added comments

main.py

@@ -39,8 +39,10 @@ while is_log_heater != 0 and is_log_heater != 1:
         print()
 
     try:
+        # Attempt to convert the input to int and store it.
         is_log_heater = int(input("measurement process = "))
     except ValueError:
+        # If conversion fails, set value to 2, in order to ask user again.
         is_log_heater = 2
 
 # Read the metadata necessary to control test rig from the setup file.