ComputerCraft / Tekkit Security Gatehouse

os.loadAPI("ocs/apis/sensor")

local mySensor = sensor.wrap("top")
local Player = false
local Monster = false
local pos = {}
-- These are the things to change for yourself
local door_direction = "right"
local dispenser_direction = "back"
local Y_max = 1
local Y_min = -2
local X_max = 3
local X_min = -2
local Z_max = -4
local Z_min = -7


while 1>0 do
  Player = false
  Monster = false
  os.sleep(0.5)
  for k,v in pairs(mySensor.getTargets()) do
    if v ~= nil and v["IsPlayer"] == true then
      pos = v["Position"]
      if pos["X"] > X_min and pos["X"] < X_max and pos["Y"] > Y_min and pos["Y"] < Y_max and pos["Z"] > Z_min and pos["Z"] < Z_max then
        Player = true
      end
    elseif v~= nil and v["IsPlayer"] == false then
      pos = v["Position"]
      if pos["Z"] < Z_max and pos["Z"] > Z_min and pos["Y"] > Y_min and pos["Y"] < Y_max and pos["X"] > X_min and pos["X"] < X_max then
        Monster = true
      end
    end
  end
  if Player == true then
    redstone.setAnalogOutput(door_direction,15)
  else
    redstone.setAnalogOutput(door_direction,0)
  end
  if Monster == true and Player == false then
    redstone.setAnalogOutput(dispenser_direction,15)
  else
    redstone.setAnalogOutput(dispenser_direction,0)
  end
end