AC Dimmer EpS32 - arduino

Question

I have an application on to control ESP32 Light Dimmer from the temperature read from a temperature sensor. The rule is very simple, when my sensor reads the temperature of more than 27ºC the lamp should be turned off by the Dimmer. However, this is not happening.
What the code does is, when the system is turned on the lamp turns on and the temperature is read from time to time, but when the temperature exceeds 27ºC the dimmer does not turn off the lamp. I think it might be something I'm doing wrong in the zero_crosss_int routine, because when the temperature reaches its limit the message "TRIAC OFF" is displayed.
Below the code used.
#define ZERO_CROSS 2
#define DIMMER_CONTROL 4
int dimming=64;
float programedTemp = 27.0;
int halfDimming=128;
int maxDimming=64;
void power(void *parameters){
tempSensor.requestTemperaturesByIndex(0);
temp=tempSensor.getTempCByIndex(0);
if(temp<programedTemp){
dimming=maxDimming;
if(temp<(programedTemp-1.0)){
dimming=maxDimming;
} else if(temp<programedTemp){
dimming++;
}
} else if(temp>programedTemp+0.9){
dimming=128;
}else{
dimming=halfDimming;
}
delay(4000);
}
void zero_crosss_int() {
if(dimming>=128){
delayMicroseconds(8.333);
digitalWrite(DIMMER_CONTROL, LOW); // triac Off
Serial.println((String) "=====>>> TRIAC OFF <<<=====");
}else{
int dimtime = (65*dimming);
delayMicroseconds(dimtime); // Off cycle
digitalWrite(DIMMER_CONTROL, HIGH); // triac firing
delayMicroseconds(8.333);
digitalWrite(DIMMER_CONTROL, LOW); // triac Off
}
}
void setup() {
pinMode(DIMMER_CONTROL, OUTPUT);
pinMode(ZERO_CROSS, INPUT);
attachInterrupt(ZERO_CROSS, zero_crosss_int, RISING);
Serial.begin(115200);
xTaskCreatePinnedToCore(power,"controlDimm",10000,NULL,0,&mainsPower,0);
}
void loop() {
}

Answer 1

You're doing way too much in your interrupt handler. It's amazing that it isn't just crashing constantly... the only reason that's not happening is likely because you don't do anything in loop().
It's not safe to call most of the functions you're calling in the interrupt handler. Interrupt handlers need to run for as little time as possible - other interrupts may be locked out and they may interfere with the network stack and other housekeeping functions. You absolutely should not be calling delayMicroseconds() or any Serial methods in an interrupt handler, or spending any more time there than is absolutely necessary. Almost all ESP-IDF or Arduino Core functions are not safe to call from inside an interrupt handler - the interrupt handler may interrupt another call to them while they're in an inconsistent state, or may change hardware settings while they're in the middle of using that hardware.
Your code would be much better if you structured it like this:
volatile bool zero_crossing_flag = false;
void IRAM_ATTR zero_cross_int() {
zero_crossing_flag = true;
}
void loop() {
if(zero_crossing_flag) {
zero_crossing_flag = false;
if(dimming>=128){
delayMicroseconds(8.333);
digitalWrite(DIMMER_CONTROL, LOW); // triac Off
Serial.println((String) "=====>>> TRIAC OFF <<<=====");
}else{
int dimtime = (65*dimming);
delayMicroseconds(dimtime); // Off cycle
digitalWrite(DIMMER_CONTROL, HIGH); // triac firing
delayMicroseconds(8.333);
digitalWrite(DIMMER_CONTROL, LOW); // triac Off
}
}
}
The IRAM_ATTR attribute on zero_cross_int() tells the compiler that this code must always be available. If you write an interrupt handler without IRAM_ATTR it's basically luck if it executes properly.
Restructuring your code this way will probably not solve the problem you're asking about, but it will allow it to run in a stable, reproducible way, which it's unlikely to the way it's written now.

Answer 2

Use your ZCD input to generate an interrupt. In the ISR start a Timer which generates another interrupt within 0ms(Full power) to 10ms(completely off) of the ZCD interrupt.
I don't understand to Switch off the lamp why are you using TRIAC instead of a Relay.