Improve firmware uploading to Arduino Leonardo based boards // Resolve #691

HISTORY.rst

@@ -17,6 +17,8 @@ PlatformIO 2.0
   the size of a credit card
 * Check program size before uploading to the board
   (`issue #689 <https://github.com/platformio/platformio/issues/689>`_)
+* Improved firmware uploading to Arduino Leonardo based boards
+  (`issue #691 <https://github.com/platformio/platformio/issues/691>`_)
 * Fixed issue with ``-L relative/path`` when parsing ``build_flags``
   (`issue #688 <https://github.com/platformio/platformio/issues/688>`_)
 

platformio/builder/tools/pioupload.py

@@ -54,6 +54,7 @@ def WaitForNewSerialPort(env, before):
     prev_port = env.subst("$UPLOAD_PORT")
     new_port = None
     elapsed = 0
+    sleep(1)
     while elapsed < 5 and new_port is None:
         now = util.get_serialports()
         for p in now: