/*
 * test.c
 *
 * Created: 17.05.2018 16:37:10
 * Author : santn
 */

#include <avr/io.h>

void init() {
	DDRA &= ~(1 << 0);
	DDRB = 0xFF;
}

uint8_t readShift() {
	return (PINA & 0x01);
}

uint8_t shift(uint8_t x) {
	uint8_t sh[8];
	for(int i = 0; i < 8; i++) {
		sh[i] = (x & (1 << i)) >> i;
	}

	uint8_t u = sh[0] ^ sh[2];
	uint8_t v = sh[3] ^ u;
	uint8_t w = sh[5] ^ v;

	return (w << 7) | (sh[7] << 6) | (sh[6] << 5) | (sh[5] << 4) | (sh[4] << 3) | (sh[3] << 2) | (sh[2] << 1) | sh[1];
}


int main(void) {
	init();
	volatile uint8_t noise = 1;
    while (1) {
		if(readShift() == 1) {
			noise = shift(noise);
			PORTB = noise;
		}
    }
}