/*
www.electropepper.org

Beerright 2017.

*/

#include "main.h"

#define diceDelay 100		// LED speed change while shuffling
#define toggleDelay 300		// LED speed when stoped
#define none 0


int main(int argc, char **argv)
{
	GIMSK |= _BV(PCIE);						// Enable pin change interrupt
	PCMSK |= _BV(PB4);						// Enable PORTB4 for pin change interrupt
	sei();									// Enable global interrupts
	DDRB &= ~_BV(PB4);						// Set PORTB4 to input
	set_sleep_mode(SLEEP_MODE_PWR_DOWN);	// Set sleep mode for Power-down(see datasheet)


	uint8_t randSeed = eeprom_read_byte ((uint8_t*)1);	// Reads eeprom byte 1, value
														// into variable randSeed
	++randSeed;											// Increments it
	eeprom_write_byte ((uint8_t*)1, randSeed);			// Writes value back into
														// eeprom byte 1
	srand (randSeed);									// Creates seed for random number
														// generator from randSeed value


	while (1) {
		for (stand_cycle = 0; stand_cycle < 40; stand_cycle++){	// Repeats 40 times	next 4 lines
			what_led(cur_led);									// Turn ON LED number inside variable cur_led
			_delay_ms(toggleDelay);								// Wait
			what_led(none);										// Truen off all LED's
			_delay_ms(toggleDelay);								// Wait
		}
	sleep_mode();					// Go into sleep mode to save power, will came back alive
									// after interrupt is generated
	}
}

ISR(PCINT0_vect)						// Interrupt routine on pin change
{
	for (uint8_t i = 0; i < 25; i++){	// Repeats 25 times	next 3 lines
		cur_led = ((rand() % 7) + 1);	// Creates random integer from 0 to 6 into cur_led
		what_led(cur_led);				// Turn ON LED number inside variable cur_led
		_delay_ms(diceDelay);			// Wait
	}
	stand_cycle = 0;					// Resets the standby blinking times
}


void what_led(uint8_t led)
{
	int8_t ledN = led_table[led];		// Reads led_table given number(led) into ledN
	DDRB = ledN & 0x0F;					// Copy first ledN nibble into DDRB
	ledN = (ledN & 0xF0) >> 4;			// Move second nibble into first nibble
	PORTB = ledN & 0x0F;				// Copy first ledN nibble into PORTB
}