ZeroCrossTriac.ino

#define TRIAC_PIN       5
#define ZERO_CROSS_PIN  4
#define DEBOUNCE_TIME   9000 //9ms - 10ms is the pulse period

static uint32_t lastPulse = 0;
static uint16_t period    = 5000; //5ms - 50% for each half wave

void ICACHE_RAM_ATTR onTimerISR(){
  if(GPIP(TRIAC_PIN)){//OUTPUT is HIGH
    GPOC = (1 << TRIAC_PIN);//low
    timer1_write(60);//12us
  } else GPOS = (1 << TRIAC_PIN);//high
}

void ICACHE_RAM_ATTR onPinISR(){
  uint32_t now = micros();
  if(now - lastPulse < DEBOUNCE_TIME) return;
  lastPulse = now;
  GPOS = (1 << TRIAC_PIN);//high
  timer1_write(period * 5);
}

void setup(){
  pinMode(TRIAC_PIN, OUTPUT);
  pinMode(ZERO_CROSS_PIN, INPUT);
  GPOS = (1 << TRIAC_PIN);//high
  timer1_attachInterrupt(onTimerISR);
  timer1_enable(TIM_DIV16, TIM_EDGE, TIM_SINGLE);
  attachInterrupt(ZERO_CROSS_PIN, onPinISR, RISING);
}