miner

-- Tunnel Mining Turtle (with return)
-- Mines, places torches, builds floor
-- Variables
 turtle.select(1)
 local tArgs = { ... }
 local togo = tonumber(tArgs[1])
 togo = togo or 1
 local torch = 0
 local cobble = 0
 term.clear()
 term.setCursorPos(1,1)
 -- print(os.getComputerLabel() .. " at your service!")
 print()
 print("Please place blocks as follows:")
 print("Slot 1 - Fuel (coal or lava)")
 print("Slot 2 - Torches (optional)")
 print("Slot 3 - Cobble (optional)")
 print()
 print("Press [ENTER] when ready.")
 read(input)

-- Starting Out
 if turtle.getItemCount(1) < 1 then
  print("No fuel! Abort!")
  quit()
 end
 if turtle.getItemCount(2) > 0 then
  torch = 1
 end
 if turtle.getItemCount(3) > 0 then
  cobble = 1
 end
 local i = 0
-- Functions
 function tfuel(amount)
  if turtle.getFuelLevel() < 16 then
   turtle.select(1)
   turtle.refuel(amount)
  end
 end

 function turnaround()
  turtle.turnRight()
  turtle.turnRight()
 end

 function uandd()
  if turtle.detectUp() then
   repeat
    turtle.digUp()
    sleep(0.5)
   until turtle.detectUp() == false
  end
  if turtle.detectDown() then
   repeat
    turtle.digDown()
   until turtle.detectDown() == false
  end
  if cobble > 0 then
   turtle.down()
   if turtle.detectDown() == false then
    turtle.select(3)
    turtle.placeDown()
    turtle.select(1)
   end
   turtle.up()
  end
 end

 function mydig()
  tfuel(1)
  if turtle.detect() then
   repeat
    turtle.dig()
    sleep(0.5)
   until turtle.detect() == false
   turtle.forward()
   uandd()
  else
   turtle.forward()
   uandd()
  end
 end

 function discard()
  turnaround()
  for f = 1,i do
   tfuel(1)
   while turtle.forward() == false do
    turtle.dig()
   end
  end
  for x = 2+torch+cobble,16 do
   turtle.select(x)
   turtle.dropDown()
  end
  turnaround()
  for f = 1,i do
   tfuel(1)
   while turtle.forward() == false do
    turtle.dig()
   end
  end
  turtle.select(1)
 end

-- Main Loop
 repeat
  i = i + 1
  term.clear()
  term.setCursorPos(1,1)
  local pct = (i/togo)*100
  print("Mining "..i.." of "..togo.." ("..pct.."%)")
  print("Fuel: "..turtle.getFuelLevel())
  mydig()
  turtle.turnRight()
  mydig()
  turnaround()
  turtle.forward()
  mydig()
  turnaround()
  turtle.forward()
  turtle.turnLeft()
  if togo >= 8 and torch > 0 then
   if (i % 8 == 0) then
    turtle.select(2)
    turtle.placeDown()
    turtle.select(1)
   end
  end
  -- check to see if turtle is full
  if turtle.getItemCount(16) > 0 then
   discard()
  end
  turtle.select(1)
 until i >= togo
 --Lets assume that worked and he made it
 turnaround()
 for r = 1, togo do
  tfuel(1)
  while turtle.forward() == false do
   turtle.dig()
  end
 end
 for x = 1,16 do
  turtle.select(x)
  turtle.dropDown()
 end
 turtle.select(1)