Probe Tare, Probe Activation Switch (#20379)

Co-authored-by: Scott Lahteine <github@thinkyhead.com>
Co-authored-by: Victor Mateus Oliveira <rhapsodyv@gmail.com>
Co-authored-by: Jason Smith <jason.inet@gmail.com>

Marlin/src/module/endstops.cpp

@@ -280,6 +280,12 @@ void Endstops::init() {
     #endif
   #endif
 
+  #if ENABLED(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 BOTH(MARLIN_DEV_MODE, PROBE_ACTIVATION_SWITCH)
+    print_es_state(READ(PROBE_ACTIVATION_SWITCH_PIN) == PROBE_ACTIVATION_SWITCH_STATE, PSTR(STR_PROBE_EN));
+  #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
@@ -607,9 +616,13 @@ 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 HAS_BED_PROBE
+    // When closing the gap check the enabled probe
+    if (true
+      #if ENABLED(PROBE_ACTIVATION_SWITCH)
+        || READ(PROBE_ACTIVATION_SWITCH_PIN) == PROBE_ACTIVATION_SWITCH_STATE
+      #endif
+    ) UPDATE_ENDSTOP_BIT(Z, TERN(HAS_CUSTOM_PROBE_PIN, MIN_PROBE, MIN));
   #endif
 
   #if HAS_Z_MAX && !Z_SPI_SENSORLESS

Marlin/src/module/motion.cpp

@@ -1589,8 +1589,11 @@ 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
+  #if HOMING_Z_WITH_PROBE
+    if (axis == Z_AXIS) {
+      if (TERN0(BLTOUCH, bltouch.deploy())) return;
+      if (TERN0(PROBE_TARE, probe.tare())) return;
+    }
   #endif
 
   #if DISABLED(DELTA) && defined(SENSORLESS_BACKOFF_MM)

Marlin/src/module/probe.cpp

@@ -512,6 +512,33 @@ 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 Signal to the probe to tare itself
+   *
+   * @return TRUE if the tare cold not be completed
+   */
+  bool Probe::tare() {
+    #if BOTH(PROBE_ACTIVATION_SWITCH, PROBE_TARE_ONLY_WHILE_INACTIVE)
+      if (READ(PROBE_ACTIVATION_SWITCH_PIN) == PROBE_ACTIVATION_SWITCH_STATE) {
+        SERIAL_ECHOLNPGM("Cannot tare an active probe");
+        return true;
+      }
+    #endif
+
+    SERIAL_ECHOLNPGM("Taring probe");
+    OUT_WRITE(PROBE_TARE_PIN, PROBE_TARE_STATE);
+    delay(PROBE_TARE_TIME);
+    OUT_WRITE(PROBE_TARE_PIN, !PROBE_TARE_STATE);
+    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.
  *
@@ -523,8 +550,11 @@ 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 (TERN0(PROBE_TARE, tare())) return true;
+
     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)
@@ -549,6 +579,8 @@ float Probe::run_z_probe(const bool sanity_check/*=true*/) {
   #if TOTAL_PROBING == 2
 
     // Do a first probe at the fast speed
+    if (TERN0(PROBE_TARE, tare())) return NAN;
+
     if (try_to_probe(PSTR("FAST"), z_probe_low_point, z_probe_fast_mm_s,
                      sanity_check, Z_CLEARANCE_BETWEEN_PROBES) ) return NAN;
 
@@ -586,6 +618,9 @@ 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

@@ -210,6 +210,10 @@ public:
     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);