Implement heatbed cooldown routine

- M888: Cooldown routine for the Anycubic Ultrabase (EXPERIMENTAL):
This is meant to be placed at the end Gcode of your slicer. It hovers over the print bed and does circular movements while running the fan. Works best with custom fan ducts.
- T<int>: Target bed temperature (min 15°C), 30°C if not specified
- S<int>: Fan speed between 0 and 255, full speed if not specified

Thanks to @kulfuerst for the suggestion!

Marlin/AnycubicTFT.h

@@ -58,6 +58,7 @@ public:
   char TFTstate=ANYCUBIC_TFT_STATE_IDLE;
   bool PausedByRunout=false;
   bool PausedByFilamentChange=false;
+  bool PausedByNozzleTimeout=false;
 
 private:
   char TFTcmdbuffer[TFTBUFSIZE][TFT_MAX_CMD_SIZE];
@@ -74,6 +75,7 @@ private:
   uint8_t tmp_extruder=0;
   char LastSDstatus=0;
   uint16_t HeaterCheckCount=0;
+  bool IsParked = false;
 
   struct OutageDataStruct {
     char OutageDataVersion;
@@ -100,6 +102,8 @@ private:
   void HandleSpecialMenu();
   void FilamentChangePause();
   void FilamentChangeResume();
+  void ReheatNozzle();
+  void ParkAfterStop();
 
   char     SelectedDirectory[30];
   uint8_t  SpecialMenu=false;
@@ -107,7 +111,8 @@ private:
 #if ENABLED(ANYCUBIC_FILAMENT_RUNOUT_SENSOR)
   char FilamentTestStatus=false;
   char FilamentTestLastStatus=false;
-  long FilamentRunoutCounter=0;
+  bool FilamentSetMillis=true;
+
 #endif
 };
 

Marlin/Configuration.h

@@ -81,10 +81,10 @@
 // User-specified version info of this build to display in [Pronterface, etc] terminal window during
 // startup. Implementation of an idea by Prof Braino to inform user that any changes made to this
 // build by the user have been successfully uploaded into firmware.
-#define STRING_CONFIG_H_AUTHOR "(davidramiro, for Anycubic i3 Mega)" // Who made the changes.
+#define STRING_CONFIG_H_AUTHOR "(davidramiro)" // Who made the changes.
 #define SHOW_BOOTSCREEN
-#define STRING_SPLASH_LINE1 SHORT_BUILD_VERSION // will be shown during bootup in line 1
-#define STRING_SPLASH_LINE2 WEBSITE_URL         // will be shown during bootup in line 2
+#define STRING_SPLASH_LINE1 SHORT_BUILD_VERSION   // will be shown during bootup in line 1
+#define STRING_SPLASH_LINE2 CUSTOM_BUILD_VERSION  // will be shown during bootup in line 2
 
 /**
  * *** VENDORS PLEASE READ ***

Marlin/Configuration_adv.h

@@ -1009,7 +1009,7 @@
   #define FILAMENT_UNLOAD_DELAY             5000  // (ms) Delay for the filament to cool after retract.
   #define FILAMENT_UNLOAD_PURGE_LENGTH         8  // (mm) An unretract is done, then this length is purged.
 
-  #define PAUSE_PARK_NOZZLE_TIMEOUT          300  // (seconds) Time limit before the nozzle is turned off for safety.
+  #define PAUSE_PARK_NOZZLE_TIMEOUT          600  // (seconds) Time limit before the nozzle is turned off for safety.
   #define FILAMENT_CHANGE_ALERT_BEEPS         10  // Number of alert beeps to play when a response is needed.
   #define PAUSE_PARK_NO_STEPPER_TIMEOUT           // Enable for XYZ steppers to stay powered on during filament change.
 

Marlin/Marlin.h

@@ -271,6 +271,9 @@ FORCE_INLINE bool all_axes_known() { return (axis_known_position & xyz_bits) ==
 
 extern volatile bool wait_for_heatup;
 
+// Making sure this flag can be cleared by the Anycubic display
+extern volatile bool nozzle_timed_out;
+
 #if HAS_RESUME_CONTINUE
   extern volatile bool wait_for_user;
 #endif

Marlin/Marlin_main.cpp

@@ -228,6 +228,7 @@
  * M867 - Enable/disable or toggle error correction for position encoder modules.
  * M868 - Report or set position encoder module error correction threshold.
  * M869 - Report position encoder module error.
+ * M888 - Ultrabase cooldown: Let the parts cooling fan hover above the finished print to cool down the bed. EXPERIMENTAL FEATURE!
  * M900 - Get or Set Linear Advance K-factor. (Requires LIN_ADVANCE)
  * M906 - Set or get motor current in milliamps using axis codes X, Y, Z, E. Report values if no axis codes given. (Requires at least one _DRIVER_TYPE defined as TMC2130/TMC2208/TMC2660)
  * M907 - Set digital trimpot motor current using axis codes. (Requires a board with digital trimpots)
@@ -519,6 +520,9 @@ static bool relative_mode; // = false;
 // For M109 and M190, this flag may be cleared (by M108) to exit the wait loop
 volatile bool wait_for_heatup = true;
 
+// Making sure this flag can be cleared by the Anycubic display
+volatile bool nozzle_timed_out = false;
+
 // For M0/M1, this flag may be cleared (by M108) to exit the wait-for-user loop
 #if HAS_RESUME_CONTINUE
   volatile bool wait_for_user; // = false;
@@ -7213,7 +7217,11 @@ inline void gcode_M17() {
    * Used by M125 and M600
    */
   static void wait_for_filament_reload(const int8_t max_beep_count=0) {
-    bool nozzle_timed_out = false;
+    nozzle_timed_out = false;
+    nozzle_timed_out = false;
+    #ifdef ANYCUBIC_TFT_MODEL
+      AnycubicTFT.PausedByNozzleTimeout = false;
+    #endif
 
     #if ENABLED(ULTIPANEL)
       lcd_advanced_pause_show_message(ADVANCED_PAUSE_MESSAGE_INSERT);
@@ -7246,6 +7254,14 @@ inline void gcode_M17() {
           nozzle_timed_out |= thermalManager.is_heater_idle(e);
 
       if (nozzle_timed_out) {
+
+        #ifdef ANYCUBIC_TFT_MODEL
+          AnycubicTFT.PausedByNozzleTimeout=true;
+          #ifdef ANYCUBIC_TFT_DEBUG
+            SERIAL_ECHOLNPGM("DEBUG: Nozzle timeout flag set");
+          #endif
+        #endif
+
         #if ENABLED(ULTIPANEL)
           lcd_advanced_pause_show_message(ADVANCED_PAUSE_MESSAGE_CLICK_TO_HEAT_NOZZLE);
         #endif
@@ -7287,6 +7303,9 @@ inline void gcode_M17() {
 
         wait_for_user = true; // Wait for user to load filament
         nozzle_timed_out = false;
+        #ifdef ANYCUBIC_TFT_DEBUG
+          AnycubicTFT.PausedByNozzleTimeout = false;
+        #endif
 
         #if HAS_BUZZER
           filament_change_beep(max_beep_count, true);
@@ -7320,7 +7339,11 @@ inline void gcode_M17() {
     if (!did_pause_print) return;
 
     // Re-enable the heaters if they timed out
-    bool nozzle_timed_out = false;
+    nozzle_timed_out = false;
+    #ifdef ANYCUBIC_TFT_MODEL
+      AnycubicTFT.PausedByNozzleTimeout = false;
+    #endif
+
     HOTEND_LOOP() {
       nozzle_timed_out |= thermalManager.is_heater_idle(e);
       thermalManager.reset_heater_idle_timer(e);
@@ -8508,7 +8531,7 @@ inline void gcode_M109() {
     #ifdef ANYCUBIC_TFT_MODEL
       AnycubicTFT.CommandScan();
     #endif
-    
+
     #if TEMP_RESIDENCY_TIME > 0
 
       const float temp_diff = ABS(target_temp - temp);
@@ -8547,11 +8570,11 @@ inline void gcode_M109() {
   #ifdef ANYCUBIC_TFT_MODEL
   AnycubicTFT.HeatingDone();
   #endif
-  
+
   #if DISABLED(BUSY_WHILE_HEATING)
     KEEPALIVE_STATE(IN_HANDLER);
   #endif
-  
+
   // flush the serial buffer after heating to prevent lockup by m105
   SERIAL_FLUSH();
 
@@ -8665,11 +8688,11 @@ inline void gcode_M109() {
           }
         }
       #endif
-      
+
       #ifdef ANYCUBIC_TFT_MODEL
       AnycubicTFT.CommandScan();
       #endif
-      
+
       #if TEMP_BED_RESIDENCY_TIME > 0
 
         const float temp_diff = ABS(target_temp - temp);
@@ -8697,16 +8720,16 @@ inline void gcode_M109() {
       }
 
     } while (wait_for_heatup && TEMP_BED_CONDITIONS);
-    
+
     #ifdef ANYCUBIC_TFT_MODEL
     AnycubicTFT.BedHeatingDone();
     #endif
-    
+
     if (wait_for_heatup) lcd_reset_status();
     #if DISABLED(BUSY_WHILE_HEATING)
       KEEPALIVE_STATE(IN_HANDLER);
     #endif
-    
+
      // flush the serial buffer after heating to prevent lockup by m105
      SERIAL_FLUSH();
   }
@@ -8904,7 +8927,7 @@ inline void gcode_M111() {
     #if ENABLED(ULTIPANEL)
       lcd_reset_status();
     #endif
-    
+
     #ifdef ANYCUBIC_TFT_MODEL
     AnycubicTFT.CommandScan();
     #endif
@@ -8940,7 +8963,7 @@ inline void gcode_M81() {
   #if ENABLED(ULTIPANEL)
     LCD_MESSAGEPGM(MACHINE_NAME " " MSG_OFF ".");
   #endif
-  
+
   #ifdef ANYCUBIC_TFT_MODEL
   AnycubicTFT.CommandScan();
   #endif
@@ -10992,12 +11015,23 @@ inline void gcode_M502() {
    *  Default values are used for omitted arguments.
    */
   inline void gcode_M600() {
+
     #ifdef SDSUPPORT
-        if ((AnycubicTFT.TFTstate==ANYCUBIC_TFT_STATE_SDPRINT)){
-        AnycubicTFT.TFTstate=ANYCUBIC_TFT_STATE_SDPAUSE_REQ;
-        AnycubicTFT.PausedByFilamentChange=true;
-        }
+      if (card.sdprinting) { // are we printing from sd?
+        #ifdef ANYCUBIC_TFT_DEBUG
+            SERIAL_ECHOLNPGM("DEBUG: Enter M600 TFTstate routine");
+        #endif
+        AnycubicTFT.TFTstate=ANYCUBIC_TFT_STATE_SDPAUSE_REQ; // enter correct display state to show resume button
+        #ifdef ANYCUBIC_TFT_DEBUG
+            SERIAL_ECHOLNPGM("DEBUG: Set TFTstate to SDPAUSE_REQ");
+        #endif
+        AnycubicTFT.PausedByFilamentChange=true; // set flag to ensure correct resume routine gets executed
+        #ifdef ANYCUBIC_TFT_DEBUG
+            SERIAL_ECHOLNPGM("DEBUG: Set filament change flag");
+        #endif
+      }
     #endif
+
     point_t park_point = NOZZLE_PARK_POINT;
 
     if (get_target_extruder_from_command(600)) return;
@@ -11370,6 +11404,56 @@ inline void gcode_M502() {
   }
 #endif // MAX7219_GCODE
 
+  /**
+   * M888: Cooldown routine for the Anycubic Ultrabase (EXPERIMENTAL):
+   *       This is meant to be placed at the end Gcode of your slicer.
+   *       It hovers over the print bed and does circular movements while
+   *       running the fan. Works best with custom fan ducts.
+   *
+   *  T<int>   Target bed temperature (min 15°C), 30°C if not specified
+   *  S<int>   Fan speed between 0 and 255, full speed if not specified
+   */
+  inline void gcode_M888() {
+    // don't do this if the machine is not homed
+    if (axis_unhomed_error()) return;
+
+    const float cooldown_arc[2] = { 50, 50 };
+    const uint8_t cooldown_target = MAX((parser.ushortval('T', 30)), 15);
+
+    // set hotbed temperate to zero
+    thermalManager.setTargetBed(0);
+    SERIAL_PROTOCOLLNPGM("Ultrabase cooldown started");
+
+    // set fan to speed <S>, if undefined blast at full speed
+    uint8_t cooldown_fanspeed = parser.ushortval('S', 255);
+    fanSpeeds[0] = MIN(cooldown_fanspeed, 255U);
+
+    // raise z by 2mm and move to X50, Y50
+    do_blocking_move_to_z(MIN(current_position[Z_AXIS] + 2, Z_MAX_POS), 5);
+    do_blocking_move_to_xy(50, 50, 100);
+
+    while ((thermalManager.degBed() > cooldown_target)) {
+      // queue arc movement
+      gcode_get_destination();
+      plan_arc(destination, cooldown_arc, true);
+      SERIAL_PROTOCOLLNPGM("Target not reached, queued an arc");
+
+      // delay while arc is in progress
+      while (planner.movesplanned()) {
+        idle();
+      }
+    idle();
+    }
+    // the bed should be under <T> now
+    fanSpeeds[0]=0;
+    do_blocking_move_to_xy(MAX(X_MIN_POS, 10), MIN(Y_MAX_POS, 190), 100);
+    BUZZ(100, 659);
+    BUZZ(150, 1318);
+    enqueue_and_echo_commands_P(PSTR("M84"));
+    SERIAL_PROTOCOLLNPGM("M888 cooldown routine done");
+  }
+
+
 #if ENABLED(LIN_ADVANCE)
   /**
    * M900: Get or Set Linear Advance K-factor
@@ -13105,6 +13189,8 @@ void process_parsed_command() {
         case 869: gcode_M869(); break;                            // M869: Report axis error
       #endif
 
+      case 888: gcode_M888(); break;                              // M888: Ultrabase cooldown (EXPERIMENTAL)
+
       #if ENABLED(LIN_ADVANCE)
         case 900: gcode_M900(); break;                            // M900: Set Linear Advance K factor
       #endif
@@ -14746,7 +14832,7 @@ void manage_inactivity(const bool ignore_stepper_queue/*=false*/) {
   #if ENABLED(FILAMENT_RUNOUT_SENSOR)
     runout.run();
   #endif
-  
+
   #if ENABLED(ANYCUBIC_TFT_MODEL) && ENABLED(ANYCUBIC_FILAMENT_RUNOUT_SENSOR)
   AnycubicTFT.FilamentRunout();
   #endif
@@ -14954,7 +15040,7 @@ void idle(
 #ifdef ANYCUBIC_TFT_MODEL
   AnycubicTFT.CommandScan();
 #endif
-  
+
   lcd_update();
 
   host_keepalive();
@@ -15011,7 +15097,7 @@ void kill(const char* lcd_msg) {
   #else
     UNUSED(lcd_msg);
   #endif
-  
+
   #ifdef ANYCUBIC_TFT_MODEL
     // Kill AnycubicTFT
     AnycubicTFT.KillTFT();
@@ -15106,7 +15192,7 @@ void setup() {
   MYSERIAL0.begin(BAUDRATE);
   SERIAL_PROTOCOLLNPGM("start");
   SERIAL_ECHO_START();
-  
+
   #ifdef ANYCUBIC_TFT_MODEL
     // Setup AnycubicTFT
     AnycubicTFT.Setup();
@@ -15132,6 +15218,9 @@ void setup() {
   SERIAL_ECHOPGM(MSG_MARLIN);
   SERIAL_CHAR(' ');
   SERIAL_ECHOLNPGM(SHORT_BUILD_VERSION);
+  SERIAL_ECHOPGM(MSG_MARLIN_AI3M);
+  SERIAL_CHAR(' ');
+  SERIAL_ECHOLNPGM(CUSTOM_BUILD_VERSION);
   SERIAL_EOL();
 
   #if defined(STRING_DISTRIBUTION_DATE) && defined(STRING_CONFIG_H_AUTHOR)

Marlin/Version.h

@@ -37,6 +37,12 @@
    */
   #define SHORT_BUILD_VERSION "1.1.9"
 
+  /**
+   * Defines the version of the Marlin-AI3M build. Not to be confused with
+   * Marlin's own build number, e.g. 1.1.9.
+   */
+  #define CUSTOM_BUILD_VERSION "v1.4.4"
+
   /**
    * Verbose version identifier which should contain a reference to the location
    * from where the binary was downloaded or the source code was compiled.
@@ -48,7 +54,7 @@
    * here we define this default string as the date where the latest release
    * version was tagged.
    */
-  #define STRING_DISTRIBUTION_DATE "2019-02-18"
+  #define STRING_DISTRIBUTION_DATE "2019-03-13"
 
   /**
    * Required minimum Configuration.h and Configuration_adv.h file versions.
@@ -78,7 +84,7 @@
    * has a distinct Github fork— the Source Code URL should just be the main
    * Marlin repository.
    */
-  #define SOURCE_CODE_URL "https://github.com/MarlinFirmware/Marlin"
+  #define SOURCE_CODE_URL "https://github.com/davidramiro/Marlin-AI3M"
 
   /**
    * Default generic printer UUID.

Marlin/language.h

@@ -137,7 +137,8 @@
 #define MSG_INVALID_EXTRUDER                "Invalid extruder"
 #define MSG_INVALID_SOLENOID                "Invalid solenoid"
 #define MSG_ERR_NO_THERMISTORS              "No thermistors - no temperature"
-#define MSG_M115_REPORT                     "FIRMWARE_NAME:Marlin " DETAILED_BUILD_VERSION " SOURCE_CODE_URL:" SOURCE_CODE_URL " PROTOCOL_VERSION:" PROTOCOL_VERSION " MACHINE_TYPE:" MACHINE_NAME " EXTRUDER_COUNT:" STRINGIFY(EXTRUDERS) " UUID:" MACHINE_UUID
+#define MSG_M115_REPORT                     "FIRMWARE_NAME:Marlin " DETAILED_BUILD_VERSION " MARLIN-AI3M_VERSION:" CUSTOM_BUILD_VERSION " SOURCE_CODE_URL:" SOURCE_CODE_URL " PROTOCOL_VERSION:" PROTOCOL_VERSION " MACHINE_TYPE:" MACHINE_NAME " EXTRUDER_COUNT:" STRINGIFY(EXTRUDERS) " UUID:" MACHINE_UUID
+#define MSG_MARLIN_AI3M                     "Marlin-AI3M"
 #define MSG_COUNT_X                         " Count X:"
 #define MSG_COUNT_A                         " Count A:"
 #define MSG_ERR_KILLED                      "Printer halted. kill() called!"

README.md

@@ -6,29 +6,17 @@ This is my slightly customized version of the [Marlin Firmware](https://github.c
 
 Feel free to discuss issues and work with me further optimizing this firmware!
 
-I am running this version on an i3 Mega Ultrabase V3 (for distinction of the different versions, check [this Thingiverse thread](https://www.thingiverse.com/groups/anycubic-i3-mega/forums/general/topic:27064)).
-Basically, this should work on every Ultrabase version that has two Z-axis endstops.
+This firmware works on every i3 Mega that has two Z-axis endstops. If you have an older model with only one Z endstop, a small [adjustment](https://github.com/davidramiro/Marlin-AI3M/wiki/Customization-&-Compiling#single-z-endstop) is required.
 
-The new Mega-S should work too, but you will need to enter those two commands to make the new extruder work:
-```
-M92 E384
-M500
-```
-Afterwards, calibration is highly recommended as per the instructions on the [Wiki](https://github.com/davidramiro/Marlin-AI3M/wiki/Extruder-Calibration/).
+The new **Mega-S** should work too, but you will need to enter two additional commands after flashing the firmware, mentioned in the instructions below.
+
+Looking for a **BLtouch firmware**? Head [this way](https://github.com/MNieddu91/Marlin-AI3M-BLTouch)! Mounting and configuration instructions are included.
 
 Note: This is just a firmware, not magic. A big part of print quality still depends on your slicer settings and mechanical condition of your machine.
 
 #### Make sure to take a look at the [Wiki](https://github.com/davidramiro/Marlin-AI3M/wiki/), especially the [FAQ](https://github.com/davidramiro/Marlin-AI3M/wiki/Frequently-Asked-Questions).
 
-
-## Known issues:
-
-- **Cura users: Please turn off jerk and acceleration control in your print settings (not visible by default, select advanced visibility to unlock them). Cura's high default jerk and acceleration might cause shifted layers if you use TMC2208.**
-- Estimated print times from your slicer might be slightly off.
-- Special characters on any file or folders name on the SD card will cause the file menu to freeze. Simply replace or remove every special character (Chinese, Arabic, Russian, accents, German & Scandinavian umlauts, ...) from the name. Symbols like dashes or underscores are no problem.
-**Important note: On the SD card that comes with the printer there is a folder with Chinese characters in it by default. Please rename or remove it.**
-- Cancelling prints via display is buggy sometimes, simply reboot the printer when the menu shows an error. Protip: Switch to OctoPrint.
-
+A German translation of the instructions can be found [here](https://kore.cc/i3mega/download/marlin-ai3m_german.pdf).
 
 ## Why use this?
 
@@ -40,9 +28,23 @@ While the i3 Mega is a great printer for its price and produces fantastic result
 - Even better print quality by adding Linear Advance, S-Curve Acceleration and some tweaks on jerk and acceleration.
 - Thermal runaway protection: Reducing fire risk by detecting a faulty or misaligned thermistor.
 - Very loud stock stepper motor drivers, easily replaced by Watterott or FYSETC TMC2208. To do that, you'd usually have to flip the connectors on the board, this is not necessary using this firmware.
-- No need to slice and upload custom bed leveling tests, simply start one with a simple G26 command.
+- No need to slice and upload custom bed leveling tests, test it with a single GCode command
 - Easily start an auto PID tune or mesh bed leveling via the special menu (insert SD card, select special menu and press the round arrow)
-- Filament change feature enabled: Switch colors/material mid print with `M600` (instructions below)
+- Filament change feature enabled: Switch colors/material mid print (instructions below) and control it via display.
+- The filament runout, pause and stop functionality have been overhauled and improved: The hotend now parks and retracts (on pause or stop) and purges automatically (on resume).
+- Added `M888` cooldown routine for the Anycubic Ultrabase (EXPERIMENTAL): This is meant to be placed at the end Gcode of your slicer. It hovers over the print bed and does circular movements while running the fan. Works best with custom fan ducts.
+  - Optional parameters:
+  - `T<temperature>`:   Target bed temperature (min 15°C), 30°C if not specified (do not set this under room temperature)
+  - `S<fan speed>`:   Fan speed between 0 and 255, full speed if not specified
+  - e.g. `M888 S191 T25`: run the fan at 75% until the bed has cooled down to 25°C
+
+
+## Known issues:
+
+- Power outage support is not included
+- Estimated print times from your slicer might be slightly off.
+- Special characters on any file or folders name on the SD card will cause the file menu to freeze. Simply replace or remove every special character (Chinese, Arabic, Russian, accents, German & Scandinavian umlauts, ...) from the name. Symbols like dashes or underscores are no problem.
+**Important note: On the SD card that comes with the printer there is a folder with Chinese characters in it by default. Please rename or remove it.**
 
 ## How to flash this?
 
@@ -52,15 +54,16 @@ I provided three different precompiled hex files: One for no modifications on th
 
 - Download the precompiled firmware here: [Releases](https://github.com/davidramiro/Marlin-AI3M/releases)
 - Choose the correct hex file:
-- For TMC2208 with connectors in original orientation, use `Marlin-AI3M-XXXXXX-TMC2208.hex`
-- If you use TMC2208 and already reversed your connectors, use `Marlin-AI3M-XXXXXX-TMC2208_reversed.hex`
-- If you use a newer version of the TMC2208 that doesn't require the connector to be reversed (TMC2208 "v2.0" written on the PCB, chip on the top side), please also use `Marlin-AI3M-XXXXXX-TMC2208_reversed.hex`.
-- If you use the original stepper motor drivers, use `Marlin-AI3M-XXXXXX-stock_drivers.hex`.
+- For TMC2208 with connectors in original orientation, use `Marlin-AI3M-vx.x.x-TMC2208.hex`
+- If you use TMC2208 and already reversed your connectors, use `Marlin-AI3M-vx.x.x-TMC2208_reversed.hex`
+- If you use a newer version of the TMC2208 that doesn't require the connector to be reversed (TMC2208 "v2.0" written on the PCB, chip on the top side), please also use `Marlin-AI3M-vx.x.x-TMC2208_reversed.hex`.
+- If you use the original stepper motor drivers, use `Marlin-AI3M-vx.x.x-stock_drivers.hex`.
 
 ### Or compile it yourself:
 
-- Download Arduino IDE
+- Download and install [Arduino IDE](https://www.arduino.cc/en/main/software)
 - Clone or download this repo
+- Browse into the Marlin folder and run `Marlin.ino`
 - In the IDE, under `Tools -> Board` select `Genuino Mega 2560` and `ATmega2560`
 - Open Marlin.ino in the Marlin directory of this repo
 - [Customize if needed](https://github.com/davidramiro/Marlin-AI3M/wiki/Customization-&-Compiling) (e.g. motor directions and type at line `559` to `566` and line `857` to `865` in `Configuration.h`)
@@ -71,12 +74,16 @@ I provided three different precompiled hex files: One for no modifications on th
 
 - Flash the hex with Cura, OctoPrint or similar
 - Use a tool with a terminal (OctoPrint, Pronterface, Repetier Host, ...) to send commands to your printer.
-- Connect to the printer and send the following commands:
+- **Important** Connect to the printer and send the following commands:
 - `M502` - load hard coded default values
 - `M500` - save them to EEPROM
 
-#### Calibration and other instructions have been moved to the [Wiki](https://github.com/davidramiro/Marlin-AI3M/wiki/Calibration).
+**If you are using this on a Mega-S, those two additional commands are necessary:**
+- `M92 E384` - set correct steps for the new extruder
+- `M500` - save them
+- I highly recommend calibrating the extruder.
 
+#### Calibration and other instructions have been moved to the [Wiki](https://github.com/davidramiro/Marlin-AI3M/wiki/Calibration).
 
 ## Manual Mesh Bed Leveling
 
@@ -100,7 +107,7 @@ If you have issues with an uneven bed, this is a great feature.
 - Your nozzle will now move to the first calibration position.
 - Don't adjust the bed itself with screws, only use software from here on!
 - Use a paper - I recommend using thermopaper like a receipt or baking paper
-- Use the onscreen controls to lower or raise your nozzle until you feel a light resistance: (If you want to send the same command multiple times, select the item again, even though it is still marked red.)
+- Use the onscreen controls to lower or raise your nozzle until you feel a light resistance: (**If you want to send the same command multiple times, select the item again, even though it is still marked red.**)
 
 ![Z axis controls][control]
 
@@ -109,7 +116,7 @@ If you have issues with an uneven bed, this is a great feature.
 ![Next mesh point][next]
 
 - Repeat the last two steps until all 25 points are done.
-- Your printer will beep, wait 20 seconds and then save:
+- Your printer will beep, wait 20 seconds and then save (the printer will beep once more to confirm):
 
 
 ![Save to EEPROM][save]
@@ -126,15 +133,14 @@ If you have issues with an uneven bed, this is a great feature.
 
 ### After leveling:
 
-- Reboot the printer.
 - To ensure your mesh gets used on every print from now on, go into your slicer settings and look for the start GCode
 - Look for the Z-homing (either just `G28` or `G28 Z0`) command and insert these two right underneath it:
 ```
 M501
 M420 S1
 ```
-- Enjoy never having to worry about an uneven bed again!
-
+- Your printer should now correctly print first layers even on a warped bed.
+- When working on the printer, installing a new hotend or nozzle or the bed warping over time, a new Mesh Leveling procedure is recommended.
 
 #### Manual commands for use with OctoPrint etc.:
 
@@ -153,6 +159,7 @@ G28
 G26 C H200 P25 R25
 ```
 - To adjust your filament's needed temperature, change the number of the `H` parameter
+- Default bed temperature is 60°C, if you need another temperature, add e.g. `B80`
 - If your leveling is good, you will have a complete pattern of your mesh on your bed that you can peel off in one piece
 - Don't worry if the test looks a bit messy, the important thing is just that the line width is the same all over the mesh
 - Optional: Hang it up on a wall to display it as a trophy of how great your leveling skills are.
@@ -164,11 +171,12 @@ G26 C H200 P25 R25
 
 [m600 demo]: https://kore.cc/i3mega/img/m600demo.jpg "M600 demo"
 
-**Printing via USB is highly recommended for this.**
+**BETA: This now also works without USB printing, via SD & display.**
 
-#### Configuration:
+#### Configuration (only needed once):
 - Send `M603 L0 U0` to use manual loading & unloading.
 - Send `M603 L538 U555` to use automatic loading & unloading
+  - The `L` and `U` paramters define the load and unload length in mm. The values above work well on a stock setup, if you modded your extruder, bowden tube or hotend, you might need to adjust those.
 - Save with `M500`
 
 #### Filament change process (manual loading):
@@ -178,6 +186,9 @@ G26 C H200 P25 R25
   - Place `M600` in your GCode at the desired layer or send it via terminal
   - Alternatively: Use `FilamentChange Pause` in the Special Menu
 - The nozzle will park and your printer will beep
+  - For safety reasons, the printer will turn off the hotend after 10 minutes. If you see the temperature being under the target:
+    - SD printing: Click `CONTINUE` **(only once!)** on the screen and wait for the hotend to heat up again.
+    - USB printing: Send `M108` and wait for the hotend to heat up again.
 - Remove the filament from the bowden tube
 - Insert the new filament right up to the nozzle, just until a bit of plastic oozes out
 - Remove the excess filament from the nozzle with tweezers
@@ -195,6 +206,9 @@ G26 C H200 P25 R25
   - Alternatively: Use `FilamentChange Pause` in the Special Menu
 - The nozzle will park
 - The printer will remove the filament right up to the extruder and beep when finished
+  - For safety reasons, the printer will turn off the hotend after 10 minutes. If you see the temperature being under the target:
+    - SD printing: Click `CONTINUE` **(only once!)** on the screen and wait for the hotend to heat up again.
+    - USB printing: Send `M108` and wait for the hotend to heat up again.
 - Insert the new filament just up to the end of the bowden fitting, as shown here:
 
 ![Load Filament][m600 load]
@@ -225,10 +239,15 @@ M304
 
 After flashing the new version, issue a `M502` and `M500`. After that, enter every line you saved before and finish by saving with `M500`.
 
+## Something went wrong?
+No worries. You can easily go back to the default firmware and restore the default settings.
+- Flash the hex file from the [manufacturer's website](http://www.anycubic3d.com/support/show/594016.html) (in case it's offline, I have uploaded the stock firmwares [here](https://kore.cc/i3mega/download/stockFW/) as well).
+- After flashing, send `M502` and `M500`. Now your machine is exactly as it came out of the box.
+
 
 ## Detailed changes:
 
-- Thermal runaway protection enabled and tweaked
+- Thermal runaway protection thresholds tweaked
 - Manual mesh bed leveling enabled ([check this link](https://github.com/MarlinFirmware/Marlin/wiki/Manual-Mesh-Bed-Leveling) to learn more about it)
 - Heatbed PID mode enabled
 - TMC2208 configured in standalone mode
@@ -238,8 +257,15 @@ After flashing the new version, issue a `M502` and `M500`. After that, enter eve
 - G26 Mesh Validation enabled
 - Some redundant code removed to save memory
 - Minor tweaks on default jerk and acceleration
-- Printcounter enabled (`M78`)
+- Print statistics enabled (send `M78` to read them)
 - `M600` filament change feature enabled
+  - Implemented easy resume via display
+- Filament runout behaviour tweaked
+  - Added purge and retract
+  - Move nozzle to park position on runout
+  - Prevent false positives by adding a small delay to the sensor
+- Pause and stop behaviour tweaked
+- Added `M888` cooldown routine for the Anycubic Ultrabase
 
 
 ## Changes by [derhopp](https://github.com/derhopp/):
@@ -325,3 +351,26 @@ Notable contributors include:
 ## License
 
 Marlin is published under the [GPLv3 license](https://github.com/MarlinFirmware/Marlin/blob/1.0.x/COPYING.md) because we believe in open development. The GPL comes with both rights and obligations. Whether you use Marlin firmware as the driver for your open or closed-source product, you must keep Marlin open, and you must provide your compatible Marlin source code to end users upon request. The most straightforward way to comply with the Marlin license is to make a fork of Marlin on Github, perform your modifications, and direct users to your modified fork.
+
+## Disclaimer
+
+```
+/*
+* Flashing a custom firmware happens at your own risk.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
+* AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED
+* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+* THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+```