const int PIN_PUMP = 2;       // Pump input
const int PIN_CONSUME = 3;    // Consumption input

int tank_level = 0;
unsigned long lastUpdate = 0;
unsigned long lastConsume = 0;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
}


void loop() {
  unsigned long now = millis();

  // Pump filling (increase)
  if (digitalRead(PIN_PUMP) == HIGH && now - lastUpdate >= 500) {
    if (tank_level < 100) tank_level++;
    lastUpdate = now;
  }

  // Consumption draining (decrease)
  if (digitalRead(PIN_CONSUME) == HIGH && now - lastConsume >= 1000) {
    if (tank_level > 0) tank_level--;
    lastConsume = now;
  }

  // Serial print (so Python can read)
  Serial.println(tank_level);

  // (keep your HL/HHL/OF/LL/LLL logic here)
}