diff --git a/Grbl_Esp32/Grbl_Esp32.ino b/Grbl_Esp32/Grbl_Esp32.ino
index b3133b51..120be530 100644
--- a/Grbl_Esp32/Grbl_Esp32.ino
+++ b/Grbl_Esp32/Grbl_Esp32.ino
@@ -22,6 +22,10 @@
 #    include "src/Grbl.h"
 
 void setup() {
+#    ifdef PIN_DEBUG
+    sleep(1000);
+#    endif
+
     Serial.begin(115200);
     grbl_init();
 }
diff --git a/Grbl_Esp32/src/Machines/test_drive.h b/Grbl_Esp32/src/Machines/test_drive.h
index 6618a992..ec81c4f4 100644
--- a/Grbl_Esp32/src/Machines/test_drive.h
+++ b/Grbl_Esp32/src/Machines/test_drive.h
@@ -55,10 +55,18 @@
 // Output devices:
 // - I2S
 
+// #define USE_I2S_OUT
+// #define USE_I2S_STEPS
+// #define I2S_OUT_BCK             GPIO_NUM_22
+// #define I2S_OUT_WS              GPIO_NUM_17
+// #define I2S_OUT_DATA            GPIO_NUM_21
+// 
+// #define COOLANT_MIST_PIN        "i2s.24"
+
 // x CoolantControl
 
-// #define COOLANT_MIST_PIN        "gpio.2"  // labeled Mist
-// #define COOLANT_FLOOD_PIN       "gpio.4"  // labeled Flood
+// #define COOLANT_MIST_PIN        "gpio.2"
+// #define COOLANT_FLOOD_PIN       "gpio.4"
 
 // x StandardStepper
 
diff --git a/Grbl_Esp32/src/Pin.cpp b/Grbl_Esp32/src/Pin.cpp
index d94a2417..1d64677d 100644
--- a/Grbl_Esp32/src/Pin.cpp
+++ b/Grbl_Esp32/src/Pin.cpp
@@ -76,6 +76,10 @@ bool Pin::parse(String str, Pins::PinDetail*& pinImplementation) {
     // Build an options parser:
     Pins::PinOptionsParser parser(options.begin(), options.end());
 
+#if defined PIN_DEBUG && defined ESP32
+    grbl_sendf(CLIENT_ALL, "Attempting to set up pin: %s, index %d\r\n", prefix.c_str(), int(pinNumber));
+#endif
+
     // Build this pin:
     if (prefix == "gpio") {
         pinImplementation = new Pins::GPIOPinDetail(uint8_t(pinNumber), parser);
diff --git a/Grbl_Esp32/src/Pins/GPIOPinDetail.cpp b/Grbl_Esp32/src/Pins/GPIOPinDetail.cpp
index bac52684..c9e6b752 100644
--- a/Grbl_Esp32/src/Pins/GPIOPinDetail.cpp
+++ b/Grbl_Esp32/src/Pins/GPIOPinDetail.cpp
@@ -97,7 +97,7 @@ namespace Pins {
             } else if (opt.is("high")) {
                 // Default: Active HIGH.
             } else {
-                Assert(false, "Bad GPIO option passed to pin: %s", opt());
+                Assert(false, "Bad GPIO option passed to pin %d: %s", int(index), opt());
             }
         }
 
diff --git a/Grbl_Esp32/src/Pins/I2SPinDetail.cpp b/Grbl_Esp32/src/Pins/I2SPinDetail.cpp
index 367e2207..d49be91e 100644
--- a/Grbl_Esp32/src/Pins/I2SPinDetail.cpp
+++ b/Grbl_Esp32/src/Pins/I2SPinDetail.cpp
@@ -12,28 +12,27 @@ namespace Pins {
         _readWriteMask(0) {
         // User defined pin capabilities
         for (auto opt : options) {
-            if (opt.is("pu")) {
-                _attributes = _attributes | PinAttributes::PullUp;
-            } else if (opt.is("pd")) {
-                _attributes = _attributes | PinAttributes::PullDown;
-            } else if (opt.is("low")) {
+            if (opt.is("low")) {
                 _attributes = _attributes | PinAttributes::ActiveLow;
             } else if (opt.is("high")) {
                 // Default: Active HIGH.
+            } else {
+                Assert(false, "Bad I2S option passed to pin %d: %s", int(index), opt());
             }
         }
 
         // Update the R/W mask for ActiveLow setting
         if (_attributes.has(PinAttributes::ActiveLow)) {
-            _readWriteMask = 1;
+            _readWriteMask = HIGH;
         } else {
-            _readWriteMask = 0;
+            _readWriteMask = LOW;
         }
     }
 
-    PinCapabilities I2SPinDetail::capabilities() const { return PinCapabilities::Input | PinCapabilities::Output | PinCapabilities::I2S; }
+    PinCapabilities I2SPinDetail::capabilities() const { return PinCapabilities::Output | PinCapabilities::I2S; }
 
     void I2SPinDetail::write(int high) {
+        Assert(_attributes.has(PinAttributes::Output), "Pin has no output attribute defined. Cannot write to it.");
         int value = _readWriteMask ^ high;
         i2s_out_write(_index, value);
     }
@@ -45,7 +44,7 @@ namespace Pins {
 
     void I2SPinDetail::setAttr(PinAttributes value) {
         // Check the attributes first:
-        Assert(!value.validateWith(this->_capabilities), "The requested attributes don't match the pin capabilities");
+        Assert(value.validateWith(this->_capabilities), "The requested attributes don't match the pin capabilities");
         Assert(!_attributes.conflictsWith(value), "Attributes on this pin have been set before, and there's a conflict.");
 
         _attributes = value;
@@ -55,10 +54,14 @@ namespace Pins {
         // just check for conflicts above...
 
         // If the pin is ActiveLow, we should take that into account here:
-        write(value.has(PinAttributes::InitialOn) ? HIGH : LOW);
+        if (value.has(PinAttributes::InitialOn)) {
+            i2s_out_write(_index, HIGH ^ _readWriteMask);
+        } else {
+            i2s_out_write(_index, LOW ^ _readWriteMask);
+        }
     }
 
-    String I2SPinDetail::toString() const { return String("I2S_") + int(_index); }
+    String I2SPinDetail::toString() const { return String("I2S.") + int(_index); }
 }
 
 #endif
diff --git a/Grbl_Esp32/src/Pins/I2SPinDetail.h b/Grbl_Esp32/src/Pins/I2SPinDetail.h
index 82d96992..a84cd0c4 100644
--- a/Grbl_Esp32/src/Pins/I2SPinDetail.h
+++ b/Grbl_Esp32/src/Pins/I2SPinDetail.h
@@ -5,7 +5,6 @@
 
 namespace Pins {
     class I2SPinDetail : public PinDetail {
-        uint8_t         _index;
         PinCapabilities _capabilities;
         PinAttributes   _attributes;
         int             _readWriteMask;
diff --git a/Grbl_Esp32/src/ProcessSettings.cpp b/Grbl_Esp32/src/ProcessSettings.cpp
index 098abbea..82943204 100644
--- a/Grbl_Esp32/src/ProcessSettings.cpp
+++ b/Grbl_Esp32/src/ProcessSettings.cpp
@@ -150,9 +150,9 @@ Error list_grbl_names(const char* value, WebUI::AuthenticationLevel auth_level,
 Error list_settings(const char* value, WebUI::AuthenticationLevel auth_level, WebUI::ESPResponseStream* out) {
     for (Setting* s = Setting::List; s; s = s->next()) {
         const char* displayValue = auth_failed(s, value, auth_level) ? "<Authentication required>" : s->getStringValue();
-            if (s->getType() != PIN) {
-                show_setting(s->getName(), displayValue, NULL, out);
-            }
+        if (s->getType() != PIN) {
+            show_setting(s->getName(), displayValue, NULL, out);
+        }
     }
     return Error::Ok;
 }