#include <funshield.h>

constexpr int pins[] { led1_pin, led2_pin, led3_pin, led4_pin };
constexpr int pinsCount = sizeof(pins) / sizeof(pins[0]);

constexpr unsigned long changeDelay = 300;
bool ledState = false;
unsigned long lastChange;

void setup() {
  // put your setup code here, to run once:
  for (int i = 0; i < pinsCount; ++i) {
    pinMode(pins[i], OUTPUT);
    digitalWrite(pins[i], OFF);
  }
  lastChange = millis();
}

void loop() {
  // put your main code here, to run repeatedly:
  unsigned long currentTime = millis();
  if (currentTime - lastChange >= changeDelay) {
    ledState = !ledState;
    for (int i = 0; i < pinsCount; ++i) {
      digitalWrite(pins[i], ledState ? ON : OFF);
    }
    lastChange += changeDelay;
  }
}