//#define F_CPU 7372800UL
#include <stdint.h>
#include <string.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
#include <avr/pgmspace.h>
#include <avr/eeprom.h>
#include <util/delay.h>

#include "serial.h"
#include "stdio.h"
#include "pid.h"

/* port D
 *
 *  4 1- (NMOS, inverted) 
 *  5 1+ (PMOS)
 *  6 2- (NMOS, inverted)
 *  7 2+ (PMOS)
 *
 */

#define D_1_MINUS	(1 << 4)
#define D_1_PLUS	(1 << 5)
#define D_2_MINUS	(1 << 6)
#define D_2_PLUS	(1 << 7)

const int target_temp = 30;
volatile uint16_t adc_res;
volatile uint8_t adc_new;

struct PID_DATA pid_data;

/* Turns the H-bridge off, putting the output
 * into high impedance mode. */
static void bridge_off(void)
{
	PORTD |= D_1_MINUS | D_2_MINUS;
	PORTD &= ~(D_1_PLUS | D_2_PLUS);
}

/* Turns the H-bridge on, setting 1+ 2- */
static void bridge_on_heat(void)
{
	bridge_off();
	_delay_ms(100);
	PORTD |= D_1_PLUS;
	PORTD &= ~D_2_MINUS;
}

/* Turns the H-bridge on, setting 1- 2+ */
static void bridge_on_cool(void)
{
	bridge_off();
	_delay_ms(100);
	PORTD |= D_2_PLUS;
	PORTD &= ~D_1_MINUS;
}

/* Initializes the output port needed for the H-bridge */
static void bridge_init(void)
{
	bridge_off();
	DDRD |= D_1_PLUS | D_1_MINUS | D_2_PLUS | D_2_MINUS;
}

/* initializes ADC */
static void adc_init(void)
{
	adc_new = 0;
	ADMUX = (1 << REFS1) | (1 << REFS0);
	/* select channel x (0 for now) */
	ADMUX |= 0x0;
	ADCSRA = (1 << ADEN) | (1 << ADIE) | (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);
}

/* reads ADC */
static void start_temp_conv(void) 
{
	ADCSRA |= (1<<ADSC);
}

/* ADC completion interrupt */
ISR(ADC_vect) 
{
	adc_res = ADCW;
	adc_new = 1;
}

/* ADC results to temperature conversion routine */
int adc_to_centigrade(uint16_t adc_val) {
	return 0;
}

/* Initializes TIMER1 */
static void timer_init(void)
{
	TCCR1B = (1 << WGM12) | (1 << CS12) | (1 << CS10);
	OCR1A = 7200;
	TIMSK|=(1<<OCIE1A);
}

ISR(TIMER1_COMPA_vect)
{
	serial_send("*\r\n", 3, 1);
	start_temp_conv();
}

int main(void)
{
	char params[12];

	serial_init();
	adc_init();
	timer_init();
	bridge_init();

	sei();

	bridge_on_cool();
	while (1) {
		if (adc_new) {
			sprintf(params, "%u\r\n", adc_res);
			serial_send(params, strlen(params), 1);
			adc_new = 0;
		}
		_delay_ms(100);
	}
}