pyupdi.patch

diff --git a/updi/physical.py b/updi/physical.py
index 96be64b..d9360bf 100644
--- a/updi/physical.py
+++ b/updi/physical.py
@@ -31,7 +31,15 @@ class UpdiPhysical(object):
             Standard COM port initialisation
         """
         self.logger.info("Opening {} at {} baud".format(port, baud))
-        self.ser = serial.Serial(port, baud, parity=serial.PARITY_EVEN, timeout=1, stopbits=serial.STOPBITS_TWO)
+        self.ser = serial.serial_for_url(port, baud, parity=serial.PARITY_EVEN, timeout=1, stopbits=serial.STOPBITS_TWO, rtscts=False, dsrdtr=False, do_not_open=True)
+        self.ser.rts = 0  # needed so dtr reall gets 0v
+        self.ser.dtr = 1
+
+        self.ser.open()
+        # dtr is only set when port is opened, and stable low after ~3ms.
+        # during that time some crap from uart can come in, which disturbs the updi communication
+        time.sleep(.01)
+        self.ser.flushInput()
 
     def _loginfo(self, msg, data):
         if data and isinstance(data[0], str):
@@ -56,7 +64,12 @@ class UpdiPhysical(object):
         # Which is slightly above the recommended 24.6ms
         self.ser.close()
 
-        temporary_serial = serial.Serial(self.port, 300, stopbits=serial.STOPBITS_ONE, timeout=1)
+        temporary_serial = serial.serial_for_url(self.port, 300, timeout=1, stopbits=serial.STOPBITS_ONE, rtscts=False, dsrdtr=False, do_not_open=True)
+        temporary_serial.rts = 0  # needed so dtr reall gets 0v
+        temporary_serial.dtr = 1
+        temporary_serial.open()
+        time.sleep(.01)
+        temporary_serial.flushInput()
 
         # Send two break characters, with 1 stop bit in between
         temporary_serial.write([constants.UPDI_BREAK, constants.UPDI_BREAK])