Turtle v2 Mining Teselation

if not os.loadAPI("turtle2") then return false end
turtle2:reloadConfigs()
--[[
while true do
  turtle2:digDown()
  if not turtle2:down() then break end
end

turtle2:returnHome()
]]


while true do
   startY = turtle2:getPosition().y
   while true do
      turtle2:digDown()
      if not turtle2:down() then break end
      if turtle2:hasReturned() then return end
      --sleep(3)
      for i = 0,3 do
         shouldDig = false
         turtle2.select(5)
         if not turtle2.compare() then print("not stone") shouldDig=true end
         turtle2.select(9)
         if shouldDig and(not turtle2.compare()) then print("not dirt either") turtle2:dig() end
         --sleep(2)
         turtle2:turnRight()
      end
   end
   if turtle2:hasReturned() then return end
   print("Hit bedrock. Time to come back up")
   tmpBlugdeon = false
   while turtle2:getPosition().y ~= startY do
      if (not turtle2.blugdeon) and (movement:length() == prevLength) then tmpBlugdeon,turtle2.blugdeon = true, true
      elseif tmpBlugdeon and turtle2.blugdeon then tmpBlugdeon, turtle2.blugdeon = false, false end
      turtle2:up()
      if turtle2:hasReturned() then return end
   end
   turtle2.select(2)
   turtle2:placeDown()

   turtle2:dig()
   turtle2:forward()
   turtle2:dig()
   turtle2:forward()
   turtle2:dig()
   turtle2:forward()
   turtle2:dig()
   turtle2:forward()
end

if not turtle2:hasReturned() then turtle2:returnHome() end