ALL CODE 

NODE MCU+ DHT 11
#include <ESP8266WiFi.h>
#include <DHT.h>

#define DHTPIN D2
#define DHTTYPE DHT11

const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASS";
const char* thingspeakApiKey = "YOUR_THINGSPEAK_WRITE_KEY";

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);
  dht.begin();
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
}

void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    Serial.println("DHT read failed");
    delay(2000);
    return;
  }
  // Build ThingSpeak update URL
  String url = "/update?api_key=" + String(thingspeakApiKey) + "&field1=" + String(t) + "&field2=" + String(h);
  WiFiClient client;
  if (client.connect("api.thingspeak.com", 80)) {
    client.print(String("GET ") + url + " HTTP/1.1\r\n" +
                 "Host: api.thingspeak.com\r\n" +
                 "Connection: close\r\n\r\n");
    Serial.println("Data sent to ThingSpeak: T=" + String(t) + " H=" + String(h));
  }
  client.stop();
  delay(20000); 
}


    DHT 11 NODEMCU+BUZZER

    #include <DHT.h>
#define DHTPIN D2
#define DHTTYPE DHT11
#define BUZZER_PIN D5

const float TEMP_THRESHOLD = 30.0; // °C — change as needed

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);
  Serial.begin(115200);
  dht.begin();
}

void loop() {
  float t = dht.readTemperature();
  if (isnan(t)) { Serial.println("DHT fail"); delay(2000); return; }

  Serial.println(String("Temp: ") + t);
  if (t > TEMP_THRESHOLD) {
    digitalWrite(BUZZER_PIN, HIGH); // alarm on
  } else {
    digitalWrite(BUZZER_PIN, LOW);
  }
  delay(1000);
}