TankLiquidMonitor

local mon = peripheral.wrap("top")
local tank = peripheral.wrap("right")
local modem = peripheral.wrap("back")
modem.open(100)
local amount
local cap
local percentfull
local warning = 10
local sleepTime = 10



function getTank(tank)
  local tableInfo = tank.getTankInfo("unknown")
  fluidAmount = nil
  fluidCapacity = tableInfo[1].capacity
  local contents = tableInfo[1].contents
  if contents then
    fluidAmount = contents.amount
  end
  return fluidAmount, fluidCapacity
end

while true do
  mon.clear()
  mon.setCursorPos(3,3)
  rs.setOutput("left", false)

  local fluidAmount, fluidCapacity = getTank(tank)
  cap = fluidCapacity / 1000
  amount = fluidAmount
  mon.setTextColor(colours.white)

  if fluidCapacity == nil then
    return
  end

  if amount == nil then
    amount = 0
    percentfull = 0
  else
     amount = math.floor(amount / 1000)
     percentfull = math.floor(100 * amount / cap)
  end

  if percentfull < warning then
     rs.setOutput("left", true)
     mon.setTextColour(colours.red)
  elseif percentfull > 90 then
     mon.setTextColour(colours.green)
  end
  mon.write(percentfull.."%")
  modem.transmit(100, 100, percentfull)
  print(percentfull.."%")
  sleep(sleepTime)
end
--ref: http://pastebin.com/XeHKVry4
--RabaGhast