M600 in non-MMU mode now asks for confirmation before unloading

Firmware/Marlin.h

@@ -514,7 +514,7 @@ void proc_commands();
 
 void M600_load_filament();
 void M600_load_filament_movements();
-void M600_wait_for_user(float HotendTempBckp);
+bool M600_wait_for_user(float HotendTempBckp);
 void M600_check_state(float nozzle_temp);
 void load_filament_final_feed();
 void marlin_wait_for_click();

Firmware/Marlin_main.cpp

@@ -3037,8 +3037,9 @@ static void gcode_M600(bool automatic, float x_position, float y_position, float
     st_synchronize();
 
     //Beep, manage nozzle heater and wait for user to start unload filament
-    if(!mmu_enabled) M600_wait_for_user(HotendTempBckp);
-
+    if (mmu_enabled || M600_wait_for_user(HotendTempBckp))
+    {
+
     lcd_change_fil_state = 0;
 
     // Unload filament
@@ -3085,6 +3086,8 @@ static void gcode_M600(bool automatic, float x_position, float y_position, float
         M600_load_filament();
 
     if (!automatic) M600_check_state(HotendTempBckp);
+
+    } // if (mmu_enabled || M600_wait_for_user(HotendTempBckp))
 
 		lcd_update_enable(true);
 
@@ -10320,44 +10323,76 @@ void M600_check_state(float nozzle_temp)
 //! If times out, active extruder temperature is set to 0.
 //!
 //! @param HotendTempBckp Temperature to be restored for active extruder, after user resolves MMU problem.
-void M600_wait_for_user(float HotendTempBckp) {
+bool M600_wait_for_user(float HotendTempBckp) {
 
 		KEEPALIVE_STATE(PAUSED_FOR_USER);
 
-		int counterBeep = 0;
 		unsigned long waiting_start_time = _millis();
+		unsigned long beep_start_time = 0;
 		uint8_t wait_for_user_state = 0;
-		lcd_display_message_fullscreen_P(_T(MSG_PRESS_TO_UNLOAD));
+
+                // Ask the user if he actually wants to reload
+                // filament. They may have changed their mind; or they
+                // might want to use the M600 as a comfortable pause
+                // for whatever reason (works well with the layer
+                // change feature of PrusaSlicer).
+
+                // 0 = no (skip unload)
+                // 1 = yes (do unload)
+                // -1 = timeout (last selection was NO)
+                // -2 = timeout (last selection was YES)
+                int8_t yesno = -2;
+
 		bool bFirst=true;
 
-		while (!(wait_for_user_state == 0 && lcd_clicked())){
-			manage_heater();
-			manage_inactivity(true);
+                unsigned long mill;
 
+		while (wait_for_user_state != 0 || yesno < 0){
+
+                        manage_heater();
+                        manage_inactivity(true);
+
+                        mill = _millis();
+
 			#if BEEPER > 0
-			if (counterBeep == 500) {
-				counterBeep = 0;
-			}
 			SET_OUTPUT(BEEPER);
-			if (counterBeep == 0) {
-				if((eSoundMode==e_SOUND_MODE_BLIND)|| (eSoundMode==e_SOUND_MODE_LOUD)||((eSoundMode==e_SOUND_MODE_ONCE)&&bFirst))
-				{
-					bFirst=false;
-					WRITE(BEEPER, HIGH);
-				}
+                        if (beep_start_time == 0 &&
+                            wait_for_user_state != 2 &&
+                            ((eSoundMode==e_SOUND_MODE_BLIND) ||
+                             (eSoundMode==e_SOUND_MODE_LOUD) ||
+                             ((eSoundMode==e_SOUND_MODE_ONCE) && bFirst))) {
+                            // Start a beep
+                            bFirst=false;
+                            WRITE(BEEPER, HIGH);
+                            beep_start_time = mill;
 			}
-			if (counterBeep == 20) {
-				WRITE(BEEPER, LOW);
-			}
-
-			counterBeep++;
-			#endif //BEEPER > 0
+                        #endif //BEEPER > 0
 
+                        if (wait_for_user_state == 0) {
+                            // this takes 1000ms
+                            yesno = lcd_show_fullscreen_message_yes_no_and_wait_P(_i("Unload filament now?"), 1000, yesno);
+                            if (yesno >= 0) {
+                                break;
+                            }
+                        }
+
+                        #if BEEPER > 0
+                        if (mill - beep_start_time > 900) {
+                            // Turn off beeper after 0.9s, which should be safely after the 1 second prompt timeout.
+                            WRITE(BEEPER, LOW);
+			}
+			if (mill - beep_start_time > 5000) {
+                            // Next beep after 5s
+                            beep_start_time = 0;
+			}
+                        #endif //BEEPER > 0
+
+
 			switch (wait_for_user_state) {
 			case 0: //nozzle is hot, waiting for user to press the knob to unload filament
 				delay_keep_alive(4);
 
-				if (_millis() > waiting_start_time + (unsigned long)M600_TIMEOUT * 1000) {
+				if (mill > waiting_start_time + (unsigned long)M600_TIMEOUT * 1000) {
 					lcd_display_message_fullscreen_P(_i("Press knob to preheat nozzle and continue."));////MSG_PRESS_TO_PREHEAT c=20 r=4
 					wait_for_user_state = 1;
 					setAllTargetHotends(0);
@@ -10378,14 +10413,11 @@ void M600_wait_for_user(float HotendTempBckp) {
 				}
 				break;
 			case 2: //waiting for nozzle to reach target temperature
-
 				if (abs(degTargetHotend(active_extruder) - degHotend(active_extruder)) < 1) {
-					lcd_display_message_fullscreen_P(_T(MSG_PRESS_TO_UNLOAD));
-					waiting_start_time = _millis();
+					waiting_start_time = mill;
 					wait_for_user_state = 0;
 				}
 				else {
-					counterBeep = 20; //beeper will be inactive during waiting for nozzle preheat
 					lcd_set_cursor(1, 4);
 					lcd_print(ftostr3(degHotend(active_extruder)));
 				}
@@ -10394,7 +10426,10 @@ void M600_wait_for_user(float HotendTempBckp) {
 			}
 
 		}
+
 		WRITE(BEEPER, LOW);
+
+                return (yesno == 1 ? true : false);
 }
 
 void M600_load_filament_movements()

Firmware/ultralcd.cpp

@@ -3725,40 +3725,39 @@ int8_t lcd_show_multiscreen_message_two_choices_and_wait_P(const char *msg, bool
 
 //! @brief Show single screen message with yes and no possible choices and wait with possible timeout
 //! @param msg Message to show
-//! @param allow_timeouting if true, allows time outing of the screen
-//! @param default_yes if true, yes choice is selected by default, otherwise no choice is preselected
+//! @param allow_timeouting if true, allows time outing of the screen with a default timeout. If any other
+//!        number != 0, then allows timeout with that number of milliseconds
+//! @param default_yes if true or -2, then yes choice is selected by default, otherwise no choice is preselected.
+//!        If return_immediately is true, then this should be the value of the previous call.
 //! @retval 1 yes choice selected by user
 //! @retval 0 no choice selected by user
-//! @retval -1 screen timed out
-int8_t lcd_show_fullscreen_message_yes_no_and_wait_P(const char *msg, bool allow_timeouting, bool default_yes)
+//! @retval -1 screen timed out and the cursor was on NO
+//! @retval -2 screen timed out and the cursor was on YES
+int8_t lcd_show_fullscreen_message_yes_no_and_wait_P(const char *msg, unsigned long allow_timeouting, int8_t default_yes)
 {
 
 	lcd_display_message_fullscreen_P(msg);
-
-	if (default_yes) {
-		lcd_set_cursor(0, 2);
-		lcd_puts_P(PSTR(">"));
-		lcd_puts_P(_T(MSG_YES));
-		lcd_set_cursor(1, 3);
-		lcd_puts_P(_T(MSG_NO));
-	}
-	else {
-		lcd_set_cursor(1, 2);
-		lcd_puts_P(_T(MSG_YES));
-		lcd_set_cursor(0, 3);
-		lcd_puts_P(PSTR(">"));
-		lcd_puts_P(_T(MSG_NO));
-	}
-	bool yes = default_yes ? true : false;
+
+        bool yes = (default_yes == true) || (default_yes == -2);
+
+        lcd_set_cursor(1, 2);
+        lcd_puts_P(_T(MSG_YES));
+        lcd_set_cursor(1, 3);
+        lcd_puts_P(_T(MSG_NO));
+
+        lcd_set_cursor(0, yes ? 2 : 3);
+        lcd_puts_P(PSTR(">"));
 
 	// Wait for user confirmation or a timeout.
 	unsigned long previous_millis_cmd = _millis();
+        unsigned long timeout = allow_timeouting == true ? LCD_TIMEOUT_TO_STATUS : allow_timeouting;
 	int8_t        enc_dif = lcd_encoder_diff;
 	lcd_consume_click();
 	KEEPALIVE_STATE(PAUSED_FOR_USER);
 	for (;;) {
-		if (allow_timeouting && _millis() - previous_millis_cmd > LCD_TIMEOUT_TO_STATUS)
-			return -1;
+		if (allow_timeouting && _millis() - previous_millis_cmd > timeout)
+                    return yes ? -2 : -1;
+
 		manage_heater();
 		manage_inactivity(true);
 		if (abs(enc_dif - lcd_encoder_diff) > 4) {

Firmware/ultralcd.h

@@ -66,8 +66,8 @@ extern void lcd_return_to_status();
 extern void lcd_wait_for_click();
 extern bool lcd_wait_for_click_delay(uint16_t nDelay);
 extern void lcd_show_fullscreen_message_and_wait_P(const char *msg);
-// 0: no, 1: yes, -1: timeouted
-extern int8_t lcd_show_fullscreen_message_yes_no_and_wait_P(const char *msg, bool allow_timeouting = true, bool default_yes = false);
+// 0: no, 1: yes, -1: timeouted (cursor on NO), -2: timeouted (cursor on YES)
+extern int8_t lcd_show_fullscreen_message_yes_no_and_wait_P(const char *msg, unsigned long allow_timeouting = true, int8_t default_yes = false);
 extern int8_t lcd_show_multiscreen_message_two_choices_and_wait_P(const char *msg, bool allow_timeouting, bool default_yes,
         const char *first_choice, const char *second_choice);
 extern int8_t lcd_show_multiscreen_message_yes_no_and_wait_P(const char *msg, bool allow_timeouting = true, bool default_yes = false);