Mining turtle with chests

--Save this program as startup
--Also install the refuelling program at refuel

--Place the turtle in front of the
--blocks you want it to start to strip mine.
--Place chests in slot 16 and give it some
--coal to start. It will mine 80 blocks
--forward, turn to the right, and mine
--80 blocks back. Because it mines 1x3
--It will mine a total of 240 blocks.

--When it is done mining, it will move
--to a new start position, turn around
--place a chest and dump all its contents.
--If there is enough fuel and more chests
--the turtle will repeat indefinitely


term.clear()
term.setCursorPos(1,1)

print("Turtle is now powered on.")
shell.run("refuel")

FL = turtle.getFuelLevel()
turtle.select(16)
sloot = turtle.getItemDetail()
Chest = turtle.getItemCount()


l=0

while l < 1 do

if FL > 500 and Chest > 0 and sloot.name == "minecraft:chest" then

function dig()
    turtle.digUp()
    turtle.digDown()
    turtle.dig()
    sleep(1)
    block = turtle.detect()
    while turtle.detect() == true do
        turtle.dig()
        sleep(1)
        block = turtle.detect()
    end
    turtle.forward()

end


i = 0
while i < 80 do
    dig()
    i = i + 1
end

shell.run("refuel")
turtle.turnRight()
dig()
turtle.turnRight()

i = 0
while i < 80 do
    dig()
    i = i + 1
end

turtle.digUp()
turtle.digDown()
turtle.turnLeft()
turtle.dig()
turtle.forward()
turtle.turnLeft()
turtle.turnLeft()
turtle.select(16)
turtle.place()
shell.run("refuel")

i = 1
while i < 16 do
    turtle.select(i)
    turtle.drop(64)
    i = i + 1
end

turtle.turnRight()
FL = turtle.getFuelLevel()
turtle.select(16)
Chest = turtle.getItemCount()
sloot = turtle.getItemDetail()

if sloot == nil then
    l=1
end


else

l=1
end
end

if FL < 500 then
    print("Out of fuel, Shutting down")
end

if Chest == 0 then
    print(" Trutle has run out of chests, shutting down")
end

print("Exiting")