Smart self-watering planter

Install first: Adafruit SSD1306, Adafruit GFX Library, BH1750 by Christopher Laws

#include <WiFi.h>
#include <WebServer.h>
#include <Wire.h>
#include <BH1750.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// ---- Wi-Fi ----
const char* WIFI_NAME = "your-wifi";
const char* WIFI_PASS = "your-password";

// ---- Pins (match the wiring diagram) ----
const int SOIL_PIN  = 34;  // analog
const int FLOAT_PIN = 27;  // LOW = water present
const int PUMP_PIN  = 26;  // MOSFET SIG

// ---- Calibration ----
const int DRY = 3200, WET = 1300;
const int WATER_BELOW = 35;          // percent
const unsigned long PUMP_MS = 3000;
const unsigned long REST_MS = 10UL * 60 * 1000;

BH1750 light;
Adafruit_SSD1306 oled(128, 64, &Wire, -1);
WebServer server(80);
unsigned long lastWatered = 0;
int moisture = 0; float lux = 0; bool hasWater = true;

int readMoisture() {
  long sum = 0;
  for (int i = 0; i < 10; i++) { sum += analogRead(SOIL_PIN); delay(5); }
  return constrain(map(sum / 10, DRY, WET, 0, 100), 0, 100);
}

void showStatus(const char* note) {
  oled.clearDisplay();
  oled.setTextColor(SSD1306_WHITE);
  oled.setTextSize(1); oled.setCursor(0, 0); oled.print("Moisture");
  oled.setTextSize(3); oled.setCursor(0, 12); oled.print(moisture); oled.print("%");
  oled.setTextSize(1); oled.setCursor(0, 44); oled.printf("Light %d lux", (int)lux);
  oled.setCursor(0, 56); oled.print(hasWater ? note : "Refill water");
  oled.display();
}

void handleRoot() {
  String html = "<meta name=viewport content='width=device-width'><style>body{font-family:sans-serif;padding:24px}</style>";
  html += "<h2>Your plant</h2><p>Moisture: " + String(moisture) + "%</p><p>Light: " + String((int)lux) + " lux</p>";
  html += "<p>Water: " + String(hasWater ? "OK" : "Please refill") + "</p>";
  server.send(200, "text/html", html);
}

void setup() {
  pinMode(PUMP_PIN, OUTPUT); digitalWrite(PUMP_PIN, LOW);
  pinMode(FLOAT_PIN, INPUT_PULLUP);
  Wire.begin(21, 22);
  light.begin();
  oled.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  WiFi.begin(WIFI_NAME, WIFI_PASS);
  for (int i = 0; i < 40 && WiFi.status() != WL_CONNECTED; i++) delay(250);
  server.on("/", handleRoot);
  server.begin();
  showStatus(WiFi.status() == WL_CONNECTED ? WiFi.localIP().toString().c_str() : "Offline mode");
}

void loop() {
  server.handleClient();
  static unsigned long lastRead = 0;
  if (millis() - lastRead < 3000) return;
  lastRead = millis();

  moisture = readMoisture();
  lux = light.readLightLevel();
  hasWater = digitalRead(FLOAT_PIN) == LOW;

  bool rested = lastWatered == 0 || millis() - lastWatered > REST_MS;
  if (moisture < WATER_BELOW && hasWater && rested) {
    showStatus("Watering...");
    digitalWrite(PUMP_PIN, HIGH); delay(PUMP_MS); digitalWrite(PUMP_PIN, LOW);
    lastWatered = millis();
  }
  showStatus(moisture < WATER_BELOW ? "Resting" : "Happy plant");
}