Computercraft Turtle feller

t = turtle
function start_turtle()
    while t.down do -- Bring the turtle down if it's up
        t.down()
    end
    while t.back do -- Move the turtle back against the hopper
        t.back()
    end
end

function cut_tree()
    t.dig()
    t.forward()
    t.select(16)
    while t.compareUp() == false do
        t.digUp()
        t.up()
    end
    t.select(15)
    while t.compareDown() == false do
        t.down()
    end
    t.select(1)
    turtle.back()
end


function grow_tree()
    t.select(3)
    t.place()
    t.select(2)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.place()
    sleep(.1)
    t.select(1)
end

function refuel()
    fuel_amount = t.getItemCount()
    if fuel_amount > 1 then
        turtle.refuel(fuel_amount - 1)
    end
end

function farm()
    grow_tree()
    cut_tree()
    refuel()
    sleep(5)
end

start_turtle()
while turtle.getFuelLevel > 15 do
    farm()
end