chop.lua

function refuel()
    turtle.select(2)
    turtle.refuel(1)
    turtle.select(1)
end
function dig()
    turtle.dig()
    turtle.forward()
    turtle.digDown()

    for i=1, 5, 1 do
        turtle.digUp()
        turtle.up()
    end

    for i =1, 5, 1 do
        turtle.dig()
        turtle.turnLeft()
        turtle.dig()
        turtle.turnLeft()
        turtle.dig()
        turtle.turnLeft()
        turtle.dig()
        turtle.turnLeft()
        turtle.down()
    end
    turtle.select(1)
    turtle.placeDown()
    turtle.back()
    refuel()
    turtle.select(2)
    turtle.dropDown()
end

while true do

    if turtle.detect() then
        dig()
    end
end