Non-blocking Arduino Arc Welder Simulator

arduinoWelder.ino

unsigned long currentMillis = 0;
unsigned long previousMillisArc = 0;
unsigned long previousMillisFlicker = 0;
int timeArcOff = 3000;
int timeArcOn = 3000;
bool arc = false; //whether there's an arc right now or not
int ledState = LOW;
const int ledPin = 2;
int timeFlickerOn = 50;
int timeFlickerOff = 170;
bool welding = true;

void setup() {
  pinMode(ledPin, OUTPUT);
}

void loop() {
  if (welding == true) { //make sure the welder is enabled
    unsigned long currentMillis = millis();

    if (arc == false && currentMillis - previousMillisArc >= timeArcOff) { //if the arc's off, but been off long enough
      arc = true;
      previousMillisArc = currentMillis;
      timeArcOff = random(3000);
    }
    else if (arc == true && currentMillis - previousMillisArc >= timeArcOn) { //if the arc's on, but been on long enough
      arc = false;
      ledState = LOW;
      previousMillisArc = currentMillis;
      timeArcOn = random(3000);
    }

    if ( arc == true && currentMillis - previousMillisFlicker >= timeFlickerOn && ledState == HIGH) {
      previousMillisFlicker = currentMillis;
      timeFlickerOn = random(20);
      ledState = LOW;
    }
    if ( arc == true && currentMillis - previousMillisFlicker >= timeFlickerOff && ledState == LOW) {
      previousMillisFlicker = currentMillis;
      timeFlickerOff = random(100);
      ledState = HIGH;
    }
    digitalWrite(ledPin, ledState);
  }
  else {
    digitalWrite(ledPin, LOW);
  }
}