CC nixie fluid readout

local tank = peripheral.find("modern_industrialization:large_tank_hatch")
local display = peripheral.find("create_source")

print("Printing tank fullness to nixie tubes")
local prevTankPercent = -1  -- the tank doesn't seem to show up when no updates are given
while true do
    local percentage = -1
    local tanks = tank.tanks()

    if #tanks > 0 or tanks[1] ~= nil then
        local amount = tanks[1].amount
        local capacity = tanks[1].capacity
        local ratio = amount / capacity
        percentage = ratio *100
        prevTankPercent = percentage
        print(tostring(os.time()).."new data")
    else
        print(tostring(os.time()) .. "outdated info")
        percentage = prevTankPercent
    end

    if percentage == -1 then
        display.clear()
        display.setCursorPos(1,1)
        display.write("??.??%")
        print(tostring(os.time()) .. "no data")
    elseif percentage == 1 then
        display.clear()
        display.setCursorPos(1,1)
        display.write("FULL")
    else
        local dig_0 = math.floor((percentage / 10) % 10)
        local dig_1 = math.floor(percentage % 10)
        local dig_2 = math.floor((percentage *10) %10)
        local dig_3 = math.floor((percentage *100) %10)

        display.clear()
        display.setCursorPos(1,1)
        display.write(tostring(dig_0))
        display.write(tostring(dig_1))
        display.write(".")
        display.write(tostring(dig_2))
        display.write(tostring(dig_3))
        display.write("%")
    end

    sleep(1)
end