Temperature sensing phase control

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1

Here is the code for temperature sensing phase control.

bool state=LOW;
int pin=10;// this pin connects to zero crossing detector circuit

int v=540;      // sets low at start of program until analog read at 1 minute
int vin = 2;   // this is the analog read pin
int us=12396;        // sets phase control turn on points
int ledPin = 11;   // pin 8 connects to random phase opto 
unsigned long previousMillis=0;

const long interval = 15000;
void setup() {
  Serial.begin(9600);
    pinMode(pin,INPUT);
    pinMode(ledPin, OUTPUT);}
   void loop() {
       unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {
      previousMillis = currentMillis;
        v = analogRead(vin);
        us= (424*v-216564);
        Serial.println(v);
        Serial.println(us);
}
   

        while (us<=9004 && us>=100){ //these readings are in temp control range
           unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {
      previousMillis = currentMillis;
        v = analogRead(vin);
        us= (424*v-216564);
    Serial.println(v);
        Serial.println(us);
}
           
          if(digitalRead(pin)==HIGH && state==LOW){ //wait for hi pulse at zero crossing
         
      digitalWrite(ledPin,LOW); // if high pulse received execute these 5 lines
     delayMicroseconds (us);   // if no hi pulse continue waiting in while loop
     digitalWrite(ledPin,HIGH);
     delayMicroseconds (9100-us);
    digitalWrite(ledPin,LOW);
  }
    }
    if (v>532){          // turns off power when maximum temp exceeded
       Serial.println(v);
          digitalWrite(ledPin,LOW);}
          if (v<511){             // turns on full power below minimum temp
             Serial.println(v);
           digitalWrite(ledPin,HIGH);}
    }
  
          


             
        ```
type or paste code here
2

Analog read on pin 2?

3

Post an annotated schematic showing exactly how you have wired this. Show all connections, power source, ground. etc. Links to technical information on each of the hardware items helps a lot. Trouble shooting a block of code without knowing what the hardware is very time consuming.

4

You should use long arithmetic here:

us = (424L * v - 216564); // Is it 216664?

Be aware that the result will be positive only when v >=511. If you call delayMicroseconds with a negative argument you will surely not get what you think.

What does that formula mean?

5

image
image1247×665 15 KB

I know I should have shown the hardware. I did the same thing with analog electronics. I actually used the beetle controller because it was so small. The diagram shows a ltspice simulation. On the left is a zero crossing voltage detector which picks up when the mains goes low. I had to add the zener to clamp the high voltage which damaged the transistor and bridge otherwise.
Use a moc3023 or other random phase triac optocoupler. I use a ntc thermistor in series with a pot to set the desired temperature. There are only 3 analog and 3 digital pins on the beetle. The maths was necessary to convert analog voltage readings to delays in the phase controller. At 50cps it takes 10ms or 1000us for 1 half cycle.
I get a range of 1.5 centigrade between on and off. Easily adjusted at the analog input with thermistor and pot. I don't need any assistance with this as it is a completed project and works great. With the values on the LTspice simulation you will get a 50% duty cycle.

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