Probe Tare, Probe Activation Switch (MarlinFirmware#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/Configuration.h

@@ -1128,6 +1128,33 @@
 // Feedrate (mm/min) for the "accurate" probe of each point
 #define Z_PROBE_SPEED_SLOW (Z_PROBE_SPEED_FAST / 6)
 
+/**
+ * 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/core/language.h

@@ -154,6 +154,7 @@
 #define STR_Z4_MIN "z4_min"
 #define STR_Z4_MAX "z4_max"
 #define STR_Z_PROBE "z_probe"
+#define STR_PROBE_EN "probe_en"
 #define STR_FILAMENT_RUNOUT_SENSOR "filament"
 #define STR_PROBE_OFFSET "Probe Offset"
 #define STR_SKEW_MIN "min_skew_factor: "

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/SanityCheck.h

@@ -1409,6 +1409,14 @@ static_assert(Y_MAX_LENGTH >= Y_BED_SIZE, "Movement bounds (Y_MIN_POS, Y_MAX_POS
  #error "Z_SAFE_HOMING is recommended when homing with a probe. Enable it or comment out this line to continue."
  #endif
 
+ #if ENABLED(PROBE_ACTIVATION_SWITCH)
+ #ifndef PROBE_ACTIVATION_SWITCH_STATE
+ #error "PROBE_ACTIVATION_SWITCH_STATE is required for PROBE_ACTIVATION_SWITCH."
+ #elif !PIN_EXISTS(PROBE_ACTIVATION_SWITCH)
+ #error "A PROBE_ACTIVATION_SWITCH_PIN is required for PROBE_ACTIVATION_SWITCH."
+ #endif
+ #endif
+
 #else
 
  /**

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 @@ class Probe {
  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

@@ -19,3 +19,12 @@ 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_ACTIVATION_SWITCH_PIN PROBE_TARE PROBE_TARE_ONLY_WHILE_INACTIVE
+exec_test $1 $2 "Creality V4.5.2 PROBE_ACTIVATION_SWITCH, Probe Tare" "$3"
+
+# clean up
+restore_configs