Question

can anyone give me a code for nodemcu wifi chip for displaying temperature and humidity to app where temp and humidity data is sent to cloud and then cloud sends the data to mobile app

Answer 1

#include <DHT.h> // Including library for dht

#include <ESP8266WiFi.h>

String apiKey = "Your API of thingsspeak"; // Enter your Write API key from ThingSpeak

const char *ssid = "Your wifi Network name"; // replace with your wifi ssid and wpa2 key

const char *pass = "Network password";

#define DHTPIN 0 //pin where the dht11 is connected

DHT dht(DHTPIN, DHT11);

WiFiClient client;

void setup()

{

Serial.begin(115200);

delay(10);

dht.begin();

Serial.println("Connecting to ");

Serial.println(ssid);

WiFi.begin(ssid, pass);

while (WiFi.status() != WL_CONNECTED)

{

delay(500);

Serial.print(".");

}

Serial.println("");

Serial.println("WiFi connected");

}

void loop()

{

  

float h = dht.readHumidity();

float t = dht.readTemperature();

  

if (isnan(h) || isnan(t))

{

Serial.println("Failed to read from DHT sensor!");

return;

}

if (client.connect(server,80)) // "184.106.153.149" or api.thingspeak.com

{  

  

String postStr = apiKey;

postStr +="&field1=";

postStr += String(t);

postStr +="&field2=";

postStr += String(h);

postStr += "\r\n\r\n";

client.print("POST /update HTTP/1.1\n");

client.print("Host: api.thingspeak.com\n");

client.print("Connection: close\n");

client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");

client.print("Content-Type: application/x-www-form-urlencoded\n");

client.print("Content-Length: ");

client.print(postStr.length());

client.print("\n\n");

client.print(postStr);

Serial.print("Temperature: ");

Serial.print(t);

Serial.print(" degrees Celcius, Humidity: ");

Serial.print(h);

Serial.println("%. Send to Thingspeak.");

}

client.stop();

Serial.println("Waiting...");

  

// thingspeak needs minimum 15 sec delay between updates, i've set it to 30 seconds

delay(10000);

}