micros()

unsigned long micros();

void setup() {
    pinLabel(1, "O1");   // sets the pin 1 label to "O1"
    pinMode(1, OUTPUT);  // sets the digital pin 1 as output
    pinLabel(2, "O2");   // sets the pin 2 label to "O2"
    pinMode(2, OUTPUT);  // sets the digital pin 2 as output
    pinLabel(3, "O3");   // sets the pin 3 label to "O3"
    pinMode(3, OUTPUT);  // sets the digital pin 3 as output
    pinLabel(4, "O4");   // sets the pin 4 label to "O4"
    pinMode(4, OUTPUT);  // sets the digital pin 4 as output
}

void loop() {
    static unsigned long lastTime = 0;
    static unsigned long counter = 0;
    if (micros() - lastTime >= 1000) {  // checks if the number of microseconds is greater than or equal to 1000
        lastTime = micros();
        counter++;
        digitalWrite(1, counter & 0x01);  // sets the output pin 1 with the first bit of the counter
        digitalWrite(2, counter & 0x02);  // sets the output pin 2 with the second bit of the counter
        digitalWrite(3, counter & 0x04);  // sets the output pin 3 with the third bit of the counter
        digitalWrite(4, counter & 0x08);  // sets the output pin 4 with the fourth bit of the counter
    }
}