Default ESP32 config uses pin 17 for INT, which conflicts with TX2. Instead use Pin 4.

Author: adamm

README.md

@@ -124,7 +124,7 @@ Currently the following boards are supported by the library:
       * GPIO16 is **NOT** usable, as it will be used for some other purposes. For example, reset the SoC itself from sleep mode.
       * GPIO6 to 11 is also **NOT** usable, as they are used to connect SPI flash chip and it is used for storing the executable binary content.
 * ESP32 is supported using the [arduino-esp32](https://github.com/espressif/arduino-esp32/)
-    * GPIO5 : SS, GPIO17 : INT, GPIO18 : SCK, GPIO19 : MISO, GPIO23 : MOSI
+    * GPIO5 : SS, GPIO4 : INT, GPIO18 : SCK, GPIO19 : MISO, GPIO23 : MOSI
 
 The following boards need to be activated manually in [settings.h](settings.h):
 

UsbCore.h

@@ -49,7 +49,7 @@ typedef MAX3421e<P3, P2> MAX3421E; // The Intel Galileo supports much faster rea
 #elif defined(ESP8266)
 typedef MAX3421e<P15, P5> MAX3421E; // ESP8266 boards
 #elif defined(ESP32)
-typedef MAX3421e<P5, P17> MAX3421E; // ESP32 boards
+typedef MAX3421e<P5, P4> MAX3421E; // ESP32 boards
 #elif (defined(__AVR_ATmega644P__) || defined(__AVR_ATmega1284P__))
 typedef MAX3421e<Pb4, Pb3> MAX3421E; // Sanguino
 #else

avrpins.h

@@ -1474,8 +1474,8 @@ MAKE_PIN(P22, 22); // SCL
 MAKE_PIN(P19, 19); // MISO
 MAKE_PIN(P23, 23); // MOSI
 MAKE_PIN(P18, 18); // SCK
+MAKE_PIN(P4, 4); // INT
 MAKE_PIN(P5, 5); // SS
-MAKE_PIN(P17, 17); // INT
 
 #endif