Published July 23, 2018 © GPL3+

Voice Controlled Lights From Anywhere

AC lights that are controlled from anywhere with internet connection using NodeMCU (ESP8266) and Jason (Android App).

IntermediateFull instructions provided2 hours3,509

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board

Can be another esp8266 or esp32 module, this is the easiest one to use and program

General Purpose Transistor NPN

5V Relay

Can be a mechanical relay or Solid State Relay, its easier with a SSR

Switch

Can be an electronics hobby switch, like a toggle, or a wall switch

Resistor 1k ohm

Breadboard (generic)

USB-A to Micro-USB Cable

A/C Light Bulb

A simple LightBulb to turn ON or OFF

Light Bulb Socket

Power Cord

5V phone charger

Jumper wires (generic)

Software apps and online services

Arduino IDE

Jason

Ubidots

Hand tools and fabrication machines

Screwdriver

Story

Description

Jason is an voice controlled assistant app that I coded for Android devices to control the electrical state of an AC appliance, until now it can control lights. You can control the lights from anywhere in the world as long as you have internet connection. This is possible by using an IoT broker, in this case we are using Ubidots.

To use it you need to build the hardware module that connects to the light bulb, (which instructions are in this tutorial) and you will also need to create an Ubidots account.

So let's get started...

Ubidots Account

The first thing you need to do is go to the Ubidots for Education website and create an account. You can sign in directly if you already have a Twitter, Github, Google or Facebook account.

Ubidots Sign Up Website

When you have already created your account you will have access to your token, bu clicking on your username at the top right corner and clicking on API Credentials. Save your token, as we are going to use later on.

Ubidots Dashboard

Token key censored, because I dont want strangers to control my home lights randomly

Jason App

The app can be downloaded from the Play Store, it is available in english and spanish.

Copy your Ubidots token into the app, by tapping the settings tab, pasting it in the Ubidots key field and tap the save button.

Settings tab

Ubidots Key Field

Saved Key in Jason

Now we need to configure a device, go to the devices tab, and tap the add button. Enter a name, preferably the name of the area where the lights are, so you can say "Turn on the kitchen lights". On the ESP32 I/O Pin choose "5", which is going to be the NodeMCU (internal ESP8266) pin connected to the relay. And tap save.

Making the Hardware

Safety First

In this project we are working with mains voltage (A/C voltage) which is dangerous if you don't know what you're doing, be very careful. NEVER touch ANY part of the circuit or work with it if it is connected to the wall power. If you don't know what you are doing, stop right here or get some help from professionals.

I am only posting this educational tutorial and I am by no means responsible for any injuries or damage you may cause.

Schematics

Schematic designed in Eagle CAD

Power the NodeMCU by connecting VIN to VCC (5V) and GND pin to GND.

Connect D8 to one end of the switch and to a 2.2K Ohm resistor conected to GND.

Connect the other end of the switch to 3.3V as the NodeMCU can only handle that voltage in its I/O Pins.

D1 to 2.2k Ohm resistor to the base of the NPN transistor

Negative DC of the relay to the colector of the transistor.

Transistor emitter to GND.

PositiveDC of the relay to 5V.

Negative of light bulb to one AC pin of the relay.

Positive of bulb to AC Live (AC Positive).

OtherAC pin of relay to Neutral (AC Negative).

NOTE: VCC 5V is going to be supplied from an usb cable connected to a simple phone transformer charger.

Breadboard

Breadboard without external components (AC, switch and USB power supply)

The switch can be a simple toggle switch or a wall switch, it just needs to detect if the user changes its state so we can still control the lights with a normal switch.

Wall Switch Front

Back of switch

The switch that I used has double throw, we only need one, so I connected its pin 1 to 3V of the NodeMCU and pin 2 of switch to NodeMCU pin D8.

Switch connected to breadboard using jumpers

The power supply is going to be a phone wall charger of 5V with a stripped usb cable.

Power connection with jumpers and alligators

By controlling the ground connection with the relay we can control the AC status of the light bulb.

AC light bulb connections (Neutral to relay1, relay2 to negative of light bulb, live to positive of lightbulb)

Alligators comming from the light bulb to relay

Code

Before you use the source code, you need to download some libraries:

Arduino core for ESP8266 (Read the "Installing with Boards Manager" step)

Ubidots ESP MQTT

Note: If you don't know how to add libraries to the arduino IDE, you can follow this easy tutorial.

Set your development board to NodeMCU 1.0 (ESP-12E Module).

You need to change some variables in the code:

Your SSID (Name of your home Wi-Fi network)

Password of your Wi-FI network

Your Ubidots token

And finally upload your code to the board.

Jason Demo

It works! If you have any questions or suggestions please leave them at the comments section.

Code

NodeMCU Jason Code

/****************************************
 * Include Libraries
 ****************************************/
#include "UbidotsESPMQTT.h"

/****************************************
 * Define Constants
 ****************************************/
/*Replace the empty string
with your Ubidots TOKEN*/
#define TOKEN ""
/*Replace the empty string
with your ssid, eg: "MyHomeNewtwork"*/
#define WIFINAME "" 
/*Replace the empty string with your
wi-fi password, eg: "mypass123456"*/
#define WIFIPASS "" 
/*Replace with any random string,
Ubidots requires it to be unique*/
#define MQTTCLIENTNAME ""


Ubidots client(TOKEN, MQTTCLIENTNAME);

/**********************
 * Auxiliar Functions
 *********************/

/*NOTE PINS ARE FROM THE 
INTERNAL ESP8266 MODULE 
NOT THE DIGITAL PINS FROM THE 
NODEMCU, MORE AT INFO: 
http://www.electronicwings.com/nodemcu/nodemcu-gpio-with-arduino-ide
*/
int outputs[] = {2,4,5,12};
int inputs[] = {13,14,15,16};
int btnStates[] = {0,0,0,0};

//This is called every time we 
//receive an update from the Ubidots server
void callback(char* topic, byte* payload, unsigned int length) {
  //Print the topic (pin) and its server state
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i=0;i<length;i++) {
    Serial.print((char)payload[i]);
  }
  bool reading = true;
  int count = 20;
  String topicPin = "";
  String payloadState = "";
  Serial.println(" ");
  while(reading){
    if((char)topic[count] != '/'){
      topicPin += (char)topic[count];
      Serial.print((char)topic[count]);
      count++;
    }
    else{
       Serial.println(" STRING: " + topicPin);
      reading = false;
    }
  }
  for (int i = 0; i < length; i++) {
    payloadState += (char)payload[i];
    Serial.print((char)payload[i]);
  }
  //Apply server value to pin
  int ledpin = topicPin.toInt();
  int state = payloadState.toInt();
  digitalWrite(ledpin, state);
  Serial.println();
}

/*********************
 Main Functions
 **********************/

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  client.wifiConnection(WIFINAME, WIFIPASS);
  client.begin(callback);
  //Subscribe to all of out Outputs pins
  for(int i=0;i<4;i++){
    char b[2];
    String str;
    str=String(outputs[i]);
    str.toCharArray(b,2);
     //Insert the dataSource and Variable's Labels
    client.ubidotsSubscribe("esp32",b); 
  }
  //Set all of our pinModes and save button states
  for(int i = 0; i<4; i++){
    pinMode(outputs[i], OUTPUT);
    pinMode(inputs[i], INPUT);
    int buttonState = digitalRead(inputs[i]);
    btnStates[i] = buttonState;
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  if(!client.connected()){
      client.reconnect();
      //Subscribe to all of out Outputs pins
      for(int i=0;i<4;i++){
        char b[2];
        String str;
        str=String(outputs[i]);
        str.toCharArray(b,2);
         //Insert the dataSource and Variable's Labels
        client.ubidotsSubscribe("esp32",b);
      }
  }
  //Check if switch has changed state
  //If it did chnage, change the light state and save it to array
  for(int i = 0; i<4; i++){
    int buttonState = digitalRead(inputs[i]);
    if(buttonState != btnStates[i]){
      digitalWrite(outputs[i], buttonState);
      btnStates[i] = buttonState;
    }
  }
  client.loop();
}