python script - "presence" - detection MagicMirror

parallel.py

from os import popen,system
from time import sleep
import subprocess
import os
from datetime import datetime, timedelta
import sys
import threading
from threading import Thread

ip= ["10.0.0.81", "10.0.0.32"]

def now():
	return datetime.now().strftime("%d.%m.%Y %H:%M:%S")

def getTemp():
    response = subprocess.Popen("vcgencmd measure_temp", shell=True, stdout=subprocess.PIPE)# > /dev/null 2>&1
    output = response.stdout.read()
    response.stdout.close()
    response.wait()
    temp = output[-7:-3]
    return temp

def findThread(id):
	from time import sleep
	#print "searching",ip[id]
	global foundPerson
	t = threading.currentThread()
	for i in range(27):
		response = os.system("ping -w 2 -c 1 " + ip[id] + "> /dev/null 2>&1")
		#print response, ip[id]
		if response == 0:
			print " FOUND DEVICE ->", ip[id],"  -  ",now()
			foundPerson = ip[id]
			break
		if foundPerson != 0:
			#print "  a thread found device, search for", ip[id],"stopped"
			break
		sleep(1)

def findDeviceThread(ip):
	global foundPerson
	foundPerson = 0
	for i in xrange(len(ip)):
		findDeviceThread = Thread( target=findThread, args=([i]) )
		findDeviceThread.start()

print "controller started ",now()
system('vcgencmd display_power 1')
wait = 60
stick = 1

while True:
	findDeviceThread(ip)
	sleep(wait)

	if foundPerson != 0:
		status=1
		if stick==1:
			sleep(300)
	else: 
		status=0
	
	if status==1 and stick == 0:
		system('vcgencmd display_power 1') 
		stick=1
		print " display on",now()
		
	elif status==0 and stick == 1:
		system('vcgencmd display_power 0')
		stick=0
		print " display off",now()
		
	if float(getTemp()) > 80:
		print "oh - TOO HOT - restarting"
		os.system("sudo reboot")

An Idea: What about making the IP address non-static by usage of the individual MAC addresses instead?
Is there not a possibility to search the IP address by using the result of arp -a ? Whith doing so you you could ping against theme even though they may change.

e.g. https://stackoverflow.com/questions/56022026/get-local-ip-address-from-a-known-mac-address-in-python