Untitled Project

#include <Arduino.h>


// Forward declarations
int readSoilRaw();
int rawToPercent(int raw);
void startAlert(unsigned long now);
void stopAlert();
void startPump(unsigned long now);
void stopPump(unsigned long now);

constexpr int SOIL_PIN = 34;
constexpr int BUZZER_PIN = 25;
constexpr int PUMP_PIN = 26;

// Calibrate these two readings for your own soil and sensor.
// RAW_DRY: probe in air/dry soil; RAW_WET: probe in fully wet soil.
constexpr int RAW_DRY = 3000;
constexpr int RAW_WET = 1500;
constexpr int DRY_THRESHOLD_PERCENT = 20;
constexpr unsigned long SAMPLE_INTERVAL_MS = 60000UL;
constexpr unsigned long PUMP_DURATION_MS = 5000UL;
constexpr unsigned long PUMP_COOLDOWN_MS = 300000UL;
constexpr unsigned long BUZZER_TOGGLE_MS = 150UL;
constexpr unsigned long ALERT_DURATION_MS = 3000UL;

unsigned long lastSampleMs = 0;
unsigned long pumpStartedMs = 0;
unsigned long lastPumpStoppedMs = 0;
unsigned long alertStartedMs = 0;
unsigned long lastBuzzerToggleMs = 0;
bool pumpRunning = false;
bool alertActive = false;
bool buzzerOn = false;

int readSoilRaw() {
  long total = 0;
  for (int i = 0; i < 16; ++i) {
    total += analogRead(SOIL_PIN);
    delay(5);
  }
  return total / 16;
}

int rawToPercent(int raw) {
  const long numerator = static_cast<long>(RAW_DRY - raw) * 100L;
  const long denominator = RAW_DRY - RAW_WET;
  if (denominator == 0) return 0;
  return constrain(static_cast<int>(numerator / denominator), 0, 100);
}

void startAlert(unsigned long now) {
  alertActive = true;
  alertStartedMs = now;
  lastBuzzerToggleMs = now;
  buzzerOn = true;
  digitalWrite(BUZZER_PIN, HIGH);
}

void stopAlert() {
  alertActive = false;
  buzzerOn = false;
  digitalWrite(BUZZER_PIN, LOW);
}

void startPump(unsigned long now) {
  pumpRunning = true;
  pumpStartedMs = now;
  digitalWrite(PUMP_PIN, HIGH);
  Serial.println("Pump ON");
}

void stopPump(unsigned long now) {
  pumpRunning = false;
  lastPumpStoppedMs = now;
  digitalWrite(PUMP_PIN, LOW);
  Serial.println("Pump OFF");
}

void setup() {
  Serial.begin(115200);
  analogReadResolution(12);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(PUMP_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);
  digitalWrite(PUMP_PIN, LOW);
  delay(200);
  lastSampleMs = millis() - SAMPLE_INTERVAL_MS;
  Serial.println("Soil watering controller ready");
}

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

  if (pumpRunning && now - pumpStartedMs >= PUMP_DURATION_MS) {
    stopPump(now);
  }

  if (alertActive) {
    if (now - alertStartedMs >= ALERT_DURATION_MS) {
      stopAlert();
    } else if (now - lastBuzzerToggleMs >= BUZZER_TOGGLE_MS) {
      lastBuzzerToggleMs = now;
      buzzerOn = !buzzerOn;
      digitalWrite(BUZZER_PIN, buzzerOn ? HIGH : LOW);
    }
  }

  if (now - lastSampleMs < SAMPLE_INTERVAL_MS) return;
  lastSampleMs = now;

  const int raw = readSoilRaw();
  const int moisture = rawToPercent(raw);
  Serial.printf("Soil raw=%d, moisture=%d%%\n", raw, moisture);

  if (moisture < DRY_THRESHOLD_PERCENT) {
    Serial.println("Soil is below 20%: watering request");
    startAlert(now);
    if (!pumpRunning && now - lastPumpStoppedMs >= PUMP_COOLDOWN_MS) {
      startPump(now);
    } else {
      Serial.println("Pump cooldown active; warning only");
    }
  }
}