SeedOilTankMonitor

function getTankAmount()--{{{
    local tank = peripheral.wrap("back")
    return tank.getTanks("unknown")[1].amount
end--}}}
while true do
    os.startTimer(60)
    event, param1, param2, param3 = os.pullEvent("timer")
    amount = getTankAmount()
    if amount > 800000 then
        rs.setOutput("left", true)
    else
        rs.setOutput("left", false)
    end
end