Thinkercad Code

// Pin definitions
const int NC_LED = 8;      // Mixer valves (on if redirect, off if normal flow)
const int NO_LED = 9;      // Tank valves (On if water level(A4) is above 300)
const int tempPin = A5;    // Temperature sensor
const int tempPotPin = A0; // Potentiometer for temperature setpoint
const int waterLevelPin = A4; // Potentiometer for water level

void setup() {
  Serial.begin(9600);
  Serial.println("System Booting");
  
  // Set pin modes
  pinMode(NC_LED, OUTPUT);
  pinMode(NO_LED, OUTPUT);
  
  // Initialize valves (both off)
  digitalWrite(NC_LED, LOW);
  digitalWrite(NO_LED, LOW);

  delay(1000);
  Serial.println("System Ready");
}

void loop() {
  // Read temperature setpoint potentiometer
  int tempPotValue = analogRead(tempPotPin);
  
  // Calculate setpoint and system state
  float setpoint = 15.0;
  bool systemActive = false;
  
  if(tempPotValue > 100) {  // Dead zone for off position
    systemActive = true;
    // Map 101-1023 to 15-35°C
    setpoint = map(tempPotValue, 101, 1023, 150, 350) / 10.0;
  }

  // Always read water level (even when system is inactive)
  int waterLevelValue = analogRead(waterLevelPin);
  bool waterLevelHigh = waterLevelValue > 300;

  if(systemActive) {
    // Read temperature
    int sensorValue = analogRead(tempPin);
    float voltage = sensorValue * (5.0 / 1023.0);
    float tempC = (voltage - 0.5) * 100.0;  // LM50 conversion
    
    // Temperature control logic
    if(tempC < setpoint) {
      digitalWrite(NC_LED, HIGH);  // Redirect water (Mixer valve)
    } else {
      digitalWrite(NC_LED, LOW);   // Normal flow
    }

    // Water level control logic
    digitalWrite(NO_LED, waterLevelHigh ? HIGH : LOW);  // Tank valve

    // Update Serial Monitor
    Serial.print("Set: ");
    Serial.print(setpoint, 1);
    Serial.print("°C | Actual: ");
    Serial.print(tempC, 1);
    Serial.print("°C | Water: ");
    Serial.print(waterLevelHigh ? "High" : "Low ");
    Serial.print(" | State: ");
    Serial.println(tempC < setpoint ? "Redirecting" : "Normal Flow");
    
  } else {  // System off
    digitalWrite(NC_LED, LOW);
    digitalWrite(NO_LED, LOW);
    
    Serial.println("System OFF - Both valves closed");
  }

  delay(200);
}