Works with multiple devices now.

Plug in a lot of devices and try: "./terminal.py /dev/ttyUSB*"

terminal.py

@@ -34,7 +34,7 @@ class Color(object):
             self.reset = colorama.Style.RESET_ALL
     def code(self, n):
         return self.codes[n % self.total]
-color = Color()
+g_color = Color()
 
 if os.name == 'nt':
     import msvcrt
@@ -90,19 +90,30 @@ else:
 class Miniterm:
     """Normal interactive terminal"""
 
-    def __init__(self, serial, suppress_bytes = None):
-        self.serial = serial
+    def __init__(self, serials, suppress_bytes = None):
+        self.serials = serials
         self.suppress_bytes = suppress_bytes or ""
+        self.last_color = ""
         self.threads = []
 
     def start(self):
         self.alive = True
-        # serial->console
-        self.threads.append(threading.Thread(target=self.reader))
-        # console->serial
+
+        # serial->console, all devices
+        for (n, serial) in enumerate(self.serials):
+            self.threads.append(threading.Thread(
+                target = self.reader,
+                args = (serial, g_color.code(n))
+                ))
+
+        # console->serial, just the first device
         self.console = Console()
-        self.threads.append(threading.Thread(target=self.writer))
-        # start them
+        self.threads.append(threading.Thread(
+            target = self.writer,
+            args = (self.serials[0],)
+            ))
+
+        # start all threads
         for thread in self.threads:
             thread.daemon = True
             thread.start()
@@ -115,13 +126,16 @@ class Miniterm:
             while thread.isAlive():
                 thread.join(0.1)
 
-    def reader(self):
+    def reader(self, serial, color):
         """loop and copy serial->console"""
         try:
             while self.alive:
-                data = self.serial.read(1)
+                data = serial.read(1)
                 if not data:
                     continue
+                if color != self.last_color:
+                    self.last_color = color
+                    sys.stdout.write(color)
                 if ((ord(data) >= 32 and ord(data) < 128) or
                     data == '\r' or data == '\n' or data == '\t'):
                     sys.stdout.write(data)
@@ -133,7 +147,7 @@ class Miniterm:
             self.console.cleanup()
             os._exit(1)
 
-    def writer(self):
+    def writer(self, serial):
         """loop and copy console->serial until ^C"""
         try:
             while self.alive:
@@ -157,20 +171,32 @@ class Miniterm:
                     # Don't send these bytes
                     continue
                 else:
-                    self.serial.write(c)                    # send character
+                    serial.write(c)                    # send character
         except Exception as e:
             traceback.print_exc()
             self.console.cleanup()
             os._exit(1)
 
     def run(self):
-        saved_timeout = self.serial.timeout
-        self.serial.timeout = 0.1
+        # Set all serial port timeouts to 0.1 sec
+        saved_timeouts = []
+        for (n, serial) in enumerate(self.serials):
+            saved_timeouts.append(serial.timeout)
+            serial.timeout = 0.1
+
+        # Handle SIGINT gracefully
         signal.signal(signal.SIGINT, lambda *args: self.stop())
+
+        # Go
         self.start()
         self.join()
+
+        # Restore serial port timeouts
+        for (n, serial) in enumerate(self.serials):
+            serial.timeout = saved_timeouts[n]
+
+        # Cleanup
         print ""
-        self.serial.timeout = saved_timeout
         self.console.cleanup()
 
 if __name__ == "__main__":
@@ -195,7 +221,8 @@ if __name__ == "__main__":
     args = parser.parse_args()
 
     devs = []
-    color.setup(len(args.device))
+    used_nodes = []
+    g_color.setup(len(args.device))
     for (n, device) in enumerate(args.device):
         m = re.search(r"^(.*)@([1-9][0-9]*)$", device)
         if m is not None:
@@ -204,18 +231,24 @@ if __name__ == "__main__":
         else:
             node = device
             baud = args.baudrate
+        if node in used_nodes:
+            sys.stderr.write("error: %s already open!\n" % node)
+            raise SystemExit(1)
         try:
             dev = serial.Serial(node, baud)
         except serial.serialutil.SerialException:
             sys.stderr.write("error opening %s\n" % node)
             raise SystemExit(1)
         if not args.quiet:
-            print color.code(n) + node + ", " + str(args.baudrate) + " baud"
+            print (g_color.code(n)
+                   + node + ", " + str(args.baudrate) + " baud"
+                   + g_color.reset)
+        used_nodes.append(node)
         devs.append(dev)
 
     if not args.quiet:
-        print color.reset + "^C to exit"
-        print color.reset + "----------"
-    term = Miniterm(dev)
+        print "^C to exit"
+        print "----------"
+    term = Miniterm(devs)
     term.run()