Door sensor

-- Credit to this for getting me started: http://www.youtube.com/watch?v=34R4KfLmMSY
os.loadAPI("ocs/apis/sensors")

-- From: http://www.youtube.com/watch?v=34R4KfLmMSY
function printDict(data)
for i,v in pairs(data) do
  print(tostring(i).." - "..tostring(v))
end
end

function getDistance(sensorData,targetData)
distanceData = {}
distanceData["xDistance"] = math.abs(sensorData["xCoord"] - targetData["xCoord"])
distanceData["yDistance"] = math.abs((sensorData["yCoord"] - 2) - targetData["yCoord"]) -- Note: the - 2 is because the sensor is above my door
distanceData["zDistance"] = math.abs(sensorData["zCoord"] - targetData["zCoord"])

-- Add the largest distance to the array
distanceData["distance"] = distanceData["xDistance"]
if distanceData["yDistance"] > distanceData["distance"] then
  distanceData["distance"] = distanceData["yDistance"]
elseif distanceData["zDistance"] > distanceData["distance"] then
  distanceData["distance"] = distanceData["zDistance"]
end

return distanceData
end

function isPlayerClose()
-- Get list of targets in range of probe
targets = sensors.getAvailableTargetsforProbe(controller,sensorName,probeName)

-- Loop through this list of targets getting the info about each one
for i=1,# targets do
  -- Get the target data, i.e. x,y,z coods and type
  targetData = sensors.getSensorReadingAsDict(controller,sensorName,targets[i],probeName)

  -- If the target is a player, i.e. has the name "vq" then check if it is close
  if targetData["name"] == "vq" then
   -- Get the distances to the target
   distanceData = getDistance(sensorData,targetData)

   -- If a player is close enough return true
   if distanceData["distance"] < 4 then
        return true
   end
  end
end

-- If no players were close return false
return false
end


-- Get the side the controller is on
controller = sensors.getController()

-- Get sensors, e.g. FactoryDoor. Useful to find the names of your sensors
-- data = sensors.getSensors(controller)
-- printDict(data)

-- Set the sensor name for the one you wish to control
sensorName = "Sensor"

-- Get information about the sensor, e.g. its name, location, range
sensorData = sensors.getSensorInfo(controller,sensorName)

-- Change sensor range
sensors.setSensorRange(controller,sensorName,"3")

-- Get probes, e.g. TargetInfo, Players, etc
-- IMPORTANT: the program will fail unless the line below is called, Im not sure why but I guess it is a bug
data = sensors.getProbes(controller,sensorName)
-- printDict(data)
probeName = "TargetInfo"

-- Loop the program so it keeps checking for targets, making sure it sleeps when in any infinite loop
while true do
if isPlayerClose() then
  redstone.setOutput("back",true)

  -- Keep the door open until the player gets a certain distance away
  while isPlayerClose() do
   sleep(.5)
  end
  redstone.setOutput("back",false)
end
sleep(.5)
end