From 4ce69701621469dafdcf34652eb9379c64a738fe Mon Sep 17 00:00:00 2001
From: Scott Lahteine <thinkyhead@users.noreply.github.com>
Date: Sat, 18 Feb 2023 00:51:59 -0600
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Add=20PANELDUE=20support?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Marlin/Configuration.h                        |   6 +
 Marlin/src/gcode/gcode.cpp                    |   4 +
 Marlin/src/gcode/gcode.h                      |   5 +
 Marlin/src/gcode/lcd/M408.cpp                 | 186 ++++++++++++++++
 Marlin/src/gcode/sd/M20.cpp                   |  53 ++++-
 Marlin/src/inc/Conditionals-2-LCD.h           |   4 +-
 Marlin/src/inc/SanityCheck.h                  |   1 +
 .../src/lcd/extui/paneldue/paneldue_extui.cpp | 199 ++++++++++++++++++
 Marlin/src/sd/cardreader.cpp                  |  50 ++++-
 Marlin/src/sd/cardreader.h                    |   9 +
 buildroot/tests/mega2560                      |  19 ++
 ini/features.ini                              |   1 +
 12 files changed, 529 insertions(+), 8 deletions(-)
 create mode 100644 Marlin/src/gcode/lcd/M408.cpp
 create mode 100644 Marlin/src/lcd/extui/paneldue/paneldue_extui.cpp

diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
index 64187f41bfcb0..ec50fc6847c37 100644
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@@ -3249,6 +3249,12 @@
 //
 //#define NEXTION_TFT
 
+//
+// PanelDue touch controller by Escher3D
+// http://escher3d.com/pages/order/products/product2.php
+//
+//#define PANELDUE
+
 //
 // Third-party or vendor-customized controller interfaces.
 // Sources should be installed in 'src/lcd/extui'.
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 1ccb10753cbcc..2523788e5835d 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -870,6 +870,10 @@ void GcodeSuite::process_parsed_command(const bool no_ok/*=false*/) {
         case 407: M407(); break;                                  // M407: Display measured filament diameter
       #endif
 
+      #if ENABLED(PANELDUE)
+        case 408: M408(); break;                                  // M408: Report machine state in JSON format
+      #endif
+
       #if HAS_FILAMENT_SENSOR
         case 412: M412(); break;                                  // M412: Enable/Disable filament runout detection
       #endif
diff --git a/Marlin/src/gcode/gcode.h b/Marlin/src/gcode/gcode.h
index 421dda9aec0fa..685800fa7aae3 100644
--- a/Marlin/src/gcode/gcode.h
+++ b/Marlin/src/gcode/gcode.h
@@ -233,6 +233,7 @@
  * M405 - Enable Filament Sensor flow control. "M405 D<delay_cm>". (Requires FILAMENT_WIDTH_SENSOR)
  * M406 - Disable Filament Sensor flow control. (Requires FILAMENT_WIDTH_SENSOR)
  * M407 - Display measured filament diameter in millimeters. (Requires FILAMENT_WIDTH_SENSOR)
+ * M408 - Report machine state in JSON format. (Requires PANELDUE)
  * M410 - Quickstop. Abort all planned moves.
  * M412 - Enable / Disable Filament Runout Detection. (Requires FILAMENT_RUNOUT_SENSOR)
  * M413 - Enable / Disable Power-Loss Recovery. (Requires POWER_LOSS_RECOVERY)
@@ -1043,6 +1044,10 @@ class GcodeSuite {
     static void M407();
   #endif
 
+  #if ENABLED(PANELDUE)
+    static void M408();
+  #endif
+
   #if HAS_FILAMENT_SENSOR
     static void M412();
     static void M412_report(const bool forReplay=true);
diff --git a/Marlin/src/gcode/lcd/M408.cpp b/Marlin/src/gcode/lcd/M408.cpp
new file mode 100644
index 0000000000000..31fadd9b23e2b
--- /dev/null
+++ b/Marlin/src/gcode/lcd/M408.cpp
@@ -0,0 +1,186 @@
+/**
+ * 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/>.
+ *
+ */
+
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(PANELDUE)
+
+#include "../gcode.h"
+#include "../../module/planner.h"
+#include "../../module/printcounter.h"
+#include "../../module/temperature.h"
+#include "../../sd/cardreader.h"
+#include "../../lcd/marlinui.h"
+
+#if ENABLED(LCD_SET_PROGRESS_MANUALLY)
+  extern uint8_t progress_bar_percent;
+#endif
+
+/**
+ * M408: Report machine state in JSON format for PanelDue
+ *
+ *  S<style> Include static values with S1
+ *
+ * Since Marlin doesn't use sequence numbers, the R parameter is omitted.
+ *
+ */
+
+inline void json_key(const char * const name) {
+  SERIAL_ECHOPGM(",\"", name, "\":");
+}
+
+inline void json_array_print(const char * const name, const float val[], const int8_t size) {
+  json_key(name);
+  SERIAL_CHAR('[');
+  for (uint8_t i = 0; i < size; i++) {
+    SERIAL_ECHO(val[i]);
+    if (i < size - 1) SERIAL_CHAR(',');
+  }
+  SERIAL_CHAR(']');
+  safe_delay(1);
+}
+
+void GcodeSuite::M408() {
+  float tmp[10];
+  SERIAL_CHAR('{');
+
+  // status: SD printing or idle
+  json_key(PSTR("status"));
+  SERIAL_ECHO(IS_SD_PRINTING() ? F("\"P\"") : F("\"I\""));
+
+  // heaters: current bed, hotend temperatures
+  tmp[0] = TERN0(HAS_HEATED_BED, thermalManager.degBed());
+  HOTEND_LOOP() tmp[e + 1] = thermalManager.degHotend(e);
+  json_array_print(PSTR("heaters"), tmp, HOTENDS + 1);
+
+  // active: target bed, hotend temperatures
+  tmp[0] = TERN0(HAS_HEATED_BED, thermalManager.degTargetBed());
+  HOTEND_LOOP() tmp[e + 1] = thermalManager.degTargetHotend(e);
+  json_array_print(PSTR("active"), tmp, HOTENDS + 1);
+
+  // standby: in Marlin, same as active
+  json_array_print(PSTR("standby"), tmp, HOTENDS + 1);
+
+  // hstat: in Marlin, heating or off
+  json_key(PSTR("hstat"));
+  SERIAL_CHAR('[');
+  SERIAL_CHAR(TERN0(HAS_HEATED_BED, thermalManager.degTargetBed()) ? '2' : '0');
+  HOTEND_LOOP() {
+    SERIAL_CHAR(',');
+    SERIAL_CHAR(thermalManager.degTargetHotend(e) ? '2' : '0');
+  }
+  SERIAL_CHAR(']');
+
+  // pos: tool position
+  tmp[0] = current_position.x; tmp[1] = current_position.y; tmp[2] = current_position.z;
+  json_array_print(PSTR("pos"), tmp, 3);
+
+  // extr: extruder position
+  for (uint8_t e = 0; e < EXTRUDERS; e++) tmp[e] = current_position.e;
+  json_array_print(PSTR("extr"), tmp, EXTRUDERS);
+
+  // sfactor: feedrate %
+  json_key(PSTR("sfactor"));
+  SERIAL_ECHO(feedrate_percentage);
+
+  // efactor: flow %
+  for (uint8_t e = 0; e < EXTRUDERS; e++) tmp[e] = planner.flow_percentage[e];
+  json_array_print(PSTR("efactor"), tmp, EXTRUDERS);
+
+  // tool: selected extruder
+  json_key(PSTR("tool"));
+  SERIAL_ECHO(active_extruder);
+
+  // probe: the last Z probe reading (just 0 for now)
+  json_key(PSTR("probe"));
+  SERIAL_ECHOPGM("\"0\"");
+
+  #if FAN_COUNT > 0
+    // fanPercent: the last Z probe reading
+    for (uint8_t i = 0; i < FAN_COUNT; i++) tmp[i] = map(thermalManager.fan_speed[i], 0, 255, 0, 100);
+    json_array_print(PSTR("fanPercent"), tmp, FAN_COUNT);
+
+    // fanRPM: print cooling fan faux RPM
+    json_key(PSTR("fanRPM"));
+    SERIAL_ECHO(int(thermalManager.fan_speed[0] * 10));
+  #endif
+
+  // homed: axis homed status
+  json_key(PSTR("homed"));
+  LOOP_NUM_AXES(i) {
+    SERIAL_CHAR(i ? ',' : '[');
+    SERIAL_ECHO(int(TEST(axes_homed, i)));
+  }
+  SERIAL_CHAR(']');
+
+  #if ENABLED(SDSUPPORT)
+    // fraction_printed: print progress
+    json_key(PSTR("fraction_printed"));
+    SERIAL_ECHO(0.01 * ui.get_progress_percent());
+  #endif
+
+  #if HAS_DISPLAY
+    // message
+    if (ui.status_message[0]) {
+      json_key(PSTR("message"));
+      SERIAL_ECHOPGM("\"", &ui.status_message);
+      SERIAL_CHAR('"');
+    }
+  #endif
+
+  // Extra fields
+  if (parser.intval('S') == 1) {
+    // myName
+    json_key(PSTR("myName"));
+    SERIAL_ECHOPGM("\"" MACHINE_NAME "\"");
+    // firmwareName
+    json_key(PSTR("firmwareName"));
+    SERIAL_ECHOPGM("\"Marlin\"");
+    // geometry
+    json_key(PSTR("geometry"));
+    SERIAL_ECHOPGM("\""
+      TERN_(IS_FULL_CARTESIAN, "cartesian")
+      TERN_(IS_SCARA, "scara")
+      TERN_(DELTA, "delta")
+      TERN_(COREXY, "corexy")
+      TERN_(COREXZ, "corexz")
+      TERN_(COREYZ, "coreyz")
+      TERN_(COREYX, "coreyx")
+      TERN_(COREZX, "corezx")
+      TERN_(COREZY, "corezy")
+      "\""
+    );
+    // axes
+    json_key(PSTR("axes"));
+    SERIAL_CHAR('3');
+    // volumes: the number of SD card slots available
+    json_key(PSTR("volumes"));
+    SERIAL_CHAR(TERN(SDSUPPORT, '1', '0'));
+    // numTools: extruder count
+    json_key(PSTR("numTools"));
+    SERIAL_CHAR('0' + EXTRUDERS);
+  }
+
+  SERIAL_EOL();
+}
+
+#endif // PANELDUE
diff --git a/Marlin/src/gcode/sd/M20.cpp b/Marlin/src/gcode/sd/M20.cpp
index 9dca2bb3e036c..f55e35dade7ec 100644
--- a/Marlin/src/gcode/sd/M20.cpp
+++ b/Marlin/src/gcode/sd/M20.cpp
@@ -41,11 +41,54 @@
  */
 void GcodeSuite::M20() {
   if (card.flag.mounted) {
-    SERIAL_ECHOLNPGM(STR_BEGIN_FILE_LIST);
-    card.ls(TERN0(CUSTOM_FIRMWARE_UPLOAD,     parser.boolval('F') << LS_ONLY_BIN)
-          | TERN0(LONG_FILENAME_HOST_SUPPORT, parser.boolval('L') << LS_LONG_FILENAME)
-          | TERN0(M20_TIMESTAMP_SUPPORT,      parser.boolval('T') << LS_TIMESTAMP));
-    SERIAL_ECHOLNPGM(STR_END_FILE_LIST);
+    #if ENABLED(PANELDUE)
+      const bool json = parser.intval('S') == 2;
+      if (json) {
+        // The P parameter gives the path
+        char *path = parser.stringval('P');
+
+        #if DISABLED(GCODE_QUOTED_STRINGS)
+          // 'S' before 'P' or 'S' is part of the path
+          if (path < parser.stringval('S')) path = nullptr;
+        #endif
+
+        // Get the CWD as the root for dive
+        SdFile *listDirPtr;
+
+        bool ok = true;
+
+        // If any path was specified, dive into it
+        if (path && path[0]) {
+          // Ensure the path ends with a slash
+          const size_t len = strlen(path);
+          if (len > 1 && path[len - 1] != '/') strcat(path, "/");
+          // Dive listDirPtr down to the path
+          ok = (bool)card.diveToFile(false, listDirPtr, path);
+        }
+        else
+          path = (char*)".";
+
+        if (ok) {
+          // Remove the slash at the end
+          const size_t len = strlen(path);
+          if (len > 1 && path[len - 1] == '/') path[len - 1] = '\0';
+          // Print a flat listing of the folder in JSON
+          SERIAL_ECHOPGM("{\"dir\":\"", path, "\",");
+          card.lsJSON(0, *listDirPtr); // Don't enter subfolders (but list folders)
+          SERIAL_ECHOLNPGM("}");
+        }
+      }
+    #else
+      constexpr bool json = false;
+    #endif
+
+    if (!json) {
+      SERIAL_ECHOLNPGM(STR_BEGIN_FILE_LIST);
+      card.ls(TERN0(CUSTOM_FIRMWARE_UPLOAD,     parser.boolval('F') << LS_ONLY_BIN)
+            | TERN0(LONG_FILENAME_HOST_SUPPORT, parser.boolval('L') << LS_LONG_FILENAME)
+            | TERN0(M20_TIMESTAMP_SUPPORT,      parser.boolval('T') << LS_TIMESTAMP));
+      SERIAL_ECHOLNPGM(STR_END_FILE_LIST);
+    }
   }
   else
     SERIAL_ECHO_MSG(STR_NO_MEDIA);
diff --git a/Marlin/src/inc/Conditionals-2-LCD.h b/Marlin/src/inc/Conditionals-2-LCD.h
index cc01e93aa7f81..e558df0d3d854 100644
--- a/Marlin/src/inc/Conditionals-2-LCD.h
+++ b/Marlin/src/inc/Conditionals-2-LCD.h
@@ -549,7 +549,7 @@
 #endif
 
 // Extensible UI serial touch screens. (See src/lcd/extui)
-#if ANY(HAS_DGUS_LCD, MALYAN_LCD, ANYCUBIC_LCD_I3MEGA, ANYCUBIC_LCD_CHIRON, NEXTION_TFT, TOUCH_UI_FTDI_EVE, DWIN_LCD_PROUI)
+#if ANY(HAS_DGUS_LCD, MALYAN_LCD, ANYCUBIC_LCD_I3MEGA, ANYCUBIC_LCD_CHIRON, NEXTION_TFT, TOUCH_UI_FTDI_EVE, DWIN_LCD_PROUI, PANELDUE)
   #define IS_EXTUI 1 // Just for sanity check.
   #define EXTENSIBLE_UI
 #endif
@@ -568,7 +568,7 @@
 #endif
 
 // Serial Controllers require LCD_SERIAL_PORT
-#if ANY(IS_DWIN_MARLINUI, HAS_DWIN_E3V2, HAS_DGUS_LCD, MALYAN_LCD, ANYCUBIC_LCD_I3MEGA, ANYCUBIC_LCD_CHIRON, NEXTION_TFT)
+#if ANY(IS_DWIN_MARLINUI, HAS_DWIN_E3V2, HAS_DGUS_LCD, MALYAN_LCD, ANYCUBIC_LCD_I3MEGA, ANYCUBIC_LCD_CHIRON, NEXTION_TFT, PANELDUE)
   #define LCD_IS_SERIAL_HOST 1
 #endif
 
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index 42d63ee398760..4a45c7758caa8 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -2763,6 +2763,7 @@ static_assert(NUM_SERVOS <= NUM_SERVO_PLUGS, "NUM_SERVOS (or some servo index) i
   + ENABLED(MAKRPANEL) \
   + ENABLED(MALYAN_LCD) \
   + ENABLED(NEXTION_TFT) \
+  + ENABLED(PANELDUE) \
   + ENABLED(MKS_LCD12864A) \
   + ENABLED(MKS_LCD12864B) \
   + ENABLED(OLED_PANEL_TINYBOY2) \
diff --git a/Marlin/src/lcd/extui/paneldue/paneldue_extui.cpp b/Marlin/src/lcd/extui/paneldue/paneldue_extui.cpp
new file mode 100644
index 0000000000000..083267a031315
--- /dev/null
+++ b/Marlin/src/lcd/extui/paneldue/paneldue_extui.cpp
@@ -0,0 +1,199 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2024 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/>.
+ *
+ */
+
+/**
+ * lcd/extui/paneldue/paneldue_extui.cpp
+ */
+
+#include "../../../inc/MarlinConfigPre.h"
+
+#if ENABLED(PANELDUE)
+
+#include "../ui_api.h"
+
+namespace ExtUI {
+  void onStartup() {
+    /* Initialize the display module here. The following
+     * routines are available for access to the GPIO pins:
+     *
+     *   SET_OUTPUT(pin)
+     *   SET_INPUT_PULLUP(pin)
+     *   SET_INPUT(pin)
+     *   WRITE(pin,value)
+     *   READ(pin)
+     */
+  }
+  void onIdle() {}
+  void onPrinterKilled(FSTR_P const error, FSTR_P const component) {}
+
+  void onMediaMounted() {}
+  void onMediaError()   {}
+  void onMediaRemoved() {}
+
+  void onHeatingError(const heater_id_t heater_id) {}
+  void onMinTempError(const heater_id_t heater_id) {}
+  void onMaxTempError(const heater_id_t heater_id) {}
+
+  void onPlayTone(const uint16_t frequency, const uint16_t duration/*=0*/) {}
+  void onPrintTimerStarted() {}
+  void onPrintTimerPaused() {}
+  void onPrintTimerStopped() {}
+
+  #if HAS_FILAMENT_SENSOR
+    void onFilamentRunout(const extruder_t extruder) {}
+  #endif
+
+  void onUserConfirmRequired(const char * const msg) {}
+
+  // For fancy LCDs include an icon ID, message, and translated button title
+  void onUserConfirmRequired(const int icon, const char * const cstr, FSTR_P const fBtn) {}
+  void onUserConfirmRequired(const int icon, FSTR_P const fstr, FSTR_P const fBtn) {}
+
+  void onStatusChanged(const char * const) {}
+
+  #if ENABLED(ADVANCED_PAUSE_FEATURE)
+    void onPauseMode(
+      const PauseMessage message,
+      const PauseMode mode/*=PAUSE_MODE_SAME*/,
+      const uint8_t extruder/*=active_extruder*/
+    ) {
+      stdOnPauseMode(message, mode, extruder);
+    }
+  #endif
+
+  void onHomingStart() {}
+  void onHomingDone() {}
+
+  void onPrintDone() {}
+
+  void onFactoryReset() {}
+
+  void onStoreSettings(char *buff) {
+    // Called when saving to EEPROM (i.e. M500). If the ExtUI needs
+    // permanent data to be stored, it can write up to eeprom_data_size bytes
+    // into buff.
+
+    // Example:
+    //  static_assert(sizeof(myDataStruct) <= eeprom_data_size);
+    //  memcpy(buff, &myDataStruct, sizeof(myDataStruct));
+  }
+
+  void onLoadSettings(const char *buff) {
+    // Called while loading settings from EEPROM. If the ExtUI
+    // needs to retrieve data, it should copy up to eeprom_data_size bytes
+    // from buff
+
+    // Example:
+    //  static_assert(sizeof(myDataStruct) <= eeprom_data_size);
+    //  memcpy(&myDataStruct, buff, sizeof(myDataStruct));
+  }
+
+  void onPostprocessSettings() {
+    // Called after loading or resetting stored settings
+  }
+
+  void onSettingsStored(const bool success) {
+    // Called after the entire EEPROM has been written,
+    // whether successful or not.
+  }
+
+  void onSettingsLoaded(const bool success) {
+    // Called after the entire EEPROM has been read,
+    // whether successful or not.
+  }
+
+  #if HAS_LEVELING
+    void onLevelingStart() {}
+    void onLevelingDone() {}
+    #if ENABLED(PREHEAT_BEFORE_LEVELING)
+      celsius_t getLevelingBedTemp() { return LEVELING_BED_TEMP; }
+    #endif
+  #endif
+
+  #if HAS_MESH
+    void onMeshUpdate(const int8_t xpos, const int8_t ypos, const_float_t zval) {
+      // Called when any mesh points are updated
+    }
+
+    void onMeshUpdate(const int8_t xpos, const int8_t ypos, const probe_state_t state) {
+      // Called to indicate a special condition
+    }
+  #endif
+
+  #if ENABLED(PREVENT_COLD_EXTRUSION)
+    void onSetMinExtrusionTemp(const celsius_t) {}
+  #endif
+
+  #if ENABLED(POWER_LOSS_RECOVERY)
+    void onSetPowerLoss(const bool onoff) {
+      // Called when power-loss is enabled/disabled
+    }
+    void onPowerLoss() {
+      // Called when power-loss state is detected
+    }
+    void onPowerLossResume() {
+      // Called on resume from power-loss
+    }
+  #endif
+
+  #if HAS_PID_HEATING
+    void onPIDTuning(const pidresult_t rst) {
+      // Called for temperature PID tuning result
+      switch (rst) {
+        case PID_STARTED:
+        case PID_BED_STARTED:
+        case PID_CHAMBER_STARTED: break;
+        case PID_BAD_HEATER_ID:   break;
+        case PID_TEMP_TOO_HIGH:   break;
+        case PID_TUNING_TIMEOUT:  break;
+        case PID_DONE:            break;
+      }
+    }
+    void onStartM303(const int count, const heater_id_t hid, const celsius_t temp) {
+      // Called by M303 to update the UI
+    }
+  #endif
+
+  #if ENABLED(MPC_AUTOTUNE)
+    void onMPCTuning(const mpcresult_t rst) {
+      // Called for temperature MPC tuning result
+      switch (rst) {
+        case MPC_STARTED:     break;
+        case MPC_TEMP_ERROR:  break;
+        case MPC_INTERRUPTED: break;
+        case MPC_DONE:        break;
+      }
+    }
+  #endif
+
+  #if ENABLED(PLATFORM_M997_SUPPORT)
+    void onFirmwareFlash() {}
+  #endif
+
+  void onSteppersDisabled() {}
+  void onSteppersEnabled() {}
+  void onAxisDisabled(const axis_t) {}
+  void onAxisEnabled(const axis_t) {}
+
+} // ExtUI
+
+#endif // PANELDUE
diff --git a/Marlin/src/sd/cardreader.cpp b/Marlin/src/sd/cardreader.cpp
index 56daa369fca67..ddc47919690b7 100644
--- a/Marlin/src/sd/cardreader.cpp
+++ b/Marlin/src/sd/cardreader.cpp
@@ -176,7 +176,7 @@ CardReader::CardReader() {
   IF_DISABLED(NO_SD_AUTOSTART, autofile_cancel());
 
   workDirDepth = 0;
-  ZERO(workDirParents);
+  //LOOP_L_N(i, MAX_DIR_DEPTH) workDirParents[i] = SdFile();
 
   #if ALL(HAS_MEDIA, HAS_SD_DETECT)
     SET_INPUT_PULLUP(SD_DETECT_PIN);
@@ -364,6 +364,54 @@ void CardReader::ls(const uint8_t lsflags/*=0*/) {
   }
 }
 
+#if ENABLED(PANELDUE)
+
+  //
+  // Recursive method to list files in JSON format
+  // The PanelDue will call this with no depth to get
+  // just the contents of the current folder. However,
+  // it's possible to set up code that will get the
+  // full card listing in a format much more compact
+  // than the current M20 output for many folders.
+  //
+  void CardReader::printListingJSON(const uint8_t depth, SdFile parent) {
+    dir_t p;
+    while (parent.readDir(&p, longFilename) > 0) {
+      if (depth && DIR_IS_SUBDIR(&p)) {
+        // Get the short name for the item, which we know is a folder
+        char dosFilename[FILENAME_LENGTH];
+        createFilename(dosFilename, p);
+
+        // Put this folder on the stack and recurse into it.
+        SdFile child; // child.close() in destructor
+        if (!child.open(&parent, dosFilename, O_READ)) return;
+
+        // Make the folder an object with an array inside
+        SERIAL_ECHOPGM("{\"", dosFilename, "\":[");
+        printListingJSON(depth - 1, child);
+        SERIAL_ECHOPGM("]},");
+      }
+      else if (is_visible_entity(p)) {
+        SERIAL_CHAR('"');
+        if (flag.filenameIsDir) SERIAL_CHAR('*');
+        SERIAL_ECHO(createFilename(filename, p));
+        SERIAL_ECHOPGM("\",");
+      }
+    }
+  }
+
+  //
+  // List all files on the SD card
+  //
+  void CardReader::lsJSON(const uint8_t depth, SdFile parent) {
+    SERIAL_ECHOPGM("\"files\":[");
+    parent.rewind();
+    printListingJSON(depth, parent);
+    SERIAL_ECHOPGM("]");
+  }
+
+#endif // PANELDUE
+
 #if ENABLED(LONG_FILENAME_HOST_SUPPORT)
 
   //
diff --git a/Marlin/src/sd/cardreader.h b/Marlin/src/sd/cardreader.h
index 1d2ba3ae6f1a0..6c34a875c2a5a 100644
--- a/Marlin/src/sd/cardreader.h
+++ b/Marlin/src/sd/cardreader.h
@@ -220,6 +220,10 @@ class CardReader {
 
   static void ls(const uint8_t lsflags=0);
 
+  #if ENABLED(PANELDUE)
+    static void lsJSON(const uint8_t depth, SdFile parent);
+  #endif
+
   #if ENABLED(POWER_LOSS_RECOVERY)
     static bool jobRecoverFileExists();
     static void openJobRecoveryFile(const bool read);
@@ -246,6 +250,8 @@ class CardReader {
   static int16_t write(void *buf, uint16_t nbyte) { return file.isOpen() ? file.write(buf, nbyte) : -1; }
   static void setIndex(const uint32_t index)      { file.seekSet((sdpos = index)); }
 
+  //static inline int16_t get()                            { sdpos = file.curPosition(); return (int16_t)file.read(); }
+
   // TODO: rename to diskIODriver()
   static DiskIODriver* diskIODriver() { return driver; }
 
@@ -357,6 +363,9 @@ class CardReader {
     MediaFile parent, const char * const prepend, const uint8_t lsflags
     OPTARG(LONG_FILENAME_HOST_SUPPORT, const char * const prependLong=nullptr)
   );
+  #if ENABLED(PANELDUE)
+    static void printListingJSON(const uint8_t depth, SdFile parent);
+  #endif
 
   #if ENABLED(SDCARD_SORT_ALPHA)
     static void flush_presort();
diff --git a/buildroot/tests/mega2560 b/buildroot/tests/mega2560
index d61f17b51c6dd..3a6dffb611e30 100755
--- a/buildroot/tests/mega2560
+++ b/buildroot/tests/mega2560
@@ -86,6 +86,25 @@ opt_enable REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
 opt_disable X_DRIVER_TYPE Y_DRIVER_TYPE Z_DRIVER_TYPE
 exec_test $1 $2 "E Axis Only | DOGM MarlinUI" "$3"
 
+#
+# Test MegaController with PANELDUE and many features
+#
+restore_configs
+opt_set MOTHERBOARD BOARD_MEGACONTROLLER LCD_LANGUAGE de CONTROLLERFAN_SPEED_IDLE 128 I2C_SLAVE_ADDRESS 63 \
+        PWM_MOTOR_CURRENT "{ 1300, 1300, 1250 }"
+opt_enable EEPROM_SETTINGS EEPROM_CHITCHAT \
+           PANELDUE SDSUPPORT PCA9632 SOUND_MENU_ITEM \
+           AUTO_BED_LEVELING_BILINEAR PROBE_MANUALLY G26_MESH_VALIDATION MESH_EDIT_MENU \
+           LIN_ADVANCE ADVANCE_K_EXTRA \
+           INCH_MODE_SUPPORT TEMPERATURE_UNITS_SUPPORT EXPERIMENTAL_I2CBUS M100_FREE_MEMORY_WATCHER \
+           NOZZLE_PARK_FEATURE NOZZLE_CLEAN_FEATURE \
+           ADVANCED_PAUSE_FEATURE PARK_HEAD_ON_PAUSE ADVANCED_PAUSE_CONTINUOUS_PURGE FILAMENT_LOAD_UNLOAD_GCODES \
+           PRINTCOUNTER SERVICE_NAME_1 SERVICE_INTERVAL_1 M114_DETAIL \
+           FAN_SOFT_PWM USE_CONTROLLER_FAN CONTROLLER_FAN_EDITABLE
+opt_add M100_FREE_MEMORY_DUMPER
+opt_add M100_FREE_MEMORY_CORRUPTOR
+exec_test $1 $2 "MEGACONTROLLER | PanelDUE | M100 | PWM_MOTOR_CURRENT | PRINTCOUNTER | Advanced Pause ..." "$3"
+
 #
 # Mixing Extruder with 5 steppers, Russian
 #
diff --git a/ini/features.ini b/ini/features.ini
index a502808f095e4..aa6533e554f25 100644
--- a/ini/features.ini
+++ b/ini/features.ini
@@ -208,6 +208,7 @@ EXTUI_EXAMPLE                          = build_src_filter=+<src/lcd/extui/exampl
 TOUCH_UI_FTDI_EVE                      = build_src_filter=+<src/lcd/extui/ftdi_eve_touch_ui>
 MALYAN_LCD                             = build_src_filter=+<src/lcd/extui/malyan>
 NEXTION_TFT                            = build_src_filter=+<src/lcd/extui/nextion>
+PANELDUE                               = build_src_filter=+<src/lcd/extui/paneldue> +<src/gcode/lcd/M408.cpp>
 USE_UHS2_USB                           = build_src_filter=+<src/sd/usb_flashdrive/lib-uhs2>
 USE_UHS3_USB                           = build_src_filter=+<src/sd/usb_flashdrive/lib-uhs3>
 USB_FLASH_DRIVE_SUPPORT                = build_src_filter=+<src/sd/usb_flashdrive/Sd2Card_FlashDrive.cpp>