#include <avr/io.h>
#include "batmon.h"

void batmon_init()
{
	ADCSRA = (1 << ADPS2) | (1 << ADPS1); // 125 kHz ADC clock
	ADMUX = ADC_CHANNEL | (1 << REFS0) | (1 << REFS1) | (1 << ADLAR); // Internal 1.2V bandgap, left adj.
	ADCSRB = 0; // Manual start
#if ADC_CHANNEL < 7
	DIDR0 = (1 << ADC_CHANNEL); // Disconnect digital channel
#endif

	// Enable voltage divider
	PORT_ADCC(DDR) |= PIN_ADCC;
	PORT_ADCC(PORT) &= ~PIN_ADCC;

	// Enable ADC
	ADCSRA |= (1 << ADEN);
}

inline uint8_t batmon_get_voltage()
{
	ADCSRA |= (1 << ADSC); // TODO: Check whether this increases the power consumption of the chip by much
	return ADCH;
}