wokwi_t85_avrgcc-blink - Wokwi ESP32, STM32, Arduino Simulator

#include <avr/io.h>
#include <util/delay.h>

#define ledPin PB4

int main(void)
{
  DDRB |= (1<<ledPin);

  while (1){
    PORTB ^= (1<<ledPin);
    _delay_ms(500);
  }
}