#include <avr/io.h>
#include <avr/interrupt.h>
#include <stdint.h>
#include <stdbool.h>


#define STRINGIZE(s) #s
#define S(s) STRINGIZE(s)


// Button:		PA4
// Ready-LED:	PA5
// Motor:			PA6
// Heizung:		PA7


// UART-Steuerung

#define UART_TX_DDR DDRA
#define UART_TX_PORT PORTA
#define UART_TX PA0

#define UART_Baud 9600

#include <util/delay.h>
#include <softuart.h>


// Laminatorsteuerung

#define motor_an()			PORTA |= (1 << PA6)
#define motor_aus()			PORTA &= ~(1 << PA6)

#define heizung_an()		PORTA |= (1 << PA7)
#define heizung_aus()		PORTA &= ~(1 << PA7)

#define Temperatur			180


volatile unsigned char timer_divisor = 0;

volatile unsigned int measurement_divisor = 0;

volatile unsigned int motorcontrol_divisor = 0;
volatile unsigned char motorcontrol = 0;

volatile unsigned char button_debounce = 0;

volatile bool last_button_state = 0;
volatile bool motor_feed = 0;
volatile bool ready = 0;

int main(void)
{
  ADMUX = (0 << REFS1) | (1 << REFS0) | (0b00010);		// Externe Referenz, ADC2
  ADCSR = (1 << ADEN) | (0b110);											// ADC Prescaler 64, 125kHz ADCfrequenz bei 8Mhz Takt

  DDRA |= (1 << PA5) | (1 << PA6) | (1 << PA7);				// Ausgänge : Ready-LED, Motor, Heizung
  PORTA |= (1 << PA4);																// Pull-Up für Button

  rs232_init_tx();

  motor_an();																					// Motor zum aufheizen durchlaufen lassen
  heizung_an();

  rs232_send("Laminator Controller by The-PoWl.de");
  rs232_send("Preset temperatur: " S(Temperatur) "°C");

  sei();

  TCCR0 = (1 << CS00);																// Timer0 mit Prescaler 1
  TIMSK = (1 << TOIE0);																// Timer0 Overflow Interrupt enabled

  while(1);
}

ISR(TIMER0_OVF0_vect)
{
	// 8.000.000 / 256 = 31250 / 31 = ~1008 ISRs/s bzw. 0,992ms/ISR
  if(timer_divisor == 31)
  {
	  timer_divisor = 0;

		// 1008 ISRs/s / 1008 = 1 ISRs/s bzw. 1s/ISR
    if(measurement_divisor == 1008)
		{
		  measurement_divisor = 0;

      // Temperaturmessung + Heizungssteuerung
		  ADCSR |= (1 << ADSC);														// ADC Messung starten
			loop_until_bit_is_set(ADCSR, ADIF);

      unsigned int buffer;
      char sendbuffer[5];

      buffer = ADC;

      sendbuffer[0] = (buffer / 1000) + 48;
      buffer %= 1000;
      sendbuffer[1] = (buffer / 100) + 48;
      buffer %= 100;
      sendbuffer[2] = (buffer / 10) + 48;
      buffer %= 10;
      sendbuffer[3] = buffer + 48;
      sendbuffer[4] = 0;

      rs232_send(sendbuffer);

			if(ADC > 380 - Temperatur)
			{
			  heizung_an();
			}
			else
			{
			  heizung_aus();

        if(!ready)
				{
					PORTA |= (1 << PA5);													// Ready
					ready = 1;

					motor_aus();
        }
			}
    }

		// Wenn ready
		if(ready)
		{
			// Tasterkennung + Entprellung
	    if(last_button_state != bit_is_clear(PINA, PA4) && !button_debounce)
	    {
			  button_debounce = 10;													// 10ms Prellzeit
      
				if(bit_is_clear(PINA, PA4))										// Nur auf fallende Flanke reagieren
				{
          rs232_send("Tipp :-]");

					if(motor_feed)
					{
		 				motor_aus();
						motor_feed = 0;

						motorcontrol_divisor = 0;									// Motorsteuerung zurücksetzen
						motorcontrol = 0;
					}
					else
					{
		 				motor_an();
						motor_feed = 1;
					}
				}

				last_button_state = bit_is_clear(PINA, PA4);
			}
	    if(button_debounce)
			{
			  button_debounce--;
			}

			// 1008 ISRs/s / 504 = 2 ISRs/s bzw. 0.5s/ISR
			// Wenn Motorvorlauf nicht aktiv
	    if(motorcontrol_divisor == 504 && !motor_feed)
			{
			  motorcontrol_divisor = 0;

			  // Motorsteuerung, 0.5s AN, 2s AUS
				if(motorcontrol == 0)
				{
					motor_an();
				}
				if(motorcontrol == 1)
				{
				  motor_aus();
				}

				if(motorcontrol < 4)
				{
				  motorcontrol++;
				}
				else
				{
					motorcontrol = 0;
	      }
	    }

			motorcontrol_divisor++;
		}

		measurement_divisor++;
  }

  timer_divisor++;
}