Tree Farm Collector

-- collector for the tree farm
-- place facing away from the tree farm
-- ten blocks from the center of the tree farm
-- place fuel blocks in the last slot (16)
-- place chest to the right of the turtle
--   (as it is facing away)

function fuel()
  if turtle.getFuelLevel() < 30 then
    turtle.select(16)
    if turtle.refuel(16) then
      return true
    end
    print("Refuelling failed.")
    return false
  end
end

function tunnel()
  for i=1,10,1 do
    turtle.dig()
    turtle.forward()
  end
  for i=1,3,1 do
    turtle.digUp()
    turtle.up()
  end
end

function reverseTunnel()
  for i=1,3,1 do
    turtle.digDown()
    turtle.down()
  end
  for i=1,10,1 do
    turtle.dig()
    turtle.forward()
  end
end

function dump()
  turtle.turnRight()
  for i=1,15,1 do
    turtle.select(i)
    turtle.drop()
  end
end

function collect()
  print("Fueling")
  fuel()
  print("Going back for more")
  reverseTunnel()
  turtle.select(1)
  print("Picking up stuff")
  sucked = true
  while sucked == true do
    sucked = turtle.suck()
  end
  turtle.turnRight()
  turtle.turnRight()
  print("Coming back")
  tunnel()
  print("Dumping")
  dump()
  turtle.turnRight()
end

while true do
  collect()
  print("Waiting 15 minutes")
  os.sleep(900)
end