diff --git a/Grbl_Esp32/src/CoolantControl.cpp b/Grbl_Esp32/src/CoolantControl.cpp
index 9496632b..de7feb2a 100644
--- a/Grbl_Esp32/src/CoolantControl.cpp
+++ b/Grbl_Esp32/src/CoolantControl.cpp
@@ -28,9 +28,9 @@ void CoolantControl::init() {
     static bool init_message = true;  // used to show messages only once.
 
     if (init_message) {
-        if (!flood_.undefined())
+        if (flood_.defined())
             grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Flood coolant on pin %s", flood_.name().c_str());
-        if (!mist_.undefined())
+        if (mist_.defined())
             grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Mist coolant on pin %s", mist_.name().c_str());
         init_message = false;
     }
@@ -46,7 +46,7 @@ CoolantState CoolantControl::get_state() {
     CoolantState cl_state = {};
     bool         pinState;
 
-    if (flood_ != Pin::UNDEFINED) {
+    if (flood_.defined()) {
         auto pinState = flood_.read();
 #ifdef INVERT_COOLANT_FLOOD_PIN
         pinState = !pinState;
@@ -57,7 +57,7 @@ CoolantState CoolantControl::get_state() {
         }
     }
 
-    if (mist_ != Pin::UNDEFINED) {
+    if (mist_.defined()) {
         auto pinState = mist_.read();
 #ifdef INVERT_COOLANT_MIST_PIN
         pinState = !pinState;
@@ -72,7 +72,7 @@ CoolantState CoolantControl::get_state() {
 }
 
 void CoolantControl::write(CoolantState state) {
-    if (flood_ != Pin::UNDEFINED) {
+    if (flood_.defined()) {
         bool pinState = state.Flood;
 #ifdef INVERT_COOLANT_FLOOD_PIN
         pinState = !pinState;
@@ -80,7 +80,7 @@ void CoolantControl::write(CoolantState state) {
         flood_.write(pinState);
     }
 
-    if (mist_ != Pin::UNDEFINED) {
+    if (mist_.defined()) {
         bool pinState = state.Mist;
 #ifdef INVERT_COOLANT_MIST_PIN
         pinState = !pinState;
@@ -126,8 +126,7 @@ void CoolantControl::sync(CoolantState state) {
 
 void CoolantControl::validate() const {}
 
-void CoolantControl::handle(Configuration::HandlerBase& handler)
-{
+void CoolantControl::handle(Configuration::HandlerBase& handler) {
     handler.handle("flood", flood_);
     handler.handle("mist", mist_);
 }
diff --git a/Grbl_Esp32/src/CoolantControl.h b/Grbl_Esp32/src/CoolantControl.h
index dba99a04..860de4bb 100644
--- a/Grbl_Esp32/src/CoolantControl.h
+++ b/Grbl_Esp32/src/CoolantControl.h
@@ -32,11 +32,12 @@ class CoolantControl : public Configuration::Configurable {
     Pin flood_;
 
     void write(CoolantState state);
+
 public:
     CoolantControl() = default;
 
-    bool hasMist() const { return mist_ != Pin::UNDEFINED; }
-    bool hasFlood() const { return flood_ != Pin::UNDEFINED; }
+    bool hasMist() const { return mist_.defined(); }
+    bool hasFlood() const { return flood_.defined(); }
 
     // Initializes coolant control pins.
     void init();
diff --git a/Grbl_Esp32/src/Limits.cpp b/Grbl_Esp32/src/Limits.cpp
index ff8c24fb..27720b3e 100644
--- a/Grbl_Esp32/src/Limits.cpp
+++ b/Grbl_Esp32/src/Limits.cpp
@@ -118,7 +118,7 @@ void limits_go_home(uint8_t cycle_mask) {
     }
     // Set search mode with approach at seek rate to quickly engage the specified cycle_mask limit switches.
     bool     approach    = true;
-    float    homing_rate = homing_seek_rate->get(); // TODO FIXME: in YAML this is per-axis. We should move this into the loop.
+    float    homing_rate = homing_seek_rate->get();  // TODO FIXME: in YAML this is per-axis. We should move this into the loop.
     uint8_t  n_active_axis;
     AxisMask limit_state, axislock;
     do {
@@ -243,7 +243,7 @@ void limits_go_home(uint8_t cycle_mask) {
     auto pulloff = homing_pulloff->get();
     for (uint8_t idx = 0; idx < n_axis; idx++) {
         Axis* axisConf = MachineConfig::instance()->_axes->_axis[idx];
-        auto homing = axisConf->_homing;
+        auto  homing   = axisConf->_homing;
         auto  steps    = axisConf->_stepsPerMm;
         if (cycle_mask & bit(idx)) {
             float travel = axisConf->_maxTravel;
@@ -273,7 +273,7 @@ void limits_init() {
     for (int axis = 0; axis < n_axis; axis++) {
         for (int gang_index = 0; gang_index < 2; gang_index++) {
             auto gangConfig = MachineConfig::instance()->_axes->_axis[axis]->_gangs[gang_index];
-            if (gangConfig->_endstops != nullptr && !gangConfig->_endstops->_dual.undefined()) {
+            if (gangConfig->_endstops != nullptr && gangConfig->_endstops->_dual.defined()) {
                 Pin& pin = gangConfig->_endstops->_dual;
 
 #ifndef DISABLE_LIMIT_PIN_PULL_UP
@@ -316,7 +316,7 @@ void limits_disable() {
     for (int axis = 0; axis < n_axis; axis++) {
         for (int gang_index = 0; gang_index < 2; gang_index++) {
             auto gangConfig = MachineConfig::instance()->_axes->_axis[axis]->_gangs[gang_index];
-            if (gangConfig->_endstops != nullptr && !gangConfig->_endstops->_dual.undefined()) {
+            if (gangConfig->_endstops != nullptr && gangConfig->_endstops->_dual.defined()) {
                 Pin& pin = gangConfig->_endstops->_dual;
                 pin.detachInterrupt();
             }
@@ -333,7 +333,7 @@ AxisMask limits_get_state() {
     for (int axis = 0; axis < n_axis; axis++) {
         for (int gang_index = 0; gang_index < 2; gang_index++) {
             auto gangConfig = MachineConfig::instance()->_axes->_axis[axis]->_gangs[gang_index];
-            if (gangConfig->_endstops != nullptr && !gangConfig->_endstops->_dual.undefined()) {
+            if (gangConfig->_endstops != nullptr && gangConfig->_endstops->_dual.defined()) {
                 Pin& pin = gangConfig->_endstops->_dual;
                 pinMask |= (pin.read() << axis);
             }
@@ -393,19 +393,19 @@ void limitCheckTask(void* pvParameters) {
 }
 
 float limitsMaxPosition(uint8_t axis) {
-    auto axisConfig = MachineConfig::instance()->_axes->_axis[axis];
-    auto homing = axisConfig->_homing;
-    float mpos = (homing != nullptr) ? homing->_mpos : 0;
-    auto maxtravel = axisConfig->_maxTravel;
+    auto  axisConfig = MachineConfig::instance()->_axes->_axis[axis];
+    auto  homing     = axisConfig->_homing;
+    float mpos       = (homing != nullptr) ? homing->_mpos : 0;
+    auto  maxtravel  = axisConfig->_maxTravel;
 
     return (homing == nullptr || homing->_positiveDirection) ? mpos + maxtravel : mpos;
 }
 
 float limitsMinPosition(uint8_t axis) {
-    auto axisConfig = MachineConfig::instance()->_axes->_axis[axis];
-    auto homing = axisConfig->_homing;
-    float mpos = (homing != nullptr) ? homing->_mpos : 0;
-    auto maxtravel = axisConfig->_maxTravel;
+    auto  axisConfig = MachineConfig::instance()->_axes->_axis[axis];
+    auto  homing     = axisConfig->_homing;
+    float mpos       = (homing != nullptr) ? homing->_mpos : 0;
+    auto  maxtravel  = axisConfig->_maxTravel;
 
     return (homing == nullptr || homing->_positiveDirection) ? mpos : mpos - maxtravel;
 }
@@ -428,12 +428,10 @@ bool __attribute__((weak)) limitsCheckTravel(float* target) {
 
 bool limitsSwitchDefined(uint8_t axis, uint8_t gang_index) {
     auto gangConfig = MachineConfig::instance()->_axes->_axis[axis]->_gangs[gang_index];
-    
-    if (gangConfig->_endstops != nullptr)
-    {
-        return !gangConfig->_endstops->_dual.undefined();
-    }
-    else {
+
+    if (gangConfig->_endstops != nullptr) {
+        return gangConfig->_endstops->_dual.defined();
+    } else {
         return false;
     }
 }
diff --git a/Grbl_Esp32/src/MachineConfig.cpp b/Grbl_Esp32/src/MachineConfig.cpp
index 394cdaef..33b838ad 100644
--- a/Grbl_Esp32/src/MachineConfig.cpp
+++ b/Grbl_Esp32/src/MachineConfig.cpp
@@ -18,18 +18,18 @@
 // TODO FIXME: Split this file up into several files, perhaps put it in some folder and namespace Machine?
 
 void Endstops::validate() const {
-//    if (!_dual.undefined()) {
-//        Assert(_positive.undefined(), "If dual endstops are defined, you cannot also define positive and negative endstops");
-//        Assert(_negative.undefined(), "If dual endstops are defined, you cannot also define positive and negative endstops");
-//    }
-//    if (!_positive.undefined() || !_negative.undefined()) {
-//        Assert(_positive.undefined(), "If positive or negative endstops are defined, you cannot also define dual endstops");
-//    }
+    //    if (_dual.defined()) {
+    //        Assert(_positive.undefined(), "If dual endstops are defined, you cannot also define positive and negative endstops");
+    //        Assert(_negative.undefined(), "If dual endstops are defined, you cannot also define positive and negative endstops");
+    //    }
+    //    if (_positive.defined() || _negative.defined()) {
+    //        Assert(_positive.undefined(), "If positive or negative endstops are defined, you cannot also define dual endstops");
+    //    }
 }
 
 void Endstops::handle(Configuration::HandlerBase& handler) {
-//     handler.handle("positive", _positive);
-//     handler.handle("negative", _negative);
+    //     handler.handle("positive", _positive);
+    //     handler.handle("negative", _negative);
     handler.handle("dual", _dual);
     handler.handle("hard_limits", _hardLimits);
 }
@@ -102,14 +102,13 @@ void Axes::init() {
 #ifdef USE_STEPSTICK
     grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Using StepStick Mode");
 
-    if (StepperResetPin->get() != Pin::UNDEFINED) {
+    if (StepperResetPin->get().defined()) {
         // !RESET pin on steppers  (MISO On Schematic)
         StepperResetPin->get().setAttr(Pin::Attr::Output | Pin::Attr::InitialOn);
     }
 #endif
 
-    if (!_sharedStepperDisable.undefined())
-    {
+    if (_sharedStepperDisable.defined()) {
         _sharedStepperDisable.setAttr(Pin::Attr::Output);
         grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Shared stepper disable pin:%s", _sharedStepperDisable.name());
     }
@@ -322,10 +321,10 @@ Axes::~Axes() {
 }
 
 void I2SOBus::validate() const {
-    if (!_bck.undefined() || !_data.undefined() || !_ws.undefined()) {
-        Assert(!_bck.undefined(), "I2SO BCK pin should be configured once.");
-        Assert(!_data.undefined(), "I2SO Data pin should be configured once.");
-        Assert(!_ws.undefined(), "I2SO WS pin should be configured once.");
+    if (_bck.defined() || _data.defined() || _ws.defined()) {
+        Assert(_bck.defined(), "I2SO BCK pin should be configured once.");
+        Assert(_data.defined(), "I2SO Data pin should be configured once.");
+        Assert(_ws.defined(), "I2SO WS pin should be configured once.");
     }
 }
 
@@ -336,11 +335,11 @@ void I2SOBus::handle(Configuration::HandlerBase& handler) {
 }
 
 void SPIBus::validate() const {
-    if (!_ss.undefined() || !_miso.undefined() || !_mosi.undefined() || !_sck.undefined()) {
-        Assert(!_ss.undefined(), "SPI SS pin should be configured once.");
-        Assert(!_miso.undefined(), "SPI MISO pin should be configured once.");
-        Assert(!_mosi.undefined(), "SPI MOSI pin should be configured once.");
-        Assert(!_sck.undefined(), "SPI SCK pin should be configured once.");
+    if (_ss.defined() || _miso.defined() || _mosi.defined() || _sck.defined()) {
+        Assert(_ss.defined(), "SPI SS pin should be configured once.");
+        Assert(_miso.defined(), "SPI MISO pin should be configured once.");
+        Assert(_mosi.defined(), "SPI MOSI pin should be configured once.");
+        Assert(_sck.defined(), "SPI SCK pin should be configured once.");
     }
 }
 
diff --git a/Grbl_Esp32/src/Pin.h b/Grbl_Esp32/src/Pin.h
index 850d03ba..e83df722 100644
--- a/Grbl_Esp32/src/Pin.h
+++ b/Grbl_Esp32/src/Pin.h
@@ -67,6 +67,7 @@ public:
     inline bool operator!=(const Pin& o) const { return _index != o._index; }
 
     inline bool undefined() const { return (*this) == UNDEFINED; }
+    inline bool defined() const { return (*this) != UNDEFINED; }
 
     inline uint8_t getNative(Capabilities expectedBehavior) const {
         auto detail = Pins::PinLookup::_instance.GetPin(_index);
@@ -89,7 +90,7 @@ public:
         detail->setAttr(attributes);
     }
 
-    inline Attr getAttr() const { 
+    inline Attr getAttr() const {
         auto detail = Pins::PinLookup::_instance.GetPin(_index);
         return detail->getAttr();
     }
diff --git a/Grbl_Esp32/src/Probe.h b/Grbl_Esp32/src/Probe.h
index f21332df..eb1a5520 100644
--- a/Grbl_Esp32/src/Probe.h
+++ b/Grbl_Esp32/src/Probe.h
@@ -42,7 +42,7 @@ class Probe : public Configuration::Configurable {
 public:
     Probe() = default;
 
-    bool exists() const { return _probePin != Pin::UNDEFINED; }
+    bool exists() const { return _probePin.defined(); }
 
     // Probe pin initialization routine.
     void init();
diff --git a/Grbl_Esp32/src/SDCard.cpp b/Grbl_Esp32/src/SDCard.cpp
index 7a118c3e..85c8fa62 100644
--- a/Grbl_Esp32/src/SDCard.cpp
+++ b/Grbl_Esp32/src/SDCard.cpp
@@ -144,7 +144,7 @@ SDState get_sd_state(bool refresh) {
         SPI.begin(sckPin, misoPin, mosiPin, ssPin);  // this will get called for each motor, but does not seem to hurt anything
 
         //no need to go further if SD detect is not correct
-        if (SDCardDetPin->get() != Pin::UNDEFINED) {
+        if (SDCardDetPin->get().defined()) {
             if (!((SDCardDetPin->get().read() == SDCARD_DET_VAL) ? true : false)) {
                 sd_state = SDState::NotPresent;
                 return sd_state;
diff --git a/Grbl_Esp32/src/Spindles/10vSpindle.cpp b/Grbl_Esp32/src/Spindles/10vSpindle.cpp
index 0f1b5124..580ed095 100644
--- a/Grbl_Esp32/src/Spindles/10vSpindle.cpp
+++ b/Grbl_Esp32/src/Spindles/10vSpindle.cpp
@@ -34,7 +34,7 @@ namespace Spindles {
         _forward_pin = SpindleForwardPin->get();
         _reverse_pin = SpindleReversePin->get();
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             grbl_msg_sendf(CLIENT_ALL, MsgLevel::Info, "Warning: Spindle output pin not defined");
             return;  // We cannot continue without the output pin
         }
@@ -74,7 +74,7 @@ namespace Spindles {
     uint32_t _10v::set_rpm(uint32_t rpm) {
         uint32_t pwm_value;
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             return rpm;
         }
 
@@ -121,10 +121,10 @@ namespace Spindles {
 	*/
 
     SpindleState _10v::get_state() {
-        if (_current_pwm_duty == 0 || _output_pin == Pin::UNDEFINED) {
+        if (_current_pwm_duty == 0 || _output_pin.undefined()) {
             return SpindleState::Disable;
         }
-        if (_direction_pin != Pin::UNDEFINED) {
+        if (_direction_pin.defined()) {
             return _direction_pin.read() ? SpindleState::Cw : SpindleState::Ccw;
         }
         return SpindleState::Cw;
diff --git a/Grbl_Esp32/src/Spindles/BESCSpindle.cpp b/Grbl_Esp32/src/Spindles/BESCSpindle.cpp
index 357e0d6c..1e10dd65 100644
--- a/Grbl_Esp32/src/Spindles/BESCSpindle.cpp
+++ b/Grbl_Esp32/src/Spindles/BESCSpindle.cpp
@@ -54,7 +54,7 @@ namespace Spindles {
     void BESC::init() {
         get_pins_and_settings();  // these gets the standard PWM settings, but many need to be changed for BESC
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             grbl_msg_sendf(CLIENT_ALL, MsgLevel::Info, "Warning: BESC output pin not defined");
             return;  // We cannot continue without the output pin
         }
@@ -97,7 +97,7 @@ namespace Spindles {
     uint32_t BESC::set_rpm(uint32_t rpm) {
         uint32_t pwm_value;
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             return rpm;
         }
 
diff --git a/Grbl_Esp32/src/Spindles/DacSpindle.cpp b/Grbl_Esp32/src/Spindles/DacSpindle.cpp
index 8f4d3077..f29beb79 100644
--- a/Grbl_Esp32/src/Spindles/DacSpindle.cpp
+++ b/Grbl_Esp32/src/Spindles/DacSpindle.cpp
@@ -28,7 +28,7 @@ namespace Spindles {
     void Dac::init() {
         get_pins_and_settings();
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             return;
         }
 
@@ -47,7 +47,7 @@ namespace Spindles {
         _enable_pin.setAttr(Pin::Attr::Output);
         _direction_pin.setAttr(Pin::Attr::Output);
 
-        is_reversable = (_direction_pin != Pin::UNDEFINED);
+        is_reversable = _direction_pin.defined();
         use_delays    = true;
 
         config_message();
@@ -63,7 +63,7 @@ namespace Spindles {
     }
 
     uint32_t Dac::set_rpm(uint32_t rpm) {
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             return rpm;
         }
 
diff --git a/Grbl_Esp32/src/Spindles/Laser.cpp b/Grbl_Esp32/src/Spindles/Laser.cpp
index 418e2e90..f9ceefe9 100644
--- a/Grbl_Esp32/src/Spindles/Laser.cpp
+++ b/Grbl_Esp32/src/Spindles/Laser.cpp
@@ -51,7 +51,7 @@ namespace Spindles {
 
         _enable_pin = LaserEnablePin->get();
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             grbl_msg_sendf(CLIENT_ALL, MsgLevel::Info, "Warning: LASER_OUTPUT_PIN not defined");
             return;  // We cannot continue without the output pin
         }
diff --git a/Grbl_Esp32/src/Spindles/PWMSpindle.cpp b/Grbl_Esp32/src/Spindles/PWMSpindle.cpp
index 3344f0c6..94d6a97a 100644
--- a/Grbl_Esp32/src/Spindles/PWMSpindle.cpp
+++ b/Grbl_Esp32/src/Spindles/PWMSpindle.cpp
@@ -34,7 +34,7 @@ namespace Spindles {
     void PWM::init() {
         get_pins_and_settings();
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             grbl_msg_sendf(CLIENT_ALL, MsgLevel::Info, "Warning: Spindle output pin not defined");
             return;  // We cannot continue without the output pin
         }
@@ -75,7 +75,7 @@ namespace Spindles {
 
         _direction_pin = SpindleDirectionPin->get();
 
-        is_reversable = (_direction_pin != Pin::UNDEFINED);
+        is_reversable = _direction_pin.defined();
 
         _pwm_freq      = spindle_pwm_freq->get();
         _pwm_precision = calc_pwm_precision(_pwm_freq);  // detewrmine the best precision
@@ -111,7 +111,7 @@ namespace Spindles {
     uint32_t PWM::set_rpm(uint32_t rpm) {
         uint32_t pwm_value;
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             return rpm;
         }
 
@@ -174,10 +174,10 @@ namespace Spindles {
     }
 
     SpindleState PWM::get_state() {
-        if (_current_pwm_duty == 0 || _output_pin == Pin::UNDEFINED) {
+        if (_current_pwm_duty == 0 || _output_pin.undefined()) {
             return SpindleState::Disable;
         }
-        if (_direction_pin != Pin::UNDEFINED) {
+        if (_direction_pin.defined()) {
             return _direction_pin.read() ? SpindleState::Cw : SpindleState::Ccw;
         }
         return SpindleState::Cw;
@@ -202,7 +202,7 @@ namespace Spindles {
     }
 
     void PWM::set_output(uint32_t duty) {
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             return;
         }
 
@@ -228,7 +228,7 @@ namespace Spindles {
     }
 
     void PWM::set_enable_pin(bool enable) {
-        if (_enable_pin == Pin::UNDEFINED) {
+        if (_enable_pin.undefined()) {
             return;
         }
 
diff --git a/Grbl_Esp32/src/Spindles/RelaySpindle.cpp b/Grbl_Esp32/src/Spindles/RelaySpindle.cpp
index 4799b50a..fd3b0322 100644
--- a/Grbl_Esp32/src/Spindles/RelaySpindle.cpp
+++ b/Grbl_Esp32/src/Spindles/RelaySpindle.cpp
@@ -30,7 +30,7 @@ namespace Spindles {
     void Relay::init() {
         get_pins_and_settings();
 
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             return;
         }
 
@@ -38,7 +38,7 @@ namespace Spindles {
         _enable_pin.setAttr(Pin::Attr::Output);
         _direction_pin.setAttr(Pin::Attr::Output);
 
-        is_reversable = (_direction_pin != Pin::UNDEFINED);
+        is_reversable = _direction_pin.defined();
         use_delays    = true;
 
         config_message();
@@ -55,7 +55,7 @@ namespace Spindles {
     }
 
     uint32_t Relay::set_rpm(uint32_t rpm) {
-        if (_output_pin == Pin::UNDEFINED) {
+        if (_output_pin.undefined()) {
             return rpm;
         }
 
diff --git a/Grbl_Esp32/src/Spindles/VFDSpindle.cpp b/Grbl_Esp32/src/Spindles/VFDSpindle.cpp
index b90d0ab5..81e1f569 100644
--- a/Grbl_Esp32/src/Spindles/VFDSpindle.cpp
+++ b/Grbl_Esp32/src/Spindles/VFDSpindle.cpp
@@ -301,19 +301,19 @@ namespace Spindles {
         bool pins_settings_ok = true;
 
         _txd_pin = VFDRS485TXDPin->get();
-        if (_txd_pin == Pin::UNDEFINED) {
+        if (_txd_pin.undefined()) {
             grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Undefined VFD_RS485_TXD_PIN");
             pins_settings_ok = false;
         }
 
         _rxd_pin = VFDRS485RXDPin->get();
-        if (_rxd_pin == Pin::UNDEFINED) {
+        if (_rxd_pin.undefined()) {
             grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Undefined VFD_RS485_RXD_PIN");
             pins_settings_ok = false;
         }
 
         _rts_pin = VFDRS485RTSPin->get();
-        if (_rts_pin == Pin::UNDEFINED) {
+        if (_rts_pin.undefined()) {
             grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Undefined VFD_RS485_RTS_PIN");
             pins_settings_ok = false;
         }
diff --git a/Grbl_Esp32/src/Stepper.cpp b/Grbl_Esp32/src/Stepper.cpp
index 6d3c5892..981ca5d0 100644
--- a/Grbl_Esp32/src/Stepper.cpp
+++ b/Grbl_Esp32/src/Stepper.cpp
@@ -994,10 +994,9 @@ void IRAM_ATTR Stepper_Timer_Stop() {
 
 bool get_stepper_disable() {  // returns true if steppers are disabled
     auto axesConfig = MachineConfig::instance()->_axes;
-    if (!axesConfig->_sharedStepperDisable.undefined()) {
+    if (axesConfig->_sharedStepperDisable.defined()) {
         bool disabled = axesConfig->_sharedStepperDisable.read();
         return disabled;
-    } else {
-        return false;  // thery are never disabled if there is no pin defined
     }
+    return false;  // they are never disabled if there is no pin defined
 }
diff --git a/Grbl_Esp32/src/System.cpp b/Grbl_Esp32/src/System.cpp
index d23dede5..c61fc925 100644
--- a/Grbl_Esp32/src/System.cpp
+++ b/Grbl_Esp32/src/System.cpp
@@ -49,7 +49,7 @@ bool         debouncing = false;  // debouncing in process
 void system_ini() {  // Renamed from system_init() due to conflict with esp32 files
     // setup control inputs
 
-    if (ControlSafetyDoorPin->get() != Pin::UNDEFINED) {
+    if (ControlSafetyDoorPin->get().defined()) {
         grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Door switch on pin %s", ControlSafetyDoorPin->getStringValue());
         auto pin  = ControlSafetyDoorPin->get();
         auto attr = Pin::Attr::Input | Pin::Attr::ISR;
@@ -60,7 +60,7 @@ void system_ini() {  // Renamed from system_init() due to conflict with esp32 fi
         pin.attachInterrupt(isr_control_inputs, CHANGE);
     }
 
-    if (ControlResetPin->get() != Pin::UNDEFINED) {
+    if (ControlResetPin->get().defined()) {
         grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Reset switch on pin %s", ControlResetPin->getStringValue());
         auto pin  = ControlResetPin->get();
         auto attr = Pin::Attr::Input | Pin::Attr::ISR;
@@ -71,7 +71,7 @@ void system_ini() {  // Renamed from system_init() due to conflict with esp32 fi
         pin.attachInterrupt(isr_control_inputs, CHANGE);
     }
 
-    if (ControlFeedHoldPin->get() != Pin::UNDEFINED) {
+    if (ControlFeedHoldPin->get().defined()) {
         grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Hold switch on pin %s", ControlFeedHoldPin->getStringValue());
         auto pin  = ControlFeedHoldPin->get();
         auto attr = Pin::Attr::Input | Pin::Attr::ISR;
@@ -82,7 +82,7 @@ void system_ini() {  // Renamed from system_init() due to conflict with esp32 fi
         pin.attachInterrupt(isr_control_inputs, CHANGE);
     }
 
-    if (ControlCycleStartPin->get() != Pin::UNDEFINED) {
+    if (ControlCycleStartPin->get().defined()) {
         grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Start switch on pin %s", ControlCycleStartPin->getStringValue());
         auto pin  = ControlCycleStartPin->get();
         auto attr = Pin::Attr::Input | Pin::Attr::ISR;
@@ -93,7 +93,7 @@ void system_ini() {  // Renamed from system_init() due to conflict with esp32 fi
         pin.attachInterrupt(isr_control_inputs, CHANGE);
     }
 
-    if (MacroButton0Pin->get() != Pin::UNDEFINED) {
+    if (MacroButton0Pin->get().defined()) {
         auto pin  = MacroButton0Pin->get();
         auto attr = Pin::Attr::Input | Pin::Attr::ISR;
         if (pin.capabilities().has(Pins::PinCapabilities::PullUp)) {
@@ -103,7 +103,7 @@ void system_ini() {  // Renamed from system_init() due to conflict with esp32 fi
         pin.attachInterrupt(isr_control_inputs, CHANGE);
     }
 
-    if (MacroButton1Pin->get() != Pin::UNDEFINED) {
+    if (MacroButton1Pin->get().defined()) {
         auto pin  = MacroButton1Pin->get();
         auto attr = Pin::Attr::Input | Pin::Attr::ISR;
         if (pin.capabilities().has(Pins::PinCapabilities::PullUp)) {
@@ -113,7 +113,7 @@ void system_ini() {  // Renamed from system_init() due to conflict with esp32 fi
         pin.attachInterrupt(isr_control_inputs, CHANGE);
     }
 
-    if (MacroButton2Pin->get() != Pin::UNDEFINED) {
+    if (MacroButton2Pin->get().defined()) {
         auto pin  = MacroButton2Pin->get();
         auto attr = Pin::Attr::Input | Pin::Attr::ISR;
         if (pin.capabilities().has(Pins::PinCapabilities::PullUp)) {
@@ -123,7 +123,7 @@ void system_ini() {  // Renamed from system_init() due to conflict with esp32 fi
         pin.attachInterrupt(isr_control_inputs, CHANGE);
     }
 
-    if (MacroButton3Pin->get() != Pin::UNDEFINED) {
+    if (MacroButton3Pin->get().defined()) {
         auto pin  = MacroButton3Pin->get();
         auto attr = Pin::Attr::Input | Pin::Attr::ISR;
         if (pin.capabilities().has(Pins::PinCapabilities::PullUp)) {
@@ -244,42 +244,42 @@ ControlPins system_control_get_state() {
     ControlPins pin_states;
     pin_states.value = 0;
 
-    defined_pins.bit.safetyDoor = ControlSafetyDoorPin->get() != Pin::UNDEFINED;
+    defined_pins.bit.safetyDoor = ControlSafetyDoorPin->get().defined();
     if (ControlSafetyDoorPin->get().read()) {
         pin_states.bit.safetyDoor = true;
     }
 
-    defined_pins.bit.reset = ControlResetPin->get() != Pin::UNDEFINED;
+    defined_pins.bit.reset = ControlResetPin->get().defined();
     if (ControlResetPin->get().read()) {
         pin_states.bit.reset = true;
     }
 
-    defined_pins.bit.feedHold = ControlFeedHoldPin->get() != Pin::UNDEFINED;
+    defined_pins.bit.feedHold = ControlFeedHoldPin->get().defined();
     if (ControlFeedHoldPin->get().read()) {
         pin_states.bit.feedHold = true;
     }
 
-    defined_pins.bit.cycleStart = ControlCycleStartPin->get() != Pin::UNDEFINED;
+    defined_pins.bit.cycleStart = ControlCycleStartPin->get().defined();
     if (ControlCycleStartPin->get().read()) {
         pin_states.bit.cycleStart = true;
     }
 
-    defined_pins.bit.macro0 = MacroButton0Pin->get() != Pin::UNDEFINED;
+    defined_pins.bit.macro0 = MacroButton0Pin->get().defined();
     if (MacroButton0Pin->get().read()) {
         pin_states.bit.macro0 = true;
     }
 
-    defined_pins.bit.macro1 = MacroButton1Pin->get() != Pin::UNDEFINED;
+    defined_pins.bit.macro1 = MacroButton1Pin->get().defined();
     if (MacroButton1Pin->get().read()) {
         pin_states.bit.macro1 = true;
     }
 
-    defined_pins.bit.macro2 = MacroButton2Pin->get() != Pin::UNDEFINED;
+    defined_pins.bit.macro2 = MacroButton2Pin->get().defined();
     if (MacroButton2Pin->get().read()) {
         pin_states.bit.macro2 = true;
     }
 
-    defined_pins.bit.macro3 = MacroButton3Pin->get() != Pin::UNDEFINED;
+    defined_pins.bit.macro3 = MacroButton3Pin->get().defined();
     if (MacroButton3Pin->get().read()) {
         pin_states.bit.macro3 = true;
     }
diff --git a/Grbl_Esp32/src/UserOutput.cpp b/Grbl_Esp32/src/UserOutput.cpp
index 1a5dead9..84069bbf 100644
--- a/Grbl_Esp32/src/UserOutput.cpp
+++ b/Grbl_Esp32/src/UserOutput.cpp
@@ -26,7 +26,7 @@ namespace UserOutput {
         _number = number;
         _pin    = pin;
 
-        if (_pin == Pin::UNDEFINED) {
+        if (_pin.undefined()) {
             return;
         }
 
@@ -62,7 +62,7 @@ namespace UserOutput {
         _pin           = pin;
         _pwm_frequency = pwm_frequency;
 
-        if (pin == Pin::UNDEFINED) {
+        if (pin.undefined()) {
             return;
         }
 
@@ -104,7 +104,7 @@ namespace UserOutput {
     // returns true if able to set value
     bool AnalogOutput::set_level(uint32_t numerator) {
         // look for errors, but ignore if turning off to prevent mask turn off from generating errors
-        if (_pin == Pin::UNDEFINED) {
+        if (_pin.undefined()) {
             return false;
         }