Script for Mining Turtle

--3x3 tunnel maker With TurtleOS 1.8
--based on Luke Ryszard script

--[[
ITEMS IN GUI!
[  ][  ][  ][  ]
[  ][  ][  ][  ]
[  ][  ][  ][  ]
[  ][  ][15][16]

15 - fuel spot
16 - torch spot
]]
function RMine()
    turtle.turnRight()
    turtle.dig()
    turtle.forward()
    turtle.digUp()
    turtle.digDown()
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.forward()
    turtle.digDown()
    turtle.turnRight()
end -- end RMine()

function LMine()
    turtle.turnLeft()
    turtle.dig()
    turtle.forward()
    turtle.digUp()
    turtle.digDown()
    turtle.turnRight()
    turtle.turnRight()
    turtle.forward()
    turtle.digDown()
    turtle.turnLeft()
end -- end LMine()

function checkFuel()
  if turtle.getFuelLevel() <= 10 then
    turtle.select(15)
    turtle.refuel(1)
    turtle.select(1)
  end --if
end --checkFuel()

-- Create the turnAround function
function turnAround()
  turtle.turnRight()
  turtle.turnRight()
end --turnAround()

-- Digs the tunnel for the given length
function tunnel(givenLength)
  local distance = 0
  turtle.up()
  for index = 1,givenLength do
    turtle.dig()
    if turtle.forward() then
      distance = distance + 1
    end --if
    turtle.digUp()
    turtle.select(1)
    turtle.placeDown()
    LMine()
    RMine()
-- Places a torch every 10 blocks
    if distance == 10 then
      turtle.select(16)
      print("Placing torch...")
      turnAround()
      turtle.place()
      turnAround()
      distance = 0
      checkFuel()
    end --if
  end --for

-- Sends the turtle back to the start
    turtle.up()
    for index = 1,givenLength do
      turtle.back()
    end --for
    turtle.down()
end --tunnel()

-- Main script
print("Input tunnel length:")
local length = read()
print("starting excavation...")
checkFuel()
tunnel(length)
print("The tunnel has been excavated!")