Rework the print job timer to use the stopwatch class

Marlin/Marlin.h

 
 #include "WString.h"
 
+#include "stopwatch.h"
+
 #ifdef USBCON
   #if ENABLED(BLUETOOTH)
     #define MYSERIAL bluetoothSerial
   extern float retract_recover_length, retract_recover_length_swap, retract_recover_feedrate;
 #endif
 
-extern millis_t print_job_start_ms;
-extern millis_t print_job_stop_ms;
+// Print job timer
+extern stopwatch print_job_timer;
 
 // Handling multiple extruders pins
 extern uint8_t active_extruder;
 
 extern void calculate_volumetric_multipliers();
 
-// Print job timer related functions
-millis_t print_job_timer();
-bool print_job_start(millis_t t = 0);
-bool print_job_stop(bool force = false);
-
 #endif //MARLIN_H

Marlin/Marlin_main.cpp

 millis_t previous_cmd_ms = 0;
 static millis_t max_inactive_time = 0;
 static millis_t stepper_inactive_time = (DEFAULT_STEPPER_DEACTIVE_TIME) * 1000L;
-millis_t print_job_start_ms = 0; ///< Print job start time
-millis_t print_job_stop_ms = 0;  ///< Print job stop time
+stopwatch print_job_timer = stopwatch();
 static uint8_t target_extruder;
 
 #if ENABLED(AUTO_BED_LEVELING_FEATURE)
       ) {
         if (card_eof) {
           SERIAL_PROTOCOLLNPGM(MSG_FILE_PRINTED);
-          print_job_stop(true);
+          print_job_timer.stop();
           char time[30];
-          millis_t t = print_job_timer();
+          millis_t t = print_job_timer.duration();
           int hours = t / 60 / 60, minutes = (t / 60) % 60;
           sprintf_P(time, PSTR("%i " MSG_END_HOUR " %i " MSG_END_MINUTE), hours, minutes);
           SERIAL_ECHO_START;
    */
   inline void gcode_M24() {
     card.startFileprint();
-    print_job_start();
+    print_job_timer.start();
   }
 
   /**
  * M31: Get the time since the start of SD Print (or last M109)
  */
 inline void gcode_M31() {
-  millis_t t = print_job_timer();
+  millis_t t = print_job_timer.duration();
   int min = t / 60, sec = t % 60;
   char time[30];
   sprintf_P(time, PSTR("%i min, %i sec"), min, sec);
   if (setTargetedHotend(104)) return;
   if (DEBUGGING(DRYRUN)) return;
 
-  // Start hook must happen before setTargetHotend()
-  print_job_start();
-
   if (code_seen('S')) {
     float temp = code_value();
     setTargetHotend(temp, target_extruder);
         setTargetHotend1(temp == 0.0 ? 0.0 : temp + duplicate_extruder_temp_offset);
     #endif
 
+    /**
+     * We use halve EXTRUDE_MINTEMP here to allow nozzles to be put into hot
+     * stand by mode, for instance in a dual extruder setup, without affecting
+     * the running print timer.
+     */
+    if (temp <= (EXTRUDE_MINTEMP/2)) {
+      print_job_timer.stop();
+      LCD_MESSAGEPGM(WELCOME_MSG);
+    }
+    /**
+     * We do not check if the timer is already running because this check will
+     * be done for us inside the stopwatch::start() method thus a running timer
+     * will not restart.
+     */
+    else print_job_timer.start();
+
     if (temp > degHotend(target_extruder)) LCD_MESSAGEPGM(MSG_HEATING);
   }
-
-  if (print_job_stop()) LCD_MESSAGEPGM(WELCOME_MSG);
 }
 
 #if HAS_TEMP_HOTEND || HAS_TEMP_BED
   if (setTargetedHotend(109)) return;
   if (DEBUGGING(DRYRUN)) return;
 
-  // Start hook must happen before setTargetHotend()
-  print_job_start();
-
   no_wait_for_cooling = code_seen('S');
   if (no_wait_for_cooling || code_seen('R')) {
     float temp = code_value();
         setTargetHotend1(temp == 0.0 ? 0.0 : temp + duplicate_extruder_temp_offset);
     #endif
 
+    /**
+     * We use halve EXTRUDE_MINTEMP here to allow nozzles to be put into hot
+     * stand by mode, for instance in a dual extruder setup, without affecting
+     * the running print timer.
+     */
+    if (temp <= (EXTRUDE_MINTEMP/2)) {
+      print_job_timer.stop();
+      LCD_MESSAGEPGM(WELCOME_MSG);
+    }
+    /**
+     * We do not check if the timer is already running because this check will
+     * be done for us inside the stopwatch::start() method thus a running timer
+     * will not restart.
+     */
+    else print_job_timer.start();
+
     if (temp > degHotend(target_extruder)) LCD_MESSAGEPGM(MSG_HEATING);
   }
 
-  if (print_job_stop()) LCD_MESSAGEPGM(WELCOME_MSG);
-
   #if ENABLED(AUTOTEMP)
     autotemp_enabled = code_seen('F');
     if (autotemp_enabled) autotemp_factor = code_value();
   for (int i = 0; i < EXTRUDERS; i++)
     volumetric_multiplier[i] = calculate_volumetric_multiplier(filament_size[i]);
 }
-
-/**
- * Start the print job timer
- *
- * The print job is only started if all extruders have their target temp at zero
- * otherwise the print job timew would be reset everytime a M109 is received.
- *
- * @param t start timer timestamp
- *
- * @return true if the timer was started at function call
- */
-bool print_job_start(millis_t t /* = 0 */) {
-  for (int i = 0; i < EXTRUDERS; i++) if (degTargetHotend(i) > 0) return false;
-  print_job_start_ms = (t) ? t : millis();
-  print_job_stop_ms = 0;
-  return true;
-}
-
-/**
- * Check if the running print job has finished and stop the timer
- *
- * When the target temperature for all extruders is zero then we assume that the
- * print job has finished printing. There are some special conditions under which
- * this assumption may not be valid: If during a print job for some reason the
- * user decides to bring a nozzle temp down and only then heat the other afterwards.
- *
- * @param force stops the timer ignoring all pre-checks
- *
- * @return boolean true if the print job has finished printing
- */
-bool print_job_stop(bool force /* = false */) {
-  if (!print_job_start_ms) return false;
-  if (!force) for (int i = 0; i < EXTRUDERS; i++) if (degTargetHotend(i) > 0) return false;
-  print_job_stop_ms = millis();
-  return true;
-}
-
-/**
- * Output the print job timer in seconds
- *
- * @return the number of seconds
- */
-millis_t print_job_timer() {
-  if (!print_job_start_ms) return 0;
-  return (((print_job_stop_ms > print_job_start_ms)
-    ? print_job_stop_ms : millis()) - print_job_start_ms) / 1000;
-}

Marlin/dogm_lcd_implementation.h

     }
 
     u8g.setPrintPos(80,48);
-    if (print_job_start_ms != 0) {
-      uint16_t time = (((print_job_stop_ms > print_job_start_ms)
-                       ? print_job_stop_ms : millis()) - print_job_start_ms) / 60000;
+    uint16_t time = print_job_timer.duration() / 60;
+    if (time != 0) {
       lcd_print(itostr2(time/60));
       lcd_print(':');
       lcd_print(itostr2(time%60));

Marlin/temperature.cpp

   setTargetBed(0);
 
   // If all heaters go down then for sure our print job has stopped
-  print_job_stop(true);
+  print_job_timer.stop();
 
   #define DISABLE_HEATER(NR) { \
     setTargetHotend(NR, 0); \

Marlin/ultralcd_implementation_hitachi_HD44780.h

 
     lcd.setCursor(LCD_WIDTH - 6, 2);
     lcd.print(LCD_STR_CLOCK[0]);
-    if (print_job_start_ms != 0) {
-      uint16_t time = (((print_job_stop_ms > print_job_start_ms)
-                       ? print_job_stop_ms : millis()) - print_job_start_ms) / 60000;
+
+    uint16_t time = print_job_timer.duration() / 60;
+    if (time != 0) {
       lcd.print(itostr2(time / 60));
       lcd.print(':');
       lcd.print(itostr2(time % 60));