Merge pull request #5729 from Bob-the-Kuhn/guaranteed-BLTouch-detection

guaranteed BLTouch detection

Marlin/Marlin_main.cpp

     flow_percentage[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(100);
 
 bool axis_relative_modes[] = AXIS_RELATIVE_MODES,
-     volumetric_enabled = 
+     volumetric_enabled =
       #if ENABLED(VOLUMETRIC_DEFAULT_ON)
         true
       #else
   #define STOW_PROBE() set_probe_deployed(false)
 
   #if ENABLED(BLTOUCH)
+    void bltouch_command(int angle) {
+      servo[Z_ENDSTOP_SERVO_NR].move(angle);  // Give the BL-Touch the command and wait
+      safe_delay(375);
+    }
+
     FORCE_INLINE void set_bltouch_deployed(const bool &deploy) {
-      servo[Z_ENDSTOP_SERVO_NR].move(deploy ? BLTOUCH_DEPLOY : BLTOUCH_STOW);
+      bltouch_command(deploy ? BLTOUCH_DEPLOY : BLTOUCH_STOW);
       #if ENABLED(DEBUG_LEVELING_FEATURE)
         if (DEBUGGING(LEVELING)) {
           SERIAL_ECHOPAIR("set_bltouch_deployed(", deploy);
 
     // When deploying make sure BLTOUCH is not already triggered
     #if ENABLED(BLTOUCH)
-      if (deploy && TEST_BLTOUCH()) { stop(); return true; }
+      if (deploy && TEST_BLTOUCH()) {      // If BL-Touch says it's triggered
+        bltouch_command(BLTOUCH_RESET);    // try to reset it.
+        set_bltouch_deployed(true);        // Also needs to deploy and stow to
+        set_bltouch_deployed(false);       // clear the triggered condition.
+        if (TEST_BLTOUCH()) {              // If it still claims to be triggered...
+          stop();                          // punt!
+          return true;
+        }
+      }
     #elif ENABLED(Z_PROBE_SLED)
       if (axis_unhomed_error(true, false, false)) { stop(); return true; }
     #elif ENABLED(Z_PROBE_ALLEN_KEY)
    *  R  Set the Right limit of the probing grid
    *
    * Parameters with BILINEAR only:
-   * 
+   *
    *  Z  Supply an additional Z probe offset
    *
    * Global Parameters:
         mixing_virtual_tool_mix[t][i] = mixing_factor[i];
   #endif
 
+  #if ENABLED(BLTOUCH)
+    bltouch_command(BLTOUCH_RESET);    // Just in case the BLTouch is in the error state, try to
+    set_bltouch_deployed(true);        // reset it. Also needs to deploy and stow to clear the
+    set_bltouch_deployed(false);       // error condition.
+  #endif
+
   #if ENABLED(EXPERIMENTAL_I2CBUS) && I2C_SLAVE_ADDRESS > 0
     i2c.onReceive(i2c_on_receive);
     i2c.onRequest(i2c_on_request);

Marlin/endstops.h

 
 extern Endstops endstops;
 
+#if HAS_BED_PROBE
+  #define ENDSTOPS_ENABLED  (endstops.enabled || endstops.z_probe_enabled)
+#else
+  #define ENDSTOPS_ENABLED  endstops.enabled
+#endif
+
+
 #endif // ENDSTOPS_H

Marlin/stepper.cpp

 void Stepper::isr() {
   #define _ENABLE_ISRs() cli(); SBI(TIMSK0, OCIE0B); ENABLE_STEPPER_DRIVER_INTERRUPT()
 
+  uint16_t timer, remainder, ocr_val;
+
+  static uint32_t step_remaining = 0;
+
+  #define ENDSTOP_NOMINAL_OCR_VAL 3000    // check endstops every 1.5ms to guarantee two stepper ISRs within 5ms for BLTouch
+  #define OCR_VAL_TOLERANCE 1000          // First max delay is 2.0ms, last min delay is 0.5ms, all others 1.5ms
+
   #if DISABLED(ADVANCE) && DISABLED(LIN_ADVANCE)
-    //Disable Timer0 ISRs and enable global ISR again to capture UART events (incoming chars)
-    CBI(TIMSK0, OCIE0B); //Temperature ISR
+    // Disable Timer0 ISRs and enable global ISR again to capture UART events (incoming chars)
+    CBI(TIMSK0, OCIE0B); // Temperature ISR
     DISABLE_STEPPER_DRIVER_INTERRUPT();
     sei();
   #endif
 
+  #define _SPLIT(L) (ocr_val = (uint16_t)L)
+  #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+    #define SPLIT(L) _SPLIT(L)
+  #else                 // sample endstops in between step pulses
+    #define SPLIT(L) do { \
+      _SPLIT(L); \
+      if (ENDSTOPS_ENABLED && L > ENDSTOP_NOMINAL_OCR_VAL) { \
+        remainder = (uint16_t)L % (ENDSTOP_NOMINAL_OCR_VAL); \
+        ocr_val = (remainder < OCR_VAL_TOLERANCE) ? ENDSTOP_NOMINAL_OCR_VAL + remainder : ENDSTOP_NOMINAL_OCR_VAL; \
+        step_remaining = (uint16_t)L - ocr_val; \
+      } \
+    } while(0)
+
+    if (step_remaining && ENDSTOPS_ENABLED) {   // Just check endstops - not yet time for a step
+      endstops.update();
+      ocr_val = step_remaining;
+      if (step_remaining > ENDSTOP_NOMINAL_OCR_VAL) {
+        step_remaining = step_remaining - ENDSTOP_NOMINAL_OCR_VAL;
+        ocr_val = ENDSTOP_NOMINAL_OCR_VAL;
+      }
+      else step_remaining = 0;  //  last one before the ISR that does the step
+      _NEXT_ISR(ocr_val);  //
+
+      NOLESS(OCR1A, TCNT1 + 16);
+
+      _ENABLE_ISRs(); // re-enable ISRs
+      return;
+    }
+  # endif
+
   if (cleaning_buffer_counter) {
     --cleaning_buffer_counter;
     current_block = NULL;
   }
 
   // Update endstops state, if enabled
-  if ((endstops.enabled
-    #if HAS_BED_PROBE
-      || endstops.z_probe_enabled
-    #endif
-    )
-    #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
-      && e_hit
-    #endif
-  ) {
-    endstops.update();
 
-    #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+
+  #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+    if (ENDSTOPS_ENABLED && e_hit) {
+      endstops.update();
       e_hit--;
-    #endif
-  }
+    }
+  #else
+    if (ENDSTOPS_ENABLED) endstops.update();
+  #endif
 
   // Take multiple steps per interrupt (For high speed moves)
   bool all_steps_done = false;
 
     // step_rate to timer interval
     uint16_t timer = calc_timer(acc_step_rate);
-    _NEXT_ISR(timer);
+
+    SPLIT(timer);  // split step into multiple ISRs if larger than  ENDSTOP_NOMINAL_OCR_VAL
+    _NEXT_ISR(ocr_val);
+
     acceleration_time += timer;
 
     #if ENABLED(LIN_ADVANCE)
 
     // step_rate to timer interval
     uint16_t timer = calc_timer(step_rate);
-    _NEXT_ISR(timer);
+
+    SPLIT(timer);  // split step into multiple ISRs if larger than  ENDSTOP_NOMINAL_OCR_VAL
+    _NEXT_ISR(ocr_val);
+
     deceleration_time += timer;
 
     #if ENABLED(LIN_ADVANCE)
 
     #endif
 
-    _NEXT_ISR(OCR1A_nominal);
+    SPLIT(OCR1A_nominal);  // split step into multiple ISRs if larger than  ENDSTOP_NOMINAL_OCR_VAL
+    _NEXT_ISR(ocr_val);
+
     // ensure we're running at the correct step rate, even if we just came off an acceleration
     step_loops = step_loops_nominal;
   }
   // Timer interrupt for E. e_steps is set in the main routine;
 
   void Stepper::advance_isr() {
-    
+
     nextAdvanceISR = eISR_Rate;
-    
+
     #define SET_E_STEP_DIR(INDEX) \
       if (e_steps[INDEX]) E## INDEX ##_DIR_WRITE(e_steps[INDEX] < 0 ? INVERT_E## INDEX ##_DIR : !INVERT_E## INDEX ##_DIR)
 
 
     // Run Advance stepping ISR if flagged
     if (!nextAdvanceISR) advance_isr();
-  
+
     // Is the next advance ISR scheduled before the next main ISR?
     if (nextAdvanceISR <= nextMainISR) {
       // Set up the next interrupt
       // Will call Stepper::isr on the next interrupt
       nextMainISR = 0;
     }
-  
+
     // Don't run the ISR faster than possible
     NOLESS(OCR1A, TCNT1 + 16);
 

Marlin/temperature.cpp

   #include "stepper.h"
 #endif
 
+#if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+  #include "endstops.h"
+#endif
+
 #if ENABLED(USE_WATCHDOG)
   #include "watchdog.h"
 #endif
     }
   #endif
 
+  #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+
+    extern volatile uint8_t e_hit;
+
+    if (e_hit && ENDSTOPS_ENABLED) {
+      endstops.update();  // call endstop update routine
+      e_hit--;
+    }
+  #endif
+
   SBI(TIMSK0, OCIE0B); //re-enable Temperature ISR
 }