# blink-led program written in C for AVR Microcontroller

```
#include <avr/io.h>
#define F_CPU 16000000UL
#include <util/delay.h>
#define BLINK_DELAY_MS 1000

void setup() {
  DDRD = 0b00000100;
  PORTD = 0b00000000;
}

void loop() {
  PORTD = 0b00000100;
  _delay_ms(BLINK_DELAY_MS);
  PORTD = 0b00000000;
  _delay_ms(BLINK_DELAY_MS);
}

int main(void) {
  setup();
  for (;;) {
    loop();
  }
}
```