Tune timeouts in serial

NanoVNASaver/Hardware/Serial.py

@@ -23,15 +23,21 @@ import serial
 
 logger = logging.getLogger(__name__)
 
+
 def drain_serial(serial_port: serial.Serial):
     """drain up to 64k outstanding data in the serial incoming buffer"""
     # logger.debug("Draining: %s", serial_port)
+    timeout = serial_port.timeout
+    serial_port.timeout = 0.05
     for _ in range(512):
         cnt = len(serial_port.read(128))
         if not cnt:
+            serial_port.timeout = timeout
             return
+    serial_port.timeout = timeout
     logger.warning("unable to drain all data")
 
+
 class Interface(serial.Serial):
     def __init__(self, interface_type: str, comment, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -40,6 +46,7 @@ class Interface(serial.Serial):
         self.comment = comment
         self.port = None
         self.baudrate = 115200
+        self.timeout = 0.05
         self.lock = Lock()
 
     def __str__(self):