diff --git a/Grbl_Esp32/src/Machines/test_drive.h b/Grbl_Esp32/src/Machines/test_drive.h
index 95d57d22..41a6324a 100644
--- a/Grbl_Esp32/src/Machines/test_drive.h
+++ b/Grbl_Esp32/src/Machines/test_drive.h
@@ -46,32 +46,60 @@
     #undef DEFAULT_HOMING_CYCLE_1
 #endif
 
-#define SPINDLE_TYPE    SpindleType::NONE
 
 #ifdef USE_RMT_STEPS
 #undef USE_RMT_STEPS  // Suppress unused variable warning
 #endif
 
 
-// Output devices :
+// Output devices:
 // - I2S
-// x CoolantControl
-// - StandardStepper
-#define X_STEP_PIN              "gpio.2"
-#define X_DIRECTION_PIN         "gpio.4"
-#define X_DISABLE_PIN           "gpio.16"
 
-// - Unipolar
-// - 10V
+// x CoolantControl
+
+// #define COOLANT_MIST_PIN        "gpio.2"  // labeled Mist
+// #define COOLANT_FLOOD_PIN       "gpio.4"  // labeled Flood
+
+// x StandardStepper
+
+// #define X_STEP_PIN              "gpio.2"
+// #define X_DIRECTION_PIN         "gpio.4"
+// #define X_DISABLE_PIN           "gpio.16"
+
+// x Unipolar
+
+// #define X_UNIPOLAR
+// #define X_PIN_PHASE_0           "gpio.2"
+// #define X_PIN_PHASE_1           "gpio.4"
+// #define X_PIN_PHASE_2           "gpio.16"
+// #define X_PIN_PHASE_3           "gpio.15"
+
+// Spindles:
+
+#define SPINDLE_TYPE            SpindleType::NONE
+
+// #define SPINDLE_OUTPUT_PIN	    "gpio.15"
+// #define SPINDLE_ENABLE_PIN	    "gpio.2"
+// #define SPINDLE_DIRECTION_PIN	"gpio.4"
+// #define SPINDLE_FORWARD_PIN	    "gpio.16"
+// #define SPINDLE_REVERSE_PIN	    "gpio.17"
+
+// x 10V
+// #define SPINDLE_TYPE            SpindleType::_10V
+
+// x PWM
+// #define SPINDLE_TYPE            SpindleType::PWM
+
+// x Relay
+// #define SPINDLE_TYPE            SpindleType::RELAY
+
 // - BESC
 // - DAC
-// - Laser
-// - PWM
-// - Relay
-// - Stepper
 // 
 // Input devices :
-// -Probe
+// x Probe
+// #define PROBE_PIN               "gpio.18:pu"  // labeled Probe
+
 // - User Analog / Digital pins
 // - Limits
 // - System : ControlSafetyDoor
diff --git a/Grbl_Esp32/src/Pins/DebugPinDetail.cpp b/Grbl_Esp32/src/Pins/DebugPinDetail.cpp
index 5446f2ff..c0741336 100644
--- a/Grbl_Esp32/src/Pins/DebugPinDetail.cpp
+++ b/Grbl_Esp32/src/Pins/DebugPinDetail.cpp
@@ -1,15 +1,31 @@
 #include "DebugPinDetail.h"
 
-#include "../Grbl.h"  // for printf
-#include <Arduino.h>  // for timer
+#include "../Grbl.h"         // for printf
+#include <Arduino.h>         // for timer
+#include <HardwareSerial.h>  // HW serial
+#include <cstdio>            // vsnprintf
 
 namespace Pins {
+    inline void WriteSerial(const char* format, ...) {
+        char    buf[50];
+        va_list arg;
+        va_list copy;
+        va_start(arg, format);
+        va_copy(copy, arg);
+        size_t len = vsnprintf(buf, 50, format, arg);
+        va_end(copy);
+        Serial.print("[MSG: ");
+        Serial.print(buf);
+        Serial.println(" ]");
+        va_end(arg);
+    }
+
     // I/O:
     void DebugPinDetail::write(int high) {
         if (high != _isHigh) {
             _isHigh = high;
             if (shouldEvent()) {
-                grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Writing pin %s = %d", toString().c_str(), high);
+                WriteSerial( "Write %s < %d", toString().c_str(), high);
             }
         }
         _implementation->write(high);
@@ -18,7 +34,7 @@ namespace Pins {
     int DebugPinDetail::read() {
         auto result = _implementation->read();
         if (shouldEvent()) {
-            grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Reading pin %s = %d", toString().c_str(), result);
+            WriteSerial("Read  %s > %d", toString().c_str(), result);
         }
         return result;
     }
@@ -49,7 +65,7 @@ namespace Pins {
         buf[n++] = 0;
 
         if (shouldEvent()) {
-            grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Setting pin attr %s = %s", toString().c_str(), buf);
+            WriteSerial("Set pin attr %s = %s", toString().c_str(), buf);
         }
         _implementation->setAttr(value);
     }
@@ -57,7 +73,7 @@ namespace Pins {
     void DebugPinDetail::CallbackHandler::handle(void* arg) {
         auto handler = static_cast<CallbackHandler*>(arg);
         if (handler->_myPin->shouldEvent()) {
-            grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Received ISR on pin %s", handler->_myPin->toString().c_str());
+            WriteSerial("Received ISR on pin %s", handler->_myPin->toString().c_str());
         }
         handler->callback(handler->argument);
     }
@@ -69,7 +85,7 @@ namespace Pins {
         _isrHandler.callback = callback;
 
         if (shouldEvent()) {
-            grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Attaching interrupt to pin %s, mode %d", toString().c_str(), mode);
+            WriteSerial("Attaching interrupt to pin %s, mode %d", toString().c_str(), mode);
         }
         _implementation->attachInterrupt(_isrHandler.handle, &_isrHandler, mode);
     }
@@ -90,7 +106,7 @@ namespace Pins {
         } else if (_eventCount == 10) {
             _lastEvent = time;
             ++_eventCount;
-            grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Suppressing events...");
+            WriteSerial("Suppressing events...");
             return false;
         } else {
             _lastEvent = time;
diff --git a/Grbl_Esp32/src/Pins/GPIOPinDetail.cpp b/Grbl_Esp32/src/Pins/GPIOPinDetail.cpp
index e7563e41..bac52684 100644
--- a/Grbl_Esp32/src/Pins/GPIOPinDetail.cpp
+++ b/Grbl_Esp32/src/Pins/GPIOPinDetail.cpp
@@ -143,12 +143,6 @@ namespace Pins {
             pinModeValue |= OUTPUT;
         }
 
-        // TODO FIXME: For now, I added PU capabilities to 'value' as well. This *should* be removed once the
-        // code that uses #define's to decide this is gone.
-        if (value.has(PinAttributes::PullUp)) {
-            pinModeValue |= PULLUP;
-        }
-
         // PU/PD should be specified by the user. Code has nothing to do with them:
         if (_attributes.has(PinAttributes::PullUp)) {
             pinModeValue |= PULLUP;