/*
 * --------------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 23):
 * As long as you retain this notice you can do whatever you want with this stuff.
 * If we meet some day, and you think this stuff is worth it, you can buy me a beer
 * in return. Niklas Roy.
 * Revision 23 is based on revision 42 of this license by Poul-Henning Kamp
 *
 * Please note that this code is a quick hack, which is only poorly commented and
 * meant for reference use only.
 *
 * Code is written in AVR-GCC and runs on an ATmega8 with 1MHz internal oscillator.
 * --------------------------------------------------------------------------------
 */

#define F_CPU 1000000UL
#define STOP_L 186
#define STOP_R 131
#define STOP OCR1A =3000;OCR1B =3000;

#define LED1ON  PORTC |= (1<<PC1) | (1<<PC2);
#define LED1OFF PORTC &= ~((1<<PC1) | (1<<PC2));
#define LED2ON  PORTC |= (1<<PC3) | (1<<PC4);
#define LED2OFF PORTC &= ~((1<<PC3) | (1<<PC4));

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

uint8_t  obstacle();
void     makesound();
int8_t   velocity=1;
uint8_t  sound=100;
uint8_t  sound_count=0;
uint16_t note_count;
uint8_t  note_speed=4;
uint8_t  general_count=0;
uint8_t  g_count2=0;
uint8_t  redo=0;
int8_t   curve=0;

int main(void){

	TCCR1A |= (1<<COM1A1) | (1<<COM1B1) | (1<<WGM11);  // non-inverting mode for OC1A
	TCCR1B |= (1<<WGM13) | (1<<WGM12) | (1<<CS11);     // Mode 14, Prescaler 8
	ADCSRA=0b11100111 ;      					       //ADC enable, free running, no interrupts, clock divide 128
	ICR1 = 2500;
	DDRB |= (1<<PB1) | (1<<PB2);                       //OC1A, OC1B set to output (go to left and right servo inputs)
	DDRC |= (1<<PC1) | (1<<PC2) | (1<<PC3) | (1<<PC4); //LED Outputs
	DDRD |= (1<<PD1);                                  //Speaker Out
	STOP

	while(1){

		general_count++;
		if (general_count==0)g_count2++;
		if (g_count2==4){
			g_count2=0;
			PORTC ^= (1<<PC1); //toggle LED1
			PORTC ^= (1<<PC2); //toggle LED1
		}
		makesound();

		if (obstacle()|redo){
			STOP
			for (uint16_t i=0;i<10000;i++){makesound();note_count+=100;}

			OCR1A = STOP_L-20;
			OCR1B = STOP_R+20;
			_delay_ms(500);

			switch (random()%4){
				case 0:
				OCR1A = STOP_L+20;
				OCR1B = STOP_R+20;
				_delay_ms(1000);
				break;
				case 1:
				OCR1A = STOP_L+20;
				OCR1B = STOP_R+20;
				_delay_ms(500);
				break;
				case 2:
				OCR1A = STOP_L-20;
				OCR1B = STOP_R-20;
				_delay_ms(1000);
				break;
				case 3:
				OCR1A = STOP_L-20;
				OCR1B = STOP_R-20;
				_delay_ms(500);
				break;
				}


			redo=0;
			for (uint8_t i=1;i<=50;i++){
				OCR1A = STOP_L+i;
				OCR1B = STOP_R-i;
				_delay_ms(50);
				if (obstacle()){i=50;redo=1;STOP}
			}

		}else{
			makesound();
			OCR1A = (STOP_L+50)+curve;
			OCR1B = (STOP_R-50)+curve;
		}
	}
}

uint8_t obstacle(){
	uint8_t analog_in;
	ADMUX=0b0110101;      						// ADC: AVcc=ref. - left adjust - ADC5
	for (int i=0;i<3;i++){
		analog_in=ADCH;   	     		        // read adc (8Bit)
	}
	uint8_t obs_tf=0;
	if (analog_in>19) obs_tf=1;
	return obs_tf;
}

void makesound(){
	note_count+=note_speed;
	sound_count+=3;
	if (sound_count>=sound) {
		sound_count=0;
		PORTD ^= (1<<PD1); //toggle speaker
		}
	if (note_count<150){
		PORTC ^= (1<<PC3); //toggle LED2
		PORTC ^= (1<<PC4); //toggle LED2
		switch (random()%5){
			case 0:
			sound=sound/4*3;
			break;
			case 1:
			sound=sound/3*2;
			break;
			case 2:
			sound=sound*3/2;
			break;
			case 4:
			sound=sound*4/3;
			break;
			}
		if (sound>180) sound/=2;
		if (sound<40) sound=sound*3+1;
		curve= (random()%70)-35;
		note_speed=(random()%8+1);
	}
}