const int LED_PIN2 = 2;
    const int LED_PIN3 = 3;

    #define LED_ON HIGH
    #define LED_OFF LOW
    
void setup() {
    Serial.begin(115200);
    pinMode(LED_PIN2, OUTPUT);
    pinMode(LED_PIN3, OUTPUT);
    digitalWrite(LED_PIN2, LED_OFF);         // Give the output pins a definite, known state at start up
    digitalWrite(LED_PIN3, LED_OFF);
    Serial.println("Setup complete");
}

void loop() {
    flashEqualOnOffPin2();
    flashUnequalOnOffPin3();
}

void flashEqualOnOffPin2() {
    uint32_t currentMillis = millis();
    static uint32_t lastMillis;
    const uint32_t onOffTime = 500;                 //Duration for LED to be on or off before changing state, in miliseconds
    
    if (currentMillis - lastMillis >= onOffTime) {
        lastMillis += onOffTime;


        
    if (digitalRead(LED_PIN2) == LED_ON) {
            digitalWrite(LED_PIN2, LED_OFF);
        } else {
            digitalWrite(LED_PIN2, LED_ON);
        }
    }
}

void flashUnequalOnOffPin3() {
    uint32_t currentMillis = millis();
    static uint32_t lastMillis;
    const uint32_t onTime = 1750;     //Duration for LED to be on, in miliseconds
    const uint32_t offTime = 350;     //Duration for LED to be off, in miliseconds

        if (digitalRead(LED_PIN3) == LED_ON) {                      // Read the current state of pin 3
            if (currentMillis - lastMillis >= onTime) {             // Pin 3 is high (LED on), check on time and turn LED off if time has expired
                lastMillis += onTime;                               // Add the value of onTime to lastMillis ready to start the next timing interval
                digitalWrite(LED_PIN3, LED_OFF);                    // Turn LED off
            }
     } else {
        if (currentMillis - lastMillis >= offTime) {                // Pin 3 is low (LED off), check off time and turn LED on if time has expired
            lastMillis += offTime;                                  // Add the value of offTime to lastMillis ready to start the next timing interval
            digitalWrite(LED_PIN3, LED_ON);                         // Turn LED on
        }
     }
}