/***********************************************************************
(c) JA 2023

remarks:
based on http://tahmidmc.blogspot.com/2013/02/sine-wave-generation-with-fast-pwm-mode_2525.html
also read http://tahmidmc.blogspot.com/2013/02/demystifying-use-of-table-pointer-in.html
adapted to atmega328, original written by Tahmid for the atmega16
array has 160 elements, why?
1/16000000 * 1000 = 0,0000625
0,0000625 * 160 = 10 ms
can not be fully tested in Tinkercad because fast PWM mode does not simulate.

last mod.: 16/05/2023
***********************************************************************/

/*
const unsigned int sin_table[32] =
{0, 100, 199, 296, 390, 480, 566, 645, 718, 
783, 840, 889, 928, 958, 979, 989, 989, 979, 958, 928, 889, 840, 783,
 718, 645, 566, 480, 390, 296, 199, 100, 0};
*/
/*
const unsigned int sin_table[64] =
{0, 50, 99, 149, 198, 247, 294, 342, 388, 433,
478, 521, 563, 603, 642, 679, 715, 749, 781,
811, 839, 865, 889, 911, 930, 947, 962, 974,
984, 991, 996, 999, 999, 996, 991, 984, 974,
962, 947, 930, 911, 889, 865, 839, 811, 781,
749, 715, 679, 642, 603, 563, 521, 478, 433,
388, 342, 294, 247, 198, 149, 99, 50, 0};
*/
const unsigned int sin_table[160] =
{0, 20, 39, 59, 79, 99, 118, 138, 157, 177, 196,
215, 235, 254, 273, 292, 311, 329, 348, 366, 385,
403, 421, 439, 456, 474, 491, 508, 525, 542, 558,
574, 590, 606, 622, 637, 652, 667, 682, 696, 710,
724, 737, 750, 763, 776, 788, 800, 812, 823, 834,
845, 855, 865, 875, 884, 893, 902, 910, 918, 926,
933, 940, 946, 953, 958, 964, 969, 973, 978, 981,
985, 988, 991, 993, 995, 997, 998, 998, 999, 999,
998, 998, 997, 995, 993, 991, 988, 985, 981, 978,
973, 969, 964, 958, 953, 946, 940, 933, 926, 918,
910, 902, 893, 884, 875, 865, 855, 845, 834, 823,
812, 800, 788, 776, 763, 750, 737, 724, 710, 696,
682, 667, 652, 637, 622, 606, 590, 574, 558, 542,
525, 508, 491, 474, 456, 439, 421, 403, 385, 366,
348, 329, 311, 292, 273, 254, 235, 215, 196, 177,
157, 138, 118, 99, 79, 59, 39, 20, 1};

#define FETA PB0  //PB0 = UNO D8
#define FETB PB3  //PB3 = UNO D11
#define FETC PB4  //PB4 = UNO D12
#define FETD PB5  //PB5 = UNO D13

bool Direction;
//0 -> MOS A + D
//1 -> MOS B + C

//unsigned int TBL_POINTER_NEW, TBL_POINTER_OLD, TBL_POINTER_SHIFT, SET_FREQ;
unsigned char DUTY_CYCLE;

ISR(TIMER1_OVF_vect)  //updated every 62.5us (= 1/16MHz * 1 + 999 timer counts -> value in ICR)
{
    DUTY_CYCLE++;
    if (DUTY_CYCLE > 159)
    {
      if (Direction == 0)
      {
          //MOSA = 0;
          //MOSD = 0;
          PORTB &= 0b11011110;  //~(1<<FETA);  //MOSA
          //bitClear(PORTB, FETA);
          //PORTB &= 0b11011111;  //~(1<<FETD);  //MOSD
          //bitClear(PORTB, FETD);

          Direction = 1;  //change here to create a deadtime

          //MOSB = 1;
          //MOSC = 1;
          //PORTB |= 0b00001000;  //(1<<FETB); //MOSB
          bitSet(PORTB, FETB);
          //PORTB |= 0b00010000;  //(1<<FETC); //MOSC
          bitSet(PORTB, FETC);
      }
      else
      {
          //MOSB = 0;
          //MOSC = 0;
          PORTB &= 0b11100111;  //~(1<<FETB);  //MOSB
          //bitClear(PORTB, FETB);
          //PORTB &= 0b11101111;  //~(1<<FETC);  //MOSC
          //bitClear(PORTB, FETC);

          Direction = 0;  //change here to create a deadtime

          //MOSA = 1;
          //MOSD = 1;
          //PORTB |= 0b00000001;  //(1<<FETA); //MOSA
          bitSet(PORTB, FETA);
          //PORTB |= 0b00100000;  //(1<<FETD); //MOSD
          bitSet(PORTB, FETD);
      }
      DUTY_CYCLE = 0;
    }
    OCR1A = sin_table[DUTY_CYCLE];
}

int main(void)
{
  asm volatile ("nop");

  pinMode(FETA, OUTPUT);
  digitalWrite(FETA, LOW);  //MOSA = PB0, make sure upper FET A is off

  pinMode(FETC, OUTPUT);
  digitalWrite(FETC, LOW);  //MOSC = PB4, make sure upper FET C is off

  pinMode(FETB, OUTPUT);
  digitalWrite(FETB, HIGH); //MOSB = PB3, turn on lower FET B

  pinMode(FETD, OUTPUT);
  digitalWrite(FETD, HIGH); //MOSD = PB5, turn on lower FET D

  pinMode(9, OUTPUT);
  //digitalWrite(9, HIGH); //turn on OC1A (PB1) output, now both lower FETS (B+D) must be on giving 0A over the load
  digitalWrite(9, LOW);
     //DDRC = 0xFF;
     //DDRD = 0XFF;

     //SET_FREQ = 410;
     //TBL_POINTER_SHIFT = 0;
     //TBL_POINTER_NEW = 0;
     //TBL_POINTER_OLD = 0;
     DUTY_CYCLE = 0;

  asm volatile ("nop");
      //OCR1AH = 0;
      //OCR1AL = 0;
  OCR1A = sin_table[DUTY_CYCLE];

  TCCR1A = 0;
  TCCR1B = 0;
  //TCCR1A = 0x82;  //mega16, 0b10000010
  //mode 14 fast PWM (xxxxxx10+), (xx0000xxx), Clear OC1A on Compare Match (Set output to low level) (10xxxxxx)
  TCCR1A |= (1<<COM1A1);
  TCCR1A |= (1<<WGM11); //Fast PWM, ICR1 TOP
     //TCCR1B = 0x19; //mega16, 0b00011001
  TCCR1B |= (1<<WGM12); //Fast PWM, ICR1 TOP
  TCCR1B |= (1<<WGM13); //Fast PWM, ICR1 TOP

  asm volatile ("nop");
    //ICR1H = 0x03;
    //ICR1L = 0xE7;
  ICR1 = 999; //TOP -> 16kHz

  asm volatile ("nop");
      //TIMSK = 0x04; //mega16
  TIMSK1 = 0x01;  //mega328, set TOIE1: Timer/Counter1, Overflow Interrupt Enable

  asm volatile ("nop");
  TCCR1B |= (1<<CS10);  //Start TC1, CLKio/1

  sei(); //SREG_I_bit = 1;

  while(1);
  {
    asm volatile ("nop");
  }

  return 1;
}