Changed default values to null and made handling for those in code

Author: Antti Kauppila

ESP8266Interface.cpp

@@ -21,6 +21,22 @@
 #include "nsapi_types.h"
 
 
+#ifndef MBED_CONF_ESP8266_TX
+#ifdef TARGET_FF_ARDUINO
+#define MBED_CONF_ESP8266_TX D1
+#else
+#define MBED_CONF_ESP8266_TX NC
+#endif
+#endif
+
+#ifndef MBED_CONF_ESP8266_RX
+#ifdef TARGET_FF_ARDUINO
+#define MBED_CONF_ESP8266_RX D0
+#else
+#define MBED_CONF_ESP8266_RX NC
+#endif
+#endif
+
 // Firmware version
 #define ESP8266_VERSION 2
 

mbed_lib.json

@@ -3,11 +3,11 @@
     "config": {
         "tx": {
             "help": "TX pin for serial connection",
-            "value": "NC"
+            "value": null
         },
         "rx": {
             "help": "RX pin for serial connection",
-            "value": "NC"
+            "value": null
         },
         "debug": {
             "help": "Enable debug logs",