#include <WiFi.h>
#include <HTTPClient.h>

const char* ssid = "syntell wireless ";
const char* password = "$ynWifi001";
const char* serverName = "http://api.thingspeak.com/update";
String apiKey = "your_API_KEY";

const int flowSensorPin = 4;
volatile int pulseCount = 0;
float flowRate;
unsigned long totalMilliLitres = 0;
unsigned long oldTime = 0;

// Interrupt Service Routine (ISR) for counting pulses
void IRAM_ATTR pulseCounter() {
  pulseCount++;
}

void setup() {
  Serial.begin(115200);
  pinMode(flowSensorPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(flowSensorPin), pulseCounter, FALLING);

  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
 …