added forgotten interface changes (#46)

* - added contact

* - made windows compatible

* - missed a file

atests/nfc_nci/nci_interface.py

@@ -1,21 +1,29 @@
 import serial
+import select
 import time
 
 
 class nci_interface():
     def __init__(self):
         self._serial_connection = None
 
-    def open_nci_connection_via_uart(self, device: str, baudrate: int):
+    def open_nci_connection_via_uart(self, device: str, baudrate: int, timeout=1.0):
         """
         Opens a connection to a NCI device via UART.
 
         Returns a tuple of two file objects, first one for reading and second one for writing.
         """
-        self._serial_connection = serial.Serial(device, baudrate, timeout=1)
+        class timeoutExceptionOnTimeoutSerial(serial.Serial):
+            def read(self, size=1):
+                retBuf = super().read(size)
+                assert len(retBuf) >= size, f"Timeout while reading from serial port, received {len(retBuf)} bytes instead of {size}"
+                assert len(retBuf) == size, f"Received more data ({len(retBuf)}) then requested ({size}). "
+                return retBuf
+
+        self._serial_connection = timeoutExceptionOnTimeoutSerial(device, baudrate, timeout=timeout)
         self._serial_connection.reset_input_buffer()
-        return (open(self._serial_connection.fd, "rb", buffering=0, closefd=False),
-                open(self._serial_connection.fd, "wb", buffering=0, closefd=False),)
+        return self._serial_connection # Alternatively, on linux we can use self._serial_connection.fileno() + select instead of the timeout read...
+
 
     def wait_for_data_from_nci(self, timeout: float = 1.0):
         """
@@ -24,12 +32,14 @@ def wait_for_data_from_nci(self, timeout: float = 1.0):
         Raises an exception if the NCI connection is not open.
         """
         if self._serial_connection and self._serial_connection.is_open:
-            endTime = time.time() + timeout
-            while time.time() < endTime:
-                if self._serial_connection.in_waiting:
-                    return
-                time.sleep(0.001)
-            assert self._serial_connection.in_waiting, "Timeout while waiting for data from NCI device"
+            try:
+                select.select([self._serial_connection.fileno()], [], [], timeout)
+            except AttributeError:
+                    # Windows does not support select on serial ports, so we have to do it the hard way
+                    endTime = time.time() + timeout
+                    while time.time() < endTime and not self._serial_connection.in_waiting:
+                        time.sleep(0.001)
+                    assert self._serial_connection.in_waiting, "Timeout while waiting for data from NCI device"
         else:
             raise Exception("NCI connection is not open")