make some small changes

read_arduino.py

@@ -51,7 +51,13 @@ def read():
         exit(0)
     else:
         controller = serial.Serial(port, baudrate=baud)
-
+        
+    # open the file and add a line of header to it, then close
+    f = open(file_name, "a", newline="", encoding="utf-8")
+    writer = csv.writer(f)
+    header = ['Time', 'Resistance']
+    writer.writerow(header)
+    f.close()
     while controller.isOpen():
         try:
             read_data = controller.readline().decode("utf-8")