Followup to new endstop interrupts feature

- Fix typos, verbiage
- Fix naming of `setup_endstop_interrupts`
- Some formatting, indentation, spacing

Marlin/Configuration.h

@@ -445,8 +445,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/Marlin_main.cpp

@@ -92,6 +92,7 @@
 #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
@@ -10020,7 +10021,7 @@ void setup() {
   #endif
 
   #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
-    setup_enstop_interrupts();
+    setup_endstop_interrupts();
   #endif
 }
 

Marlin/endstop_interrupts.h

@@ -21,13 +21,18 @@
  */
 
 /**
- *  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.
+ * Endstop Interrupts
  *
- *  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)
+ * Without endstop interrupts the endstop pins must be polled continually in
+ * the stepper-ISR via endstops.update(), most of the time finding no change.
+ * With this feature endstops.update() is called only when we know that at
+ * least one endstop has changed state, saving valuable CPU cycles.
+ *
+ * This feature only works when all used endstop pins can generate either an
+ * 'external interrupt' or a 'pin change interrupt'.
+ *
+ * Test whether pins issue interrupts on your board by flashing 'pin_interrupt_test.ino'.
+ * (Located in Marlin/buildroot/share/pin_interrupt_test/pin_interrupt_test.ino)
  */
 
  #ifndef _ENDSTOP_INTERRUPTS_H_
@@ -37,8 +42,8 @@
  * 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.
+ * So we extend them here because these 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
@@ -70,7 +75,7 @@
 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
+// 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
@@ -84,35 +89,26 @@
 
 // Use one Routine to handle each group
 // One ISR for all EXT-Interrupts
-  void endstop_ISR(void) {
-    endstop_ISR_worker();
-  }
+void endstop_ISR(void) { endstop_ISR_worker(); }
 
+// Handlers for pin change interrupts
 #ifdef PCINT0_vect
-    ISR(PCINT0_vect) { // handle pin change interrupt
-      endstop_ISR_worker();
-    }
+  ISR(PCINT0_vect) { endstop_ISR_worker(); }
 #endif
 
 #ifdef PCINT1_vect
-    ISR(PCINT1_vect) { // handle pin change interrupt
-      endstop_ISR_worker();
-    }
+  ISR(PCINT1_vect) { endstop_ISR_worker(); }
 #endif
 
 #ifdef PCINT2_vect
-    ISR(PCINT2_vect) { // handle pin change interrupt
-      endstop_ISR_worker();
-    }
+  ISR(PCINT2_vect) { endstop_ISR_worker(); }
 #endif
 
 #ifdef PCINT3_vect
-    ISR(PCINT3_vect) { // handle pin change interrupt
-      endstop_ISR_worker();
-    }
+  ISR(PCINT3_vect) { endstop_ISR_worker(); }
 #endif
 
-  void setup_enstop_interrupts( void ) {
+void setup_endstop_interrupts( void ) {
 
   #if HAS_X_MAX
     #if (digitalPinToInterrupt(X_MAX_PIN) != NOT_AN_INTERRUPT) // if pin has an external interrupt
@@ -204,8 +200,7 @@
     #endif
   #endif
 
-    // When we arive here without error each pin has ether a EXT-interrupt or a PCI.
+  // If we arrive here without raising an assertion, each pin has either an EXT-interrupt or a PCI.
 }
 
-
 #endif //_ENDSTOP_INTERRUPTS_H_

Marlin/example_configurations/Cartesio/Configuration.h

@@ -445,8 +445,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/Felix/Configuration.h

@@ -427,8 +427,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/Felix/DUAL/Configuration.h

@@ -427,8 +427,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/Hephestos/Configuration.h

@@ -437,8 +437,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/Hephestos_2/Configuration.h

@@ -439,8 +439,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/K8200/Configuration.h

@@ -462,8 +462,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/K8400/Configuration.h

@@ -445,8 +445,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

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

@@ -445,8 +445,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h

@@ -445,8 +445,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/RigidBot/Configuration.h

@@ -442,8 +442,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/SCARA/Configuration.h

@@ -460,8 +460,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/TAZ4/Configuration.h

@@ -466,8 +466,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/WITBOX/Configuration.h

@@ -437,8 +437,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/adafruit/ST7565/Configuration.h

@@ -445,8 +445,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

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

@@ -489,8 +489,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/delta/generic/Configuration.h

@@ -489,8 +489,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/delta/kossel_mini/Configuration.h

@@ -489,8 +489,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/delta/kossel_pro/Configuration.h

@@ -478,8 +478,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/delta/kossel_xl/Configuration.h

@@ -487,8 +487,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/makibox/Configuration.h

@@ -448,8 +448,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/example_configurations/tvrrug/Round2/Configuration.h

@@ -435,8 +435,8 @@
 #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.
+// Enable this feature if all enabled endstop pins are interrupt-capable.
+// This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
 //=============================================================================

Marlin/stepper.cpp

@@ -378,19 +378,21 @@ void Stepper::isr() {
   }
 
   // Update endstops state, if enabled
-  if (endstops.enabled
+  if ((endstops.enabled
     #if HAS_BED_PROBE
       || endstops.z_probe_enabled
     #endif
     )
     #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
-    if(e_hit) {
+      && 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;