/************************************************
 *  THIS USES A INFARED SENSOR ON PIN C2 TO MAKE
 *  A SIMPLE THEREMIN-LIKE MUSICAL INSTRUMENT
 *  SPEAKER IS ON B0
 * 
 *  RYAN T ALLEY
 *  JUNE 7, 2010
 ************************************************/
#include "oulib.h"
#include "oulib_serial_buffered.h"

uint16_t getSensor(void);

int main (void)
{

DDRB = 0b00000001;  // OUTPUT on PIN B0
DDRC = 0b00000000;  // INPUT on PIN C2

adc_set_reference(ADC_REF_AREF);	//  AREF pin must be connected to +5 V
adc_set_adlar(0);			//
adc_set_prescalar(ADC_PRESCALAR_128);	//
adc_set_enable(ADC_ENABLE);		//

sei();

while(1)
	{
		PORTB = PORTB ^ 0x1;
		delay_us(8 * getSensor());	//  8 is a scalar (to lower pitch)
	};

	return (0);
}

// STOLEN CODE:  Supposed to:  Read the analog value from the sensor (pin C2) and convert to digital

uint16_t getSensor(void)  
{
	uint16_t dval;
	uint16_t x;
	uint16_t y;
	uint16_t z;
	
	adc_set_channel(ADC_CHANNEL_2);	//  read from pin C2 (ADC2), port 25
	adc_start_conversion();
	
	dval = adc_read();
	if (dval < 35) { 		//  This value cannot go below 34 or could divide by zero
		dval = 34;
	}
	x = dval-29; 			//  Logarithmic model as described above
	y = x/4;
	z = 10230/y;
	return (z); 			//  puts distances in mm
}