Merge pull request #10 from jmsojo/patch-1

Add automated search for COM port if one wasn't provided.

src/elliptec/controller.py

@@ -13,38 +13,79 @@ class Controller:
     last_response = None
     last_status = None
 
-    def __init__(
-        self,
-        port,
-        baudrate=9600,
-        bytesize=8,
-        parity=serial.PARITY_NONE,
-        stopbits=serial.STOPBITS_ONE,
-        timeout=2,
-        write_timeout=0.5,
-        debug=True,
-    ):
-        try:
-            self.s = serial.Serial(
-                port,
-                baudrate=baudrate,
-                bytesize=bytesize,
-                parity=parity,
-                stopbits=stopbits,
-                timeout=timeout,
-                write_timeout=write_timeout,
-            )
-        except serial.SerialException:
-            print("Could not open port {port}.")
-            # TODO: nicer/more logical shutdown (this kills the entire app?)
-            sys.exit()
+    def __init__(self, 
+                 port = None, 
+                 baudrate=9600, 
+                 bytesize=8, 
+                 parity=serial.PARITY_NONE, 
+                 stopbits=serial.STOPBITS_ONE, 
+                 timeout=2, 
+                 write_timeout=0.5, 
+                 debug=True):
+        if port == None: 
+            self.__search_and_connect(baudrate, 
+                                      bytesize, 
+                                      parity, 
+                                      stopbits, 
+                                      timeout, 
+                                      write_timeout)
+        else: 
+            self.__connect_to_port(port, 
+                                   baudrate, 
+                                   bytesize, 
+                                   parity, 
+                                   stopbits, 
+                                   timeout, 
+                                   write_timeout)
 
-        self.debug = debug
-        self.port = port
+    def __enter__(self):
+        return self
 
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+
+    def __connect_to_port(self, 
+                          port, 
+                          baudrate, 
+                          bytesize, 
+                          parity, 
+                          stopbits, 
+                          timeout, 
+                          write_timeout):
+        try:
+            self.s = serial.Serial(port, 
+                                   baudrate=baudrate, 
+                                   bytesize=bytesize, 
+                                   parity=parity, 
+                                   stopbits=stopbits, 
+                                   timeout=timeout, 
+                                   write_timeout=write_timeout)
+
+        except serial.SerialException:
+            print('Could not open port %s' % port)
+            self.s.close()
+
         if self.s.is_open:
             if self.debug:
-                print(f"Controller on port {port}: Connection established!")
+                print('Controller on port {}: Connection established!'.format(port))
+
+    def __search_and_connect(self, 
+                             baudrate, 
+                             bytesize, 
+                             parity, 
+                             stopbits, 
+                             timeout, 
+                             write_timeout):
+        port_list = serial.tools.list_ports.comports()
+        for port in port_list:
+            self.__connect_to_port(port, 
+                                   baudrate, 
+                                   bytesize, 
+                                   parity, 
+                                   stopbits, 
+                                   timeout, 
+                                   write_timeout)
+            break
 
     def __enter__(self):
         return self