/*
 * Button pressed LED ON
 * A C program that activates the LED connected 
 * to the PA5 pin when pressing the button 
 * connected to the PA4 pin of the MidTiny board (Base ATtiny1614).
 *
 * Author: Harley Lara
 * Create: 03 May 2021
 * License: (CC BY-SA 4.0) Attribution-ShareAlike 4.0 International
 *
 * This work may be reproduced, modified, distributed,
 * performed, and displayed for any purpose, but must
 * acknowledge this project. Copyright is retained and
 * must be preserved. The work is provided as is; no
 * warranty is provided, and users accept all liability.
 */

#define F_CPU 3333333
#include <avr/io.h>
#include <util/delay.h>

#define LED PIN5_bm // Define LED pin
#define BUTTON PIN4_bm // Define BUTTON pin

int main() {

  PORTA.DIR |= LED; // Define the LED port as output
  PORTA.OUT &= ~LED; // Set the initial state of the LED OFF

  PORTA.DIR &= ~BUTTON; // Define the button port as input
  PORTA.PIN4CTRL = 0; // Don't use the internal pullup resistor

  while (true) {
    _delay_ms(10); // Wait
    if (PORTA.IN & BUTTON) // If the button is pressed
    {
      PORTA.OUT ^= LED; // LED toggle ON/OFF
    } else {
      PORTA.OUT &= ~LED; // If the button is not pressed set LED OFF
    }
  }

  return 0;
}