Strip Mine turtle

--[[
	** Prep the Turtle before running! **
	Slots 1,2,3 are for blocks not to mine (smooth stone, gravel, dirt)
	Slot 15 is the block to backfill holes (recommend cobble)
	Slot 16 is for fuel
]]--
consoleID = 1
depth = 0

function fuel()
	if turtle.getFuelLevel() <= depth + 10 then
		turtle.select(16)
		turtle.refuel(1)
		rednet.send(consoleID,"Refueled. Fuel level: "..turtle.getFuelLevel())
	end
end

function isValuable()
	if turtle.detect() == false then
		return false
	end
	for i=1,3 do
		turtle.select(i)
		if turtle.compare() then
			return false
		end
	end
	return true
end

function checkWalls(dp)
	for j=1,4 do
		if isValuable() then
			rednet.send(consoleID,"Found ore at depth "..dp)
			turtle.dig()
		end
		turtle.turnRight()
	end
end

------ ( Program Start ) ------

rednet.open("right")
term.clear()
print("Ben's Simple Turtle Miner")
print("-------------------------")

term.write("Go on mining run? (y/n): ")

while read() == "y" do

	depth = 0
	print("Commencing mining.")
	rednet.send(consoleID,"Commencing mining.")

	fuel()
	turtle.digDown()
	for st=1,2 do
		turtle.down()
		depth = depth + 1
		turtle.digDown()
	end

	-- plug entrance hole
	turtle.select(15)
	turtle.placeUp()

	while not turtle.detectDown() do
		fuel()
		turtle.down()
		depth = depth + 1
		if depth%10==0 then
			rednet.send(consoleID,"At depth "..depth)
		end
		checkWalls(depth)
		turtle.digDown()
	end

	rednet.send(consoleID,"Moving to next shaft location...")

	for mv=1,6 do
		fuel()
		turtle.up()
		depth = depth - 1
	end

	-- move forward 2 blocks
	for z=1,2 do
		fuel()
		while not turtle.forward() do
			turtle.dig()
			sleep(.8)
		end
	end

	-- turn right and move one block
	turtle.turnRight()
	fuel()
	while not turtle.forward() do
		turtle.dig()
		sleep(.8)
	end
	turtle.turnLeft()

	-- go down to bedrock
	turtle.digDown()
	while not turtle.detectDown() do
		fuel()
		turtle.down()
		depth = depth + 1
		turtle.digDown()
	end

	rednet.send(consoleID,"Returning to surface!")

	for k=depth,3,-1 do
		checkWalls(k)
		turtle.digUp()
		fuel()
		while not turtle.up() do
			turtle.digUp()
			sleep(.5)
		end
		if k%10 == 0 then
			rednet.send(consoleID,"At depth "..k)
		end
	end

	fuel()
	turtle.digUp()
	turtle.up()
	turtle.digUp()
	turtle.up()

	-- fill exit hole
	turtle.select(15)
	turtle.placeDown()

	turtle.forward()
	turtle.forward()
	turtle.turnRight()
	turtle.forward()
	turtle.turnLeft()

	term.write("Go on mining run? (y/n): ")
end

print("Cancelled mining.")
rednet.send(consoleID,"Cancelled mining.")

rednet.close("right")