Add initial support for probes requiring Tare and Enable pins

Marlin/Configuration.h

@@ -1006,6 +1006,33 @@
 // Feedrate (mm/min) for the "accurate" probe of each point
 #define Z_PROBE_SPEED_SLOW (Z_PROBE_SPEED_FAST / 2)
 
+/**
+ * Probe Activation Switch
+ * A switch indicating proper deployment, or an optical
+ * switch triggered when the carriage is near the bed.
+ */
+//#define PROBE_ACTIVATION_SWITCH
+#if ENABLED(PROBE_ACTIVATION_SWITCH)
+  #define PROBE_ACTIVATION_SWITCH_STATE LOW // State indicating probe is active
+  //#define PROBE_ACTIVATION_SWITCH_PIN PC6 // Override default pin
+#endif
+
+/**
+ * Tare Probe (determine zero-point) prior to each probe.
+ * Useful for a strain gauge or piezo sensor that needs to factor out
+ * elements such as cables pulling on the carriage.
+ */
+//#define PROBE_TARE
+#if ENABLED(PROBE_TARE)
+  #define PROBE_TARE_TIME  200    // (ms) Time to hold tare pin
+  #define PROBE_TARE_DELAY 200    // (ms) Delay after tare before
+  #define PROBE_TARE_STATE HIGH   // State to write pin for tare
+  //#define PROBE_TARE_PIN PA5    // Override default pin
+  #if ENABLED(PROBE_ACTIVATION_SWITCH)
+    //#define PROBE_TARE_ONLY_WHILE_INACTIVE  // Fail to tare/probe if PROBE_ACTIVATION_SWITCH is active
+  #endif
+#endif
+
 /**
  * Multiple Probing
  *

Marlin/src/gcode/probe/M401_M402.cpp

@@ -33,6 +33,7 @@
  */
 void GcodeSuite::M401() {
   probe.deploy();
+  TERN_(PROBE_TARE, probe.tare());
   report_current_position();
 }
 

Marlin/src/inc/Conditionals_post.h

@@ -2373,7 +2373,7 @@
 #endif
 
 #if HAS_BED_PROBE && (EITHER(PROBING_HEATERS_OFF, PROBING_FANS_OFF) || DELAY_BEFORE_PROBING > 0)
-  #define QUIET_PROBING 1
+  #define HAS_QUIET_PROBING 1
 #endif
 #if EITHER(ADVANCED_PAUSE_FEATURE, PROBING_HEATERS_OFF)
   #define HEATER_IDLE_HANDLER 1

Marlin/src/lcd/menu/menu_bed_corners.cpp

@@ -104,7 +104,7 @@ static int8_t bed_corner;
     #if ENABLED(BLTOUCH) && DISABLED(BLTOUCH_HS_MODE)
       bltouch.deploy(); // DEPLOY in LOW SPEED MODE on every probe action
     #endif
-    TERN_(QUIET_PROBING, probe.set_probing_paused(true));
+    TERN_(HAS_QUIET_PROBING, probe.set_probing_paused(true));
 
     // Move down until the probe is triggered
     do_blocking_move_to_z(last_z - (LEVEL_CORNERS_PROBE_TOLERANCE), manual_feedrate_mm_s.z);
@@ -141,7 +141,7 @@ static int8_t bed_corner;
       TERN_(LEVEL_CORNERS_VERIFY_RAISED, verify_corner = true);
     }
 
-    TERN_(QUIET_PROBING, probe.set_probing_paused(false));
+    TERN_(HAS_QUIET_PROBING, probe.set_probing_paused(false));
 
     #if ENABLED(BLTOUCH) && DISABLED(BLTOUCH_HS_MODE)
       bltouch.stow();

Marlin/src/module/endstops.cpp

@@ -280,6 +280,12 @@ void Endstops::init() {
     #endif
   #endif
 
+  #if PIN_EXISTS(PROBE_ACTIVATION_SWITCH)
+    SET_INPUT(PROBE_ACTIVATION_SWITCH_PIN);
+  #endif
+
+  TERN_(PROBE_TARE, probe.tare());
+
   TERN_(ENDSTOP_INTERRUPTS_FEATURE, setup_endstop_interrupts());
 
   // Enable endstops
@@ -458,6 +464,9 @@ void _O2 Endstops::report_states() {
   #if HAS_Z4_MAX
     ES_REPORT(Z4_MAX);
   #endif
+  #if ENABLED(PROBE_ACTIVATION_SWITCH)
+    print_es_state(READ(PROBE_ACTIVATION_SWITCH_PIN) == PROBE_ACTIVATION_SWITCH_STATE, PSTR("Probe Enable Pin"));
+  #endif
   #if HAS_CUSTOM_PROBE_PIN
     print_es_state(PROBE_TRIGGERED(), PSTR(STR_Z_PROBE));
   #endif
@@ -582,7 +591,7 @@ void Endstops::update() {
     #endif
   #endif
 
-  #if HAS_Z_MIN && !Z_SPI_SENSORLESS
+  #if HAS_Z_MIN && NONE(Z_SPI_SENSORLESS, Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN)
     UPDATE_ENDSTOP_BIT(Z, MIN);
     #if ENABLED(Z_MULTI_ENDSTOPS)
       #if HAS_Z2_MIN
@@ -607,10 +616,12 @@ void Endstops::update() {
     #endif
   #endif
 
-  // When closing the gap check the enabled probe
-  #if HAS_CUSTOM_PROBE_PIN
-    UPDATE_ENDSTOP_BIT(Z, MIN_PROBE);
+  #if ENABLED(PROBE_ACTIVATION_SWITCH)
+    if (READ(PROBE_ACTIVATION_SWITCH_PIN) == PROBE_ACTIVATION_SWITCH_STATE)
   #endif
+    {
+      UPDATE_ENDSTOP_BIT(Z, TERN(HAS_CUSTOM_PROBE_PIN, MIN_PROBE, MIN));
+    }
 
   #if HAS_Z_MAX && !Z_SPI_SENSORLESS
     // Check both Z dual endstops

Marlin/src/module/motion.cpp

@@ -1321,7 +1321,7 @@ void do_homing_move(const AxisEnum axis, const float distance, const feedRate_t
 
   if (is_home_dir) {
 
-    #if HOMING_Z_WITH_PROBE && QUIET_PROBING
+    #if HOMING_Z_WITH_PROBE && HAS_QUIET_PROBING
       if (axis == Z_AXIS) probe.set_probing_paused(true);
     #endif
 
@@ -1360,7 +1360,7 @@ void do_homing_move(const AxisEnum axis, const float distance, const feedRate_t
 
   if (is_home_dir) {
 
-    #if HOMING_Z_WITH_PROBE && QUIET_PROBING
+    #if HOMING_Z_WITH_PROBE && HAS_QUIET_PROBING
       if (axis == Z_AXIS) probe.set_probing_paused(false);
     #endif
 
@@ -1589,9 +1589,14 @@ void homeaxis(const AxisEnum axis) {
   // Fast move towards endstop until triggered
   if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("Home 1 Fast:");
 
-  #if BOTH(HOMING_Z_WITH_PROBE, BLTOUCH)
-    if (axis == Z_AXIS && bltouch.deploy()) return; // The initial DEPLOY
-  #endif
+  if (axis == Z_AXIS) {
+    #if BOTH(HOMING_Z_WITH_PROBE, BLTOUCH)
+      if (bltouch.deploy()) return; // The initial DEPLOY
+    #endif
+    #if BOTH(HOMING_Z_WITH_PROBE, PROBE_TARE)
+      if (probe.tare()) return;
+    #endif
+  }
 
   #if DISABLED(DELTA) && defined(SENSORLESS_BACKOFF_MM)
     const xy_float_t backoff = SENSORLESS_BACKOFF_MM;

Marlin/src/module/probe.cpp

@@ -73,7 +73,7 @@
   #include "../feature/tmc_util.h"
 #endif
 
-#if QUIET_PROBING
+#if HAS_QUIET_PROBING
   #include "stepper/indirection.h"
 #endif
 
@@ -236,7 +236,7 @@ xyz_pos_t Probe::offset; // Initialized by settings.load()
 
 #endif // Z_PROBE_ALLEN_KEY
 
-#if QUIET_PROBING
+#if HAS_QUIET_PROBING
 
   void Probe::set_probing_paused(const bool p) {
     TERN_(PROBING_HEATERS_OFF, thermalManager.pause(p));
@@ -254,7 +254,7 @@ xyz_pos_t Probe::offset; // Initialized by settings.load()
     );
   }
 
-#endif // QUIET_PROBING
+#endif // HAS_QUIET_PROBING
 
 /**
  * Raise Z to a minimum height to make room for a probe to move
@@ -437,7 +437,7 @@ bool Probe::probe_down_to_z(const float z, const feedRate_t fr_mm_s) {
     endstops.enable(true);
   #endif
 
-  TERN_(QUIET_PROBING, set_probing_paused(true));
+  TERN_(HAS_QUIET_PROBING, set_probing_paused(true));
 
   // Move down until the probe is triggered
   do_blocking_move_to_z(z, fr_mm_s);
@@ -451,7 +451,7 @@ bool Probe::probe_down_to_z(const float z, const feedRate_t fr_mm_s) {
     #endif
   ;
 
-  TERN_(QUIET_PROBING, set_probing_paused(false));
+  TERN_(HAS_QUIET_PROBING, set_probing_paused(false));
 
   // Re-enable stealthChop if used. Disable diag1 pin on driver.
   #if ENABLED(SENSORLESS_PROBING)
@@ -479,6 +479,34 @@ bool Probe::probe_down_to_z(const float z, const feedRate_t fr_mm_s) {
   return !probe_triggered;
 }
 
+#if ENABLED(PROBE_TARE)
+  /**
+   * @brief Tare the Z probe
+   *
+   * @details Signals to the probe to tare measurement
+   *
+   * @return TRUE if the tare cold not be completed
+   */
+  bool Probe::tare() {
+    #if ENABLED(PROBE_TARE_ONLY_WHILE_INACTIVE)
+      if ((READ(PROBE_ACTIVATION_SWITCH_PIN) == PROBE_ACTIVATION_SWITCH_STATE)) {
+        SERIAL_ECHOLN("Cannot tare probe, already active");
+        return true;
+      }
+    #endif
+
+    SERIAL_ECHOLN("Taring the probe");
+    const uint8_t value = !PROBE_TARE_STATE ? HIGH : LOW;
+    OUT_WRITE(PROBE_TARE_PIN, PROBE_TARE_STATE);
+    delay(PROBE_TARE_TIME);
+    OUT_WRITE(PROBE_TARE_PIN, value);
+    delay(PROBE_TARE_DELAY);
+
+    endstops.hit_on_purpose();
+    return false;
+  }
+#endif
+
 /**
  * @brief Probe at the current XY (possibly more than once) to find the bed Z.
  *
@@ -490,8 +518,13 @@ bool Probe::probe_down_to_z(const float z, const feedRate_t fr_mm_s) {
 float Probe::run_z_probe(const bool sanity_check/*=true*/) {
   DEBUG_SECTION(log_probe, "Probe::run_z_probe", DEBUGGING(LEVELING));
 
-  auto try_to_probe = [&](PGM_P const plbl, const float &z_probe_low_point, const feedRate_t fr_mm_s, const bool scheck, const float clearance) {
+  auto try_to_probe = [&](PGM_P const plbl, const float &z_probe_low_point, const feedRate_t fr_mm_s, const bool scheck, const float clearance) -> bool {
     // Do a first probe at the fast speed
+
+    #if ENABLED(PROBE_TARE)
+      if (tare()) return true;
+    #endif
+
     const bool probe_fail = probe_down_to_z(z_probe_low_point, fr_mm_s),            // No probe trigger?
                early_fail = (scheck && current_position.z > -offset.z + clearance); // Probe triggered too high?
     #if ENABLED(DEBUG_LEVELING_FEATURE)
@@ -516,6 +549,10 @@ float Probe::run_z_probe(const bool sanity_check/*=true*/) {
   #if TOTAL_PROBING == 2
 
     // Do a first probe at the fast speed
+    #if ENABLED(PROBE_TARE)
+      if (tare()) return NAN;
+    #endif
+
     if (try_to_probe(PSTR("FAST"), z_probe_low_point, z_probe_fast_mm_s,
                      sanity_check, Z_CLEARANCE_BETWEEN_PROBES) ) return NAN;
 
@@ -553,6 +590,9 @@ float Probe::run_z_probe(const bool sanity_check/*=true*/) {
     )
   #endif
     {
+      // If the probe won't tare, return
+      if (TERN0(PROBE_TARE, tare()) return true;
+
       // Probe downward slowly to find the bed
       if (try_to_probe(PSTR("SLOW"), z_probe_low_point, MMM_TO_MMS(Z_PROBE_SPEED_SLOW),
                        sanity_check, Z_CLEARANCE_MULTI_PROBE) ) return NAN;

Marlin/src/module/probe.h

@@ -202,10 +202,14 @@ class Probe {
     static void servo_probe_init();
   #endif
 
-  #if QUIET_PROBING
+  #if HAS_QUIET_PROBING
     static void set_probing_paused(const bool p);
   #endif
 
+  #if ENABLED(PROBE_TARE)
+    static bool tare();
+  #endif
+
 private:
   static bool probe_down_to_z(const float z, const feedRate_t fr_mm_s);
   static void do_z_raise(const float z_raise);

buildroot/tests/STM32F103RET6_creality-tests

@@ -12,10 +12,18 @@ set -e
 use_example_configs "Creality/Ender-3 V2"
 opt_enable MARLIN_DEV_MODE
 exec_test $1 $2 "Ender 3 v2" "$3"
+restore_configs
 
 use_example_configs "Creality/Ender-3 V2"
 opt_disable CLASSIC_JERK
 opt_add SDCARD_EEPROM_EMULATION
 exec_test $1 $2 "Ender 3 v2, SD EEPROM, w/o CLASSIC_JERK" "$3"
+restore_configs
 
+opt_set SERIAL_PORT 1
+opt_set MOTHERBOARD BOARD_CREALITY_V452
+opt_disable NOZZLE_TO_PROBE_OFFSET
+opt_enable NOZZLE_AS_PROBE Z_SAFE_HOMING Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN
+opt_enable PROBE_ACTIVATION_SWITCH PROBE_TARE PROBE_TARE_ONLY_WHILE_INACTIVE
+exec_test $1 $2 "Creality V4.5.2 PROBE_ACTIVATION_SWITCH, Probe Tare" "$3"
 restore_configs