Extreme Reactors temp PID for opencomputers

-- keeps reactor working efficiently at all times; increases power load when necessary, goes idle at 90% power until below 10%

local reactor=require('component').br_reactor

local curPower,controlRodLevel,powerMode,tickCount=0,50,0,0

local upTicks=0

local integral=0

local controlRodNumber=reactor.getNumberOfControlRods()

powerMode = reactor.getEnergyStored()<9000000

local function reactorActivities()
  tickCount=tickCount+1
  curPower = reactor.getEnergyStored()
  if curPower>9000000 then
    powerMode=false
  elseif curPower<1000000 and curPower>0 then
    powerMode=true
  end
  if powerMode then
    upTicks=upTicks+1
    reactor.setActive(true)
    local temperature = reactor.getFuelTemperature and reactor.getFuelTemperature() or reactor.getTemperature()
    oldError=curError or 0
    curError = temperature - 950 or 0
    integral=integral+curError or 0
    derivative = tickCount>1 and curError - oldError or 0
    local deltaControlRodLevel=(Kp*curError)+(Ki*integral)+(Kd*derivative)
    local numberOfControlRodsToAddOneTo=math.floor((deltaControlRodLevel%1)*controlRodNumber)
    deltaControlRodLevel=deltaControlRodLevel<0 and math.ceil(deltaControlRodLevel) or deltaControlRodLevel>0 and math.floor(deltaControlRodLevel) or 0
    controlRodLevel = controlRodLevel+deltaControlRodLevel
    if controlRodLevel>100 or controlRodLevel<0 then
     integral=0
    end
    controlRodLevel = controlRodLevel>100 and 100 or controlRodLevel<0 and 0 or controlRodLevel
    for i=0,controlRodNumber-1 do
        reactor.setControlRodLevel(i,controlRodLevel+(i<numberOfControlRodsToAddOneTo and 1 or 0))
    end
  else
    reactor.setActive(false)
  end
end

local args = {...}

interval = 0.5
Kp=0.5
Ki=0.005*interval
Kd=0.01*interval

while reactor.getConnected() do
   pcall(reactorActivities)
   os.sleep(interval)
end