diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 4a60ec61390..47b42aa8ddd 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -1152,7 +1152,7 @@
#endif
/**
- * Automatic backlash, position and hotend offset calibration
+ * Automatic backlash, position, and hotend offset calibration
*
* Enable G425 to run automatic calibration using an electrically-
* conductive cube, bolt, or washer mounted on the bed.
diff --git a/Marlin/src/HAL/AVR/inc/SanityCheck.h b/Marlin/src/HAL/AVR/inc/SanityCheck.h
index 411b0198f13..ff1610f7416 100644
--- a/Marlin/src/HAL/AVR/inc/SanityCheck.h
+++ b/Marlin/src/HAL/AVR/inc/SanityCheck.h
@@ -40,13 +40,15 @@
#if SERIAL_IN_USE(0)
// D0-D1. No known conflicts.
#endif
-#if NOT_TARGET(__AVR_ATmega644P__, __AVR_ATmega1284P__)
- #if SERIAL_IN_USE(1) && (CHECK_SERIAL_PIN(18) || CHECK_SERIAL_PIN(19))
- #error "Serial Port 1 pin D18 and/or D19 conflicts with another pin on the board."
- #endif
-#else
- #if SERIAL_IN_USE(1) && (CHECK_SERIAL_PIN(10) || CHECK_SERIAL_PIN(11))
- #error "Serial Port 1 pin D10 and/or D11 conflicts with another pin on the board."
+#if SERIAL_IN_USE(1)
+ #if NOT_TARGET(__AVR_ATmega644P__, __AVR_ATmega1284P__)
+ #if CHECK_SERIAL_PIN(18) || CHECK_SERIAL_PIN(19)
+ #error "Serial Port 1 pin D18 and/or D19 conflicts with another pin on the board."
+ #endif
+ #else
+ #if CHECK_SERIAL_PIN(10) || CHECK_SERIAL_PIN(11)
+ #error "Serial Port 1 pin D10 and/or D11 conflicts with another pin on the board."
+ #endif
#endif
#endif
#if SERIAL_IN_USE(2) && (CHECK_SERIAL_PIN(16) || CHECK_SERIAL_PIN(17))
diff --git a/Marlin/src/HAL/STM32/inc/SanityCheck.h b/Marlin/src/HAL/STM32/inc/SanityCheck.h
index a440695a06f..e8ddfa17200 100644
--- a/Marlin/src/HAL/STM32/inc/SanityCheck.h
+++ b/Marlin/src/HAL/STM32/inc/SanityCheck.h
@@ -50,3 +50,62 @@
#if ANY(TFT_COLOR_UI, TFT_LVGL_UI, TFT_CLASSIC_UI) && NOT_TARGET(STM32H7xx, STM32F4xx, STM32F1xx)
#error "TFT_COLOR_UI, TFT_LVGL_UI and TFT_CLASSIC_UI are currently only supported on STM32H7, STM32F4 and STM32F1 hardware."
#endif
+
+/**
+ * Check for common serial pin conflicts
+ */
+#define _CHECK_SERIAL_PIN(N) (( \
+ BTN_EN1 == N || DOGLCD_CS == N || HEATER_BED_PIN == N || FAN_PIN == N || \
+ SDIO_D2_PIN == N || SDIO_D3_PIN == N || SDIO_CK_PIN == N || SDIO_CMD_PIN == N \
+ ))
+#define CHECK_SERIAL_PIN(T,N) defined(UART##N##_##T##_PIN) && _CHECK_SERIAL_PIN(UART##N##_##T##_PIN)
+#if SERIAL_IN_USE(1)
+ #if CHECK_SERIAL_PIN(TX,1)
+ #error "Serial Port 1 TX IO pins conflict with another pin on the board."
+ #endif
+ #if CHECK_SERIAL_PIN(RX,1)
+ #error "Serial Port 1 RX IO pins conflict with another pin on the board."
+ #endif
+#endif
+#if SERIAL_IN_USE(2)
+ #if CHECK_SERIAL_PIN(TX,2)
+ #error "Serial Port 2 TX IO pins conflict with another pin on the board."
+ #endif
+ #if CHECK_SERIAL_PIN(RX,2)
+ #error "Serial Port 2 RX IO pins conflict with another pin on the board."
+ #endif
+#endif
+#if SERIAL_IN_USE(3)
+ #if CHECK_SERIAL_PIN(TX,3)
+ #error "Serial Port 3 TX IO pins conflict with another pin on the board."
+ #endif
+ #if CHECK_SERIAL_PIN(RX,3)
+ #error "Serial Port 3 RX IO pins conflict with another pin on the board."
+ #endif
+#endif
+#if SERIAL_IN_USE(4)
+ #if CHECK_SERIAL_PIN(TX,4)
+ #error "Serial Port 4 TX IO pins conflict with another pin on the board."
+ #endif
+ #if CHECK_SERIAL_PIN(RX,4)
+ #error "Serial Port 4 RX IO pins conflict with another pin on the board."
+ #endif
+#endif
+#if SERIAL_IN_USE(5)
+ #if CHECK_SERIAL_PIN(TX,5)
+ #error "Serial Port 5 TX IO pins conflict with another pin on the board."
+ #endif
+ #if CHECK_SERIAL_PIN(RX,5)
+ #error "Serial Port 5 RX IO pins conflict with another pin on the board."
+ #endif
+#endif
+#if SERIAL_IN_USE(6)
+ #if CHECK_SERIAL_PIN(TX,6)
+ #error "Serial Port 6 TX IO pins conflict with another pin on the board."
+ #endif
+ #if CHECK_SERIAL_PIN(RX,6)
+ #error "Serial Port 6 RX IO pins conflict with another pin on the board."
+ #endif
+#endif
+#undef CHECK_SERIAL_PIN
+#undef _CHECK_SERIAL_PIN
diff --git a/Marlin/src/inc/Conditionals_post.h b/Marlin/src/inc/Conditionals_post.h
index bb9a1ac6402..417ce4479a2 100644
--- a/Marlin/src/inc/Conditionals_post.h
+++ b/Marlin/src/inc/Conditionals_post.h
@@ -2446,11 +2446,11 @@
//
// Flag the indexed hardware serial ports in use
-#define SERIAL_IN_USE(N) ( (defined(SERIAL_PORT) && SERIAL_PORT == N) \
- || (defined(SERIAL_PORT_2) && SERIAL_PORT_2 == N) \
- || (defined(SERIAL_PORT_3) && SERIAL_PORT_3 == N) \
- || (defined(MMU2_SERIAL_PORT) && MMU2_SERIAL_PORT == N) \
- || (defined(LCD_SERIAL_PORT) && LCD_SERIAL_PORT == N) )
+#define SERIAL_IN_USE(N) ( (defined(SERIAL_PORT) && N == SERIAL_PORT) \
+ || (defined(SERIAL_PORT_2) && N == SERIAL_PORT_2) \
+ || (defined(SERIAL_PORT_3) && N == SERIAL_PORT_3) \
+ || (defined(MMU2_SERIAL_PORT) && N == MMU2_SERIAL_PORT) \
+ || (defined(LCD_SERIAL_PORT) && N == LCD_SERIAL_PORT) )
// Flag the named hardware serial ports in use
#define TMC_UART_IS(A,N) (defined(A##_HARDWARE_SERIAL) && (CAT(HW_,A##_HARDWARE_SERIAL) == HW_Serial##N || CAT(HW_,A##_HARDWARE_SERIAL) == HW_MSerial##N))
diff --git a/Marlin/src/pins/pinsDebug_list.h b/Marlin/src/pins/pinsDebug_list.h
index 2cd54ecf18b..077c94a60f8 100644
--- a/Marlin/src/pins/pinsDebug_list.h
+++ b/Marlin/src/pins/pinsDebug_list.h
@@ -2231,6 +2231,80 @@
REPORT_NAME_DIGITAL(__LINE__, TFT_RESET_PIN)
#endif
+//
+// Hardware UART
+//
+#if SERIAL_IN_USE(1)
+ #if PIN_EXISTS(UART1_TX)
+ REPORT_NAME_DIGITAL(__LINE__, UART1_TX_PIN)
+ #endif
+ #if PIN_EXISTS(UART1_RX)
+ REPORT_NAME_DIGITAL(__LINE__, UART1_RX_PIN)
+ #endif
+#endif
+#if SERIAL_IN_USE(2)
+ #if PIN_EXISTS(UART2_TX)
+ REPORT_NAME_DIGITAL(__LINE__, UART2_TX_PIN)
+ #endif
+ #if PIN_EXISTS(UART2_RX)
+ REPORT_NAME_DIGITAL(__LINE__, UART2_RX_PIN)
+ #endif
+#endif
+#if SERIAL_IN_USE(3)
+ #if PIN_EXISTS(UART3_TX)
+ REPORT_NAME_DIGITAL(__LINE__, UART3_TX_PIN)
+ #endif
+ #if PIN_EXISTS(UART3_RX)
+ REPORT_NAME_DIGITAL(__LINE__, UART3_RX_PIN)
+ #endif
+#endif
+#if SERIAL_IN_USE(4)
+ #if PIN_EXISTS(UART4_TX)
+ REPORT_NAME_DIGITAL(__LINE__, UART4_TX_PIN)
+ #endif
+ #if PIN_EXISTS(UART4_RX)
+ REPORT_NAME_DIGITAL(__LINE__, UART4_RX_PIN)
+ #endif
+#endif
+#if SERIAL_IN_USE(5)
+ #if PIN_EXISTS(UART5_TX)
+ REPORT_NAME_DIGITAL(__LINE__, UART5_TX_PIN)
+ #endif
+ #if PIN_EXISTS(UART5_RX)
+ REPORT_NAME_DIGITAL(__LINE__, UART5_RX_PIN)
+ #endif
+#endif
+#if SERIAL_IN_USE(6)
+ #if PIN_EXISTS(UART6_TX)
+ REPORT_NAME_DIGITAL(__LINE__, UART6_TX_PIN)
+ #endif
+ #if PIN_EXISTS(UART6_RX)
+ REPORT_NAME_DIGITAL(__LINE__, UART6_RX_PIN)
+ #endif
+#endif
+
+//
+// SDIO
+//
+#if PIN_EXISTS(SDIO_D0)
+ REPORT_NAME_DIGITAL(__LINE__, SDIO_D0_PIN)
+#endif
+#if PIN_EXISTS(SDIO_D1)
+ REPORT_NAME_DIGITAL(__LINE__, SDIO_D1_PIN)
+#endif
+#if PIN_EXISTS(SDIO_D2)
+ REPORT_NAME_DIGITAL(__LINE__, SDIO_D2_PIN)
+#endif
+#if PIN_EXISTS(SDIO_D3)
+ REPORT_NAME_DIGITAL(__LINE__, SDIO_D3_PIN)
+#endif
+#if PIN_EXISTS(SDIO_CK)
+ REPORT_NAME_DIGITAL(__LINE__, SDIO_CK_PIN)
+#endif
+#if PIN_EXISTS(SDIO_CMD)
+ REPORT_NAME_DIGITAL(__LINE__, SDIO_CMD_PIN)
+#endif
+
//
// Miscellaneous
//
diff --git a/Marlin/src/pins/stm32f1/pins_CREALITY_V4.h b/Marlin/src/pins/stm32f1/pins_CREALITY_V4.h
index 11384799a39..f633ee0983c 100644
--- a/Marlin/src/pins/stm32f1/pins_CREALITY_V4.h
+++ b/Marlin/src/pins/stm32f1/pins_CREALITY_V4.h
@@ -173,14 +173,14 @@
* GND | 9 10 | 5V
* ------
*/
- #define EXP3_01_PIN PC6
- #define EXP3_02_PIN PB2
- #define EXP3_03_PIN PB10
- #define EXP3_04_PIN PB11
- #define EXP3_05_PIN PB14
- #define EXP3_06_PIN PB13
- #define EXP3_07_PIN PB12
- #define EXP3_08_PIN PB15
+ #define EXP3_01_PIN PC6
+ #define EXP3_02_PIN PB2
+ #define EXP3_03_PIN PB10
+ #define EXP3_04_PIN PB11
+ #define EXP3_05_PIN PB14
+ #define EXP3_06_PIN PB13
+ #define EXP3_07_PIN PB12
+ #define EXP3_08_PIN PB15
#elif EITHER(VET6_12864_LCD, DWIN_VET6_CREALITY_LCD)
@@ -194,14 +194,14 @@
* GND | 9 10 | 5V
* ------
*/
- #define EXP3_01_PIN -1
- #define EXP3_02_PIN PC5
- #define EXP3_03_PIN PB10
- #define EXP3_04_PIN -1
- #define EXP3_05_PIN PA6
- #define EXP3_06_PIN PA5
- #define EXP3_07_PIN PA4
- #define EXP3_08_PIN PA7
+ #define EXP3_01_PIN -1
+ #define EXP3_02_PIN PC5
+ #define EXP3_03_PIN PB10
+ #define EXP3_04_PIN -1
+ #define EXP3_05_PIN PA6
+ #define EXP3_06_PIN PA5
+ #define EXP3_07_PIN PA4
+ #define EXP3_08_PIN PA7
#elif EITHER(CR10_STOCKDISPLAY, FYSETC_MINI_12864_2_1)
#error "Define RET6_12864_LCD or VET6_12864_LCD to select pins for the LCD with the Creality V4 controller."
@@ -283,3 +283,26 @@
#define NEOPIXEL_PIN PA13
#endif
+
+// Pins for documentation and sanity checks only.
+// Changing these will not change the pin they are on.
+
+// Hardware UART pins
+#define UART1_TX_PIN PA9 // default uses CH340 RX
+#define UART1_RX_PIN PA10 // default uses CH340 TX
+#define UART2_TX_PIN PA2 // default uses HEATER_BED_PIN
+#define UART2_RX_PIN PA3 // not connected
+#define UART3_TX_PIN PB10 // default uses LCD connector
+#define UART3_RX_PIN PB11 // default uses LCD connector
+#define UART4_TX_PIN PC10 // default uses sdcard SDIO_D2
+#define UART4_RX_PIN PC11 // default uses sdcard SDIO_D3
+#define UART5_TX_PIN PC12 // default uses sdcard SDIO_CK
+#define UART5_RX_PIN PD2 // default uses sdcard SDIO_CMD
+
+// SDIO pins
+#define SDIO_D0_PIN PC8
+#define SDIO_D1_PIN PC9
+#define SDIO_D2_PIN PC10
+#define SDIO_D3_PIN PC11
+#define SDIO_CK_PIN PC12
+#define SDIO_CMD_PIN PD2