variable temperature controller with AD595 and LCD(2x16)

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1

I have the schematic. Does anybody have PID code for same? I would like to vary setpoint with up/down switches.

2

I don't have any info on your device, but I'm doing essentially the same thing with my brewing thermostat. Here's the code, but there is more stuff in the topic itself.

#include <LiquidCrystal.h>

int des = 20;           //set temperature variable
int lastdes = 0;
int tempc = 0;          //temperature variable
int Counter1 = 0;       // counter for the number of button presses
int Counter2 = 0;       // counter for the number of button presses
int State1 = 0;         // current state of the button
int State2 = 0;         // current state of the button
int lastState1 = 0;     // previous state of the button
int lastState2 = 0;
int val = 0;





int pin = 1;            //LM35 input
const int set1 = 1;     //temp up and temp down buttons
const int set2 = 2;
int heat = 0;           //output to heater control
int indicate = 4;       //visual indicator output


LiquidCrystal lcd(8, 9, 10, 11, 12, 13);   // initialize the library with the numbers of the interface pins

void setup() {
  lcd.begin(16, 2);
  lcd.print("SET: ACT: HEAT?");  // Print headings to the LCD.
  analogReference(INTERNAL);     
  pinMode(heat, OUTPUT);
  pinMode(indicate, OUTPUT);
  pinMode(set1, INPUT);
  pinMode(set2, INPUT);

}

void loop() {
 State1 = digitalRead(set1);
  State2 = digitalRead(set2);  
  if (State1 != lastState1) {
        if (State1 == HIGH && des!= 100) {      //if up button is pressed, add 1 to des
        des++;
     } 
    
  }
  
  if (State2 != lastState2) {  //if down button is pressed, subtract 1 from des
       if (State2 == HIGH && des != 0) {
       des--; 
    }
  }
  analogRead(pin);
  delay(10);
  tempc = (100* (long)analogRead(pin)/1024.0);  //save temperature reading as 'tempc'
  delay(1);                                     //gives a range of about 30
  
  lcd.setCursor(1, 1);
  lcd.print("    ");     //clear field
  lcd.setCursor(1, 1);
  lcd.print(des);     //print set temperature
  
   delay(50);
  lcd.setCursor(6,1);
  lcd.print("  ");    //clear field
  lcd.setCursor(6,1);
  lcd.print(tempc );  //print actual temperature
  
delay(50);
  if(tempc <= des){                 //if actual temperature is less than
    digitalWrite(heat, HIGH);       //or equal to the set temperature, turn the heater on
    digitalWrite(indicate, HIGH);
    lcd.setCursor(11,1);
    lcd.print("ON ");
    delay(50);
}
  else  if(tempc > des){             //otherwise leave the heater off
    digitalWrite(heat, LOW);
    digitalWrite(indicate, LOW);
    lcd.setCursor(11,1);
    lcd.print("OFF");
  
  }
}
3

That code looks just what I need. Thanks a million!

brushless.

4

brushless:
I have the schematic. Does anybody have PID code for same? I would like to vary setpoint with up/down switches.

Do you have a copy of the schematic and did it work with the code below as I would like to make one and where did you get your sensor please.

Many thanks Bob

5

Hi I second BBBOB, do you have the Schematic hookup for switches etc.

6

bowlerhatman:
I don't have any info on your device, but I'm doing essentially the same thing with my brewing thermostat. Here's the code, but there is more stuff in the topic itself.

#include <LiquidCrystal.h>

int des = 20;           //set temperature variable
int lastdes = 0;
int tempc = 0;          //temperature variable
int Counter1 = 0;       // counter for the number of button presses
int Counter2 = 0;       // counter for the number of button presses
int State1 = 0;         // current state of the button
int State2 = 0;         // current state of the button
int lastState1 = 0;     // previous state of the button
int lastState2 = 0;
int val = 0;

int pin = 1;            //LM35 input
const int set1 = 1;     //temp up and temp down buttons
const int set2 = 2;
int heat = 0;           //output to heater control
int indicate = 4;       //visual indicator output

LiquidCrystal lcd(8, 9, 10, 11, 12, 13);   // initialize the library with the numbers of the interface pins

void setup() {
 lcd.begin(16, 2);
 lcd.print("SET: ACT: HEAT?");  // Print headings to the LCD.
 analogReference(INTERNAL);    
 pinMode(heat, OUTPUT);
 pinMode(indicate, OUTPUT);
 pinMode(set1, INPUT);
 pinMode(set2, INPUT);

}

void loop() {
State1 = digitalRead(set1);
 State2 = digitalRead(set2);  
 if (State1 != lastState1) {
       if (State1 == HIGH && des!= 100) {      //if up button is pressed, add 1 to des
       des++;
    }
   
 }
 
 if (State2 != lastState2) {  //if down button is pressed, subtract 1 from des
      if (State2 == HIGH && des != 0) {
      des--;
   }
 }
 analogRead(pin);
 delay(10);
 tempc = (100* (long)analogRead(pin)/1024.0);  //save temperature reading as 'tempc'
 delay(1);                                     //gives a range of about 30
 
 lcd.setCursor(1, 1);
 lcd.print("    ");     //clear field
 lcd.setCursor(1, 1);
 lcd.print(des);     //print set temperature
 
  delay(50);
 lcd.setCursor(6,1);
 lcd.print("  ");    //clear field
 lcd.setCursor(6,1);
 lcd.print(tempc );  //print actual temperature
 
delay(50);
 if(tempc <= des){                 //if actual temperature is less than
   digitalWrite(heat, HIGH);       //or equal to the set temperature, turn the heater on
   digitalWrite(indicate, HIGH);
   lcd.setCursor(11,1);
   lcd.print("ON ");
   delay(50);
}
 else  if(tempc > des){             //otherwise leave the heater off
   digitalWrite(heat, LOW);
   digitalWrite(indicate, LOW);
   lcd.setCursor(11,1);
   lcd.print("OFF");
 
 }
}

please post schematics.

Thanks.