//for uno, nano ...LED_BUILTIN pin 13
void setup() {
DDRB |= 1 << 5;
}
void loop() {
PORTB = !((millis() >> 6) & B01001) << 5;
}
//--------------------------------------------------
/*
void setup() {
pinMode(LED_BUILTIN, OUTPUT);
}
void loop() {
digitalWrite(LED_BUILTIN, !((millis() >> 6) & B01001));
}
*/