diff --git a/Arduino/CanGrow/CanGrow.ino b/Arduino/CanGrow/CanGrow.ino
index 11f015e..33430da 100644
--- a/Arduino/CanGrow/CanGrow.ino
+++ b/Arduino/CanGrow/CanGrow.ino
@@ -134,7 +134,7 @@ void setup() {
   Wifi_Init();
   Webserver_Init();
   Serial.printf(":: [SETUP] Usable Pins: %d\n", GPIOindex_length);
-  for(byte i = 0; i < GPIOindex_length; i++) {
+  for(byte i = 1; i <= GPIOindex_length; i++) {
     Serial.printf(":: [SETUP] Pin Index: %d, GPIO: %d, Notes: ", i, GPIOindex[i].gpio);
     Serial.println(GPIO_Index_note_descr[GPIOindex[i].note]);
   }
diff --git a/Arduino/CanGrow/include/CanGrow_ESP32.h b/Arduino/CanGrow/include/CanGrow_ESP32.h
index c1bd1c2..2acadf4 100644
--- a/Arduino/CanGrow/include/CanGrow_ESP32.h
+++ b/Arduino/CanGrow/include/CanGrow_ESP32.h
@@ -63,7 +63,8 @@
 // 
 const byte GPIOindex_length = 21;
 // initialize pinIndex with all usable GPIOs
-GPIO_Index GPIOindex[] = {  { 0, FLASHMODE_LOW },
+GPIO_Index GPIOindex[] = {{ 255, 255 },
+                          { 0, FLASHMODE_LOW },
                           { 4 },
                           { 5 },
                           { 12, BOOTFAILS_HIGH },
diff --git a/Arduino/CanGrow/include/CanGrow_ESP8266.h b/Arduino/CanGrow/include/CanGrow_ESP8266.h
index 98eefa2..446d0d9 100644
--- a/Arduino/CanGrow/include/CanGrow_ESP8266.h
+++ b/Arduino/CanGrow/include/CanGrow_ESP8266.h
@@ -47,7 +47,8 @@
 
 const byte GPIOindex_length = 6;
 // initialize pinIndex with all usable GPIOs
-GPIO_Index GPIOindex[] = {  { 0, BOOTFAILS_LOW },
+GPIO_Index GPIOindex[] = {{ 255, 255 },
+                          { 0, BOOTFAILS_LOW },
                           { 12 },
                           { 13 },
                           { 14 },
diff --git a/Arduino/CanGrow/include/Webserver/Common.h b/Arduino/CanGrow/include/Webserver/Common.h
index 7cc00cd..0ba05fa 100644
--- a/Arduino/CanGrow/include/Webserver/Common.h
+++ b/Arduino/CanGrow/include/Webserver/Common.h
@@ -118,7 +118,7 @@ String Html_SelectOpt_GPIOindex(byte selectId = 255) {
   
   String gpioIndex_html;
     // iterate through through all available GPIOs in index
-    for(byte i = 0; i < GPIOindex_length; i++) {
+    for(byte i = 1; i <= GPIOindex_length; i++) {
       bool gpioUsed = Check_GPIOindex_Used(i);
       
       gpioIndex_html += "<option value='";
diff --git a/Arduino/CanGrow/include/Webserver/Page_system.h b/Arduino/CanGrow/include/Webserver/Page_system.h
index ea7ccd1..2bccc45 100644
--- a/Arduino/CanGrow/include/Webserver/Page_system.h
+++ b/Arduino/CanGrow/include/Webserver/Page_system.h
@@ -339,6 +339,28 @@ String Proc_WebPage_system_output(const String& var) {
         output_tr_td += config.system.output.name[i];
         output_tr_td += "</td><td>";
         output_tr_td += Output_Type_descr[config.system.output.type[i]];
+        
+        if((config.system.output.type[i] == OUTPUT_TYPE_GPIO) || (config.system.output.type[i] == OUTPUT_TYPE_I2C)) {
+          output_tr_td += " (";
+        }
+        
+        switch(config.system.output.type[i]) {
+          case OUTPUT_TYPE_GPIO:
+            output_tr_td += GPIOindex[config.system.output.gpio[i]].gpio;
+          break;
+          
+          case OUTPUT_TYPE_I2C:
+            output_tr_td += config.system.output.i2c[i];
+          break;
+          
+          default:
+          break;
+        }
+        
+        if((config.system.output.type[i] == OUTPUT_TYPE_GPIO) || (config.system.output.type[i] == OUTPUT_TYPE_I2C)) {
+          output_tr_td += ")";
+        }
+        
         output_tr_td += "</td><td>";
         output_tr_td += Output_Device_descr[config.system.output.device[i]];
         output_tr_td += "</td><td>";
@@ -805,6 +827,18 @@ String Proc_WebPage_system_sensor(const String& var) {
         output_tr_td += config.system.sensor.name[i];
         output_tr_td += "</td><td>";
         output_tr_td += SensorIndex[config.system.sensor.type[i]].name;
+        
+        if((config.system.sensor.i2c_address[i] != "") || (config.system.sensor.gpio[i] > 0)) {
+          output_tr_td += " (";
+          if(config.system.sensor.gpio[i] > 0) {
+            output_tr_td += GPIOindex[config.system.sensor.gpio[i]].gpio;
+          } else {
+            output_tr_td += config.system.sensor.i2c_address[i];
+          }
+          output_tr_td += ")";
+        }
+        
+                
         output_tr_td += "</td><td>";
 
         // edit button
diff --git a/Arduino/CanGrow/include/Webserver/Page_system_HTML.h b/Arduino/CanGrow/include/Webserver/Page_system_HTML.h
index 54a4f81..952a0e2 100644
--- a/Arduino/CanGrow/include/Webserver/Page_system_HTML.h
+++ b/Arduino/CanGrow/include/Webserver/Page_system_HTML.h
@@ -282,7 +282,7 @@ const char* Page_system_sensor_add_HTML PROGMEM = R"(%HEADER%
 
 <u>I2C address</u>:<br>
 <p>leave empty for default</p>
-<input type='text' name='i2c_address' maxlength='5' value='%SENSOR_I2C_ADDRESS%' required><br>
+<input type='text' name='i2c_address' maxlength='5' value='%SENSOR_I2C_ADDRESS%' ><br>
 
 <u>GPIO</u>:<br>
 <select name='gpio'>