add link

main.py

@@ -7,6 +7,8 @@ ser = serial.Serial('/dev/ttyACM0', baudrate = 9600, timeout = 1)
 
 #time.sleep(3)
 
+# https://stackoverflow.com/questions/13017840/using-pyserial-is-it-possible-to-wait-for-data
+
 while 1:
     # {  "command": "switch",  "arg": "one",  "state": "off"}
     userInput = input('> ')