#include "header.h"

// 1.1.7 : AVCC is the supply voltage pin for the A/D Converter, PC3:0, and ADC7:6
// 1.1.8 : AREF is the analog reference pin for the A/D Converter
// 24.4 : frequency needs to be between 50kHz and 200kHz, for less than 10bits accuracy it can be >200kHz
//  -> Frequence_ADC = Frequance_CPU / Prescaler (Fadc = Fcpu/P):
//     - P = 2   -> Fadc = 16,000,000 / 2   = 8,000,000 = 8MHz
//     - P = 4   -> Fadc = 16,000,000 / 4   = 4,000,000 = 4MHz
//     - P = 8   -> Fadc = 16,000,000 / 8   = 2,000,000 = 2MHz
//     - P = 16  -> Fadc = 16,000,000 / 16  = 1,000,000 = 1MHz
//     - P = 32  -> Fadc = 16,000,000 / 32  =   500,000 = 500KHz
//     - P = 64  -> Fadc = 16,000,000 / 64  =   250,000 = 250KHz -> OK
//     - P = 128 -> Fadc = 16,000,000 / 128 =   125,000 = 125KHz -> OK

#define ADC_PRESCALER	128							// Table 24-5 : can only be 2, 4, 8, 16, 32, 64, or 128

volatile uint8_t adc_channel = ADC_POTENTIOMETER;	// Table 14-6 : alternate function for RV1 on PC0 -> ADC0, LDR on PC1 -> ADC1, NTC on PC2 -> ADC2 ...

// read 3 analog values at 10 bits and print them in uart as decimal : potentiometer RV1 (Variable Resistor), photoresistor LDR (Light Dependent Resistor), thermistor NTC (Negative Temperature Coefficient)
int main() {
    char buffer[4];
	SREG |= ENABLE_GLOBAL_INTERRUPT;				// 7.3.1 : Status Register, bit 7 : I – Global Interrupt Enable
	uart_init();
	adc_init(ADC_PRESCALER);

	timer_1B_init();

	while(1);
}