Charcoal Farm

local saplingSlot = 1

function forward()
  while not turtle.forward() do
    turtle.dig()
    turtle.attack()
  end
end


function back()
  while not turtle.back() do
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.dig()
    turtle.turnLeft()
    turtle.turnLeft()
  end
end

function plant()
  turtle.select(saplingSlot)
  forward()
  turtle.dig()
  turtle.place()
  back()
  turtle.place()
  turtle.turnRight()
  forward()
  turtle.turnLeft()
  forward()
  turtle.dig()
  turtle.place()
  back()
  turtle.place()
  turtle.turnLeft()
  forward()
  turtle.turnRight()
  while turtle.compare() do
    sleep(5)
  end
end

function chop()
  turtle.dig()
  forward()
  local height= 0
  while turtle.digUp() do
    turtle.dig()
    turtle.up()
    height=height+1
  end
  turtle.turnRight()
  turtle.dig()
  forward()
  turtle.turnLeft()
  for i=height, 1,-1 do
    turtle.digDown()
    turtle.dig()
    turtle.down()
  end
  turtle.dig()
  turtle.turnLeft()
  forward()
  turtle.turnRight()
  back()
end

function unload()
  for slot=1,16 do
    if slot ~= saplingSlot then
      turtle.select(slot)
      turtle.dropDown()
    end
  end
end

while true do
  plant()
  chop()
  unload()
end