Liquid Level Monitor Adv

--[[
Liquid Level Monitor v1.1
by Fooman

http://www.youtube.com/user/Foooman

]]--

--Side of Computer with Nuclear Information Reader
local nuclearReaderSide = "right"
--Side of Computer with Howler Alarm
local howlerAlarmSide = "back"
--Side of Computer with Monitor
local monitorSide = "left"
--Time interval (seconds) between updates
local updateInterval = 5
--Amount of Liquid (amount/capacity) to trigger alarm
local alarmTrigger = 0.25
--Number of Tanks to monitor
local tankQuantity = 1

local nonKitable = 18000

local lCapacity
local lAmount

nr = peripheral.wrap(nuclearReaderSide)
m = peripheral.wrap(monitorSide)
m.setTextScale(0.5)
local wm,hm = m.getSize()

local function monitorCentered(str,ypos)
    m.setCursorPos(wm/2 - #str/2 + 1, ypos)
    m.write(str)
end
local function monitorLeft(str,ypos)
    m.setCursorPos(1 , ypos)
    m.write(str)
end

function getLiquid()
    --Reset Counter to nonKitable base value
    lAmount = 0
    lCapacity = nonKitable
    for i = 1,tankQuantity do
        --get Counter for all BC Tanks
        local a,b,c, info = nr.get(i)
        --Error on bad sensor kit
        if b ~= "OK" then error("bad sensor kit: "..b) end
        for system, status in pairs(info) do
            status = tostring(status)
            if system == "capacity" then
                lCapacity = lCapacity + status
            elseif system == "amount" then
                lAmount = lAmount + status
            end
        end
    end
    --Add nonKitable to Amount if nonzero
    if lAmount > 0 then
        lAmount = lAmount + nonKitable
    end
end

function alarmTrig()
    if (lAmount/lCapacity) <= alarmTrigger then
        rs.setOutput(howlerAlarmSide, true)
    else
        rs.setOutput(howlerAlarmSide, false)
    end
end

function updateMonitor()
    m.clear()
    monitorCentered("Fuel Amount",2)
    monitorCentered(tostring(lAmount).." mB", 7)
end


--Operation
term.clear()
local updateTimer = os.startTimer(0.05)

while true do
    event, param1, param2, param3 = os.pullEvent()
    if event == "timer" then
        getLiquid()
        alarmTrig()
        updateMonitor()
        updateTimer = os.startTimer(updateInterval)
    end
end