def screensavermanager():
set_backlight('on')
Clock.unschedule(turnscreenoff)
print('ScreenSaverManager called')
print('unschedule previous turn-off')
Clock.schedule_once(turnscreenoff,300)
print('Turn screen on and schedule screen turn shutdown')
def turnscreenoff(self,*args):
set_backlight('off')
print('Screen turns off')