ComputerCraft - WaterTank

-- Valve, Monitor & Wireless Modem
        local val = peripheral.wrap("back")
        local mon = peripheral.wrap("top")
        local wmod = peripheral.wrap("bottom")

        local warning = 20       -- Warning level in %
        local cap                -- Tank capacity
        local amount             -- Amount liquid in tank
        local percentfull        -- Percent liquid in tank
        local lastpercent = 1000 -- Percent last loop
        local sendmsg            -- Message to send
        local sleeptime          -- How long to sleep
        local sendFreq = 1       -- Modem Frequency
        local warnFreq = 2       -- Modem Frequency
        local content = "Water[1]"  -- What is in tank?
        local WarningLast = false
        -- Make sure frequency match the main computer

        -- Set warning lamp to off


        -- Main prog loop, never stop
        while true do
          --mon.clear()
          --mon.setCursorPos(1,1)

          -- Fill table with data from tank valve
          tanksTable = val.getTankInfo("unknown")
          maintank = tanksTable[1]

          -- Get values for tank capacity and amount
          cap = maintank.capacity / 1000   -- in buckets
          amount = maintank.amount    -- in millibuckets

          -- If tank is empty, to avoid math issues with 0
          if amount == nil then
            amount = 0
            percentfull = 0
          else
            -- Use math.floor to convert to integers
            amount = math.floor(amount / 1000)
            percentfull = math.floor(100 * amount / cap)
          end

          --mon.write(content)
          --mon.setCursorPos(1,2)
          --mon.write("Amount: " ..amount .."/"..cap .." B.")
          --mon.setCursorPos(1,3)
          --mon.write("Amount: " ..percentfull .."%  ")

          -- Check for change since last loop
          if percentfull == lastpercent and percentfull > warning then
            print("Still " ..percentfull .. "%, nothing sent.")
          else
          sendmsg = content ..": " ..percentfull .."%"
          if percentfull < warning then
            if WarningLast == false then
            WarningLast = true
            sendmsg = sendmsg .. " [WARNING]"
            else
            WarningLast = false
            end
            wmod.transmit(warnFreq,0,sendmsg)
          else
            wmod.transmit(sendFreq,0,sendmsg)
          end
            print("Sent: " ..sendmsg)
          end

          -- Save for next loop
          lastpercent = percentfull
          sleeptime = 1


          -- Sleep either 1 or 10 seconds
          sleep(sleeptime)
        end