If you want you can use this example script(Python) replace YourSerialPort:

import serial

ser = serial.Serial('/dev/ttyYourSerialPort',9600)

while True:

  buttonState = ser.read()

  if buttonState == '1':

    print("Button 1 On")

  if buttonState == '3':

    print("Button 2 On")

  if buttonState == '5':

    print("Button 3 On")

  if buttonState == '7':

    print("Button 4 On")