const int pwmPin = 9;       // PWM output pin to control MOSFET
const int potPin = A0;      // Potentiometer input pin
const int sensePin = A1;    // Voltage sense pin

void setup() {
  pinMode(pwmPin, OUTPUT);
    pinMode(potPin, INPUT);
      pinMode(sensePin, INPUT);
        Serial.begin(9600);       // For debugging
        }

        void loop() {
          int setVoltage = analogRead(potPin); // Read desired voltage from pot
            setVoltage = map(setVoltage, 0, 1023, 0, 255); // Map to PWM range

              int actualVoltage = analogRead(sensePin); // Read actual output voltage
                actualVoltage = map(actualVoltage, 0, 1023, 0, 255); // Map to PWM range

                  int error = setVoltage - actualVoltage; // Calculate error

                    // Adjust PWM signal to correct output voltage
                      int pwmValue = constrain(setVoltage + error, 0, 255);
                        analogWrite(pwmPin, pwmValue);

                          // Debugging
                            Serial.print("Set Voltage: ");
                              Serial.print(setVoltage);
                                Serial.print(" Actual Voltage: ");
                                  Serial.print(actualVoltage);
                                    Serial.print(" PWM Value: ");
                                      Serial.println(pwmValue);

                                        delay(100); // Small delay for stability
                                        }