From 7d76a42a137f47256e07c22f07b4a30bfe188567 Mon Sep 17 00:00:00 2001
From: "Andrew J. Kroll" <a@oo.ms>
Date: Mon, 17 Jun 2013 15:01:10 -0400
Subject: [PATCH] Don't override if already defined

---
 printhex.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/printhex.h b/printhex.h
index b3364a8f..af6d43e5 100644
--- a/printhex.h
+++ b/printhex.h
@@ -23,7 +23,9 @@ e-mail   :  support@circuitsathome.com
 #include <WProgram.h>
 #endif
 
+#ifndef USB_HOST_SERIAL
 #define USB_HOST_SERIAL Serial
+#endif
 
 void E_Notifyc(char c, int lvl);