Harvester

local x, y, z = gps.locate()
row = {514, 518, 521, 525, 528, 532}
local row_Count = 1
drop = {520, 527}
local drop_Count = 1

function reverse()
   turtle.turnLeft()
   turtle.turnLeft()
end

function up_Line()
   reverse()
   for i = 1, 5 do
      turtle.forward()
   end
   turtle.up()
   for j = 1, 7 do
      turtle.forward()
   end
   turtle.up()
   for k = 1, 7 do
      turtle.forward()
   end
   row_Count = 1
   drop_Count = 1
   reverse()
end

function clear()
   if turtle.detect() == true then
      turtle.dig()
   end
end

function check()
   turtle.select(2)
   if turtle.compare() then
      while turtle.detect() == true do
         turtle.dig()
      end
      turtle.select(1)
      turtle.place()
   end
end

function check_Row()
   turtle.turnLeft()
   check()
   reverse()
   check()
   turtle.turnLeft()
end

function at_Row()
   x, y, z = gps.locate()
   if z == row[row_Count] then
   print("I am at row "..row_Count.."")
      check_Row()
      row_Count = row_Count + 1
   end
end

function at_Drop()
   x, y, z = gps.locate()
   if z == drop[drop_Count] then
      print("I am at drop "..drop_Count.."")
      turtle.down()
      drop_Count = drop_Count + 1
   end
end


function down_Line()
   for i = 1, 19 do
      clear()
      at_Row()
      at_Drop()
      turtle.forward()
   end
end

-- Main Func --
while true do
   local time = os.time()
   if time == 12.000 then
      down_Line()
      up_Line()
   end
   sleep(0.05)
end