Oak farmer collector

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

function left()
  turtle.turnLeft()
  turtle.suck()
end

function right()
  turtle.turnRight()
  turtle.suck()
end

function forward()
  turtle.forward()
  turtle.suck()
end

function collect()
  turtle.up()
  dump()
  turtle.down()
  left()
  forward()
  for i=1,3,1 do
    right()
    for x=1,4,1 do
      forward()
    end
  end
  right()
  forward()
  left()
  forward()
  left()
  forward()
  forward()
  for i=1,3,1 do
    left()
    for x=1,6,1 do
      forward()
    end
  end
  left()
  forward()
  forward()
  left()
  forward()
end

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