day00/ex01/main.c

#include <avr/io.h>

#define LED_PORT PORTB0

int main(void) {
	// set pin to output
	// DDRB is the register that set the direction of the pins (IN/OUT)
	// we want to say that the LED_PORT pin is an OUT pin, which isnt the default
	DDRB  |= (_BV(LED_PORT));

	// say to pull high the pins
	// since the pin is set to output, this works !
	PORTB |= (_BV(LED_PORT));
	while (1)
		;
}