Update examples to use default configured Bus where it makes sense

Author: hardbyte

examples/cyclic.py

@@ -114,7 +114,9 @@ def main():
         arbitration_id=0x00, data=[0, 0, 0, 0, 0, 0], is_extended_id=False
     )
 
-    with can.Bus(interface="virtual") as bus:
+    # this uses the default configuration (for example from environment variables, or a
+    # config file) see https://python-can.readthedocs.io/en/stable/configuration.html
+    with can.Bus() as bus:
         bus.send(reset_msg)
 
         simple_periodic_send(bus)

examples/receive_all.py

@@ -11,12 +11,15 @@
 def receive_all():
     """Receives all messages and prints them to the console until Ctrl+C is pressed."""
 
-    with can.Bus(interface="pcan", channel="PCAN_USBBUS1", bitrate=250000) as bus:
-        # bus = can.Bus(interface='ixxat', channel=0, bitrate=250000)
-        # bus = can.Bus(interface='vector', app_name='CANalyzer', channel=0, bitrate=250000)
+    # this uses the default configuration (for example from environment variables, or a
+    # config file) see https://python-can.readthedocs.io/en/stable/configuration.html
+    with can.Bus() as bus:
 
         # set to read-only, only supported on some interfaces
-        bus.state = BusState.PASSIVE
+        try:
+            bus.state = BusState.PASSIVE
+        except NotImplementedError:
+            pass
 
         try:
             while True:

examples/virtual_can_demo.py renamed to examples/send_multiple.py

@@ -16,7 +16,10 @@ def producer(thread_id: int, message_count: int = 16) -> None:
     :param thread_id: the id of the thread/process
     :param message_count: the number of messages that shall be sent
     """
-    with can.Bus(interface="socketcan", channel="vcan0") as bus:  # type: ignore
+
+    # this uses the default configuration (for example from environment variables, or a
+    # config file) see https://python-can.readthedocs.io/en/stable/configuration.html
+    with can.Bus() as bus:  # type: ignore
         for i in range(message_count):
             msg = can.Message(
                 arbitration_id=0x0CF02200 + thread_id,