CREATE TABLE water_readings (
    id INT AUTO_INCREMENT PRIMARY KEY,
    sensor_id INT NOT NULL,
    volume FLOAT NOT NULL,
    recorded_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
////////////////////////////////////////////////////////////////////////////
<?php
$servername = "localhost";
$username = "db_user";
$password = "db_pass";
$dbname = "flow_db";

$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) { die("Connection failed: " . $conn->connect_error); }

// Get JSON from POST body
$json = file_get_contents('php://input');
$data = json_decode($json, true);

if (!empty($data['sensors'])) {
    foreach ($data['sensors'] as $sensor) {
        $sensor_id = $sensor['id'];
        $volume = $sensor['volume'];
        
        $sql = "INSERT INTO water_readings (sensor_id, volume) VALUES ('$sensor_id', '$volume')";
        $conn->query($sql);
    }
    echo "Success";
} else {
    echo "No data received";
}
$conn->close();
?>
/////////////////////////////////////////////////////////////////////////////
#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>

// WiFi and Server Config
const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";
const char* serverUrl = "http://your-server-ip/api/insert_flow.php";

// Sensor Configuration
const int sensorPins[] = {25, 26, 27, 14, 12}; // Use ESP32 interrupt-capable pins
volatile long pulseCounts[5] = {0, 0, 0, 0, 0};
float totalVolumes[5] = {0.0, 0.0, 0.0, 0.0, 0.0};

// Calibration: YF-S201 produces ~450 pulses per liter
const float calibrationFactor = 450.0;

// Interrupt Service Routines (ISRs)
void IRAM_ATTR pulseCounter0() { pulseCounts[0]++; }
void IRAM_ATTR pulseCounter1() { pulseCounts[1]++; }
void IRAM_ATTR pulseCounter2() { pulseCounts[2]++; }
void IRAM_ATTR pulseCounter3() { pulseCounts[3]++; }
void IRAM_ATTR pulseCounter4() { pulseCounts[4]++; }

void (*isrFunctions[])() = {pulseCounter0, pulseCounter1, pulseCounter2, pulseCounter3, pulseCounter4};

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  
  for (int i = 0; i < 5; i++) {
    pinMode(sensorPins[i], INPUT_PULLUP);
    attachInterrupt(digitalPinToInterrupt(sensorPins[i]), isrFunctions[i], RISING);
  }

  while (WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); }
  Serial.println("\nWiFi Connected");
}

void loop() {
  // Update volumes every 10 seconds
  static unsigned long lastUpdate = 0;
  if (millis() - lastUpdate > 10000) {
    lastUpdate = millis();
    
    StaticJsonDocument<300> doc;
    JsonArray data = doc.createNestedArray("sensors");

    for (int i = 0; i < 5; i++) {
      totalVolumes[i] = pulseCounts[i] / calibrationFactor; // Calculate liters
      JsonObject s = data.createNestedObject();
      s["id"] = i + 1;
      s["volume"] = totalVolumes[i];
    }

    String jsonPayload;
    serializeJson(doc, jsonPayload);

    if (WiFi.status() == WL_CONNECTED) {
      HTTPClient http;
      http.begin(serverUrl);
      http.addHeader("Content-Type", "application/json");
      int httpResponseCode = http.POST(jsonPayload);
      
      Serial.print("HTTP Response: ");
      Serial.println(httpResponseCode);
      http.end();
    }
  }
}