playerDetector

local sensor = peripheral.wrap("left")


while true do
  players = sensor.getPlayers()
  if #players == 0 then
    rs.setOutput("back",true)
  else
  for _, name in pairs(sensor.getPlayers()) do
    if(name ~= "") then
      rs.setOutput("back", false)
    end
  end
  end
  sleep(1)
end