ArduinoNanoIRTransmitter

const double _F = F_CPU / 38000.0 + 0.5 - 1;
const double _D = _F * 0.33 + 0.5 - 1;

const uint16_t _cv[] = { 40085, 36.39716198 };

const uint16_t _cp[][2] =
{
  { 97,   24 },
  { 24,   24 },
  { 48,   24 },
  { 24, 1032 },
  { 48, 1032 },
};

const uint8_t _cs[][64] =
{
  { 39,
    0, 2, 1, 2, 1, 1, 2, 1, 2, 1, 1, 1, 3,
    0, 2, 1, 2, 1, 1, 2, 1, 2, 1, 1, 1, 3,
    0, 2, 1, 2, 1, 1, 2, 1, 2, 1, 1, 1, 1 },
  { 39,
    0, 2, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 3,
    0, 2, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 3,
    0, 2, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 1 },
};

const uint16_t *_cw = _cv;
const uint16_t (*_cu)[2] = _cp;
const uint8_t *_ct = _cs[1];

volatile uint8_t _cr = 0;
uint16_t _cc = 0;
uint16_t _ci = 0;
uint16_t _cj = 0;

ISR(TIMER1_COMPB_vect)
{
  if (!_cr)
    return;

  if (!(TCCR1A & _BV(COM1A1)) && _cc == 0 && _ci == 0)
  {
    TCCR1A |= _BV(COM1A1);
    ++_ci;
    return;
  }

  if (_cc >= _cu[_ct[_ci]][_cj % 2] - 1)
  {
    if (_ci > _ct[0] - 1)
    {
      TCCR1A &= ~_BV(COM1A1);

      _cr = 0;
      _ci = 0;
      _cj = 0;
    }
    else
    {
      TCCR1A ^= _BV(COM1A1);

      if (_cj % 2)
        ++_ci;

      ++_cj;
    }

    _cc = 0;
  }
  else
    ++_cc;
}

int main()
{
  sei();

  Serial.begin(115200);
  Serial.println("main()");

  DDRB = _BV(PORTB1) | _BV(PORTB2);
  TIMSK1 = _BV(OCIE1B);
  ICR1 = (uint16_t)_F;
  OCR1A = (uint16_t)_D;
  OCR1B = (uint16_t)_D;
  TCCR1A = _BV(COM1B1) | _BV(WGM11);
  TCCR1B = _BV(WGM12) | _BV(WGM13) | _BV(CS00);

  for (;;)
  {
    if (Serial.available())
    {
      uint8_t k = Serial.read();
      switch (k)
      {
      case 's':
        {
          uint16_t f = F_CPU * 1.0 / _cw[0] + 0.5 - 1;
          uint16_t d = f * (_cw[1] / 100.0) + 0.5 - 1;

          char buf[64] = { 0 };
          sprintf(buf, "f=%u, d=%u", f, d);
          Serial.println(buf);

          ICR1 = f;
          OCR1A = d;
          OCR1B = d;
        }
        break;
      case 't':
        _cr = 1;
        break;
      default:
        break;
      }
    }
  }

  return 0;
}