Having a bunch of fun with mine. Hooked up the IR sensor from my CamJam #2 kit to input one (wasn’t really sure what I was doing but it seemed to work!).
import explorerhat
def alert(pin):
  print "*** WARNING!!! INTRUDER ALERT!!! ***"
  print("Zone : " + pin.name)
  return
explorerhat.input.one.pressed(alert)
explorerhat.pause()
was all it took to get something working