.c

#define F_CPU 16000000UL

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

#include "lib/twi.h"
#include "lib/millis.h"
#include "lib/uart.h"

uint8_t twi_scanner(uint8_t address);

int main(void)
{
	//while(1);
	uart_init(UART_BAUD_SELECT(9600, F_CPU));
	millis_init();
	sei();
	millis_t lastChange = 0;
	millis_t lastChange2 = 0;
	
	while(1) {
		
		millis_t now = millis();
		 /*
		if(now - lastChange >= 3000) {
			
			int active_addresses[5] = {0}, index = 0;
			
			for (int i = 0; i <= 128; i++) {
				
				if (twi_scanner(i)) {
					active_addresses[index] = i;
					index++;
				} // end if
				
			} // end for

			lastChange = now;
			
		} // end if millis */
		
		
		
		if(now - lastChange2 >= 3000) {
			unsigned char i = 0;
			   
			twi_init();
			twi_start();
			twi_write_address( (0x8<<1) | TW_WRITE);
			twi_write_data('R');
			twi_write_data('E');
			twi_write_data(24);
			twi_stop();
			
			_delay_ms(100);
			
			twi_init();
			twi_start();
			twi_read_address((0x8<<1) | TW_READ);
			twi_read_data();
			twi_read_data();
			twi_read_data();
			twi_read_data();
			
			 
			 twi_stop();   
			
			// uart_puts(i);
			 
			while (1);

			lastChange2 = now;
			
		} // end if millis2
		
		
		
		
	}
}



uint8_t twi_scanner(uint8_t address)
{
	twi_init();
	twi_start();
	
	if ((TWSR & TW_STATUS_MASK ) != TW_START) {
		twi_stop();
		return 0;
	}
	
	twi_write( (address<<1) | TW_WRITE);
	
	if ((TWSR & TW_STATUS_MASK ) != TW_MT_SLA_ACK) {
		twi_stop();
		return 0;
	}
	
	twi_stop();
	
	return 1;
}