Nether Traveller Turtle v1.5

--Nether Traveller by VADemon

itemCount = turtle.getItemCount(1)

turtle.select(1)

function addCount()
    itemCount = itemCount - 1
    if itemCount == 0 then
        for i = 2, 16 do
            if turtle.getItemCount(1)==64 then
                itemCount = 64
                turtle.select(1)
                break
            else
                turtle.select(i)
                turtle.transferTo(1, turtle.getItemSpace(1) )
                itemCount = turtle.getItemSpace(1)
            end
        end
        -- if checked all slots, but <64 in total
        print("I'm low on blocks!")
        if itemCount == 0 then
            print("No blocks left! Refill me please!")
            print("Stopping!")
            ready = true
        end
    end
end

function goForward()
    --sleep(1)
    turtle.dig()

    if turtle.forward() then

        if not turtle.detectDown() then
            if not turtle.placeDown() then
                print("Can't place a block, though there's nothing underneath!")
                print("Stopping!")
                ready = true
            end
            addCount()
        end

    else
        print("Something is on my way! Can't move.")
        sleep(4)
    end
end

print("Press \"S\" to stop!")

local ready = false
parallel.waitForAny(
    function()
        while not ready do
            local event, key = os.pullEvent("key")
            if key == 31 then
                ready = true
                print("Stopping...")
            end
        end
    end,
    function()
        while not ready do
            goForward()
        end
    end
)