[2.0.x] Add endstop noise filter (#10796)

Marlin/Configuration.h

@@ -554,6 +554,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/default/Configuration.h

@@ -554,6 +554,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/AlephObjects/TAZ4/Configuration.h

@@ -573,6 +573,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/AliExpress/CL-260/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Anet/A6/Configuration.h

@@ -573,6 +573,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 #define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Anet/A8/Configuration.h

@@ -560,6 +560,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 #define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Azteeg/X5GT/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/BIBO/TouchX/default/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/BQ/Hephestos/Configuration.h

@@ -541,6 +541,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/BQ/Hephestos_2/Configuration.h

@@ -554,6 +554,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 #define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/BQ/WITBOX/Configuration.h

@@ -541,6 +541,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Cartesio/Configuration.h

@@ -552,6 +552,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Creality/CR-10/Configuration.h

@@ -563,6 +563,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Creality/CR-10S/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Creality/CR-10mini/Configuration.h

@@ -572,6 +572,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Creality/CR-8/Configuration.h

@@ -563,6 +563,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Creality/Ender-2/Configuration.h

@@ -557,6 +557,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Creality/Ender-3/Configuration.h

@@ -557,6 +557,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Creality/Ender-4/Configuration.h

@@ -563,6 +563,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Felix/Configuration.h

@@ -534,6 +534,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Felix/DUAL/Configuration.h

@@ -534,6 +534,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/FolgerTech/i3-2020/Configuration.h

@@ -558,6 +558,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Geeetech/GT2560/Configuration.h

@@ -568,6 +568,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Geeetech/I3_Pro_X-GT2560/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Geeetech/Prusa i3 Pro B/bltouch/Configuration.h

@@ -568,6 +568,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Geeetech/Prusa i3 Pro B/noprobe/Configuration.h

@@ -568,6 +568,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Geeetech/Prusa i3 Pro C/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Geeetech/Prusa i3 Pro W/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Infitary/i3-M508/Configuration.h

@@ -557,6 +557,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/JGAurora/A5/Configuration.h

@@ -565,6 +565,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/MakerParts/Configuration.h

@@ -573,6 +573,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Malyan/M150/Configuration.h

@@ -562,6 +562,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Malyan/M200/Configuration.h

@@ -552,6 +552,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Micromake/C1/basic/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Micromake/C1/enhanced/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Mks/Sbase/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/RepRapPro/Huxley/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/RepRapWorld/Megatronics/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/RigidBot/Configuration.h

@@ -549,6 +549,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/SCARA/Configuration.h

@@ -566,6 +566,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/STM32F10/Configuration.h

@@ -555,6 +555,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/STM32F4/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Sanguinololu/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/TheBorg/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/TinyBoy2/Configuration.h

@@ -604,6 +604,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 #define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Tronxy/X1/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Tronxy/X5S/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Tronxy/XY100/Configuration.h

@@ -564,6 +564,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/UltiMachine/Archim2/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Velleman/K8200/Configuration.h

@@ -583,6 +583,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Velleman/K8400/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Velleman/K8400/Dual-head/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration.h

@@ -563,6 +563,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/adafruit/ST7565/Configuration.h

@@ -553,6 +553,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration.h

@@ -626,6 +626,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/delta/FLSUN/kossel/Configuration.h

@@ -626,6 +626,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration.h

@@ -626,6 +626,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/delta/Hatchbox_Alpha/Configuration.h

@@ -631,6 +631,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/delta/generic/Configuration.h

@@ -616,6 +616,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/delta/kossel_mini/Configuration.h

@@ -616,6 +616,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/delta/kossel_pro/Configuration.h

@@ -602,6 +602,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/delta/kossel_xl/Configuration.h

@@ -620,6 +620,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/gCreate/gMax1.5+/Configuration.h

@@ -566,6 +566,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 #define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/makibox/Configuration.h

@@ -556,6 +556,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/stm32f103ret6/Configuration.h

@@ -555,6 +555,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/tvrrug/Round2/Configuration.h

@@ -542,6 +542,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/config/examples/wt150/Configuration.h

@@ -558,6 +558,23 @@
 // This will remove the need to poll the interrupt pins, saving many CPU cycles.
 //#define ENDSTOP_INTERRUPTS_FEATURE
 
+/**
+ * Endstop Noise Filter
+ *
+ * Enable this option if endstops falsely trigger due to noise.
+ * NOTE: Enabling this feature means adds an error of +/-0.2mm, so homing
+ * will end up at a slightly different position on each G28. This will also
+ * reduce accuracy of some bed probes.
+ * For mechanical switches, the better approach to reduce noise is to install
+ * a 100 nanofarads ceramic capacitor in parallel with the switch, making it
+ * essentially noise-proof without sacrificing accuracy.
+ * This option also increases MCU load when endstops or the probe are enabled.
+ * So this is not recommended. USE AT YOUR OWN RISK.
+ * (This feature is not required for common micro-switches mounted on PCBs
+ * based on the Makerbot design, since they already include the 100nF capacitor.)
+ */
+//#define ENDSTOP_NOISE_FILTER
+
 //=============================================================================
 //============================== Movement Settings ============================
 //=============================================================================

Marlin/src/module/delta.cpp

@@ -267,7 +267,7 @@ bool home_delta() {
 
   // If an endstop was not hit, then damage can occur if homing is continued.
   // This can occur if the delta height not set correctly.
-  if (!(Endstops::endstop_hit_bits & (_BV(X_MAX) | _BV(Y_MAX) | _BV(Z_MAX)))) {
+  if (!(endstops.trigger_state() & (_BV(X_MAX) | _BV(Y_MAX) | _BV(Z_MAX)))) {
     LCD_MESSAGEPGM(MSG_ERR_HOMING_FAILED);
     SERIAL_ERROR_START();
     SERIAL_ERRORLNPGM(MSG_ERR_HOMING_FAILED);

Marlin/src/module/endstops.cpp

@@ -36,9 +36,6 @@
   #include HAL_PATH(../HAL, endstop_interrupts.h)
 #endif
 
-// TEST_ENDSTOP: test the current status of an endstop
-#define TEST_ENDSTOP(ENDSTOP) (TEST(current_endstop_bits, ENDSTOP))
-
 #if HAS_BED_PROBE
   #define ENDSTOPS_ENABLED  (endstops.enabled || endstops.z_probe_enabled)
 #else
@@ -50,9 +47,14 @@ Endstops endstops;
 // public:
 
 bool Endstops::enabled, Endstops::enabled_globally; // Initialized by settings.load()
-volatile uint8_t Endstops::endstop_hit_bits; // use X_MIN, Y_MIN, Z_MIN and Z_MIN_PROBE as BIT value
+volatile uint8_t Endstops::hit_state;
 
-Endstops::esbits_t Endstops::current_endstop_bits = 0;
+Endstops::esbits_t Endstops::live_state = 0;
+#if ENABLED(ENDSTOP_NOISE_FILTER)
+  Endstops::esbits_t Endstops::old_live_state,
+                     Endstops::validated_live_state;
+  uint8_t Endstops::endstop_poll_count;
+#endif
 
 #if HAS_BED_PROBE
   volatile bool Endstops::z_probe_enabled = false;
@@ -230,7 +232,7 @@ void Endstops::poll() {
     endstops.run_monitor();  // report changes in endstop status
   #endif
 
-  #if DISABLED(ENDSTOP_INTERRUPTS_FEATURE)
+  #if DISABLED(ENDSTOP_INTERRUPTS_FEATURE) || ENABLED(ENDSTOP_NOISE_FILTER)
     if (ENDSTOPS_ENABLED) endstops.update();
   #endif
 }
@@ -264,7 +266,7 @@ void Endstops::not_homing() {
 
 // Clear endstops (i.e., they were hit intentionally) to suppress the report
 void Endstops::hit_on_purpose() {
-  endstop_hit_bits = 0;
+  hit_state = 0;
 
   #if ENABLED(ENDSTOP_INTERRUPTS_FEATURE)
     if (enabled) endstops.update(); // If enabling, update state now
@@ -293,7 +295,7 @@ void Endstops::hit_on_purpose() {
 #endif
 
 void Endstops::report_state() {
-  if (endstop_hit_bits) {
+  if (hit_state) {
     #if ENABLED(ULTRA_LCD)
       char chrX = ' ', chrY = ' ', chrZ = ' ', chrP = ' ';
       #define _SET_STOP_CHAR(A,C) (chr## A = C)
@@ -306,7 +308,7 @@ void Endstops::report_state() {
       _SET_STOP_CHAR(A,C); }while(0)
 
     #define _ENDSTOP_HIT_TEST(A,C) \
-      if (TEST(endstop_hit_bits, A ##_MIN) || TEST(endstop_hit_bits, A ##_MAX)) \
+      if (TEST(hit_state, A ##_MIN) || TEST(hit_state, A ##_MAX)) \
         _ENDSTOP_HIT_ECHO(A,C)
 
     #define ENDSTOP_HIT_TEST_X() _ENDSTOP_HIT_TEST(X,'X')
@@ -321,7 +323,7 @@ void Endstops::report_state() {
 
     #if ENABLED(Z_MIN_PROBE_ENDSTOP)
       #define P_AXIS Z_AXIS
-      if (TEST(endstop_hit_bits, Z_MIN_PROBE)) _ENDSTOP_HIT_ECHO(P, 'P');
+      if (TEST(hit_state, Z_MIN_PROBE)) _ENDSTOP_HIT_ECHO(P, 'P');
     #endif
     SERIAL_EOL();
 
@@ -397,69 +399,23 @@ void Endstops::M119() {
 // The following routines are called from an ISR context. It could be the temperature ISR, the
 // endstop ISR or the Stepper ISR.
 
-#if ENABLED(X_DUAL_ENDSTOPS)
+#define _ENDSTOP(AXIS, MINMAX) AXIS ##_## MINMAX
-  void Endstops::test_dual_x_endstops(const EndstopEnum es1, const EndstopEnum es2) {
+#define _ENDSTOP_PIN(AXIS, MINMAX) AXIS ##_## MINMAX ##_PIN
-    const byte x_test = TEST_ENDSTOP(es1) | (TEST_ENDSTOP(es2) << 1); // bit 0 for X, bit 1 for X2
+#define _ENDSTOP_INVERTING(AXIS, MINMAX) AXIS ##_## MINMAX ##_ENDSTOP_INVERTING
-    if (x_test && stepper.movement_non_null(X_AXIS)) {
-      SBI(endstop_hit_bits, X_MIN);
-      if (!stepper.performing_homing || (x_test == 0x3))  //if not performing home or if both endstops were trigged during homing...
-        stepper.quick_stop();
-    }
-  }
-#endif
-#if ENABLED(Y_DUAL_ENDSTOPS)
-  void Endstops::test_dual_y_endstops(const EndstopEnum es1, const EndstopEnum es2) {
-    const byte y_test = TEST_ENDSTOP(es1) | (TEST_ENDSTOP(es2) << 1); // bit 0 for Y, bit 1 for Y2
-    if (y_test && stepper.movement_non_null(Y_AXIS)) {
-      SBI(endstop_hit_bits, Y_MIN);
-      if (!stepper.performing_homing || (y_test == 0x3))  //if not performing home or if both endstops were trigged during homing...
-        stepper.quick_stop();
-    }
-  }
-#endif
-#if ENABLED(Z_DUAL_ENDSTOPS)
-  void Endstops::test_dual_z_endstops(const EndstopEnum es1, const EndstopEnum es2) {
-    const byte z_test = TEST_ENDSTOP(es1) | (TEST_ENDSTOP(es2) << 1); // bit 0 for Z, bit 1 for Z2
-    if (z_test && stepper.movement_non_null(Z_AXIS)) {
-      SBI(endstop_hit_bits, Z_MIN);
-      if (!stepper.performing_homing || (z_test == 0x3))  //if not performing home or if both endstops were trigged during homing...
-        stepper.quick_stop();
-    }
-  }
-#endif
 
 // Check endstops - Could be called from ISR!
 void Endstops::update() {
 
-  #define _ENDSTOP(AXIS, MINMAX) AXIS ##_## MINMAX
-  #define _ENDSTOP_PIN(AXIS, MINMAX) AXIS ##_## MINMAX ##_PIN
-  #define _ENDSTOP_INVERTING(AXIS, MINMAX) AXIS ##_## MINMAX ##_ENDSTOP_INVERTING
-  #define _ENDSTOP_HIT(AXIS, MINMAX) SBI(endstop_hit_bits, _ENDSTOP(AXIS, MINMAX))
-
   #define SET_BIT(N,B,TF) do{ if (TF) SBI(N,B); else CBI(N,B); }while(0)
   // UPDATE_ENDSTOP_BIT: set the current endstop bits for an endstop to its status
-  #define UPDATE_ENDSTOP_BIT(AXIS, MINMAX) SET_BIT(current_endstop_bits, _ENDSTOP(AXIS, MINMAX), (READ(_ENDSTOP_PIN(AXIS, MINMAX)) != _ENDSTOP_INVERTING(AXIS, MINMAX)))
+  #define UPDATE_ENDSTOP_BIT(AXIS, MINMAX) SET_BIT(live_state, _ENDSTOP(AXIS, MINMAX), (READ(_ENDSTOP_PIN(AXIS, MINMAX)) != _ENDSTOP_INVERTING(AXIS, MINMAX)))
   // COPY_BIT: copy the value of SRC_BIT to DST_BIT in DST
   #define COPY_BIT(DST, SRC_BIT, DST_BIT) SET_BIT(DST, DST_BIT, TEST(DST, SRC_BIT))
 
-  #define UPDATE_ENDSTOP(AXIS,MINMAX) do { \
-      UPDATE_ENDSTOP_BIT(AXIS, MINMAX); \
-      if (TEST_ENDSTOP(_ENDSTOP(AXIS, MINMAX))) { \
-        _ENDSTOP_HIT(AXIS, MINMAX); \
-        planner.endstop_triggered(_AXIS(AXIS)); \
-      } \
-    }while(0)
-
   #if ENABLED(G38_PROBE_TARGET) && PIN_EXISTS(Z_MIN_PROBE) && !(CORE_IS_XY || CORE_IS_XZ)
     // If G38 command is active check Z_MIN_PROBE for ALL movement
     if (G38_move) {
       UPDATE_ENDSTOP_BIT(Z, MIN_PROBE);
-      if (TEST_ENDSTOP(_ENDSTOP(Z, MIN_PROBE))) {
-        if      (stepper.movement_non_null(_AXIS(X))) { _ENDSTOP_HIT(X, MIN); planner.endstop_triggered(_AXIS(X)); }
-        else if (stepper.movement_non_null(_AXIS(Y))) { _ENDSTOP_HIT(Y, MIN); planner.endstop_triggered(_AXIS(Y)); }
-        else if (stepper.movement_non_null(_AXIS(Z))) { _ENDSTOP_HIT(Z, MIN); planner.endstop_triggered(_AXIS(Z)); }
-        G38_endstop_hit = true;
-      }
     }
   #endif
 
@@ -553,11 +509,10 @@ void Endstops::update() {
           #if HAS_X2_MIN
             UPDATE_ENDSTOP_BIT(X2, MIN);
           #else
-            COPY_BIT(current_endstop_bits, X_MIN, X2_MIN);
+            COPY_BIT(live_state, X_MIN, X2_MIN);
           #endif
-          test_dual_x_endstops(X_MIN, X2_MIN);
         #else
-          if (X_MIN_TEST) UPDATE_ENDSTOP(X, MIN);
+          if (X_MIN_TEST) UPDATE_ENDSTOP_BIT(X, MIN);
         #endif
       #endif
     }
@@ -568,11 +523,10 @@ void Endstops::update() {
           #if HAS_X2_MAX
             UPDATE_ENDSTOP_BIT(X2, MAX);
           #else
-            COPY_BIT(current_endstop_bits, X_MAX, X2_MAX);
+            COPY_BIT(live_state, X_MAX, X2_MAX);
           #endif
-          test_dual_x_endstops(X_MAX, X2_MAX);
         #else
-          if (X_MAX_TEST) UPDATE_ENDSTOP(X, MAX);
+          if (X_MAX_TEST) UPDATE_ENDSTOP_BIT(X, MAX);
         #endif
       #endif
     }
@@ -586,11 +540,10 @@ void Endstops::update() {
           #if HAS_Y2_MIN
             UPDATE_ENDSTOP_BIT(Y2, MIN);
           #else
-            COPY_BIT(current_endstop_bits, Y_MIN, Y2_MIN);
+            COPY_BIT(live_state, Y_MIN, Y2_MIN);
           #endif
-          test_dual_y_endstops(Y_MIN, Y2_MIN);
         #else
-          UPDATE_ENDSTOP(Y, MIN);
+          UPDATE_ENDSTOP_BIT(Y, MIN);
         #endif
       #endif
     }
@@ -601,11 +554,10 @@ void Endstops::update() {
           #if HAS_Y2_MAX
             UPDATE_ENDSTOP_BIT(Y2, MAX);
           #else
-            COPY_BIT(current_endstop_bits, Y_MAX, Y2_MAX);
+            COPY_BIT(live_state, Y_MAX, Y2_MAX);
           #endif
-          test_dual_y_endstops(Y_MAX, Y2_MAX);
         #else
-          UPDATE_ENDSTOP(Y, MAX);
+          UPDATE_ENDSTOP_BIT(Y, MAX);
         #endif
       #endif
     }
@@ -619,14 +571,13 @@ void Endstops::update() {
           #if HAS_Z2_MIN
             UPDATE_ENDSTOP_BIT(Z2, MIN);
           #else
-            COPY_BIT(current_endstop_bits, Z_MIN, Z2_MIN);
+            COPY_BIT(live_state, Z_MIN, Z2_MIN);
           #endif
-          test_dual_z_endstops(Z_MIN, Z2_MIN);
         #else
           #if ENABLED(Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN)
-            if (z_probe_enabled) UPDATE_ENDSTOP(Z, MIN);
+            if (z_probe_enabled) UPDATE_ENDSTOP_BIT(Z, MIN);
           #else
-            UPDATE_ENDSTOP(Z, MIN);
+            UPDATE_ENDSTOP_BIT(Z, MIN);
           #endif
         #endif
       #endif
@@ -634,8 +585,7 @@ void Endstops::update() {
       // When closing the gap check the enabled probe
       #if ENABLED(Z_MIN_PROBE_ENDSTOP)
         if (z_probe_enabled) {
-          UPDATE_ENDSTOP(Z, MIN_PROBE);
+          UPDATE_ENDSTOP_BIT(Z, MIN_PROBE);
-          if (TEST_ENDSTOP(Z_MIN_PROBE)) SBI(endstop_hit_bits, Z_MIN_PROBE);
         }
       #endif
     }
@@ -647,13 +597,149 @@ void Endstops::update() {
           #if HAS_Z2_MAX
             UPDATE_ENDSTOP_BIT(Z2, MAX);
           #else
-            COPY_BIT(current_endstop_bits, Z_MAX, Z2_MAX);
+            COPY_BIT(live_state, Z_MAX, Z2_MAX);
           #endif
-          test_dual_z_endstops(Z_MAX, Z2_MAX);
         // If this pin is not hijacked for the bed probe
         // then it belongs to the Z endstop
         #elif DISABLED(Z_MIN_PROBE_ENDSTOP) || Z_MAX_PIN != Z_MIN_PROBE_PIN
-          UPDATE_ENDSTOP(Z, MAX);
+          UPDATE_ENDSTOP_BIT(Z, MAX);
+        #endif
+      #endif
+    }
+  }
+
+  // All endstops were updated.
+  #if ENABLED(ENDSTOP_NOISE_FILTER)
+    if (old_live_state != live_state) { // We detected a change. Reinit the timeout
+      /**
+       * Filtering out noise on endstops requires a delayed decision. Let's assume, due to noise,
+       * that 50% of endstop signal samples are good and 50% are bad (assuming normal distribution
+       * of random noise). Then the first sample has a 50% chance to be good or bad. The 2nd sample
+       * also has a 50% chance to be good or bad. The chances of 2 samples both being bad becomes
+       * 50% of 50%, or 25%. That was the previous implementation of Marlin endstop handling. It
+       * reduces chances of bad readings in half, at the cost of 1 extra sample period, but chances
+       * still exist. The only way to reduce them further is to increase the number of samples.
+       * To reduce the chance to 1% (1/128th) requires 7 samples (adding 7ms of delay).
+       */
+      endstop_poll_count = 7;
+      old_live_state = live_state;
+    }
+    else if (endstop_poll_count && !--endstop_poll_count)
+      validated_live_state = live_state;
+
+  #else
+
+    // Lets accept the new endstop values as valid - We assume hardware filtering of lines
+    esbits_t validated_live_state = live_state;
+
+  #endif
+
+  // Endstop readings are validated in validated_live_state
+
+  // Test the current status of an endstop
+  #define TEST_ENDSTOP(ENDSTOP) (TEST(validated_live_state, ENDSTOP))
+
+  // Record endstop was hit
+  #define _ENDSTOP_HIT(AXIS, MINMAX) SBI(hit_state, _ENDSTOP(AXIS, MINMAX))
+
+  // Call the endstop triggered routine for single endstops
+  #define PROCESS_ENDSTOP(AXIS,MINMAX) do { \
+      if (TEST_ENDSTOP(_ENDSTOP(AXIS, MINMAX))) { \
+        _ENDSTOP_HIT(AXIS, MINMAX); \
+        planner.endstop_triggered(_AXIS(AXIS)); \
+      } \
+    }while(0)
+
+  // Call the endstop triggered routine for single endstops
+  #define PROCESS_DUAL_ENDSTOP(AXIS1, AXIS2, MINMAX) do { \
+      if (TEST_ENDSTOP(_ENDSTOP(AXIS1, MINMAX)) || TEST_ENDSTOP(_ENDSTOP(AXIS2, MINMAX))) { \
+        _ENDSTOP_HIT(AXIS1, MINMAX); \
+        planner.endstop_triggered(_AXIS(AXIS1)); \
+      } \
+    }while(0)
+
+  #if ENABLED(G38_PROBE_TARGET) && PIN_EXISTS(Z_MIN_PROBE) && !(CORE_IS_XY || CORE_IS_XZ)
+    // If G38 command is active check Z_MIN_PROBE for ALL movement
+    if (G38_move) {
+      if (TEST_ENDSTOP(_ENDSTOP(Z, MIN_PROBE))) {
+        if      (stepper.movement_non_null(_AXIS(X))) { _ENDSTOP_HIT(X, MIN); planner.endstop_triggered(_AXIS(X)); }
+        else if (stepper.movement_non_null(_AXIS(Y))) { _ENDSTOP_HIT(Y, MIN); planner.endstop_triggered(_AXIS(Y)); }
+        else if (stepper.movement_non_null(_AXIS(Z))) { _ENDSTOP_HIT(Z, MIN); planner.endstop_triggered(_AXIS(Z)); }
+        G38_endstop_hit = true;
+      }
+    }
+  #endif
+
+  // Now, we must signal, after validation, if an endstop limit is pressed or not
+  if (X_MOVE_TEST) {
+    if (stepper.motor_direction(X_AXIS_HEAD)) { // -direction
+      #if HAS_X_MIN
+        #if ENABLED(X_DUAL_ENDSTOPS)
+          PROCESS_DUAL_ENDSTOP(X, X2, MIN);
+        #else
+          if (X_MIN_TEST) PROCESS_ENDSTOP(X, MIN);
+        #endif
+      #endif
+    }
+    else { // +direction
+      #if HAS_X_MAX
+        #if ENABLED(X_DUAL_ENDSTOPS)
+          PROCESS_DUAL_ENDSTOP(X, X2, MAX);
+        #else
+          if (X_MAX_TEST) PROCESS_ENDSTOP(X, MAX);
+        #endif
+      #endif
+    }
+  }
+
+  if (Y_MOVE_TEST) {
+    if (stepper.motor_direction(Y_AXIS_HEAD)) { // -direction
+      #if HAS_Y_MIN
+        #if ENABLED(Y_DUAL_ENDSTOPS)
+          PROCESS_DUAL_ENDSTOP(Y, Y2, MIN);
+        #else
+          PROCESS_ENDSTOP(Y, MIN);
+        #endif
+      #endif
+    }
+    else { // +direction
+      #if HAS_Y_MAX
+        #if ENABLED(Y_DUAL_ENDSTOPS)
+          PROCESS_DUAL_ENDSTOP(Y, Y2, MAX);
+        #else
+          PROCESS_ENDSTOP(Y, MAX);
+        #endif
+      #endif
+    }
+  }
+
+  if (Z_MOVE_TEST) {
+    if (stepper.motor_direction(Z_AXIS_HEAD)) { // Z -direction. Gantry down, bed up.
+      #if HAS_Z_MIN
+        #if ENABLED(Z_DUAL_ENDSTOPS)
+          PROCESS_DUAL_ENDSTOP(Z, Z2, MIN);
+        #else
+          #if ENABLED(Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN)
+            if (z_probe_enabled) PROCESS_ENDSTOP(Z, MIN);
+          #else
+            PROCESS_ENDSTOP(Z, MIN);
+          #endif
+        #endif
+      #endif
+
+      // When closing the gap check the enabled probe
+      #if ENABLED(Z_MIN_PROBE_ENDSTOP)
+        if (z_probe_enabled) PROCESS_ENDSTOP(Z, MIN_PROBE);
+      #endif
+    }
+    else { // Z +direction. Gantry up, bed down.
+      #if HAS_Z_MAX
+        #if ENABLED(Z_DUAL_ENDSTOPS)
+          PROCESS_DUAL_ENDSTOP(Z, Z2, MAX);
+        #elif DISABLED(Z_MIN_PROBE_ENDSTOP) || Z_MAX_PIN != Z_MIN_PROBE_PIN
+          // If this pin is not hijacked for the bed probe
+          // then it belongs to the Z endstop
+          PROCESS_ENDSTOP(Z, MAX);
         #endif
       #endif
     }
@@ -676,96 +762,96 @@ void Endstops::update() {
    */
   void Endstops::monitor() {
 
-    static uint16_t old_endstop_bits_local = 0;
+    static uint16_t old_live_state_local = 0;
     static uint8_t local_LED_status = 0;
-    uint16_t current_endstop_bits_local = 0;
+    uint16_t live_state_local = 0;
 
     #if HAS_X_MIN
-      if (READ(X_MIN_PIN)) SBI(current_endstop_bits_local, X_MIN);
+      if (READ(X_MIN_PIN)) SBI(live_state_local, X_MIN);
     #endif
     #if HAS_X_MAX
-      if (READ(X_MAX_PIN)) SBI(current_endstop_bits_local, X_MAX);
+      if (READ(X_MAX_PIN)) SBI(live_state_local, X_MAX);
     #endif
     #if HAS_Y_MIN
-      if (READ(Y_MIN_PIN)) SBI(current_endstop_bits_local, Y_MIN);
+      if (READ(Y_MIN_PIN)) SBI(live_state_local, Y_MIN);
     #endif
     #if HAS_Y_MAX
-      if (READ(Y_MAX_PIN)) SBI(current_endstop_bits_local, Y_MAX);
+      if (READ(Y_MAX_PIN)) SBI(live_state_local, Y_MAX);
     #endif
     #if HAS_Z_MIN
-      if (READ(Z_MIN_PIN)) SBI(current_endstop_bits_local, Z_MIN);
+      if (READ(Z_MIN_PIN)) SBI(live_state_local, Z_MIN);
     #endif
     #if HAS_Z_MAX
-      if (READ(Z_MAX_PIN)) SBI(current_endstop_bits_local, Z_MAX);
+      if (READ(Z_MAX_PIN)) SBI(live_state_local, Z_MAX);
     #endif
     #if HAS_Z_MIN_PROBE_PIN
-      if (READ(Z_MIN_PROBE_PIN)) SBI(current_endstop_bits_local, Z_MIN_PROBE);
+      if (READ(Z_MIN_PROBE_PIN)) SBI(live_state_local, Z_MIN_PROBE);
     #endif
     #if HAS_X2_MIN
-      if (READ(X2_MIN_PIN)) SBI(current_endstop_bits_local, X2_MIN);
+      if (READ(X2_MIN_PIN)) SBI(live_state_local, X2_MIN);
     #endif
     #if HAS_X2_MAX
-      if (READ(X2_MAX_PIN)) SBI(current_endstop_bits_local, X2_MAX);
+      if (READ(X2_MAX_PIN)) SBI(live_state_local, X2_MAX);
     #endif
     #if HAS_Y2_MIN
-      if (READ(Y2_MIN_PIN)) SBI(current_endstop_bits_local, Y2_MIN);
+      if (READ(Y2_MIN_PIN)) SBI(live_state_local, Y2_MIN);
     #endif
     #if HAS_Y2_MAX
-      if (READ(Y2_MAX_PIN)) SBI(current_endstop_bits_local, Y2_MAX);
+      if (READ(Y2_MAX_PIN)) SBI(live_state_local, Y2_MAX);
     #endif
     #if HAS_Z2_MIN
-      if (READ(Z2_MIN_PIN)) SBI(current_endstop_bits_local, Z2_MIN);
+      if (READ(Z2_MIN_PIN)) SBI(live_state_local, Z2_MIN);
     #endif
     #if HAS_Z2_MAX
-      if (READ(Z2_MAX_PIN)) SBI(current_endstop_bits_local, Z2_MAX);
+      if (READ(Z2_MAX_PIN)) SBI(live_state_local, Z2_MAX);
     #endif
 
-    uint16_t endstop_change = current_endstop_bits_local ^ old_endstop_bits_local;
+    uint16_t endstop_change = live_state_local ^ old_live_state_local;
 
     if (endstop_change) {
       #if HAS_X_MIN
-        if (TEST(endstop_change, X_MIN)) SERIAL_PROTOCOLPAIR("  X_MIN:", TEST(current_endstop_bits_local, X_MIN));
+        if (TEST(endstop_change, X_MIN)) SERIAL_PROTOCOLPAIR("  X_MIN:", TEST(live_state_local, X_MIN));
       #endif
       #if HAS_X_MAX
-        if (TEST(endstop_change, X_MAX)) SERIAL_PROTOCOLPAIR("  X_MAX:", TEST(current_endstop_bits_local, X_MAX));
+        if (TEST(endstop_change, X_MAX)) SERIAL_PROTOCOLPAIR("  X_MAX:", TEST(live_state_local, X_MAX));
       #endif
       #if HAS_Y_MIN
-        if (TEST(endstop_change, Y_MIN)) SERIAL_PROTOCOLPAIR("  Y_MIN:", TEST(current_endstop_bits_local, Y_MIN));
+        if (TEST(endstop_change, Y_MIN)) SERIAL_PROTOCOLPAIR("  Y_MIN:", TEST(live_state_local, Y_MIN));
       #endif
       #if HAS_Y_MAX
-        if (TEST(endstop_change, Y_MAX)) SERIAL_PROTOCOLPAIR("  Y_MAX:", TEST(current_endstop_bits_local, Y_MAX));
+        if (TEST(endstop_change, Y_MAX)) SERIAL_PROTOCOLPAIR("  Y_MAX:", TEST(live_state_local, Y_MAX));
       #endif
       #if HAS_Z_MIN
-        if (TEST(endstop_change, Z_MIN)) SERIAL_PROTOCOLPAIR("  Z_MIN:", TEST(current_endstop_bits_local, Z_MIN));
+        if (TEST(endstop_change, Z_MIN)) SERIAL_PROTOCOLPAIR("  Z_MIN:", TEST(live_state_local, Z_MIN));
       #endif
       #if HAS_Z_MAX
-        if (TEST(endstop_change, Z_MAX)) SERIAL_PROTOCOLPAIR("  Z_MAX:", TEST(current_endstop_bits_local, Z_MAX));
+        if (TEST(endstop_change, Z_MAX)) SERIAL_PROTOCOLPAIR("  Z_MAX:", TEST(live_state_local, Z_MAX));
       #endif
       #if HAS_Z_MIN_PROBE_PIN
-        if (TEST(endstop_change, Z_MIN_PROBE)) SERIAL_PROTOCOLPAIR("  PROBE:", TEST(current_endstop_bits_local, Z_MIN_PROBE));
+        if (TEST(endstop_change, Z_MIN_PROBE)) SERIAL_PROTOCOLPAIR("  PROBE:", TEST(live_state_local, Z_MIN_PROBE));
       #endif
       #if HAS_X2_MIN
-        if (TEST(endstop_change, X2_MIN)) SERIAL_PROTOCOLPAIR("  X2_MIN:", TEST(current_endstop_bits_local, X2_MIN));
+        if (TEST(endstop_change, X2_MIN)) SERIAL_PROTOCOLPAIR("  X2_MIN:", TEST(live_state_local, X2_MIN));
       #endif
       #if HAS_X2_MAX
-        if (TEST(endstop_change, X2_MAX)) SERIAL_PROTOCOLPAIR("  X2_MAX:", TEST(current_endstop_bits_local, X2_MAX));
+        if (TEST(endstop_change, X2_MAX)) SERIAL_PROTOCOLPAIR("  X2_MAX:", TEST(live_state_local, X2_MAX));
       #endif
       #if HAS_Y2_MIN
-        if (TEST(endstop_change, Y2_MIN)) SERIAL_PROTOCOLPAIR("  Y2_MIN:", TEST(current_endstop_bits_local, Y2_MIN));
+        if (TEST(endstop_change, Y2_MIN)) SERIAL_PROTOCOLPAIR("  Y2_MIN:", TEST(live_state_local, Y2_MIN));
       #endif
       #if HAS_Y2_MAX
-        if (TEST(endstop_change, Y2_MAX)) SERIAL_PROTOCOLPAIR("  Y2_MAX:", TEST(current_endstop_bits_local, Y2_MAX));
+        if (TEST(endstop_change, Y2_MAX)) SERIAL_PROTOCOLPAIR("  Y2_MAX:", TEST(live_state_local, Y2_MAX));
       #endif
       #if HAS_Z2_MIN
-        if (TEST(endstop_change, Z2_MIN)) SERIAL_PROTOCOLPAIR("  Z2_MIN:", TEST(current_endstop_bits_local, Z2_MIN));
+        if (TEST(endstop_change, Z2_MIN)) SERIAL_PROTOCOLPAIR("  Z2_MIN:", TEST(live_state_local, Z2_MIN));
       #endif
       #if HAS_Z2_MAX
-        if (TEST(endstop_change, Z2_MAX)) SERIAL_PROTOCOLPAIR("  Z2_MAX:", TEST(current_endstop_bits_local, Z2_MAX));
+        if (TEST(endstop_change, Z2_MAX)) SERIAL_PROTOCOLPAIR("  Z2_MAX:", TEST(live_state_local, Z2_MAX));
       #endif
       SERIAL_PROTOCOLPGM("\n\n");
       analogWrite(LED_PIN, local_LED_status);
       local_LED_status ^= 255;
-      old_endstop_bits_local = current_endstop_bits_local;
+      old_live_state_local = live_state_local;
     }
   }
 

Marlin/src/module/endstops.h

@@ -51,7 +51,6 @@ class Endstops {
   public:
 
     static bool enabled, enabled_globally;
-    static volatile uint8_t endstop_hit_bits; // use X_MIN, Y_MIN, Z_MIN and Z_MIN_PROBE as BIT value
 
     #if ENABLED(X_DUAL_ENDSTOPS) || ENABLED(Y_DUAL_ENDSTOPS) || ENABLED(Z_DUAL_ENDSTOPS)
       typedef uint16_t esbits_t;
@@ -65,11 +64,19 @@ class Endstops {
         static float z_endstop_adj;
       #endif
     #else
-      typedef byte esbits_t;
+      typedef uint8_t esbits_t;
     #endif
 
-    static esbits_t current_endstop_bits;
+  private:
+    static esbits_t live_state;
+    static volatile uint8_t hit_state;      // Use X_MIN, Y_MIN, Z_MIN and Z_MIN_PROBE as BIT index
+    #if ENABLED(ENDSTOP_NOISE_FILTER)
+      static esbits_t old_live_state,       // Old endstop value for debouncing and denoising
+                      validated_live_state; // The validated (accepted as true) endstop bits
+      static uint8_t endstop_poll_count;    // Countdown from threshold for polling
+    #endif
 
+  public:
     Endstops() {};
 
     /**
@@ -93,6 +100,16 @@ class Endstops {
      */
     static void update();
 
+    /**
+     * Get Endstop hit state.
+     */
+    FORCE_INLINE static uint8_t trigger_state() { return hit_state; }
+
+    /**
+     * Get current endstops state
+     */
+    FORCE_INLINE static esbits_t state() { return live_state; }
+
     /**
      * Print an error message reporting the position when the endstops were last hit.
      */
@@ -127,18 +144,6 @@ class Endstops {
       static void monitor();
       static void run_monitor();
     #endif
-
-  private:
-
-    #if ENABLED(X_DUAL_ENDSTOPS)
-      static void test_dual_x_endstops(const EndstopEnum es1, const EndstopEnum es2);
-    #endif
-    #if ENABLED(Y_DUAL_ENDSTOPS)
-      static void test_dual_y_endstops(const EndstopEnum es1, const EndstopEnum es2);
-    #endif
-    #if ENABLED(Z_DUAL_ENDSTOPS)
-      static void test_dual_z_endstops(const EndstopEnum es1, const EndstopEnum es2);
-    #endif
 };
 
 extern Endstops endstops;

Marlin/src/module/probe.cpp

@@ -515,7 +515,7 @@ static bool do_probe_move(const float z, const float fr_mm_s) {
   do_blocking_move_to_z(z, fr_mm_s);
 
   // Check to see if the probe was triggered
-  const bool probe_triggered = TEST(Endstops::endstop_hit_bits,
+  const bool probe_triggered = TEST(endstops.trigger_state(),
     #if ENABLED(Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN)
       Z_MIN
     #else

Marlin/src/module/stepper.cpp

@@ -184,12 +184,12 @@ volatile int32_t Stepper::endstops_trigsteps[XYZ];
   #define DUAL_ENDSTOP_APPLY_STEP(A,V)                                                                                                      \
     if (performing_homing) {                                                                                                                \
       if (A##_HOME_DIR < 0) {                                                                                                               \
-        if (!(TEST(endstops.current_endstop_bits, A##_MIN) && count_direction[_AXIS(A)] < 0) && !LOCKED_##A##_MOTOR) A##_STEP_WRITE(V);     \
+        if (!(TEST(endstops.state(), A##_MIN) && count_direction[_AXIS(A)] < 0) && !LOCKED_##A##_MOTOR) A##_STEP_WRITE(V);     \
-        if (!(TEST(endstops.current_endstop_bits, A##2_MIN) && count_direction[_AXIS(A)] < 0) && !LOCKED_##A##2_MOTOR) A##2_STEP_WRITE(V);  \
+        if (!(TEST(endstops.state(), A##2_MIN) && count_direction[_AXIS(A)] < 0) && !LOCKED_##A##2_MOTOR) A##2_STEP_WRITE(V);  \
       }                                                                                                                                     \
       else {                                                                                                                                \
-        if (!(TEST(endstops.current_endstop_bits, A##_MAX) && count_direction[_AXIS(A)] > 0) && !LOCKED_##A##_MOTOR) A##_STEP_WRITE(V);     \
+        if (!(TEST(endstops.state(), A##_MAX) && count_direction[_AXIS(A)] > 0) && !LOCKED_##A##_MOTOR) A##_STEP_WRITE(V);     \
-        if (!(TEST(endstops.current_endstop_bits, A##2_MAX) && count_direction[_AXIS(A)] > 0) && !LOCKED_##A##2_MOTOR) A##2_STEP_WRITE(V);  \
+        if (!(TEST(endstops.state(), A##2_MAX) && count_direction[_AXIS(A)] > 0) && !LOCKED_##A##2_MOTOR) A##2_STEP_WRITE(V);  \
       }                                                                                                                                     \
     }                                                                                                                                       \
     else {                                                                                                                                  \