/*----------------------------------------------------------------------------/
/ * TinCan-Talker															
/
/ * This project, program codes and circuit diagrams, is opened under license
/ * policy of following trems.
/
/ * This project is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/ * personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/ * Copyright (C) 2015, Makarov Vladimir, all right reserved.
/
/----------------------------------------------------------------------------*/

#define F_CPU 9600000    	// MCU frequency for the delay library
#include <avr/io.h>       	// I/O library
#include <util/delay.h>    	// Delay library

int k;						// Sound value from ADCH

void servo_move(int i)
{
	OCR0A = i;
} 
   
int main(void)   // Main program
{
 
    // Port B configuration 
	DDRB = 0b00000001;
	// PB0 -> SPI.MOSI, PWM output
	// PB1 <- SPI.MISO
	// PB2 <- SPI.SCK,	ADC1 input
	// PB3 <- not connected
	// PB4 <- not connected
    // PB5 <- SPI.RESET
	PORTB = 0b00000000;
	
	// ADC configuration
	ADCH = 0x00;		// ADC Conversion Result (high byte)
	ADCL = 0X00;		// ADC Conversion Result (low byte)
	ADMUX =				// ADC Multiplexer Selection Register
		 (1<<REFS0)		// Internal Voltage Reference (1.1V)
		|(1<<ADLAR)		// ADLAR to left adjust the result 
		|(0<<MUX1)		// Analog Channel Selection Bits - ADC1
		|(1<<MUX0);		//
	ADCSRA =			// ADC Control and Status Register A
		 (1<<ADEN)		// ADC Enable
		|(0<<ADSC)		// ADC Start Conversion - is not activated
		|(0<<ADATE)		// ADC Auto Trigger Enable - is not activated
		|(0<<ADIE)		// ADC Interrupt Enable - is not activated
		|(1<<ADPS2)		// ADC Prescaler Select Bits - Fosc/64
		|(1<<ADPS1)		// 
		|(0<<ADPS0);	//
	ADCSRB =			// ADC Control and Status Register B
		 (0<< ADTS2)	// Free Running mode
		|(0<< ADTS1)	//
		|(0<< ADTS0);	//
    DIDR0 =				// Digital Input Disable Register 0
		(1<<ADC1D);		// Digital Input Disable: Pin ADC1 is disabled
	
	// Timer/Counter0 configuration
	TCCR0A =			// Timer/Counter0 Control Register A
		 (1<<COM0A1)	// Compare Match Output A Mode
		|(0<<COM0A0)	// Clear OC0A on Compare Match, OC0A connected
		|(0<<COM0B1)	// Compare Match Output B Mode
		|(0<<COM0B0)	// Normal port operation, OC0B disconnected
		|(1<<WGM01)		// Waveform Generation Mode, Fast PWM Mode
		|(1<<WGM00);	//
	TCCR0B =			// Timer/Counter Control Register B	
		(0<<WGM00)		// Waveform Generation Mode , Fast PWM Mode
		|(1<<CS02)		// Timer/Counter0 Prescaler, Fosc/256
		|(0<<CS01)		// 9600000Hz/256=37500Hz, 37500Hz/256=146Hz -> 6.8ms (Period)
		|(0<<CS00);		//
	OCR0A=37;			// Pulse wight is 1ms (angle-0)	
	
	// Pulse wight maх is 2ms -> OCR0Amax=74

	
	while (1)
	{			
		_delay_ms(100);
		ADCSRA |= (1<<ADSC);  	// ADC Start Conversion - is activated
		k = ADCH;				// Digital sound value from ADCH
		k = k/4+10;				// 256/4+10=74 
								// The maximum value of sound (256) transformed 
								// into maximum angle of the servo (180 degrees) 
								// (OCR0A=74 -> Pulse wight=1ms -> angle=180 degrees)
		if (k > 74) k = 74;		// Pulse wight maх is 2ms -> OCR0Amax=74
		if (k < 37) k = 37;		// Pulse wight min is 1ms -> OCR0Amax=37
		servo_move(k);			// Open your mouth )))
	}       								
}