FreePIE - Walk with Android Phone, to Keyboard Press

from threading import Timer

WalkingAccelThreshold = 4
KeyDelaySeconds = 0.1

def update():
   global accel
   global maxaccel
   accel = math.sqrt(math.fabs(math.pow(android[0].raw.ax, 2) + math.pow(android[0].raw.ay, 2) + math.pow(android[0].raw.az, 2) - math.pow(9.8, 2)))
   maxaccel = max(accel, maxaccel)

def timertick():
    global maxaccel
    if isexecuting:
        global timer
        timer = Timer(KeyDelaySeconds, timertick)
        timer.start()
        if maxaccel >= WalkingAccelThreshold:
            keyboard.setPressed(Key.W)
        maxaccel = 0

if starting:
   android[0].update += update
   accel = 0
   maxaccel = 0
   isexecuting = True
   timertick()

if stopping:
    if timer:
        timer.cancel()
    isexecuting = False