examples/python: PD: Add singal handler to exit the script

Also, make the script send events only in response to a command. This
way, the PD app can keep running.

Signed-off-by: Siddharth Chandrasekaran <[email protected]>

examples/python/pd_app.py

@@ -5,10 +5,19 @@
 #  SPDX-License-Identifier: Apache-2.0
 #
 
+import signal
 import argparse
 import serial
 from osdp import *
 
+exit_event = 0
+def signal_handler(sig, frame):
+    global exit_event
+    print('Received SIGINT, quitting...')
+    exit_event = 1
+
+signal.signal(signal.SIGINT, signal_handler)
+
 class SerialChannel(Channel):
     def __init__(self, device: str, speed: int):
         self.dev = serial.Serial(device, speed, timeout=0)
@@ -57,19 +66,13 @@ def __del__(self):
     'data': bytes([9,1,9,2,6,3,1,7,7,0]),
 }
 
-count = 0 # loop counter
-
-while True:
+while not exit_event:
     ## Check if we have any commands from the CP
     cmd = pd.get_command(timeout=5)
     if cmd:
         print(f"PD: Received command: {cmd}")
 
-    ## Send a card read event to CP
-    pd.notify_event(card_event)
-
-    # if count >= 5:
-    #     break
-    count += 1
+        ## Send a card read event to CP
+        pd.notify_event(card_event)
 
 pd.teardown()