ESP8266 NodeMCU Temperature and Humidity on Cayenne Platform

Using DHT11 sensor connected to nodeMCU to read Humidity and Temperature using Cayenne mydevices platform

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ESP8266 NodeMCU Temperature and Humidity on Cayenne Platform

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board

DHT11 Temperature & Humidity Sensor (4 pins)

Breadboard (generic)

Jumper wires (generic)

Software apps and online services

Arduino IDE

myDevices Cayenne

Story

1. Introduction

This Project will demonstrate how to create a temperature and humidity monitoring using ESP module, a DHT11 sensor and a Cayenne dashboard. ESP module is one of the low-cost iot device

2. Starting with Cayenne Mydevices

Create your own account if your a new user using the following link and login your account.

https://accounts.mydevices.com/auth/realms/cayenne/login-actions/registration?client_id=cayenne-web-app&tab_id=6XCGfJ48n1I

Step 1: From the screen select All Devices

Step 2: Select Generic ESP8266

Step 3: Take note of the MQTT username, passwords and client ID

3. Connecting the ESP Module and DHT11 Sensor

Connect the sensor to your ESP module following the attached schematics.

4. Programming the ESP Module

Step 1: Download the MQTT Cayenne libraries from the link as a ZIP file: https://github.com/myDevicesIoT/Cayenne-MQTT-ESP

Step 2: From the arduino IDE install the downloaded zip library from Sketch -> Include Library -> Add.ZIP Library.

Step 3: Install 2 additional libraries for DHT11 sensor as shown below

Step 4: Copy the code provided here and fill in the MQTT username, passwords and client ID taken from the Cayenne account. Also fill your network info.

Step 5: Connect your ESP module to your computer using a USB to Serial FTDI or console cable.

Step 6: Select your ESP module and port from the Tools menu.

Selecting the ESP module

Selecting the Port

Step 7: Compile the program and download to the ESP module.

5. Connecting the ESP to Cayenne Mydevices

Step 1: Right after the program was uploaded, go back to your Cayenne account and see if the connection has been established. The screen should like as follows.

Step 2: From the above screen, it can be seen that it automatically detects the sensor data. Click the '+' sign to pin into your dashboard.

Step 3: You may customize your widget according to your liking.

Step 4: (Optional) You can also add a trigger notification to send you an SMS or email when a certain threshold value was reached.

Code

Nodemcu cayenne code

/*
Cayenne DHT11 Sensor Project
*/

#define CAYENNE_PRINT Serial  // Comment this out to disable prints and save space
#define DHTPIN 0          // D3

// Uncomment whatever type you're using! In this project we used DHT11
#define DHTTYPE DHT11     // DHT 11
//#define DHTTYPE DHT22   // DHT 22, AM2302, AM2321
//#define DHTTYPE DHT21   // DHT 21, AM2301

#include <CayenneMQTTESP8266.h>
#include <DHT.h>

// WiFi network info.
char ssid[] = "xxxxx";
char wifiPassword[] = "xxxxx";

// Cayenne authentication info. This should be obtained from the Cayenne Dashboard.
char username[] = "dfsfdfdfs";
char password[] = "sdsdsd";
char clientID[] = "dsdsdsd";

DHT dht(DHTPIN, DHTTYPE);

//Variables for DHT11 values
float h;
float t;
bool humidity = false;
bool Temperature = false;


void setup()
{
	Serial.begin(9600);
  Serial.print("Setup");
	Cayenne.begin(username, password, clientID, ssid, wifiPassword);

  humidity = false;
  Temperature = false;
}

void loop()
{
	//Run Cayenne Functions
  Cayenne.loop();
}

CAYENNE_OUT(V0){
  //Serial.println("humidity");

  //Check if read failed and try until success
  do {
    //Read humidity (percent)
    h = dht.readHumidity();

    delay(1000);
  } while  (isnan(h));

  Serial.print("humidity: ");
  Serial.println(h);

  //Set Humidity to true so we know when to sleep
  humidity = true;

  //Write to Cayenne Dashboard`
  Cayenne.virtualWrite(V0, h);
}

CAYENNE_OUT(V1){
  //Serial.println("temperature");
  
  //Check if read failed and try until success
  do {
    //Read temperature as Celsius
   
    t = dht.readTemperature();
    

    delay(1000);
  } while  (isnan(t));

  Serial.print("temperature: ");
  Serial.println(t);

  //Set Temperature to true so we know when to sleep
  //Temperature = true;

  //Write to Cayenne Dashboard
  Cayenne.virtualWrite(V1, t);
}