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

// Define the button pin
#define BUTTON_PIN 2

// Define the LED pin
#define LED_PIN 5 // Corresponds to pin D5 on Arduino Uno

// Initialize UART communication at 9600 baud rate
void uart_init() {
    UBRR0H = 0;
    UBRR0L = 103; // Baud rate 9600 at 16MHz
    UCSR0B |= (1 << TXEN0); // Enable transmitter
    UCSR0C |= (1 << UCSZ01) | (1 << UCSZ00); // 8-bit data format
}

// Transmit a character via UART
void uart_transmit(unsigned char data) {
    while (!(UCSR0A & (1 << UDRE0))); // Wait for the transmit buffer to be empty
    UDR0 = data; // Put data into buffer, sends the data
}

// Setup function
void setup() {
    // Set D2 pin as input
    DDRD &= ~(1 << DDD2);
    // Enable pull-up resistor for D2 pin
    PORTD |= (1 << PORTD2);
    // Initialize UART
    uart_init();
}

// Main function
int main(void) {
    // Setup function
    setup();

    // Variable to store the previous state of the button
    int previousState = 1;

    // Loop forever
    while (1) 
    {
        // Read the current state of the button
        int currentState = (PIND & (1 << PIND2)) ? 1 : 0;

        // Check if the button state has changed since the last time it was read
        if (currentState != previousState) {
            // If the button state has changed
            _delay_ms(10); // Delay for debounce
            if (currentState == (PIND & (1 << PIND2))) { // Check if the button state is stable
                // If the button is pressed (current state is LOW)
                if (currentState == 0) {
                    // Toggle the LED state
                    //PORTD ^= (1 << PORTD5);
                    // Transmit message over UART
                    uart_transmit('1');
                }
          
               
            }
        }
        // Update the previous state to the current state
        previousState = currentState;
         //uart_transmit('0');
    }

    return 0;
}