
 #if SD_CONNECTION_IS(ONBOARD)
   #define SD_DETECT_PIN                     PC4
 #elif SD_CONNECTION_IS(LCD) && (BOTH(TOUCH_UI_FTDI_EVE, LCD_FYSETC_TFT81050) || IS_TFTGLCD_PANEL)
-  #define SD_DETECT_PIN                     PB5
-  #define SD_SS_PIN                         PA10
+  #define SD_DETECT_PIN              EXP1_01_PIN
+  #define SD_SS_PIN                  EXP1_05_PIN
 #elif SD_CONNECTION_IS(CUSTOM_CABLE)
   #error "SD CUSTOM_CABLE is not compatible with SKR Mini E3."
 #endif

Marlin/src/pins/stm32f4/pins_ARMED.h

@@ -19,11 +19,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-
-//  https://github.com/ktand/Armed
-
 #pragma once
 
+// https://github.com/ktand/Armed
+
 #include "env_validate.h"
 
 #if HOTENDS > 2 || E_STEPPERS > 2

Marlin/src/pins/stm32f4/pins_BTT_SKR_MINI_E3_V3_0_1.h

@@ -0,0 +1,350 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 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/>.
+ *
+ */
+#pragma once
+
+//#define BOARD_CUSTOM_BUILD_FLAGS -DTONE_CHANNEL=4 -DTONE_TIMER=4 -DTIMER_TONE=4
+
+#include "env_validate.h"
+
+#if HOTENDS > 1 || E_STEPPERS > 1
+  #error "BTT SKR Mini E3 V3.0.1 supports up to 1 hotend / E stepper."
+#endif
+
+#ifndef BOARD_INFO_NAME
+  #define BOARD_INFO_NAME "BTT SKR Mini E3 V3.0.1"
+#endif
+
+#define USES_DIAG_JUMPERS
+
+// Ignore temp readings during development.
+//#define BOGUS_TEMPERATURE_GRACE_PERIOD    2000
+
+#ifndef NEOPIXEL_LED
+  #define LED_PIN                           PA14
+#endif
+
+// Onboard I2C EEPROM
+#if EITHER(NO_EEPROM_SELECTED, I2C_EEPROM)
+  #undef NO_EEPROM_SELECTED
+  #define I2C_EEPROM
+  #define SOFT_I2C_EEPROM                         // Force the use of Software I2C
+  #define I2C_SCL_PIN                       PB8
+  #define I2C_SDA_PIN                       PB9
+  #define MARLIN_EEPROM_SIZE              0x1000  // 4KB
+#endif
+
+//
+// Servos
+//
+#define SERVO0_PIN                          PA0   // SERVOS
+
+//
+// Limit Switches
+//
+#define X_STOP_PIN                          PB5   // X-STOP
+#define Y_STOP_PIN                          PB6   // Y-STOP
+#define Z_STOP_PIN                          PB7   // Z-STOP
+
+//
+// Z Probe must be this pin
+//
+#define Z_MIN_PROBE_PIN                     PA1   // PROBE
+
+//
+// Filament Runout Sensor
+//
+#ifndef FIL_RUNOUT_PIN
+  #define FIL_RUNOUT_PIN                    PC15  // E0-STOP
+#endif
+
+//
+// Power-loss Detection
+//
+#ifndef POWER_LOSS_PIN
+  #define POWER_LOSS_PIN                    PC13  // Power Loss Detection: PWR-DET
+#endif
+
+#ifndef NEOPIXEL_PIN
+  #define NEOPIXEL_PIN                      PA14  // LED driving pin
+#endif
+
+#ifndef PS_ON_PIN
+  #define PS_ON_PIN                         PC14  // Power Supply Control
+#endif
+
+//
+// Steppers
+//
+#define X_ENABLE_PIN                        PC10
+#define X_STEP_PIN                          PC11
+#define X_DIR_PIN                           PC12
+
+#define Y_ENABLE_PIN                        PB13
+#define Y_STEP_PIN                          PB12
+#define Y_DIR_PIN                           PB10
+
+#define Z_ENABLE_PIN                        PB2
+#define Z_STEP_PIN                          PB1
+#define Z_DIR_PIN                           PB0
+
+#define E0_ENABLE_PIN                       PC3
+#define E0_STEP_PIN                         PC2
+#define E0_DIR_PIN                          PC1
+
+#if HAS_TMC_UART
+  /**
+   * TMC220x stepper drivers
+   * Hardware serial communication ports
+   */
+  #define X_HARDWARE_SERIAL  MSerial6
+  #define Y_HARDWARE_SERIAL  MSerial6
+  #define Z_HARDWARE_SERIAL  MSerial6
+  #define E0_HARDWARE_SERIAL MSerial6
+
+  // Default TMC slave addresses
+  #ifndef X_SLAVE_ADDRESS
+    #define X_SLAVE_ADDRESS                    0
+  #endif
+  #ifndef Y_SLAVE_ADDRESS
+    #define Y_SLAVE_ADDRESS                    2
+  #endif
+  #ifndef Z_SLAVE_ADDRESS
+    #define Z_SLAVE_ADDRESS                    1
+  #endif
+  #ifndef E0_SLAVE_ADDRESS
+    #define E0_SLAVE_ADDRESS                   3
+  #endif
+#endif
+
+//
+// Temperature Sensors
+//
+#define TEMP_0_PIN                          PC5   // Analog Input "TH0"
+#define TEMP_BED_PIN                        PC4   // Analog Input "TB0"
+
+//
+// Heaters / Fans
+//
+#define HEATER_0_PIN                        PA15  // "HE"
+#define HEATER_BED_PIN                      PB3   // "HB"
+#define FAN_PIN                             PC9   // "FAN0"
+#define FAN1_PIN                            PA8   // "FAN1"
+#define FAN2_PIN                            PC8   // "FAN2"
+
+/**
+ *              SKR Mini E3 V3.0.1
+ *                  ------
+ *  (BEEPER)  PB15 | 1  2 | PB14 (BTN_ENC)
+ *  (BTN_EN1) PA9  | 3  4 | RESET
+ *  (BTN_EN2) PA10   5  6 | PB4  (LCD_D4)
+ *  (LCD_RS)  PD2  | 7  8 | PC0  (LCD_EN)
+ *             GND | 9 10 | 5V
+ *                  ------
+ *                   EXP1
+ */
+#define EXP1_01_PIN                         PB15
+#define EXP1_02_PIN                         PB14
+#define EXP1_03_PIN                         PA9
+#define EXP1_04_PIN                         -1    // RESET
+#define EXP1_05_PIN                         PA10
+#define EXP1_06_PIN                         PB4
+#define EXP1_07_PIN                         PD2
+#define EXP1_08_PIN                         PC0
+
+#if HAS_DWIN_E3V2 || IS_DWIN_MARLINUI
+  /**
+   *        ------                ------                ------
+   * (ENT) | 1  2 | (BEEP)       |10  9 |              |10  9 |
+   *  (RX) | 3  4 |         (RX) | 8  7 | (TX)      RX | 8  7 | TX
+   *  (TX)   5  6 |        (ENT)   6  5 | (BEEP)   ENT | 6  5 | BEEP
+   *   (B) | 7  8 | (A)      (B) | 4  3 | (A)        B | 4  3 | A
+   *   GND | 9 10 | (VCC)    GND | 2  1 | VCC      GND | 2  1 | VCC
+   *        ------                ------                ------
+   *         EXP1                  DWIN               DWIN (plug)
+   *
+   * All pins are labeled as printed on DWIN PCB. Connect TX-TX, A-A and so on.
+   */
+
+  #error "DWIN_CREALITY_LCD requires a custom cable, see diagram above this line. Comment out this line to continue."
+
+  #define BEEPER_PIN                 EXP1_02_PIN
+  #define BTN_EN1                    EXP1_08_PIN
+  #define BTN_EN2                    EXP1_07_PIN
+  #define BTN_ENC                    EXP1_01_PIN
+
+#elif HAS_WIRED_LCD
+
+  #if ENABLED(CR10_STOCKDISPLAY)
+
+    #define BEEPER_PIN               EXP1_01_PIN
+    #define BTN_ENC                  EXP1_02_PIN
+
+    #define BTN_EN1                  EXP1_03_PIN
+    #define BTN_EN2                  EXP1_05_PIN
+
+    #define LCD_PINS_RS              EXP1_07_PIN
+    #define LCD_PINS_ENABLE          EXP1_08_PIN
+    #define LCD_PINS_D4              EXP1_06_PIN
+
+  #elif ENABLED(ZONESTAR_LCD)                     // ANET A8 LCD Controller - Must convert to 3.3V - CONNECTING TO 5V WILL DAMAGE THE BOARD!
+
+    #ifndef NO_CONTROLLER_CUSTOM_WIRING_WARNING
+      #error "CAUTION! ZONESTAR_LCD requires wiring modifications. See 'pins_BTT_SKR_MINI_E3_common.h' for details. (Define NO_CONTROLLER_CUSTOM_WIRING_WARNING to suppress this warning.)"
+    #endif
+
+    #define LCD_PINS_RS              EXP1_06_PIN
+    #define LCD_PINS_ENABLE          EXP1_02_PIN
+    #define LCD_PINS_D4              EXP1_07_PIN
+    #define LCD_PINS_D5              EXP1_05_PIN
+    #define LCD_PINS_D6              EXP1_03_PIN
+    #define LCD_PINS_D7              EXP1_01_PIN
+    #define ADC_KEYPAD_PIN                  PA1   // Repurpose servo pin for ADC - CONNECTING TO 5V WILL DAMAGE THE BOARD!
+
+  #elif EITHER(MKS_MINI_12864, ENDER2_STOCKDISPLAY)
+
+    #define BTN_ENC                  EXP1_02_PIN
+    #define BTN_EN1                  EXP1_03_PIN
+    #define BTN_EN2                  EXP1_05_PIN
+
+    #define DOGLCD_CS                EXP1_07_PIN
+    #define DOGLCD_A0                EXP1_06_PIN
+    #define DOGLCD_SCK               EXP1_01_PIN
+    #define DOGLCD_MOSI              EXP1_08_PIN
+
+    #define FORCE_SOFT_SPI
+    #define LCD_BACKLIGHT_PIN               -1
+
+  #elif IS_TFTGLCD_PANEL
+
+    #if ENABLED(TFTGLCD_PANEL_SPI)
+
+      #ifndef NO_CONTROLLER_CUSTOM_WIRING_WARNING
+        #error "CAUTION! TFTGLCD_PANEL_SPI requires wiring modifications. See 'pins_BTT_SKR_MINI_E3_common.h' for details. (Define NO_CONTROLLER_CUSTOM_WIRING_WARNING to suppress this warning.)"
+      #endif
+
+      /**
+       * TFTGLCD_PANEL_SPI display pinout
+       *
+       *                Board                                 Display
+       *                ------                                ------
+       * (BEEPER) PB6  | 1  2 | PB15 (SD_DET)             5V |10  9 | GND
+       *         RESET | 3  4 | PA9  (MOD_RESET)          -- | 8  7 | (SD_DET)
+       *          PB4    5  6 | PA10 (SD_CS)         (MOSI)  | 6  5 | --
+       *          PB7  | 7  8 | PD2  (LCD_CS)        (SD_CS) | 4  3 | (LCD_CS)
+       *           GND | 9 10 | 5V                   (SCK)   | 2  1 | (MISO)
+       *                ------                                ------
+       *                 EXP1                                  EXP1
+       *
+       * Needs custom cable:
+       *
+       *    Board             Display
+       *
+       *   EXP1-10 ---------- EXP1-10
+       *   EXP1-9 ----------- EXP1-9
+       *   SPI1-4 ----------- EXP1-6
+       *   EXP1-7 ----------- FREE
+       *   SPI1-3 ----------- EXP1-2
+       *   EXP1-5 ----------- EXP1-4
+       *   EXP1-4 ----------- FREE
+       *   EXP1-3 ----------- EXP1-3
+       *   SPI1-1 ----------- EXP1-1
+       *   EXP1-1 ----------- EXP1-7
+       */
+
+      #define TFTGLCD_CS             EXP1_03_PIN
+
+    #endif
+
+  #else
+    #error "Only CR10_STOCKDISPLAY, ZONESTAR_LCD, ENDER2_STOCKDISPLAY, MKS_MINI_12864, and TFTGLCD_PANEL_(SPI|I2C) are currently supported on the BIGTREE_SKR_MINI_E3."
+  #endif
+
+#endif // HAS_WIRED_LCD
+
+#if BOTH(TOUCH_UI_FTDI_EVE, LCD_FYSETC_TFT81050)
+
+  #ifndef NO_CONTROLLER_CUSTOM_WIRING_WARNING
+    #error "CAUTION! LCD_FYSETC_TFT81050 requires wiring modifications. See 'pins_BTT_SKR_MINI_E3_common.h' for details. (Define NO_CONTROLLER_CUSTOM_WIRING_WARNING to suppress this warning.)"
+  #endif
+
+  /**
+   * FYSETC TFT TFT81050 display pinout
+   *
+   *                   Board                             Display
+   *                   ------                            ------
+   * (SD_DET)    PB15 | 1  2 | PB6 (BEEPER)          5V |10  9 | GND
+   * (MOD_RESET) PA9  | 3  4 | RESET            (RESET) | 8  7 | (SD_DET)
+   * (SD_CS)     PA10   5  6 | PB4 (FREE)       (MOSI)  | 6  5 | (LCD_CS)
+   * (LCD_CS)    PD2  | 7  8 | PB7 (FREE)       (SD_CS) | 4  3 | (MOD_RESET)
+   *               5V | 9 10 | GND              (SCK)   | 2  1 | (MISO)
+   *                   ------                            ------
+   *                    EXP1                              EXP1
+   *
+   * Needs custom cable:
+   *
+   *    Board   Adapter   Display
+   *           _________
+   *   EXP1-10 ---------- EXP1-10
+   *   EXP1-9 ----------- EXP1-9
+   *   SPI1-4 ----------- EXP1-6
+   *   EXP1-7 ----------- EXP1-5
+   *   SPI1-3 ----------- EXP1-2
+   *   EXP1-5 ----------- EXP1-4
+   *   EXP1-4 ----------- EXP1-8
+   *   EXP1-3 ----------- EXP1-3
+   *   SPI1-1 ----------- EXP1-1
+   *   EXP1-1 ----------- EXP1-7
+   */
+
+  #define CLCD_SPI_BUS                         1  // SPI1 connector
+
+  #define BEEPER_PIN                 EXP1_02_PIN
+
+  #define CLCD_MOD_RESET             EXP1_03_PIN
+  #define CLCD_SPI_CS                EXP1_07_PIN
+
+#endif // TOUCH_UI_FTDI_EVE && LCD_FYSETC_TFT81050
+
+//
+// SD Support
+//
+
+#ifndef SDCARD_CONNECTION
+  #define SDCARD_CONNECTION              ONBOARD
+#endif
+
+#if SD_CONNECTION_IS(LCD) && (BOTH(TOUCH_UI_FTDI_EVE, LCD_FYSETC_TFT81050) || IS_TFTGLCD_PANEL)
+  #define SD_DETECT_PIN              EXP1_01_PIN
+  #define SD_SS_PIN                  EXP1_05_PIN
+#elif SD_CONNECTION_IS(CUSTOM_CABLE)
+  #error "SD CUSTOM_CABLE is not compatible with SKR Mini E3."
+#endif
+
+#define ONBOARD_SPI_DEVICE                     1  // SPI1 -> used only by HAL/STM32F1...
+#define ONBOARD_SD_CS_PIN                   PA4   // Chip select for "System" SD card
+
+#define ENABLE_SPI1
+#define SDSS                   ONBOARD_SD_CS_PIN
+#define SD_SS_PIN              ONBOARD_SD_CS_PIN
+#define SD_SCK_PIN                          PA5
+#define SD_MISO_PIN                         PA6
+#define SD_MOSI_PIN                         PA7

buildroot/share/PlatformIO/boards/marlin_STM32F401RC.json

@@ -0,0 +1,38 @@
+{
+  "build": {
+    "core": "stm32",
+    "cpu": "cortex-m4",
+    "extra_flags": "-DSTM32F401xC -DSTM32F4xx",
+    "f_cpu": "84000000L",
+    "mcu": "stm32f401rct6",
+    "product_line": "STM32F401xC",
+    "variant": "MARLIN_F401RC"
+  },
+  "debug": {
+    "jlink_device": "STM32F401RC",
+    "openocd_target": "stm32f4x",
+    "svd_path": "STM32F401x.svd"
+  },
+  "frameworks": [
+    "arduino",
+    "cmsis",
+    "spl",
+    "stm32cube",
+    "libopencm3"
+  ],
+  "name": "STM32F401RC (64k RAM. 256k Flash)",
+  "upload": {
+    "maximum_ram_size": 65536,
+    "maximum_size": 262144,
+    "protocol": "serial",
+    "protocols": [
+      "blackmagic",
+      "dfu",
+      "jlink",
+      "serial",
+      "stlink"
+    ]
+  },
+  "url": "https://www.st.com/en/microcontrollers-microprocessors/stm32f401rc.html",
+  "vendor": "Generic"
+}

buildroot/share/PlatformIO/variants/MARLIN_F401RC/PeripheralPins.c

@@ -0,0 +1,256 @@
+/*
+ *******************************************************************************
+ * Copyright (c) 2020-2021, STMicroelectronics
+ * All rights reserved.
+ *
+ * This software component is licensed by ST under BSD 3-Clause license,
+ * the "License"; You may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at:
+ *                        opensource.org/licenses/BSD-3-Clause
+ *
+ *******************************************************************************
+ */
+/*
+ * Automatically generated from STM32F401R(B-C)Tx.xml, STM32F401R(D-E)Tx.xml
+ * CubeMX DB release 6.0.30
+ */
+#if !defined(CUSTOM_PERIPHERAL_PINS)
+#include "Arduino.h"
+#include "PeripheralPins.h"
+
+/* =====
+ * Notes:
+ * - The pins mentioned Px_y_ALTz are alternative possibilities which use other
+ *   HW peripheral instances. You can use them the same way as any other "normal"
+ *   pin (i.e. analogWrite(PA7_ALT1, 128);).
+ *
+ * - Commented lines are alternative possibilities which are not used per default.
+ *   If you change them, you will have to know what you do
+ * =====
+ */
+
+//*** ADC ***
+
+#ifdef HAL_ADC_MODULE_ENABLED
+WEAK const PinMap PinMap_ADC[] = {
+  {PA_0, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 0, 0)}, // ADC1_IN0
+  {PA_1, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 1, 0)}, // ADC1_IN1
+  {PA_2, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 2, 0)}, // ADC1_IN2
+  {PA_3, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 3, 0)}, // ADC1_IN3
+  {PA_4, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 4, 0)}, // ADC1_IN4
+  {PA_5, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 5, 0)}, // ADC1_IN5
+  {PA_6, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 6, 0)}, // ADC1_IN6
+  {PA_7, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 7, 0)}, // ADC1_IN7
+  {PB_0, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 8, 0)}, // ADC1_IN8
+  {PB_1, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 9, 0)}, // ADC1_IN9
+  {PC_0, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 10, 0)}, // ADC1_IN10
+  {PC_1, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 11, 0)}, // ADC1_IN11
+  {PC_2, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 12, 0)}, // ADC1_IN12
+  {PC_3, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 13, 0)}, // ADC1_IN13
+  {PC_4, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 14, 0)}, // ADC1_IN14
+  {PC_5, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 15, 0)}, // ADC1_IN15
+  {NC,   NP,   0}
+};
+#endif
+
+//*** No DAC ***
+
+//*** I2C ***
+
+#ifdef HAL_I2C_MODULE_ENABLED
+WEAK const PinMap PinMap_I2C_SDA[] = {
+  {PB_3, I2C2, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF9_I2C2)},
+  {PB_4, I2C3, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF9_I2C3)},
+  {PB_7, I2C1, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C1)},
+  {PB_9, I2C1, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C1)},
+  {PC_9, I2C3, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C3)},
+  {NC,   NP,   0}
+};
+#endif
+
+#ifdef HAL_I2C_MODULE_ENABLED
+WEAK const PinMap PinMap_I2C_SCL[] = {
+  {PA_8,  I2C3, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C3)},
+  {PB_6,  I2C1, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C1)},
+  {PB_8,  I2C1, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C1)},
+  {PB_10, I2C2, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_NOPULL, GPIO_AF4_I2C2)},
+  {NC,    NP,   0}
+};
+#endif
+
+//*** TIM ***
+
+#ifdef HAL_TIM_MODULE_ENABLED
+WEAK const PinMap PinMap_TIM[] = {
+  {PA_0,      TIM2,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 1, 0)}, // TIM2_CH1
+  {PA_0_ALT1, TIM5,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 1, 0)}, // TIM5_CH1
+  {PA_1,      TIM2,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 2, 0)}, // TIM2_CH2
+  {PA_1_ALT1, TIM5,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 2, 0)}, // TIM5_CH2
+  {PA_2,      TIM2,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 3, 0)}, // TIM2_CH3
+  {PA_2_ALT1, TIM5,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 3, 0)}, // TIM5_CH3
+  {PA_2_ALT2, TIM9,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM9, 1, 0)}, // TIM9_CH1
+  {PA_3,      TIM2,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 4, 0)}, // TIM2_CH4
+  {PA_3_ALT1, TIM5,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 4, 0)}, // TIM5_CH4
+  {PA_3_ALT2, TIM9,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM9, 2, 0)}, // TIM9_CH2
+  {PA_5,      TIM2,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 1, 0)}, // TIM2_CH1
+  {PA_6,      TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1
+  {PA_7,      TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 1, 1)}, // TIM1_CH1N
+  {PA_7_ALT1, TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2
+  {PA_8,      TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 1, 0)}, // TIM1_CH1
+  {PA_9,      TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 2, 0)}, // TIM1_CH2
+  {PA_10,     TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 3, 0)}, // TIM1_CH3
+  {PA_11,     TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 4, 0)}, // TIM1_CH4
+  {PA_15,     TIM2,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 1, 0)}, // TIM2_CH1
+  {PB_0,      TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 2, 1)}, // TIM1_CH2N
+  {PB_0_ALT1, TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 3, 0)}, // TIM3_CH3
+  {PB_1,      TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 3, 1)}, // TIM1_CH3N
+  {PB_1_ALT1, TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 4, 0)}, // TIM3_CH4
+  {PB_3,      TIM2,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 2, 0)}, // TIM2_CH2
+  {PB_4,      TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1
+  {PB_5,      TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2
+  {PB_6,      TIM4,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 1, 0)}, // TIM4_CH1
+  {PB_7,      TIM4,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 2, 0)}, // TIM4_CH2
+  {PB_8,      TIM4,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 3, 0)}, // TIM4_CH3
+  {PB_8_ALT1, TIM10, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM10, 1, 0)}, // TIM10_CH1
+  {PB_9,      TIM4,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 4, 0)}, // TIM4_CH4
+  {PB_9_ALT1, TIM11, STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM11, 1, 0)}, // TIM11_CH1
+  {PB_10,     TIM2,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 3, 0)}, // TIM2_CH3
+  {PB_13,     TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 1, 1)}, // TIM1_CH1N
+  {PB_14,     TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 2, 1)}, // TIM1_CH2N
+  {PB_15,     TIM1,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 3, 1)}, // TIM1_CH3N
+  {PC_6,      TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1
+  {PC_7,      TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2
+  {PC_8,      TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 3, 0)}, // TIM3_CH3
+  {PC_9,      TIM3,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 4, 0)}, // TIM3_CH4
+  {NC,        NP,    0}
+};
+#endif
+
+//*** UART ***
+
+#ifdef HAL_UART_MODULE_ENABLED
+WEAK const PinMap PinMap_UART_TX[] = {
+  {PA_2,  USART2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART2)},
+  {PA_9,  USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
+  {PA_11, USART6, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF8_USART6)},
+  {PB_6,  USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
+  {PC_6,  USART6, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF8_USART6)},
+  {NC,    NP,     0}
+};
+#endif
+
+#ifdef HAL_UART_MODULE_ENABLED
+WEAK const PinMap PinMap_UART_RX[] = {
+  {PA_3,  USART2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART2)},
+  {PA_10, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
+  {PA_12, USART6, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF8_USART6)},
+  {PB_7,  USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
+  {PC_7,  USART6, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF8_USART6)},
+  {NC,    NP,     0}
+};
+#endif
+
+#ifdef HAL_UART_MODULE_ENABLED
+WEAK const PinMap PinMap_UART_RTS[] = {
+  {PA_1,  USART2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART2)},
+  {PA_12, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
+  {NC,    NP,     0}
+};
+#endif
+
+#ifdef HAL_UART_MODULE_ENABLED
+WEAK const PinMap PinMap_UART_CTS[] = {
+  {PA_0,  USART2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART2)},
+  {PA_11, USART1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},
+  {NC,    NP,     0}
+};
+#endif
+
+//*** SPI ***
+
+#ifdef HAL_SPI_MODULE_ENABLED
+WEAK const PinMap PinMap_SPI_MOSI[] = {
+  {PA_7,      SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
+  {PB_5,      SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
+  {PB_5_ALT1, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
+  {PB_15,     SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
+  {PC_3,      SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
+  {PC_12,     SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
+  {NC,        NP,   0}
+};
+#endif
+
+#ifdef HAL_SPI_MODULE_ENABLED
+WEAK const PinMap PinMap_SPI_MISO[] = {
+  {PA_6,      SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
+  {PB_4,      SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
+  {PB_4_ALT1, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
+  {PB_14,     SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
+  {PC_2,      SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
+  {PC_11,     SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
+  {NC,        NP,   0}
+};
+#endif
+
+#ifdef HAL_SPI_MODULE_ENABLED
+WEAK const PinMap PinMap_SPI_SCLK[] = {
+  {PA_5,      SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
+  {PB_3,      SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
+  {PB_3_ALT1, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
+  {PB_10,     SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
+  {PB_13,     SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
+  {PC_10,     SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
+  {NC,        NP,   0}
+};
+#endif
+
+#ifdef HAL_SPI_MODULE_ENABLED
+WEAK const PinMap PinMap_SPI_SSEL[] = {
+  {PA_4,       SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
+  {PA_4_ALT1,  SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
+  {PA_15,      SPI1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI1)},
+  {PA_15_ALT1, SPI3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF6_SPI3)},
+  {PB_9,       SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
+  {PB_12,      SPI2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF5_SPI2)},
+  {NC,         NP,   0}
+};
+#endif
+
+//*** No CAN ***
+
+//*** No ETHERNET ***
+
+//*** No QUADSPI ***
+
+//*** USB ***
+
+#if defined(HAL_PCD_MODULE_ENABLED) || defined(HAL_HCD_MODULE_ENABLED)
+WEAK const PinMap PinMap_USB_OTG_FS[] = {
+  {PA_8,  USB_OTG_FS, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF10_OTG_FS)}, // USB_OTG_FS_SOF
+  {PA_9,  USB_OTG_FS, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, GPIO_AF_NONE)}, // USB_OTG_FS_VBUS
+  {PA_10, USB_OTG_FS, STM_PIN_DATA(STM_MODE_AF_OD, GPIO_PULLUP, GPIO_AF10_OTG_FS)}, // USB_OTG_FS_ID
+  {PA_11, USB_OTG_FS, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF10_OTG_FS)}, // USB_OTG_FS_DM
+  {PA_12, USB_OTG_FS, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF10_OTG_FS)}, // USB_OTG_FS_DP
+  {NC,    NP,         0}
+};
+#endif
+
+//*** SD ***
+
+#ifdef HAL_SD_MODULE_ENABLED
+WEAK const PinMap PinMap_SD[] = {
+  {PB_8,  SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D4
+  {PB_9,  SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D5
+  {PC_6,  SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D6
+  {PC_7,  SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D7
+  {PC_8,  SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D0
+  {PC_9,  SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D1
+  {PC_10, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D2
+  {PC_11, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF12_SDIO)}, // SDIO_D3
+  {PC_12, SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_NOPULL, GPIO_AF12_SDIO)}, // SDIO_CK
+  {PD_2,  SDIO, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_NOPULL, GPIO_AF12_SDIO)}, // SDIO_CMD
+  {NC,    NP,   0}
+};
+#endif
+
+#endif /* !CUSTOM_PERIPHERAL_PINS */

buildroot/share/PlatformIO/variants/MARLIN_F401RC/PinNamesVar.h

@@ -0,0 +1,52 @@
+/* Alternate pin name */
+PA_0_ALT1  = PA_0  | ALT1,
+PA_1_ALT1  = PA_1  | ALT1,
+PA_2_ALT1  = PA_2  | ALT1,
+PA_2_ALT2  = PA_2  | ALT2,
+PA_3_ALT1  = PA_3  | ALT1,
+PA_3_ALT2  = PA_3  | ALT2,
+PA_4_ALT1  = PA_4  | ALT1,
+PA_7_ALT1  = PA_7  | ALT1,
+PA_15_ALT1 = PA_15 | ALT1,
+PB_0_ALT1  = PB_0  | ALT1,
+PB_1_ALT1  = PB_1  | ALT1,
+PB_3_ALT1  = PB_3  | ALT1,
+PB_4_ALT1  = PB_4  | ALT1,
+PB_5_ALT1  = PB_5  | ALT1,
+PB_8_ALT1  = PB_8  | ALT1,
+PB_9_ALT1  = PB_9  | ALT1,
+
+/* SYS_WKUP */
+#ifdef PWR_WAKEUP_PIN1
+  SYS_WKUP1 = PA_0,
+#endif
+#ifdef PWR_WAKEUP_PIN2
+  SYS_WKUP2 = NC,
+#endif
+#ifdef PWR_WAKEUP_PIN3
+  SYS_WKUP3 = NC,
+#endif
+#ifdef PWR_WAKEUP_PIN4
+  SYS_WKUP4 = NC,
+#endif
+#ifdef PWR_WAKEUP_PIN5
+  SYS_WKUP5 = NC,
+#endif
+#ifdef PWR_WAKEUP_PIN6
+  SYS_WKUP6 = NC,
+#endif
+#ifdef PWR_WAKEUP_PIN7
+  SYS_WKUP7 = NC,
+#endif
+#ifdef PWR_WAKEUP_PIN8
+  SYS_WKUP8 = NC,
+#endif
+
+/* USB */
+#ifdef USBCON
+  USB_OTG_FS_DM   = PA_11,
+  USB_OTG_FS_DP   = PA_12,
+  USB_OTG_FS_ID   = PA_10,
+  USB_OTG_FS_SOF  = PA_8,
+  USB_OTG_FS_VBUS = PA_9,
+#endif

buildroot/share/PlatformIO/variants/MARLIN_F401RC/ldscript.ld

@@ -0,0 +1,177 @@
+/**
+ ******************************************************************************
+ * @file      LinkerScript.ld
+ * @author    Auto-generated by STM32CubeIDE
+ * @brief     Linker script for STM32F401RBTx Device from STM32F4 series
+ *                      128Kbytes FLASH
+ *                      64Kbytes RAM
+ *
+ *            Set heap size, stack size and stack location according
+ *            to application requirements.
+ *
+ *            Set memory bank area and size if external memory is used
+ ******************************************************************************
+ * @attention
+ *
+ * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
+ * All rights reserved.</center></h2>
+ *
+ * This software component is licensed by ST under BSD 3-Clause license,
+ * the "License"; You may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at:
+ *                        opensource.org/licenses/BSD-3-Clause
+ *
+ ******************************************************************************
+ */
+
+/* Entry Point */
+ENTRY(Reset_Handler)
+
+/* Highest address of the user mode stack */
+_estack = ORIGIN(RAM) + LENGTH(RAM);	/* end of "RAM" Ram type memory */
+
+_Min_Heap_Size = 0x200;	/* required amount of heap  */
+_Min_Stack_Size = 0x400;	/* required amount of stack */
+
+/* Memories definition */
+MEMORY
+{
+  RAM    (xrw)    : ORIGIN = 0x20000000,   LENGTH = LD_MAX_DATA_SIZE
+  FLASH    (rx)    : ORIGIN = 0x8000000 + LD_FLASH_OFFSET, LENGTH = LD_MAX_SIZE - LD_FLASH_OFFSET
+}
+
+/* Sections */
+SECTIONS
+{
+  /* The startup code into "FLASH" Rom type memory */
+  .isr_vector :
+  {
+    . = ALIGN(4);
+    KEEP(*(.isr_vector)) /* Startup code */
+    . = ALIGN(4);
+  } >FLASH
+
+  /* The program code and other data into "FLASH" Rom type memory */
+  .text :
+  {
+    . = ALIGN(4);
+    *(.text)           /* .text sections (code) */
+    *(.text*)          /* .text* sections (code) */
+    *(.glue_7)         /* glue arm to thumb code */
+    *(.glue_7t)        /* glue thumb to arm code */
+    *(.eh_frame)
+
+    KEEP (*(.init))
+    KEEP (*(.fini))
+
+    . = ALIGN(4);
+    _etext = .;        /* define a global symbols at end of code */
+  } >FLASH
+
+  /* Constant data into "FLASH" Rom type memory */
+  .rodata :
+  {
+    . = ALIGN(4);
+    *(.rodata)         /* .rodata sections (constants, strings, etc.) */
+    *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */
+    . = ALIGN(4);
+  } >FLASH
+
+  .ARM.extab   : {
+    . = ALIGN(4);
+    *(.ARM.extab* .gnu.linkonce.armextab.*)
+    . = ALIGN(4);
+  } >FLASH
+
+  .ARM : {
+    . = ALIGN(4);
+    __exidx_start = .;
+    *(.ARM.exidx*)
+    __exidx_end = .;
+    . = ALIGN(4);
+  } >FLASH
+
+  .preinit_array     :
+  {
+    . = ALIGN(4);
+    PROVIDE_HIDDEN (__preinit_array_start = .);
+    KEEP (*(.preinit_array*))
+    PROVIDE_HIDDEN (__preinit_array_end = .);
+    . = ALIGN(4);
+  } >FLASH
+
+  .init_array :
+  {
+    . = ALIGN(4);
+    PROVIDE_HIDDEN (__init_array_start = .);
+    KEEP (*(SORT(.init_array.*)))
+    KEEP (*(.init_array*))
+    PROVIDE_HIDDEN (__init_array_end = .);
+    . = ALIGN(4);
+  } >FLASH
+
+  .fini_array :
+  {
+    . = ALIGN(4);
+    PROVIDE_HIDDEN (__fini_array_start = .);
+    KEEP (*(SORT(.fini_array.*)))
+    KEEP (*(.fini_array*))
+    PROVIDE_HIDDEN (__fini_array_end = .);
+    . = ALIGN(4);
+  } >FLASH
+
+  /* Used by the startup to initialize data */
+  _sidata = LOADADDR(.data);
+
+  /* Initialized data sections into "RAM" Ram type memory */
+  .data :
+  {
+    . = ALIGN(4);
+    _sdata = .;        /* create a global symbol at data start */
+    *(.data)           /* .data sections */
+    *(.data*)          /* .data* sections */
+    *(.RamFunc)        /* .RamFunc sections */
+    *(.RamFunc*)       /* .RamFunc* sections */
+
+    . = ALIGN(4);
+    _edata = .;        /* define a global symbol at data end */
+
+  } >RAM AT> FLASH
+
+  /* Uninitialized data section into "RAM" Ram type memory */
+  . = ALIGN(4);
+  .bss :
+  {
+    /* This is used by the startup in order to initialize the .bss section */
+    _sbss = .;         /* define a global symbol at bss start */
+    __bss_start__ = _sbss;
+    *(.bss)
+    *(.bss*)
+    *(COMMON)
+
+    . = ALIGN(4);
+    _ebss = .;         /* define a global symbol at bss end */
+    __bss_end__ = _ebss;
+  } >RAM
+
+  /* User_heap_stack section, used to check that there is enough "RAM" Ram  type memory left */
+  ._user_heap_stack :
+  {
+    . = ALIGN(8);
+    PROVIDE ( end = . );
+    PROVIDE ( _end = . );
+    . = . + _Min_Heap_Size;
+    . = . + _Min_Stack_Size;
+    . = ALIGN(8);
+  } >RAM
+
+  /* Remove information from the compiler libraries */
+  /DISCARD/ :
+  {
+    libc.a ( * )
+    libm.a ( * )
+    libgcc.a ( * )
+  }
+
+  .ARM.attributes 0 : { *(.ARM.attributes) }
+}

buildroot/share/PlatformIO/variants/MARLIN_F401RC/variant_MARLIN_STM32F401RC.cpp

@@ -0,0 +1,223 @@
+/*
+ *******************************************************************************
+ * Copyright (c) 2020-2021, STMicroelectronics
+ * All rights reserved.
+ *
+ * This software component is licensed by ST under BSD 3-Clause license,
+ * the "License"; You may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at:
+ *                        opensource.org/licenses/BSD-3-Clause
+ *
+ *******************************************************************************
+ */
+
+#if defined(STM32F401xC)
+#include "pins_arduino.h"
+
+// Digital PinName array
+const PinName digitalPin[] = {
+  PA_0,   // D0/A0
+  PA_1,   // D1/A1
+  PA_2,   // D2/A2
+  PA_3,   // D3/A3
+  PA_4,   // D4/A4
+  PA_5,   // D5/A5
+  PA_6,   // D6/A6
+  PA_7,   // D7/A7
+  PA_8,   // D8
+  PA_9,   // D9
+  PA_10,  // D10
+  PA_11,  // D11
+  PA_12,  // D12
+  PA_13,  // D13
+  PA_14,  // D14
+  PA_15,  // D15
+  PB_0,   // D16/A8
+  PB_1,   // D17/A9
+  PB_2,   // D18
+  PB_3,   // D19
+  PB_4,   // D20
+  PB_5,   // D21
+  PB_6,   // D22
+  PB_7,   // D23
+  PB_8,   // D24
+  PB_9,   // D25
+  PB_10,  // D26
+  PB_12,  // D27
+  PB_13,  // D28
+  PB_14,  // D29
+  PB_15,  // D30
+  PC_0,   // D31/A10
+  PC_1,   // D32/A11
+  PC_2,   // D33/A12
+  PC_3,   // D34/A13
+  PC_4,   // D35/A14
+  PC_5,   // D36/A15
+  PC_6,   // D37
+  PC_7,   // D38
+  PC_8,   // D39
+  PC_9,   // D40
+  PC_10,  // D41
+  PC_11,  // D42
+  PC_12,  // D43
+  PC_13,  // D44
+  PC_14,  // D45
+  PC_15,  // D46
+  PD_2,   // D47
+  PH_0,   // D48
+  PH_1    // D49
+};
+
+// Analog (Ax) pin number array
+const uint32_t analogInputPin[] = {
+  0,  // A0,  PA0
+  1,  // A1,  PA1
+  2,  // A2,  PA2
+  3,  // A3,  PA3
+  4,  // A4,  PA4
+  5,  // A5,  PA5
+  6,  // A6,  PA6
+  7,  // A7,  PA7
+  16, // A8,  PB0
+  17, // A9,  PB1
+  31, // A10, PC0
+  32, // A11, PC1
+  33, // A12, PC2
+  34, // A13, PC3
+  35, // A14, PC4
+  36  // A15, PC5
+};
+
+// ----------------------------------------------------------------------------
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * @brief  Configures the System clock source, PLL Multiplier and Divider factors,
+ *               AHB/APBx prescalers and Flash settings
+ * @note   This function should be called only once the RCC clock configuration
+ *         is reset to the default reset state (done in SystemInit() function).
+ * @param  None
+ * @retval None
+ */
+
+/******************************************************************************/
+/*            PLL (clocked by HSE) used as System clock source                */
+/******************************************************************************/
+static uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
+{
+  RCC_OscInitTypeDef RCC_OscInitStruct;
+  RCC_ClkInitTypeDef RCC_ClkInitStruct;
+
+  /* The voltage scaling allows optimizing the power consumption when the device is
+  clocked below the maximum system frequency, to update the voltage scaling value
+  regarding system frequency refer to product datasheet. */
+  __HAL_RCC_PWR_CLK_ENABLE();
+  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
+
+  // Enable HSE oscillator and activate PLL with HSE as source
+  RCC_OscInitStruct.OscillatorType      = RCC_OSCILLATORTYPE_HSE;
+  if (bypass == 0) {
+    RCC_OscInitStruct.HSEState          = RCC_HSE_ON; // External 8 MHz xtal on OSC_IN/OSC_OUT
+  } else {
+    RCC_OscInitStruct.HSEState          = RCC_HSE_BYPASS; // External 8 MHz clock on OSC_IN
+  }
+
+  RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
+  RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSE;
+  RCC_OscInitStruct.PLL.PLLM            = HSE_VALUE / 1000000L; // Expects an 8 MHz external clock by default. Redefine HSE_VALUE if not
+  RCC_OscInitStruct.PLL.PLLN            = 336;           // VCO output clock = 336 MHz (1 MHz * 336)
+  RCC_OscInitStruct.PLL.PLLP            = RCC_PLLP_DIV4; // PLLCLK = 84 MHz (336 MHz / 4)
+  RCC_OscInitStruct.PLL.PLLQ            = 7;             // USB clock = 48 MHz (336 MHz / 7) --> OK for USB
+  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+    return 0; // FAIL
+  }
+
+  // Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers
+  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
+  RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 84 MHz
+  RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 84 MHz
+  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;           // 42 MHz
+  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 84 MHz
+  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK) {
+    return 0; // FAIL
+  }
+
+  /* Output clock on MCO1 pin(PA8) for debugging purpose */
+  /*
+  if (bypass == 0)
+    HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSE, RCC_MCODIV_2); // 4 MHz
+  else
+    HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSE, RCC_MCODIV_1); // 8 MHz
+  */
+
+  return 1; // OK
+}
+
+/******************************************************************************/
+/*            PLL (clocked by HSI) used as System clock source                */
+/******************************************************************************/
+uint8_t SetSysClock_PLL_HSI(void)
+{
+  RCC_OscInitTypeDef RCC_OscInitStruct;
+  RCC_ClkInitTypeDef RCC_ClkInitStruct;
+
+  /* The voltage scaling allows optimizing the power consumption when the device is
+    clocked below the maximum system frequency, to update the voltage scaling value
+    regarding system frequency refer to product datasheet. */
+  __HAL_RCC_PWR_CLK_ENABLE();
+  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
+
+  // Enable HSI oscillator and activate PLL with HSI as source
+  RCC_OscInitStruct.OscillatorType      = RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSE;
+  RCC_OscInitStruct.HSIState            = RCC_HSI_ON;
+  RCC_OscInitStruct.HSEState            = RCC_HSE_OFF;
+  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
+  RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
+  RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSI;
+  RCC_OscInitStruct.PLL.PLLM            = 16;            // VCO input clock = 1 MHz (16 MHz / 16)
+  RCC_OscInitStruct.PLL.PLLN            = 336;           // VCO output clock = 336 MHz (1 MHz * 336)
+  RCC_OscInitStruct.PLL.PLLP            = RCC_PLLP_DIV4; // PLLCLK = 84 MHz (336 MHz / 4)
+  RCC_OscInitStruct.PLL.PLLQ            = 7;             // USB clock = 48 MHz (336 MHz / 7) --> freq is ok but not precise enough
+  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+    return 0; // FAIL
+  }
+
+  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
+  RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
+  RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 84 MHz
+  RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 84 MHz
+  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;           // 42 MHz
+  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 84 MHz
+  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK) {
+    return 0; // FAIL
+  }
+
+  /* Output clock on MCO1 pin(PA8) for debugging purpose */
+  //HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSI, RCC_MCODIV_1); // 16 MHz
+
+  return 1; // OK
+}
+
+WEAK void SystemClock_Config(void)
+{
+  /* 1- If fail try to start with HSE and external xtal */
+  if (SetSysClock_PLL_HSE(0) == 0) {
+    /* 2- Try to start with HSE and external clock */
+    if (SetSysClock_PLL_HSE(1) == 0) {
+      /* 3- If fail start with HSI clock */
+      if (SetSysClock_PLL_HSI() == 0) {
+        Error_Handler();
+      }
+    }
+  }
+  /* Output clock on MCO2 pin(PC9) for debugging purpose */
+  //HAL_RCC_MCOConfig(RCC_MCO2, RCC_MCO2SOURCE_SYSCLK, RCC_MCODIV_4);
+}
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* STM32F401xC */

buildroot/share/PlatformIO/variants/MARLIN_F401RC/variant_MARLIN_STM32F401RC.h

@@ -0,0 +1,186 @@
+/*
+ *******************************************************************************
+ * Copyright (c) 2020-2021, STMicroelectronics
+ * All rights reserved.
+ *
+ * This software component is licensed by ST under BSD 3-Clause license,
+ * the "License"; You may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at:
+ *                        opensource.org/licenses/BSD-3-Clause
+ *
+ *******************************************************************************
+ */
+#pragma once
+
+/*----------------------------------------------------------------------------
+ *        STM32 pins number
+ *----------------------------------------------------------------------------*/
+#define PA0                     PIN_A0
+#define PA1                     PIN_A1
+#define PA2                     PIN_A2
+#define PA3                     PIN_A3
+#define PA4                     PIN_A4
+#define PA5                     PIN_A5
+#define PA6                     PIN_A6
+#define PA7                     PIN_A7
+#define PA8                     8
+#define PA9                     9
+#define PA10                    10
+#define PA11                    11
+#define PA12                    12
+#define PA13                    13
+#define PA14                    14
+#define PA15                    15
+#define PB0                     PIN_A8
+#define PB1                     PIN_A9
+#define PB2                     18
+#define PB3                     19
+#define PB4                     20
+#define PB5                     21
+#define PB6                     22
+#define PB7                     23
+#define PB8                     24
+#define PB9                     25
+#define PB10                    26
+#define PB12                    27
+#define PB13                    28
+#define PB14                    29
+#define PB15                    30
+#define PC0                     PIN_A10
+#define PC1                     PIN_A11
+#define PC2                     PIN_A12
+#define PC3                     PIN_A13
+#define PC4                     PIN_A14
+#define PC5                     PIN_A15
+#define PC6                     37
+#define PC7                     38
+#define PC8                     39
+#define PC9                     40
+#define PC10                    41
+#define PC11                    42
+#define PC12                    43
+#define PC13                    44
+#define PC14                    45
+#define PC15                    46
+#define PD2                     47
+#define PH0                     48
+#define PH1                     49
+
+// Alternate pins number
+#define PA0_ALT1                (PA0  | ALT1)
+#define PA1_ALT1                (PA1  | ALT1)
+#define PA2_ALT1                (PA2  | ALT1)
+#define PA2_ALT2                (PA2  | ALT2)
+#define PA3_ALT1                (PA3  | ALT1)
+#define PA3_ALT2                (PA3  | ALT2)
+#define PA4_ALT1                (PA4  | ALT1)
+#define PA7_ALT1                (PA7  | ALT1)
+#define PA15_ALT1               (PA15 | ALT1)
+#define PB0_ALT1                (PB0  | ALT1)
+#define PB1_ALT1                (PB1  | ALT1)
+#define PB3_ALT1                (PB3  | ALT1)
+#define PB4_ALT1                (PB4  | ALT1)
+#define PB5_ALT1                (PB5  | ALT1)
+#define PB8_ALT1                (PB8  | ALT1)
+#define PB9_ALT1                (PB9  | ALT1)
+
+#define NUM_DIGITAL_PINS        50
+#define NUM_ANALOG_INPUTS       16
+#define NUM_ANALOG_FIRST        192
+
+// On-board LED pin number
+#ifndef LED_BUILTIN
+  #define LED_BUILTIN           PNUM_NOT_DEFINED
+#endif
+
+// On-board user button
+#ifndef USER_BTN
+  #define USER_BTN              PNUM_NOT_DEFINED
+#endif
+
+// SPI definitions
+#ifndef PIN_SPI_SS
+  #define PIN_SPI_SS            PA4
+#endif
+#ifndef PIN_SPI_SS1
+  #define PIN_SPI_SS1           PA15
+#endif
+#ifndef PIN_SPI_SS2
+  #define PIN_SPI_SS2           PNUM_NOT_DEFINED
+#endif
+#ifndef PIN_SPI_SS3
+  #define PIN_SPI_SS3           PNUM_NOT_DEFINED
+#endif
+#ifndef PIN_SPI_MOSI
+  #define PIN_SPI_MOSI          PA7
+#endif
+#ifndef PIN_SPI_MISO
+  #define PIN_SPI_MISO          PA6
+#endif
+#ifndef PIN_SPI_SCK
+  #define PIN_SPI_SCK           PA5
+#endif
+
+// I2C definitions
+#ifndef PIN_WIRE_SDA
+  #define PIN_WIRE_SDA          PB3
+#endif
+#ifndef PIN_WIRE_SCL
+  #define PIN_WIRE_SCL          PB10
+#endif
+
+// Timer Definitions
+// Use TIM6/TIM7 when possible as servo and tone don't need GPIO output pin
+#ifndef TIMER_TONE
+  #define TIMER_TONE            TIM10
+#endif
+#ifndef TIMER_SERVO
+  #define TIMER_SERVO           TIM11
+#endif
+
+// UART Definitions
+#ifndef SERIAL_UART_INSTANCE
+  #define SERIAL_UART_INSTANCE  2
+#endif
+
+// Default pin used for generic 'Serial' instance
+// Mandatory for Firmata
+#ifndef PIN_SERIAL_RX
+  #define PIN_SERIAL_RX         PA3
+#endif
+#ifndef PIN_SERIAL_TX
+  #define PIN_SERIAL_TX         PA2
+#endif
+
+// Extra HAL modules
+#if !defined(HAL_SD_MODULE_DISABLED)
+  #define HAL_SD_MODULE_ENABLED
+#endif
+
+/*----------------------------------------------------------------------------
+ *        Arduino objects - C++ only
+ *----------------------------------------------------------------------------*/
+
+#ifdef __cplusplus
+  // These serial port names are intended to allow libraries and architecture-neutral
+  // sketches to automatically default to the correct port name for a particular type
+  // of use.  For example, a GPS module would normally connect to SERIAL_PORT_HARDWARE_OPEN,
+  // the first hardware serial port whose RX/TX pins are not dedicated to another use.
+  //
+  // SERIAL_PORT_MONITOR        Port which normally prints to the Arduino Serial Monitor
+  //
+  // SERIAL_PORT_USBVIRTUAL     Port which is USB virtual serial
+  //
+  // SERIAL_PORT_LINUXBRIDGE    Port which connects to a Linux system via Bridge library
+  //
+  // SERIAL_PORT_HARDWARE       Hardware serial port, physical RX & TX pins.
+  //
+  // SERIAL_PORT_HARDWARE_OPEN  Hardware serial ports which are open for use.  Their RX & TX
+  //                            pins are NOT connected to anything by default.
+  #ifndef SERIAL_PORT_MONITOR
+    #define SERIAL_PORT_MONITOR   Serial
+  #endif
+  #ifndef SERIAL_PORT_HARDWARE
+    #define SERIAL_PORT_HARDWARE  Serial
+  #endif
+#endif

ini/stm32f4.ini

@@ -656,3 +656,21 @@ upload_protocol             = jlink
 extends                     = env:STM32F401RC_creality
 debug_tool                  = stlink
 upload_protocol             = stlink
+
+#
+# BigTree SKR mini E3 V3.0.1 (STM32F401RCT6 ARM Cortex-M4)
+#
+[env:STM32F401RC_btt]
+extends                     = stm32_variant
+platform                    = ststm32@~14.1.0
+platform_packages           = framework-arduinoststm32@https://github.com/stm32duino/Arduino_Core_STM32/archive/main.zip
+board                       = marlin_STM32F401RC
+board_build.offset          = 0x4000
+board_upload.offset_address = 0x08004000
+build_flags                 = ${stm32_variant.build_flags}
+                              -DPIN_SERIAL6_RX=PC_7 -DPIN_SERIAL6_TX=PC_6
+                              -DSERIAL_RX_BUFFER_SIZE=1024 -DSERIAL_TX_BUFFER_SIZE=1024
+                              -DTIMER_SERVO=TIM3 -DTIMER_TONE=TIM4
+                              -DSTEP_TIMER_IRQ_PRIO=0
+upload_protocol             = stlink
+debug_tool                  = stlink