Redstone Timer

local exitTime = 25 -- change to whatever you want
local timer = os.startTimer(exitTime) -- starts the timer
local cp = 0
local cm = 0
while true do
  local evt, arg = os.pullEvent() -- wait for an event
  if evt == "timer" then
        if arg == timer then -- check if it's the correct timer
            redstone.setOutput("back",true)
        cp = cp +1
            print ("Next move! "..cp)
    end
  elseif evt == "redstone" then
        timer = os.startTimer(exitTime) -- restarts the timer
        redstone.setOutput("back",false)
    cm = cm +0.5
    print ("Send Items! x"..cm)
  end
  if cm >= 222 then --Lava protect
    redstone.setOutput("back",true)
    print ("Next move! "..cp)
  end
end