/*
 * Lab5_Task2_ADC_Potentiometer.c
 *
 * Created: 2024-04-26 19:41:50
 * Author : Erik Karlsson
 */ 


#include <avr/io.h>
#include <avr/interrupt.h>
#define F_CPU 16000000UL

// I/O SETTINGS
#define D6_LED PD6
#define D6_TO_OUTPUT (1 << D6_LED)

// TIMER0 SETTINGS
#define FASTPWM (1 << WGM01) | (1 << WGM00)
#define CLEAR_ON_MATCH_NON_INVERTED (1 << COM0A1) | (0 << COM0A0)
#define PRESCALER_NONE (0 << CS02) | (0 << CS01) | (1 << CS00)

// ADC SETTINGS
#define ENABLE_ADC (1 << ADEN)
#define AUTO_CONVERSION (1 << ADATE)
#define INTERNAL_VOLTAGE_REF (0 << REFS1) | (0 << REFS0)
#define ADC2_SELECTED (0 << MUX3) | (0 << MUX2) | (1 << MUX1) | (0 << MUX0)
#define ENABLE_ADC_INTERRUPT (1 << ADIE)
#define PRESCALER_2		(0 << ADPS2) | (0 << ADPS1) | (0 << ADPS0)
#define PRESCALER_4		(0 << ADPS2) | (1 << ADPS1) | (0 << ADPS0)
#define PRESCALER_8		(0 << ADPS2) | (1 << ADPS1) | (1 << ADPS0)
#define PRESCALER_16	(1 << ADPS2) | (0 << ADPS1) | (0 << ADPS0)
#define PRESCALER_32	(1 << ADPS2) | (0 << ADPS1) | (1 << ADPS0)
#define PRESCALER_64	(1 << ADPS2) | (1 << ADPS1) | (0 << ADPS0)
#define PRESCALER_128	(1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0)
#define ADC_LEFT_ADJUST (0 << ADLAR)
#define FREE_RUNNING (0 << ADTS2) | (0 << ADTS2) | (0 << ADTS2)
#define START_CONVERSION (1 << ADSC)


#define CONVERSION_IN_PROGRESS (ADCSRA & (1 << ADSC))

int main(void)
{
	Serial.begin(9600);
	INIT_TIMER0();
	LED_INIT();
	ADC_INIT();
	//sei();
    while (1)
    {
			// POLLING
			// Remain here until conversion is complete
			while (CONVERSION_IN_PROGRESS);

			// Make sure our datatype is large enough
			uint16_t adc_value = ADC;

			// Remap 0-1024 to 0-255
			unsigned int converted_value = ((uint32_t)adc_value * 255) / 1024;

			// Store value in Compare A register
			OCR0A = converted_value;
			Serial.println(adc_value);

			// Start next conversion
			ADCSRA |= START_CONVERSION;
		}
}

void ADC_INIT(){
	ADCSRA = ENABLE_ADC | ENABLE_ADC_INTERRUPT | PRESCALER_2 | START_CONVERSION;
	ADCSRB = FREE_RUNNING;
	ADMUX = INTERNAL_VOLTAGE_REF | ADC2_SELECTED;
}

void INIT_TIMER0(){
	TCCR0A = FASTPWM | CLEAR_ON_MATCH_NON_INVERTED;
	TCCR0B = PRESCALER_NONE;
}

void LED_INIT(void){
	DDRD = D6_TO_OUTPUT;
}

ISR(ADC_vect){
	// ADC is 10-bit. Max 1024
	uint16_t adc_value = ADC;
	unsigned int converted_value = ((uint32_t)adc_value * 255) / 1024;
	OCR0A = converted_value;
	//Serial.println(ADC);
	Serial.println(converted_value);
	ADCSRA |= START_CONVERSION;
}