Merge pull request #5184 from AnHardt/endstop_interrupts

Introduce endstop interrupts

Marlin/Configuration.h

@@ -445,6 +445,9 @@
 #define Z_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/Marlin_main.cpp

@@ -89,6 +89,9 @@
   #include "twibus.h"
 #endif
 
+#if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+  #include "endstop_interrupts.h"
+#endif
 /**
  * Look here for descriptions of G-codes:
  *  - http://linuxcnc.org/handbook/gcode/g-code.html
@@ -10015,6 +10018,10 @@ void setup() {
     i2c.onReceive(i2c_on_receive);
     i2c.onRequest(i2c_on_request);
   #endif
+
+  #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+    setup_enstop_interrupts();
+  #endif
 }
 
 /**

Marlin/endstop_interrupts.h

@@ -0,0 +1,211 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ *  Endstop interrupts
+ *  Without endstop interrups the stepper-ISR must always test all endstops when interested in their states (endstops.update()).
+ *  Most time the test will result in finding out nothing has changed.
+ *  With endstop interrupts endstops.update() is called only when we know that at least one endstop has changed its state.
+ *
+ *  This can work only if all __used__ endstop pins can provide ether an 'external interrupt' or a 'pin change interrupt'.
+ *  You can find out about pins issuing interrupts by running 'pin_interrupt_test.ino' (Marlin\buildroot\share\pin_interrupt_test\pin_interrupt_test.ino)
+ */
+
+ #ifndef _ENDSTOP_INTERRUPTS_H_
+   #define _ENDSTOP_INTERRUPTS_H_
+
+  /**
+   * Patch for pins_arduino.h (...\Arduino\hardware\arduino\avr\variants\mega\pins_arduino.h)  
+   *
+   * These macros for the Arduino MEGA do not include the two connected pins on Port J (D13, D14).
+   * So we extend them here because this are the normal pins for Y_MIN and Y_MAX on RAMPS.
+   * There are more PCI enabled processor pins on Port J, but they are not connected to Arduino MEGA.
+   */
+  #if defined(ARDUINO_AVR_MEGA2560) || defined(ARDUINO_AVR_MEGA)
+    #undef  digitalPinToPCICR
+    #define digitalPinToPCICR(p)    ( (((p) >= 10) && ((p) <= 15)) || \
+                                    (((p) >= 50) && ((p) <= 53)) || \
+                                    (((p) >= 62) && ((p) <= 69)) ? (&PCICR) : ((uint8_t *)0) )
+    #undef  digitalPinToPCICRbit
+    #define digitalPinToPCICRbit(p) ( (((p) >= 10) && ((p) <= 13)) || (((p) >= 50) && ((p) <= 53)) ? 0 : \
+                                    ( (((p) >= 14) && ((p) <= 15)) ? 1 : \
+                                    ( (((p) >= 62) && ((p) <= 69)) ? 2 : \
+                                    0 ) ) )
+    #undef  digitalPinToPCMSK
+    #define digitalPinToPCMSK(p)    ( (((p) >= 10) && ((p) <= 13)) || (((p) >= 50) && ((p) <= 53)) ? (&PCMSK0) : \
+                                    ( (((p) >= 14) && ((p) <= 15)) ? (&PCMSK1) : \
+                                    ( (((p) >= 62) && ((p) <= 69)) ? (&PCMSK2) : \
+                                    ((uint8_t *)0) ) ) )
+    #undef  digitalPinToPCMSKbit
+    #define digitalPinToPCMSKbit(p) ( (((p) >= 10) && ((p) <= 13)) ? ((p) - 6) : \
+                                    ( ((p) == 14) ? 2 : \
+                                    ( ((p) == 15) ? 1 : \
+                                    ( ((p) == 50) ? 3 : \
+                                    ( ((p) == 51) ? 2 : \
+                                    ( ((p) == 52) ? 1 : \
+                                    ( ((p) == 53) ? 0 : \
+                                    ( (((p) >= 62) && ((p) <= 69)) ? ((p) - 62) : \
+                                    0 ) ) ) ) ) ) ) )
+  #endif
+
+  volatile uint8_t e_hit = 0; // Different from 0 when the endstops shall be tested in detail. 
+                              // Must be reset to 0 by the test function when the tests are finished.
+
+  // Install Pin change interrupt for a pin, can be called multiple times
+  void pciSetup(byte pin) {
+    *digitalPinToPCMSK(pin) |= bit (digitalPinToPCMSKbit(pin));  // enable pin
+    PCIFR  |= bit (digitalPinToPCICRbit(pin)); // clear any outstanding interrupt
+    PCICR  |= bit (digitalPinToPCICRbit(pin)); // enable interrupt for the group
+  }
+
+  // This is what is really done inside the interrupts.
+  FORCE_INLINE void endstop_ISR_worker( void ) {
+    e_hit = 2; // Because the detection of a e-stop hit has a 1 step debouncer it has to be called at least twice.
+  }
+
+  // Use one Routine to handle each group
+  // One ISR for all EXT-Interrupts
+  void endstop_ISR(void) {
+    endstop_ISR_worker();
+  }
+
+  #ifdef PCINT0_vect
+    ISR(PCINT0_vect) { // handle pin change interrupt
+      endstop_ISR_worker();
+    }
+  #endif
+
+  #ifdef PCINT1_vect
+    ISR(PCINT1_vect) { // handle pin change interrupt
+      endstop_ISR_worker();
+    }
+  #endif
+
+  #ifdef PCINT2_vect
+    ISR(PCINT2_vect) { // handle pin change interrupt
+      endstop_ISR_worker();
+    }
+  #endif
+
+  #ifdef PCINT3_vect
+    ISR(PCINT3_vect) { // handle pin change interrupt
+      endstop_ISR_worker();
+    }
+  #endif
+
+  void setup_enstop_interrupts( void ) {
+
+    #if HAS_X_MAX
+      #if (digitalPinToInterrupt(X_MAX_PIN) != NOT_AN_INTERRUPT) // if pin has an external interrupt
+        attachInterrupt(digitalPinToInterrupt(X_MAX_PIN), endstop_ISR, CHANGE); // assign it
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(X_MAX_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR"); // if pin has no pin change interrupt - error
+        pciSetup(X_MAX_PIN);                                                            // assign it
+      #endif
+    #endif
+
+    #if HAS_X_MIN
+      #if (digitalPinToInterrupt(X_MIN_PIN) != NOT_AN_INTERRUPT)
+        attachInterrupt(digitalPinToInterrupt(X_MIN_PIN), endstop_ISR, CHANGE);
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(X_MIN_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
+        pciSetup(X_MIN_PIN);
+      #endif
+    #endif
+
+    #if HAS_Y_MAX
+      #if (digitalPinToInterrupt(Y_MAX_PIN) != NOT_AN_INTERRUPT)
+        attachInterrupt(digitalPinToInterrupt(Y_MAX_PIN), endstop_ISR, CHANGE);
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(Y_MAX_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
+        pciSetup(Y_MAX_PIN);
+      #endif
+    #endif
+
+    #if HAS_Y_MIN
+      #if (digitalPinToInterrupt(Y_MIN_PIN) != NOT_AN_INTERRUPT)
+        attachInterrupt(digitalPinToInterrupt(Y_MIN_PIN), endstop_ISR, CHANGE);
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(Y_MIN_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
+        pciSetup(Y_MIN_PIN);
+      #endif
+    #endif
+
+    #if HAS_Z_MAX
+      #if (digitalPinToInterrupt(Z_MAX_PIN) != NOT_AN_INTERRUPT)
+        attachInterrupt(digitalPinToInterrupt(Z_MAX_PIN), endstop_ISR, CHANGE);
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(Z_MAX_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
+        pciSetup(Z_MAX_PIN);
+      #endif
+    #endif
+
+    #if HAS_Z_MIN
+      #if (digitalPinToInterrupt(Z_MIN_PIN) != NOT_AN_INTERRUPT)
+        attachInterrupt(digitalPinToInterrupt(Z_MIN_PIN), endstop_ISR, CHANGE);
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(Z_MIN_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
+        pciSetup(Z_MIN_PIN);
+      #endif
+    #endif
+
+    #if HAS_Z2_MAX
+      #if (digitalPinToInterrupt(Z2_MAX_PIN) != NOT_AN_INTERRUPT)
+        attachInterrupt(digitalPinToInterrupt(Z2_MAX_PIN), endstop_ISR, CHANGE);
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(Z2_MAX_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
+        pciSetup(Z2_MAX_PIN);
+      #endif
+    #endif
+
+    #if HAS_Z2_MIN
+      #if (digitalPinToInterrupt(Z2_MIN_PIN) != NOT_AN_INTERRUPT)
+        attachInterrupt(digitalPinToInterrupt(Z2_MIN_PIN), endstop_ISR, CHANGE);
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(Z2_MIN_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
+        pciSetup(Z2_MIN_PIN);
+      #endif
+    #endif
+
+    #if HAS_Z_MIN_PROBE_PIN
+      #if (digitalPinToInterrupt(Z_MIN_PROBE_PIN) != NOT_AN_INTERRUPT)
+        attachInterrupt(digitalPinToInterrupt(Z_MIN_PROBE_PIN), endstop_ISR, CHANGE);
+      #else
+        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
+        static_assert(digitalPinToPCICR(Z_MIN_PROBE_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
+        pciSetup(Z_MIN_PROBE_PIN);
+      #endif
+    #endif
+
+    // When we arive here without error each pin has ether a EXT-interrupt or a PCI.
+  }
+
+
+#endif //_ENDSTOP_INTERRUPTS_H_

Marlin/example_configurations/Cartesio/Configuration.h

@@ -445,6 +445,9 @@
 #define Z_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/Felix/Configuration.h

@@ -427,6 +427,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/Felix/DUAL/Configuration.h

@@ -427,6 +427,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/Hephestos/Configuration.h

@@ -437,6 +437,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/Hephestos_2/Configuration.h

@@ -439,6 +439,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/K8200/Configuration.h

@@ -462,6 +462,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/K8400/Configuration.h

@@ -445,6 +445,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/K8400/Dual-head/Configuration.h

@@ -445,6 +445,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h

@@ -445,6 +445,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/RigidBot/Configuration.h

@@ -442,6 +442,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/SCARA/Configuration.h

@@ -460,6 +460,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/TAZ4/Configuration.h

@@ -466,6 +466,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/WITBOX/Configuration.h

@@ -437,6 +437,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/adafruit/ST7565/Configuration.h

@@ -445,6 +445,9 @@
 #define Z_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/delta/biv2.5/Configuration.h

@@ -489,6 +489,9 @@
 #define Z_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/delta/generic/Configuration.h

@@ -489,6 +489,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/delta/kossel_mini/Configuration.h

@@ -489,6 +489,9 @@
 #define Z_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/delta/kossel_pro/Configuration.h

@@ -478,6 +478,9 @@
 #define Z_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/delta/kossel_xl/Configuration.h

@@ -487,6 +487,9 @@
 #define Z_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/makibox/Configuration.h

@@ -448,6 +448,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/example_configurations/tvrrug/Round2/Configuration.h

@@ -435,6 +435,9 @@
 #define Z_MAX_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 #define Z_MIN_PROBE_ENDSTOP_INVERTING true  // set to true to invert the logic of the endstop.
 
+// If all used endstop pins are able to cause interrupts, you can enable ENDSTOP_INTERRUPTS_FEATURE.
+// Then the function testing the endstops will only be called, if the state of one of the endstops changed.
+//#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================
 //============================== Movement Settings ============================

Marlin/stepper.cpp

@@ -310,6 +310,10 @@ void Stepper::set_directions() {
   #endif // !ADVANCE && !LIN_ADVANCE
 }
 
+#if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+  extern volatile uint8_t e_hit;
+#endif
+
 /**
  * Stepper Driver Interrupt
  *
@@ -378,7 +382,15 @@ void Stepper::isr() {
     #if HAS_BED_PROBE
       || endstops.z_probe_enabled
     #endif
-  ) endstops.update();
+  )
+  #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+    if(e_hit) {
+  #endif
+      endstops.update();
+  #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
+      e_hit--;
+    }
+  #endif
 
   // Take multiple steps per interrupt (For high speed moves)
   bool all_steps_done = false;

buildroot/share/pin_interrupt_test/pin_interrupt_test.ino

@@ -0,0 +1,32 @@
+// Search pins uasable for endstop-interupts
+// Compile with the same settings you'd use with Marlin.
+
+#if defined(ARDUINO_AVR_MEGA2560) || defined(ARDUINO_AVR_MEGA)
+    #undef  digitalPinToPCICR
+    #define digitalPinToPCICR(p)    ( (((p) >= 10) && ((p) <= 15)) || \
+                                    (((p) >= 50) && ((p) <= 53)) || \
+                                    (((p) >= 62) && ((p) <= 69)) ? (&PCICR) : ((uint8_t *)0) )
+#endif
+
+void setup() {
+  Serial.begin(9600);
+  Serial.println("PINs causing interrups are:");
+  for(int i=2; i<NUM_DIGITAL_PINS; i++){
+    if( digitalPinToPCICR(i) != NULL || (int)digitalPinToInterrupt(i) != -1 ) {
+      for (int j= 0; j<NUM_ANALOG_INPUTS; j++){
+        if(analogInputToDigitalPin(j) == i) {
+          Serial.print("A");
+          Serial.print(j);
+          Serial.print(" = ");
+        }
+      }
+      Serial.print("D");
+      Serial.println(i);
+    }
+  }
+  Serial.println("Arduino pin numbering!");
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+}