shaft.lua

local id = 5055
rednet.open("right")
local args = {...}
local iter = 1

if #args >= 1 then
    iter = tonumber(args[1])
end

function refuel()
    if turtle.getFuelLevel() < 1 then
        for i = 1,16 do
            turtle.select(i)
            turtle.refuel(1)
        end
    end
end

function digShaft()
    local depth = 0
    turtle.digDown()
    while turtle.down() do
        turtle.digDown()
        depth = depth + 1
        refuel()
    end
    for i = 1,depth do
        refuel()
        turtle.up()
    end
    refuel()
    turtle.dig()
    turtle.digUp()
    turtle.forward()
end

function repeatDig()
    refuel()
    for i = 1, iter do
        digShaft()
    end
end

function updateHome()
    while true do
        rednet.send(id, turtle.getFuelLevel(), "fuel")
        sleep(0.5)
        local x, y, z = gps.locate()
        rednet.send(id, x..", "..y..", "..z, "gps")
        sleep(30)
    end
end

parallel.waitForAny(repeatDig, updateHome)
print("done!")