added traceback on error

raspberry-pi/main.py

@@ -6,6 +6,7 @@ import threading
 import queue
 import configparser
 import tkinter as tk
+import traceback
 
 conf = configparser.ConfigParser()
 conf.read('config.ini')
@@ -73,6 +74,7 @@ def main():
     print("stop")
   except Exception as e:
     print("Error: ",e)
+    traceback.print_exc()
   finally:
     down_queue.put("stop")