PIR Sensor display turn off

motion.py

#!/usr/bin/python3

import RPi.GPIO as GPIO
import time
import datetime
import subprocess
from threading import Timer

last_motion = time.time()

GPIO.setmode(GPIO.BCM)
GPIO_PIR = 4
DISABLE_SECONDS = 600

GPIO.setup(GPIO_PIR,GPIO.IN)

print("Waiting for PIR initialization..")

while GPIO.input(GPIO_PIR) != 0:
  time.sleep(0.1)

print("Ready..")

def motion(PIR_GPIO):
    global last_motion

    subprocess.call(["vcgencmd", "display_power", "1"])
    last_motion = time.time()
    print("{} - Motion detected!".format(datetime.datetime.now()))

GPIO.add_event_detect(GPIO_PIR, GPIO.RISING, callback=motion)

timer = None

def timer_trigger():
    global last_motion
    global timer

    time_diff = time.time() - last_motion
    print("Timer triggered. Diff: {}".format(time_diff))

    if time_diff > DISABLE_SECONDS:
        subprocess.call(["vcgencmd", "display_power", "o"])
        print("Display powered off")

    timer = Timer(DISABLE_SECONDS/2, timer_trigger)
    timer.start()

timer_trigger()

pir.service

[Unit]
Description=PIR Service

[Service]
Type=simple
Restart=always
WorkingDirectory=/home/pi
ExecStart=/home/pi/motion.py

[Install]
WantedBy=default.target