Apply MINIMUM_STEPPER_PULSE in stepper advance_isr

Marlin/stepper.cpp

@@ -709,6 +709,11 @@ void Stepper::isr() {
     // Step all E steppers that have steps
     for (uint8_t i = 0; i < step_loops; i++) {
 
+      #if MINIMUM_STEPPER_PULSE > 0
+        static uint32_t pulse_start;
+        pulse_start = TCNT0;
+      #endif
+
       START_E_PULSE(0);
       #if E_STEPPERS > 1
         START_E_PULSE(1);
@@ -720,6 +725,12 @@ void Stepper::isr() {
         #endif
       #endif
 
+      // For a minimum pulse time wait before stopping pulses
+      #if MINIMUM_STEPPER_PULSE > 0
+        #define CYCLES_EATEN_BY_E 10
+        while ((uint32_t)(TCNT0 - pulse_start) < (MINIMUM_STEPPER_PULSE * (F_CPU / 1000000UL)) - CYCLES_EATEN_BY_E) { /* nada */ }
+      #endif
+
       STOP_E_PULSE(0);
       #if E_STEPPERS > 1
         STOP_E_PULSE(1);