From 1ded874ce16fbd94329b3f22f17dcf006a7b2685 Mon Sep 17 00:00:00 2001
From: me-no-dev <hristo@espressif.com>
Date: Wed, 23 Sep 2020 13:48:28 +0300
Subject: [PATCH] Update USB.cpp

---
 cores/esp32/USB.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cores/esp32/USB.cpp b/cores/esp32/USB.cpp
index 6133212f..d2b67f6b 100644
--- a/cores/esp32/USB.cpp
+++ b/cores/esp32/USB.cpp
@@ -29,7 +29,7 @@
 #define USB_PRODUCT ARDUINO_BOARD
 #endif
 #ifndef USB_SERIAL
-#define USB_SERIAL ""
+#define USB_SERIAL "0"
 #endif
 
 extern "C" {