Attiny85 LED flasher

 This simple flashes and led connected to an Attiny


Schematic

Code

The code was written in Atmel Studio

#include <avr/io.h>
#define F_CPU 1000000UL
#include &lt;util/delay.h&gt;

// Define the I/O port to be used for the LED.
#define LED_PORT PB3
int main(void) {
// Set the LED port number as output.
DDRB |= (1 &lt;&lt; LED_PORT);
// Start infinite loop.
while (1)
{
// Set the LED bit to "1" - LED will be "on".
PORTB |= (1 &lt;&lt; LED_PORT);
// The delay function simply does N-number of "empty" loops.
_delay_ms(200);
// Set the LED bit to "0" - LED will be "off".
PORTB &amp;= ~(1 &lt;&lt; LED_PORT);
_delay_ms(400);
}
return (0);
}


And another way

#include <avr/io.h>
#define F_CPU 1000000UL
#include <util/delay.h>

// Define the I/O port to be used for the LED.
#define LED_PORT PB3
int main(void) {
// Set the LED port number as output.
DDRB |= (1 << LED_PORT);
// Start infinite loop.
while (1)
{
// Set the LED bit to "1" - LED will be "on".
PORTB |= (1 << LED_PORT);
// The delay function simply does N-number of "empty" loops.
_delay_ms(200);
// Set the LED bit to "0" - LED will be "off".
PORTB &= ~(1 << LED_PORT);
_delay_ms(400);
}
return (0);
}