Published April 9, 2019

Honey! I'm Cold!

Remote room temperature control with NodeMCU + Blynk.

BeginnerFull instructions provided1 hour672

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board

DHT-22 Temperature and Humidity Sensor (3 Pin with resistor)

SSR-25DA Solid State Relay

Wall Mounted Heater (Bumb Type)

Socket 230V

Software apps and online services

Arduino IDE

Fritzing

Story

Every time we travel, my wife complains about our home been too cold (I turn down heaters to save some $$). So, I decided to end that! I am getting divorced! :) Nooooope! I just found a way of making my dumb as a heater....heater a little less dumb! :0

I will try to be as clear as the mississippi's river mud! ;)

Firsts things first!

1. Get your stuff!

NodeMCU ESP-12
DHT-22 Temperature and Humidity Sensor
SSR 25DA Solid State Relay
230V Socket
Wall Mounted Heater (Dumb Type)

2. Connect the stuff together!

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DHT-22 Data -> NodeMCU D1

DHT-22 Vcc -> NodeMCU 3V3

DHT-22 GND -> NodeMCU GND

Relay Pos-> NodeMCU D0

Relay Neg-> NodeMCU GND

3. Prepare your code to work!

Install libraries:

Blynk

DHT-22

NodeMCU

Don't know how? Check the link below:

https://www.arduino.cc/en/guide/libraries

Visual guy? Get sleepy reading? Check this youtube video:

https://www.youtube.com/watch?v=A5eakzVo5mY

4. Creating Your Blynk App

Extracted of instructions from: http://docs.blynk.cc/

Instructions on how to setup Blynk on your phone on this link: https://www.hackster.io/Cmtelesann/blynk-nodemcu-and-dht-22-8220ab

Continuing from item 5. Add a widget.

Select "Button".

Drag-n-Drop - Tap and hold the Widget to drag it to the new position.

Widget Settings - Each Widget has it’s own settings. Tap on the widget to get to them.

Choose a name for your widget.

Select a target. My case I am using NodeMCU.

The most important parameter to set is OUTPUT. The list of outputs reflects physical pins defined by your hardware. If you are sending a value to Pin D0 on your NodeMCU - then select D0.

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4.6. Run The Project

When you are done with the Settings - press the PLAY button. This will switch you from EDIT mode to PLAY mode where you can interact with the hardware. While in PLAY mode, you won’t be able to drag or set up new widgets, press STOP and get back to EDIT mode.

You will get a message saying “Arduino UNO is offline”. We’ll deal with that in the next section.

Click on Play Icon.

Here's how it looks like when the project is running with no connection.

The red number one should go once it is connected.

Enjoy! Try adding graphs and other sensors to it!

5. Open a beer!

NodeMCU

#include "DHT.h"                              // DHT Sensor
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

char auth[] = "BlynkAuth";
char ssid[] = "SSID";
char pass[] = "Password";

DHT dhtA(5, DHT22);                           // DHT instance named dhtA, Pin on NodeMCU D1 and sensor type

int RelayPin = 0;                             // Pin on NodeMcu D0

void setup() {
  Serial.begin(9600);                         // Debug purposes only to check if DHT is working
  Blynk.begin(auth, ssid, pass);              // Connecting to blynk
  dhtA.begin();                               // Starting the DHT-22
  pinMode(RelayPin, OUTPUT);                  // Blynk reference D0
}

void loop() {
  Blynk.run();                                
  climateRoutine();                           // Climate routines
  delay(4700);                                // 4.7 sec between routines
}

void climateRoutine() {
    byte h1 = dhtA.readHumidity();            // f1 and h1 are celsius and humidity readings
    byte t1 = dhtA.readTemperature();         // from DHT/A
    Blynk.virtualWrite(V0, t1);               // Set Virtual Pin 0 frequency to PUSH in Blynk app
    Blynk.virtualWrite(V1, h1);               // Set Virtual Pin 1 frequency to PUSH in Blynk app

    if (isnan(h1) || isnan(t1)) {             // Check if there DHT is working
      Serial.println("Failed to read from DHT sensor!");
      return;
    }
}

Credits

Cmtelesann

5 projects • 15 followers

Keeping my head busy! Looking for challenges! Trying to keep up with evolution! IoT is the future!

Honey! I'm Cold!

Things used in this project

Hardware components

Software apps and online services

Story

1. Get your stuff!

2. Connect the stuff together!

3. Prepare your code to work!

4. Creating Your Blynk App

5. Open a beer!

Code

NodeMCU

Credits

Cmtelesann

Comments

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Honey! I'm Cold!

Honey! I'm Cold!

Things used in this project

Hardware components

Software apps and online services

Story

1. Get your stuff!

2. Connect the stuff together!

3. Prepare your code to work!

4. Creating Your Blynk App

5. Open a beer!

Code

NodeMCU

Credits

Cmtelesann

Comments

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