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#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include "eeprom.h"
#include "analog.h"

// for debugging!
#include "uart0.h"
#include "output.h"

#ifdef USE_MK3MAG
#include "mk3mag.h"
#endif

volatile uint16_t millisecondsCount = 0;
volatile uint8_t  runFlightControl = 0;
volatile uint16_t cntKompass = 0;
volatile uint16_t beepTime = 0;
volatile uint16_t beepModulation = 0xFFFF;

#ifdef USE_NAVICTRL
volatile uint8_t SendSPI = 0;
#endif

/*****************************************************
 * Initialize Timer 0                  
 *****************************************************/

// timer 0 is used for the PWM generation to control the offset voltage at the air pressure sensor
// Its overflow interrupt routine is used to generate the beep signal and the flight control motor update rate
void timer0_init(void) {
  uint8_t sreg = SREG;

  // disable all interrupts before reconfiguration
  cli();

  // Configure speaker port as output.

  if (BoardRelease == 10) { // Speaker at PD2
    DDRD |= (1 << DDD2);
    PORTD &= ~(1 << PORTD2);
  } else { // Speaker at PC7
    DDRC |= (1 << DDC7);
    PORTC &= ~(1 << PORTC7);
  }

  // set PB3 and PB4 as output for the PWM used as offset for the pressure sensor
  DDRB |= (1 << DDB4) | (1 << DDB3);
  PORTB &= ~((1 << PORTB4) | (1 << PORTB3));

  // Timer/Counter 0 Control Register A

  // Waveform Generation Mode is Fast PWM (Bits WGM02 = 0, WGM01 = 1, WGM00 = 1)
  // Clear OC0A on Compare Match, set OC0A at BOTTOM, noninverting PWM (Bits COM0A1 = 1, COM0A0 = 0)
  // Clear OC0B on Compare Match, set OC0B at BOTTOM, (Bits COM0B1 = 1, COM0B0 = 0)
  TCCR0A &= ~((1 << COM0A0) | (1 << COM0B0));
  TCCR0A |= (1 << COM0A1) | (1 << COM0B1) | (1 << WGM01) | (1 << WGM00);

  // Timer/Counter 0 Control Register B

  // set clock divider for timer 0 to SYSKLOCK/8 = 20MHz / 8 = 2.5MHz
  // i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz
  // hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz

  // divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)
  TCCR0B &= ~((1 << FOC0A) | (1 << FOC0B) | (1 << WGM02));
  TCCR0B = (TCCR0B & 0xF8) | (0 << CS02) | (1 << CS01) | (0 << CS00);

  // initialize the Output Compare Register A & B used for PWM generation on port PB3 & PB4
  OCR0A = 0; // for PB3
  OCR0B = 120; // for PB4

  // init Timer/Counter 0 Register
  TCNT0 = 0;

  // Timer/Counter 0 Interrupt Mask Register
  // enable timer overflow interrupt only
  TIMSK0 &= ~((1 << OCIE0B) | (1 << OCIE0A));
  TIMSK0 |= (1 << TOIE0);

  SREG = sreg;
}

/*****************************************************/
/*          Interrupt Routine of Timer 0             */
/*****************************************************/
ISR(TIMER0_OVF_vect)
{ // 9765.625 Hz
  static uint8_t cnt_1ms = 1, cnt = 0;
  uint8_t beeper_On = 0;

#ifdef USE_NAVICTRL
  if(SendSPI) SendSPI--; // if SendSPI is 0, the transmit of a byte via SPI bus to and from The Navicontrol is done
#endif

  if (!cnt--) { // every 10th run (9.765625kHz/10 = 976.5625Hz)
    cnt = 9;
    cnt_1ms ^= 1;
    if (!cnt_1ms) {
      if (runFlightControl == 1)
        DebugOut.Digital[1] |= DEBUG_MAINLOOP_TIMER;
      else
        DebugOut.Digital[1] &= ~DEBUG_MAINLOOP_TIMER;
      runFlightControl = 1; // every 2nd run (976.5625 Hz/2 = 488.28125 Hz)
    }
    millisecondsCount++; // increment millisecond counter
  }

  // beeper on if duration is not over
  if (beepTime) {
    beepTime--; // decrement BeepTime
    if (beepTime & beepModulation)
      beeper_On = 1;
    else
      beeper_On = 0;
  } else { // beeper off if duration is over
    beeper_On = 0;
    beepModulation = 0xFFFF;
  }

  // if beeper is on
  if (beeper_On) {
    // set speaker port to high.
    if (BoardRelease == 10)
      PORTD |= (1 << PORTD2); // Speaker at PD2
    else
      PORTC |= (1 << PORTC7); // Speaker at PC7
  } else { // beeper is off
    // set speaker port to low
    if (BoardRelease == 10)
      PORTD &= ~(1 << PORTD2);// Speaker at PD2
    else
      PORTC &= ~(1 << PORTC7);// Speaker at PC7
  }

#ifndef USE_NAVICTRL
  // update compass value if this option is enabled in the settings
  if (staticParams.GlobalConfig & (CFG_COMPASS_ACTIVE | CFG_GPS_ACTIVE)) {
#ifdef USE_MK3MAG
    MK3MAG_Update(); // read out mk3mag pwm
#endif
  }
#endif
}

// -----------------------------------------------------------------------
uint16_t setDelay(uint16_t t) {
  return (millisecondsCount + t - 1);
}

// -----------------------------------------------------------------------
int8_t checkDelay(uint16_t t) {
  return (((t - millisecondsCount) & 0x8000) >> 8); // check sign bit
}

// -----------------------------------------------------------------------
void delay_ms(uint16_t w) {
  uint16_t t_stop = setDelay(w);
  while (!checkDelay(t_stop))
    ;
}

// -----------------------------------------------------------------------
void delay_ms_Mess(uint16_t w) {
  uint16_t t_stop;
  t_stop = setDelay(w);
  while (!checkDelay(t_stop)) {
    if (analogDataReady) {
      analogDataReady = 0;
      analog_start();
    }
  }
}