turtle quarry

-- deploy the miner
function deploy()
    turtle.select(16)
    turtle.place()
    turtle.select(1)
end

-- returns if something was dropped below this turtle
function clearInv()
    local something = false
    for i = 1, 16 do
        turtle.select(i)
        something = something or turtle.getItemCount(i) > 0
        turtle.dropDown()
    end
    return something
end

-- retrieves the miner in the front
function getMiner()
    turtle.select(16)
    turtle.dropDown()
    turtle.dig()
    turtle.select(1)
end

redstone.setOutput("back", false)

while true do
    -- wait until we find a redstone signal
    -- and maintain this redstone signal until we are done
    if redstone.getInput("back") == true then
        redstone.setOutput("back", true)
        deploy()
        sleep(5)
        -- wait until we deployed something
        while clearInv() == false do
            sleep(math.random(5))
        end
        while clearInv() == true do
            sleep(4 + math.random() * 5)
        end
        clearInv()
        getMiner()
        redstone.setOutput("back", false)

        while redstone.getInput("back") == true do
            sleep(2)
        end
    else
        sleep(2)
    end
end