diff --git a/Marlin/src/HAL/AVR/HAL_SPI.cpp b/Marlin/src/HAL/AVR/HAL_SPI.cpp
index 319d64c8f6db..8784bb07b30e 100644
--- a/Marlin/src/HAL/AVR/HAL_SPI.cpp
+++ b/Marlin/src/HAL/AVR/HAL_SPI.cpp
@@ -34,7 +34,9 @@
 #include "../../inc/MarlinConfig.h"
 
 void spiBegin() {
-  OUT_WRITE(SD_SS_PIN, HIGH);
+  #if PIN_EXISTS(SD_SS)
+    OUT_WRITE(SD_SS_PIN, HIGH);
+  #endif
   SET_OUTPUT(SD_SCK_PIN);
   SET_INPUT(SD_MISO_PIN);
   SET_OUTPUT(SD_MOSI_PIN);
diff --git a/Marlin/src/HAL/ESP32/HAL.cpp b/Marlin/src/HAL/ESP32/HAL.cpp
index 7818dbdd87ea..6a66d519b33c 100644
--- a/Marlin/src/HAL/ESP32/HAL.cpp
+++ b/Marlin/src/HAL/ESP32/HAL.cpp
@@ -28,6 +28,10 @@
 #include <esp_adc_cal.h>
 #include <HardwareSerial.h>
 
+#if ENABLED(USE_ESP32_TASK_WDT)
+  #include <esp_task_wdt.h>
+#endif
+
 #if ENABLED(WIFISUPPORT)
   #include <ESPAsyncWebServer.h>
   #include "wifi.h"
@@ -90,8 +94,24 @@ volatile int numPWMUsed = 0,
 
 #endif
 
-void HAL_init_board() {
+#if ENABLED(USE_ESP32_EXIO)
+  HardwareSerial YSerial2(2);
+
+  void Write_EXIO(uint8_t IO, uint8_t v) {
+    if (ISRS_ENABLED()) {
+      DISABLE_ISRS();
+      YSerial2.write(0x80 | (((char)v) << 5) | (IO - 100));
+      ENABLE_ISRS();
+    }
+    else
+      YSerial2.write(0x80 | (((char)v) << 5) | (IO - 100));
+  }
+#endif
 
+void HAL_init_board() {
+  #if ENABLED(USE_ESP32_TASK_WDT)
+    esp_task_wdt_init(10, true);
+  #endif
   #if ENABLED(ESP3D_WIFISUPPORT)
     esp3dlib.init();
   #elif ENABLED(WIFISUPPORT)
@@ -127,7 +147,11 @@ void HAL_init_board() {
   // Initialize the i2s peripheral only if the I2S stepper stream is enabled.
   // The following initialization is performed after Serial1 and Serial2 are defined as
   // their native pins might conflict with the i2s stream even when they are remapped.
-  TERN_(I2S_STEPPER_STREAM, i2s_init());
+  #if ENABLED(USE_ESP32_EXIO)
+    YSerial2.begin(460800 * 3, SERIAL_8N1, 16, 17);
+  #elif ENABLED(I2S_STEPPER_STREAM)
+    i2s_init();
+  #endif
 }
 
 void HAL_idletask() {
diff --git a/Marlin/src/HAL/ESP32/HAL.h b/Marlin/src/HAL/ESP32/HAL.h
index 0f920520306f..bc0ce4e037cf 100644
--- a/Marlin/src/HAL/ESP32/HAL.h
+++ b/Marlin/src/HAL/ESP32/HAL.h
@@ -142,6 +142,10 @@ void HAL_idletask();
 inline void HAL_init() {}
 void HAL_init_board();
 
+#if ENABLED(USE_ESP32_EXIO)
+  void Write_EXIO(uint8_t IO, uint8_t v);
+#endif
+
 //
 // Delay in cycles (used by DELAY_NS / DELAY_US)
 //
diff --git a/Marlin/src/HAL/ESP32/HAL_SPI.cpp b/Marlin/src/HAL/ESP32/HAL_SPI.cpp
index 8743ac5be215..868ab1b6712d 100644
--- a/Marlin/src/HAL/ESP32/HAL_SPI.cpp
+++ b/Marlin/src/HAL/ESP32/HAL_SPI.cpp
@@ -53,11 +53,9 @@ static SPISettings spiConfig;
 // ------------------------
 
 void spiBegin() {
-  #if !PIN_EXISTS(SD_SS)
-    #error "SD_SS_PIN not defined!"
+  #if ENABLED(SDSUPPORT) && PIN_EXISTS(SD_SS)
+    OUT_WRITE(SD_SS_PIN, HIGH);
   #endif
-
-  OUT_WRITE(SD_SS_PIN, HIGH);
 }
 
 void spiInit(uint8_t spiRate) {
diff --git a/Marlin/src/HAL/ESP32/esp32.csv b/Marlin/src/HAL/ESP32/esp32.csv
new file mode 100644
index 000000000000..8f6e101f02ea
--- /dev/null
+++ b/Marlin/src/HAL/ESP32/esp32.csv
@@ -0,0 +1,6 @@
+# Name,   Type, SubType, Offset,  Size, Flags
+nvs,      data, nvs,     0x9000,   0x5000,
+otadata,  data, ota,     0xe000,   0x2000,
+app0,     app,  ota_0,   0x10000,  0x180000,
+app1,     app,  ota_1,   0x190000, 0x180000,
+spiffs,   data, spiffs,  0x310000, 0xF0000,
diff --git a/Marlin/src/HAL/ESP32/fastio.h b/Marlin/src/HAL/ESP32/fastio.h
index 8db89dca12a1..c8e3f7e343e9 100644
--- a/Marlin/src/HAL/ESP32/fastio.h
+++ b/Marlin/src/HAL/ESP32/fastio.h
@@ -40,13 +40,19 @@
 // Set pin as input with pullup mode
 #define _PULLUP(IO, v)          pinMode(IO, v ? INPUT_PULLUP : INPUT)
 
-// Read a pin wrapper
-#define READ(IO)                (IS_I2S_EXPANDER_PIN(IO) ? i2s_state(I2S_EXPANDER_PIN_INDEX(IO)) : digitalRead(IO))
-
-// Write to a pin wrapper
-#define WRITE(IO, v)            (IS_I2S_EXPANDER_PIN(IO) ? i2s_write(I2S_EXPANDER_PIN_INDEX(IO), v) : digitalWrite(IO, v))
-
-// Set pin as input wrapper
+#if ENABLED(USE_ESP32_EXIO)
+  // Read a pin wrapper
+  #define READ(IO)                digitalRead(IO)
+  // Write to a pin wrapper
+  #define WRITE(IO, v)            (IO >= 100 ? Write_EXIO(IO, v) : digitalWrite(IO, v))
+#else
+  // Read a pin wrapper
+  #define READ(IO)                (IS_I2S_EXPANDER_PIN(IO) ? i2s_state(I2S_EXPANDER_PIN_INDEX(IO)) : digitalRead(IO))
+  // Write to a pin wrapper
+  #define WRITE(IO, v)            (IS_I2S_EXPANDER_PIN(IO) ? i2s_write(I2S_EXPANDER_PIN_INDEX(IO), v) : digitalWrite(IO, v))
+#endif
+
+// Set pin as input wrapper (0x80 | (v << 5) | (IO - 100))
 #define SET_INPUT(IO)           _SET_INPUT(IO)
 
 // Set pin as input with pullup wrapper
diff --git a/Marlin/src/HAL/ESP32/i2s.cpp b/Marlin/src/HAL/ESP32/i2s.cpp
index c28c00879390..557ea319e671 100644
--- a/Marlin/src/HAL/ESP32/i2s.cpp
+++ b/Marlin/src/HAL/ESP32/i2s.cpp
@@ -23,6 +23,8 @@
 
 #include "../../inc/MarlinConfigPre.h"
 
+#if DISABLED(USE_ESP32_EXIO)
+
 #include "i2s.h"
 
 #include "../shared/Marduino.h"
@@ -340,4 +342,5 @@ void i2s_push_sample() {
   dma.current[dma.rw_pos++] = i2s_port_data;
 }
 
+#endif // !USE_ESP32_EXIO
 #endif // ARDUINO_ARCH_ESP32
diff --git a/Marlin/src/HAL/ESP32/watchdog.h b/Marlin/src/HAL/ESP32/watchdog.h
index b6c169e34742..43db8130763f 100644
--- a/Marlin/src/HAL/ESP32/watchdog.h
+++ b/Marlin/src/HAL/ESP32/watchdog.h
@@ -25,7 +25,7 @@
   extern "C" {
 #endif
 
-    esp_err_t esp_task_wdt_reset();
+  esp_err_t esp_task_wdt_reset();
 
 #ifdef __cplusplus
   }
diff --git a/Marlin/src/HAL/STM32/HAL_SPI.cpp b/Marlin/src/HAL/STM32/HAL_SPI.cpp
index 85a5238b54af..8ee476164785 100644
--- a/Marlin/src/HAL/STM32/HAL_SPI.cpp
+++ b/Marlin/src/HAL/STM32/HAL_SPI.cpp
@@ -47,7 +47,9 @@ static SPISettings spiConfig;
   #include "../shared/Delay.h"
 
   void spiBegin(void) {
-    OUT_WRITE(SD_SS_PIN, HIGH);
+    #if PIN_EXISTS(SD_SS)
+      OUT_WRITE(SD_SS_PIN, HIGH);
+    #endif
     OUT_WRITE(SD_SCK_PIN, HIGH);
     SET_INPUT(SD_MISO_PIN);
     OUT_WRITE(SD_MOSI_PIN, HIGH);
diff --git a/Marlin/src/HAL/TEENSY31_32/HAL_SPI.cpp b/Marlin/src/HAL/TEENSY31_32/HAL_SPI.cpp
index ff84e91f79d7..415c69222986 100644
--- a/Marlin/src/HAL/TEENSY31_32/HAL_SPI.cpp
+++ b/Marlin/src/HAL/TEENSY31_32/HAL_SPI.cpp
@@ -36,10 +36,9 @@ static SPISettings spiConfig;
 
 // Initialize SPI bus
 void spiBegin() {
-  #if !PIN_EXISTS(SD_SS)
-    #error "SD_SS_PIN not defined!"
+  #if PIN_EXISTS(SD_SS)
+    OUT_WRITE(SD_SS_PIN, HIGH);
   #endif
-  OUT_WRITE(SD_SS_PIN, HIGH);
   SET_OUTPUT(SD_SCK_PIN);
   SET_INPUT(SD_MISO_PIN);
   SET_OUTPUT(SD_MOSI_PIN);
diff --git a/Marlin/src/HAL/TEENSY35_36/HAL_SPI.cpp b/Marlin/src/HAL/TEENSY35_36/HAL_SPI.cpp
index e63ab1c0e3ed..d80f57b2c436 100644
--- a/Marlin/src/HAL/TEENSY35_36/HAL_SPI.cpp
+++ b/Marlin/src/HAL/TEENSY35_36/HAL_SPI.cpp
@@ -36,10 +36,9 @@
 static SPISettings spiConfig;
 
 void spiBegin() {
-  #if !PIN_EXISTS(SD_SS)
-    #error "SD_SS_PIN not defined!"
+  #if PIN_EXISTS(SD_SS)
+    OUT_WRITE(SD_SS_PIN, HIGH);
   #endif
-  OUT_WRITE(SD_SS_PIN, HIGH);
   SET_OUTPUT(SD_SCK_PIN);
   SET_INPUT(SD_MISO_PIN);
   SET_OUTPUT(SD_MOSI_PIN);
diff --git a/Marlin/src/HAL/TEENSY40_41/HAL_SPI.cpp b/Marlin/src/HAL/TEENSY40_41/HAL_SPI.cpp
index 610765ad49c7..9dcb812faf0c 100644
--- a/Marlin/src/HAL/TEENSY40_41/HAL_SPI.cpp
+++ b/Marlin/src/HAL/TEENSY40_41/HAL_SPI.cpp
@@ -51,12 +51,9 @@ static SPISettings spiConfig;
 // ------------------------
 
 void spiBegin() {
-  #ifndef SD_SS_PIN
-    #error "SD_SS_PIN is not defined!"
+  #if PIN_EXISTS(SD_SS)
+    OUT_WRITE(SD_SS_PIN, HIGH);
   #endif
-
-  OUT_WRITE(SD_SS_PIN, HIGH);
-
   //SET_OUTPUT(SD_SCK_PIN);
   //SET_INPUT(SD_MISO_PIN);
   //SET_OUTPUT(SD_MOSI_PIN);
diff --git a/Marlin/src/core/boards.h b/Marlin/src/core/boards.h
index 46b2e5cf0c61..bc29ab5deca2 100644
--- a/Marlin/src/core/boards.h
+++ b/Marlin/src/core/boards.h
@@ -422,6 +422,8 @@
 #define BOARD_MRR_ESPE                6002  // MRR ESPE based on ESP32 (with I2S stepper stream)
 #define BOARD_E4D_BOX                 6003  // E4d@BOX
 #define BOARD_FYSETC_E4               6004  // FYSETC E4
+#define BOARD_PANDA_ZHU               6005  // Panda_ZHU
+#define BOARD_PANDA_M4                6006  // Panda_M4
 
 //
 // SAMD51 ARM Cortex M4
diff --git a/Marlin/src/gcode/sd/M1001.cpp b/Marlin/src/gcode/sd/M1001.cpp
index f5ee6a94d15b..032ec1f19869 100644
--- a/Marlin/src/gcode/sd/M1001.cpp
+++ b/Marlin/src/gcode/sd/M1001.cpp
@@ -27,6 +27,7 @@
 #include "../gcode.h"
 #include "../../module/planner.h"
 #include "../../module/printcounter.h"
+#include "../../module/temperature.h"
 #include "../../sd/cardreader.h"
 
 #ifdef SD_FINISHED_RELEASECOMMAND
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index ed5a345744c1..cb3314b25fcc 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -597,9 +597,9 @@
   #error "SPINDLE_LASER_PWM (true) is now set with SPINDLE_LASER_USE_PWM (enabled)."
 #endif
 
-#if MOTHERBOARD == BOARD_DUE3DOM_MINI && PIN_EXISTS(TEMP_2) && DISABLED(TEMP_SENSOR_BOARD)
+#if MB(DUE3DOM_MINI) && PIN_EXISTS(TEMP_2) && DISABLED(TEMP_SENSOR_BOARD)
   #warning "Onboard temperature sensor for BOARD_DUE3DOM_MINI has moved from TEMP_SENSOR_2 (TEMP_2_PIN) to TEMP_SENSOR_BOARD (TEMP_BOARD_PIN)."
-#elif MOTHERBOARD == BOARD_BTT_SKR_E3_TURBO && PIN_EXISTS(TEMP_2) && DISABLED(TEMP_SENSOR_BOARD)
+#elif MB(BTT_SKR_E3_TURBO) && PIN_EXISTS(TEMP_2) && DISABLED(TEMP_SENSOR_BOARD)
   #warning "Onboard temperature sensor for BOARD_BTT_SKR_E3_TURBO has moved from TEMP_SENSOR_2 (TEMP_2_PIN) to TEMP_SENSOR_BOARD (TEMP_BOARD_PIN)."
 #endif
 
diff --git a/Marlin/src/pins/esp32/pins_PANDA_M4.h b/Marlin/src/pins/esp32/pins_PANDA_M4.h
new file mode 100644
index 000000000000..5e2e72af05df
--- /dev/null
+++ b/Marlin/src/pins/esp32/pins_PANDA_M4.h
@@ -0,0 +1,38 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2021 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
+
+/**
+ * Panda M4 pin assignments
+ */
+
+#define BOARD_INFO_NAME "Panda_M4"
+
+#include "pins_PANDA_common.h"
+
+//
+// Steppers
+//
+#define X_ENABLE_PIN                         115
+#define Y_ENABLE_PIN                         114
+#define Z_ENABLE_PIN                         113
+#define E0_ENABLE_PIN                        112
diff --git a/Marlin/src/pins/esp32/pins_PANDA_ZHU.h b/Marlin/src/pins/esp32/pins_PANDA_ZHU.h
new file mode 100644
index 000000000000..47500578976e
--- /dev/null
+++ b/Marlin/src/pins/esp32/pins_PANDA_ZHU.h
@@ -0,0 +1,61 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2021 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
+
+/**
+ * Panda ZHU pin assignments
+ */
+
+#define BOARD_INFO_NAME "Panda_ZHU"
+
+#include "pins_PANDA_common.h"
+
+//
+// Steppers
+//
+#define X_ENABLE_PIN                         128  // Shared with all steppers
+#define Y_ENABLE_PIN                X_ENABLE_PIN
+#define Z_ENABLE_PIN                X_ENABLE_PIN
+#define E0_ENABLE_PIN               X_ENABLE_PIN
+
+//#define X_CS_PIN                             0
+//#define Y_CS_PIN                            13
+//#define Z_CS_PIN                             5  // SS_PIN
+//#define E0_CS_PIN                           21
+
+#define E1_STEP_PIN                          115
+#define E1_DIR_PIN                           114
+#define E1_ENABLE_PIN               X_ENABLE_PIN
+
+#define E2_STEP_PIN                          112
+#define E2_DIR_PIN                           113
+#define E2_ENABLE_PIN               X_ENABLE_PIN
+
+#define E3_STEP_PIN                          110
+#define E3_DIR_PIN                           111
+#define E3_ENABLE_PIN               X_ENABLE_PIN
+
+#define E4_STEP_PIN                          121
+#define E4_DIR_PIN                           122
+#define E4_ENABLE_PIN               X_ENABLE_PIN
+
+#define HEATER_1_PIN                         123
diff --git a/Marlin/src/pins/esp32/pins_PANDA_common.h b/Marlin/src/pins/esp32/pins_PANDA_common.h
new file mode 100644
index 000000000000..81862fbd553c
--- /dev/null
+++ b/Marlin/src/pins/esp32/pins_PANDA_common.h
@@ -0,0 +1,98 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2021 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
+
+/**
+ * Panda common pin assignments
+ */
+
+#include "env_validate.h"
+
+#define DEFAULT_MACHINE_NAME BOARD_INFO_NAME
+
+//
+// Servos
+//
+#define SERVO0_PIN                             0
+
+//
+// Limit Switches
+//
+#define X_STOP_PIN                             4
+#define Y_STOP_PIN                            35
+#define Z_STOP_PIN                            21
+
+//
+// Steppers
+//
+#define X_STEP_PIN                           101
+#define X_DIR_PIN                            100
+
+#define Y_STEP_PIN                           103
+#define Y_DIR_PIN                            102
+
+#define Z_STEP_PIN                           105
+#define Z_DIR_PIN                            104
+
+#define E0_STEP_PIN                          107
+#define E0_DIR_PIN                           106
+
+//
+// Temperature Sensors
+//
+#define TEMP_0_PIN                            39  // Analog Input
+#define TEMP_BED_PIN                          36  // Analog Input
+
+//
+// Heaters / Fans
+//
+#define HEATER_0_PIN                         108
+#define HEATER_BED_PIN                       109
+#define FAN_PIN                              118  // FAN0
+#define FAN1_PIN                             119  // FAN1
+
+#ifndef E0_AUTO_FAN_PIN
+  #define E0_AUTO_FAN_PIN                    120  // FAN2
+#endif
+
+//
+// SD card
+//
+#if ENABLED(SDSUPPORT)
+  #define SD_MOSI_PIN                         23
+  #define SD_MISO_PIN                         19
+  #define SD_SCK_PIN                          18
+  #define SDSS                                 5
+  #define SD_DETECT_PIN                        2
+#endif
+
+#if HAS_WIRED_LCD
+  #define BEEPER_PIN                         129
+  #define BTN_ENC                             12
+
+  #define BTN_EN1                             33
+  #define BTN_EN2                             32
+
+  #define LCD_PINS_RS                         27
+  #define LCD_PINS_ENABLE                     26
+  #define LCD_PINS_D4                         14
+#endif
diff --git a/Marlin/src/pins/pins.h b/Marlin/src/pins/pins.h
index 0293da1dba85..58f3850389eb 100644
--- a/Marlin/src/pins/pins.h
+++ b/Marlin/src/pins/pins.h
@@ -681,6 +681,10 @@
   #include "esp32/pins_E4D.h"                   // ESP32                                  env:esp32
 #elif MB(FYSETC_E4)
   #include "esp32/pins_FYSETC_E4.h"             // ESP32                                  env:FYSETC_E4
+#elif MB(PANDA_ZHU)
+  #include "esp32/pins_PANDA_ZHU.h"             // ESP32                                  env:PANDA
+#elif MB(PANDA_M4)
+  #include "esp32/pins_PANDA_M4.h"              // ESP32                                  env:PANDA
 
 //
 // Adafruit Grand Central M4 (SAMD51 ARM Cortex-M4)
diff --git a/ini/esp32.ini b/ini/esp32.ini
index fcfa8296087a..9c0c44db67b9 100644
--- a/ini/esp32.ini
+++ b/ini/esp32.ini
@@ -27,3 +27,13 @@ monitor_speed = 250000
 platform               = espressif32@2.1.0
 extends                = env:esp32
 board_build.partitions = default_16MB.csv
+
+[env:PANDA]
+platform      = espressif32@2.1.0
+extends       = env:esp32
+build_flags   = ${env:esp32.build_flags} -DUSE_ESP32_EXIO -DUSE_ESP32_TASK_WDT
+lib_deps      = ${common.lib_deps}
+  SoftwareSerialEsp32
+board_build.partitions = Marlin/src/HAL/ESP32/esp32.csv
+upload_speed  = 115200
+monitor_speed = 115200
diff --git a/ini/stm32f1-maple.ini b/ini/stm32f1-maple.ini
index 00ba93aa6359..e11aa035601f 100644
--- a/ini/stm32f1-maple.ini
+++ b/ini/stm32f1-maple.ini
@@ -65,8 +65,7 @@ build_flags       = ${common_stm32f1.build_flags}
 extra_scripts     = ${common_stm32f1.extra_scripts}
   pre:buildroot/share/PlatformIO/scripts/STM32F1_create_variant.py
   buildroot/share/PlatformIO/scripts/STM32F103RC_MEEB_3DP.py
-lib_deps          = ${common.lib_deps}
-  SoftwareSerialM
+lib_deps          = ${common_stm32f1.lib_deps}
   USBComposite for STM32F1@0.91
 custom_marlin.NEOPIXEL_LED = Adafruit NeoPixel=https://github.com/ccccmagicboy/Adafruit_NeoPixel#meeb_3dp_use
 debug_tool        = stlink
@@ -377,7 +376,8 @@ extra_scripts             = ${common.extra_scripts}
   buildroot/share/PlatformIO/scripts/offset_and_rename.py
 build_flags               = ${common_stm32f1.build_flags}
   -D__STM32F1__=1 -DDEBUG_LEVEL=0 -DSS_TIMER=4 -DSERIAL_USB
-lib_deps                  = USBComposite for STM32F1@0.91
+lib_deps                  = ${common_stm32f1.lib_deps}
+  USBComposite for STM32F1@0.91
 lib_ignore                = Adafruit NeoPixel, SPI, SailfishLCD, SailfishRGB_LED, SlowSoftI2CMaster, TMCStepper
 
 [env:STM32F103RC_ZM3E2_USB_maple]