Published August 21, 2020 © GPL3+

Smart Switch Controller

Control wall mounted switches smartly using three different methods - android app, ok google voice command and hand gestures.

IntermediateFull instructions provided3 hours1,912

Things used in this project

Hardware components

Bolt IoT Bolt WiFi Module

Arduino UNO

l293d motor driver

Breadboard (generic)

SparkFun Ultrasonic Sensor - HC-SR04

LED (generic)

Temperature Sensor

Resistor 1k ohm

9V battery (generic)

servo motor

Jumper wires (generic)

DC Motor, 12 V

Software apps and online services

Arduino IDE

MIT App Inventor 2

Bolt IoT Bolt Cloud

IFTTT Web service

Hand tools and fabrication machines

Soldering iron (generic)

Hot glue gun (generic)

Story

1. INTRODUCTION

Have you ever felt like controlling your home appliances such as fan, light, geyser, etc. working on wall mounted switches remotely? Well, you could always use the relay module to control them but what if you want to use this device on a different switchboard? It will be quite difficult to disconnect the relay module each time to control switches in different rooms of house. So I came up with this project using a servo motor which toggles the wall mounted switches ON and OFF in 3 different remote control ways i.e Google assistant, Android app and Hand gestures. A simple arrangement using one more motor helps to move the servo motor from one switch to another. In this project I have demonstrated control of 2 switches.

2. WORKING

3. BUILDING THE PROJECT

Let us now see step by step guide to building the project.

Step 1:Getting the Bolt API Key and Device ID

Now click on the API Tab and under the section for Generate Key, click on Enable.

Next click on the copy button to copy your API key. Your API key will may look something like this: f1f918e9-d9c2-4e5b-aed0-b7cb743f74cf

Step2:Creating the UART Control Command

Since we are using Arduino Uno in this project to perform the functions, we need to send a string to the Arduino board from Bolt Wifi module. This can be done by using serial Write command under UART commands.

Click here Bolt Cloud go to Docs Tab -> API Documentation -> UART Commands API -> Send Serial Data Output, to understand how to create a API command link to send a string to Bolt.

The structure of the command is:

https://cloud.boltiot.com/remote/API_KEY/serialWrite?data=STRING&deviceName=DEVICE_ID

The parameters that you need to replace are:API_KEY: You can get it from API tab on cloud dashboard.STRING: This is the string that we will send to Arduino through Bolt. We will decide which strings to send, later while writing the code for Arduino. DEVICE_ID: The id of your device. You can get it from cloud dashboard.

The sample command to send a string "f" over the TX line of device having ID BOLT13819450 is:

https://cloud.boltiot.com/remote/f1f918e9-d9c2-4e5b-aed0-b7cb743f74cf/serialWrite?data=f&deviceName=BOLT13819450

Make sure that you change the API Key to your own API Key and device ID which you got in the previous step.

Since we will use three methods i.e Google assistant, Android app and Hand gesture for controlling the switches let us see how to setup each method.

Step3:IFTTT integration via Google Assistant and Webhooks

Go to IFTTT to create a new applet by clicking here

Login using your Gmail account. Make sure you use same account which you'll be using on your mobile to interact with Google Assistant.

Click on '+This' to create the trigger.

Choose Google Assistant -> Say Specific Phrase

1 / 2

Type the phrase you want to trigger the action. Make sure to specify the trigger command in different ways for example I used

a) turn on the light

b) put on the light

c) put the light on

Click on 'Create Trigger'

Click on '+That'

Select Webhooks and then Make a web request.

1 / 2

Enter the API URL you got in the previous Step. Make sure that you change the API Key and device name.

Method will be GET

Content type will be Application/json

Here is how your screen will look like

Click on 'Create Action' and then Click on 'Finish'

So whenever we want to turn on the lights, we send a string "f" to the TX line of Bolt.

Now you have to follow same procedure to send strings "d", "s", "a" to turn off the lights, turn on the fan and turn off the fan respectively. Use suitable phrases.

The sample code for turning off the light would be:

https://cloud.boltiot.com/remote/f1f918e9-d9c2-4e5b-aed0-b7cb743f74cf/serialWrite?data=d&deviceName=BOLT13819450

That's it. You are done.

Now wake your Android phone by saying "OK Google" and say the phrase you had set while creating the trigger to use your appliances remotely.

Step 4 :Creatingan Android application using MIT App Inventor2

Go to MIT App Inventor by clicking here. Create a free account and click on Create Apps! Then click on Start new project.

Below is the design of the app I created. You can view the components I added on the right side.

After the design is complete, click on the Blocks tab besides Designer tab. And add the blocks to get the following sketch on Screen1.

Create four more Screens with names LightsON, LightsOFF, FanON and FanOFF.

Below is the image of Screen LightsON.

Create similar blocks for rest of the three screens.

Remember to change the URL highlighted in red color with the commands we created before that is:

https://cloud.boltiot.com/remote/API_KEY/serialWrite?data=STRING&deviceName=DEVICE_ID

The parameters that you need to replace are:API_KEY: You can get it from API tab on cloud dashboard.STRING: This is the string that we will send to Arduino through Bolt. ( "f", "d", "s", "a")DEVICE_ID: The ID of your device. You can get it from cloud dashboard.

Get the.apk file from BUILD tab and your android app is ready!

Step5:Hardware connections

The connections are as follows:

Arduinopin2 ---> Input pin Servo.

pin 3, 4 --> Input 1, 2 of L293D motor driver.

pin 7 ---> LED

pin 11 ---> Echo pin Ultrasonic sensor

pin 12 ---> Trig pin Ultrasonic sensor

pin A1 ---> Output pin of LM35 temperature sensor

pin TX ---> pin RX of BOLT wifi module

pin RX ---> pin TX of BOLT wifi module

Give 3.3v, 5v and Gnd for necessary components as shown in schematic diagram.

Step 6:Upload code to the Arduino board

Upload the below given code into the Arduino.

NOTE: WHILE UPLOADING THE CODE TO THE ARDUINO BOARD DISCONNECT THE TX AND RX PINS TO THE BOLT MODULE.

4. CONCLUSION

That's it! Now you can make a similar hardware arrangement as I made as per the need of your switchboard.

Use the google assistant or android app or even hand gestures using ultrasonic sensor to toggle on and off the switch positions you have programmed.

Code

Arduino code for the project

#include <Servo.h>             //Servo library
Servo servo;                   //initialize a servo object for the connected servo                  
int angle;                     //angle of servo
#define motp 3                 //movement motor
#define motn 4
#define eco 11                 //distance sensor
#define trig 12
#define led 7                  //indicator led
long duration;                 
int pos=1,temp,tempC,distance,tym=0,l=0,f=0;
float t=0;

void setup() 
{ 
  Serial.begin(9600);
  servo.attach(2);             //attach the signal pin of servo to pin2 of arduino
  servo.write(28);             //set the initial angle of servo to 28 degree  
  pinMode(3,OUTPUT);           
  pinMode(4,OUTPUT);
  pinMode(10,OUTPUT);
  pinMode(trig,OUTPUT);
  pinMode(eco,INPUT);
  pinMode(led,OUTPUT);
} 

  
void loop() 
{ 
  if(tym > 10800 && (l>0 || f>0))             //after the last control if 3 hrs are passed automatically turn off all apliances
  {
    if(pos == 1){
       tog_off();
       fanP();
       tog_off();
       lightP();
       t = 0;
       l=0;
       f=0;
       tym = 0;
      }
    else if(pos == 2)
      {
       tog_off();
       lightP();
       tog_off();
       t = 0;
       l=0;
       f=0;
       tym = 0;
      }
  }
  temp = analogRead(A1);       //measure the temperature of the room
  temp = (temp*500)/1023;
  tempC = temp;
  
  
  if (Serial.available()){
    char x = Serial.read();    //character read from bolt cloud
    if(x == 'a'){              // case 1 fan off
      digitalWrite(led,HIGH);
      delay(100);
      digitalWrite(led,LOW);
      if(pos == 2){
       tog_off();
       t = 0;
       f=0;
       tym = 0;
      }
      else if(pos == 1)
      {
       fanP();
       tog_off();
       t = 0;
       f=0;
       tym = 0;
      }
    }
    else if(x == 's'){         //case 2 fan on
      digitalWrite(led,HIGH);
      delay(100);
      digitalWrite(led,LOW);
      if(pos == 2)
      {
       tog_on();
       t = 0;
       f++;
       tym = 0;
      }
      else if(pos == 1)
      {
       fanP(); 
       tog_on();
       t = 0;
       f++;
       tym = 0;
      }
    }
    else if(x == 'd'){         //case 3 light off
      digitalWrite(led,HIGH);
      delay(100);
      digitalWrite(led,LOW);
      if(pos == 1){
       tog_off();
       t = 0;
       l=0;
       tym = 0;
      }
      else if(pos == 2)
      {
       lightP();
       tog_off();
       t = 0;
       l=0;
       tym = 0;
      }
    }
    else if(x == 'f'){         //case 4 light on
      digitalWrite(led,HIGH);
      delay(100);
      digitalWrite(led,LOW);
      if(pos == 1)
      {
       tog_on();
       t = 0;
       l++;
       tym = 0;
      }
      else if(pos == 2)
      {
       lightP(); 
       tog_on();  
       t = 0;
       l++;
       tym = 0;
      }
    }
  }

  if(tempC >= 35)              //temperature gone above 35 deg C turn on the fan
    {
      if(pos == 2)
      {
       tog_on();
       t = 0;
       f++;
       tym = 0;
      }
      else if(pos == 1)
      {
       fanP(); 
       tog_on();
       t = 0;
       f++;
       tym = 0;
      }
    }

  if(l>0 || f>0)
  {
    tym = tym + 0.4;
  }

  manual();                   // check gesture controls
    
  delay(100);                 // for auto positioning the servo after 60 sec of use
  t = t + 0.4;
  if(t >= 60 && pos == 2){
    lightP();
  }
}

void lightP()                 // function- light position
{
  digitalWrite(motp,HIGH);
  digitalWrite(motn,LOW);
  delay(13000);
  digitalWrite(motp,LOW);
  digitalWrite(motn,LOW);
  pos = 1;
}

void fanP()                   // function- fan position
{
  digitalWrite(motp,LOW);
  digitalWrite(motn,HIGH);
  delay(13000);
  digitalWrite(motp,LOW);
  digitalWrite(motn,LOW);
  pos = 2;
}

void tog_off()                //toggle off
{
  servo.write(0); //off
  delay(1000);
  servo.write(28);
}

void tog_on()                 //toggle on
{
  servo.write(50); //on 
  delay(1000);
  servo.write(28);
}

void manual()                //gesture control
{
  digitalWrite(trig,LOW);
  delayMicroseconds(2);
  digitalWrite(trig,HIGH);
  delay(200);
  digitalWrite(trig,LOW);
  duration=pulseIn(eco,HIGH);
  distance=duration*0.034/2;
  if(distance<=20)            //if distance less than 20cm turn off light and fan
  {
    digitalWrite(led,HIGH);
    delay(100);
    digitalWrite(led,LOW);
    if(pos == 2)
      {
       tog_off();
       lightP();
       tog_off();
       t = 0;
       l=0;
       tym = 0;
      }
    else if(pos == 1 && f>0 && l>0){
       fanP();
       tog_off();
       t = 0;
       l=0;
       f=0;
       tym = 0;
       lightP();
       tog_off();
      }  
    else if(pos == 1 && l>0){
        tog_off();
        t = 0;
        l = 0;
        tym = 0;
      }
    else if(pos == 1 && f>0){
       fanP();
       tog_off();
       t = 0;
       f=0;
       tym = 0;
       lightP();
    }
  }

  else if(distance>=20 && distance<=40)        //if distance is 20cm to 40cm turn on the light
  {
      digitalWrite(led,HIGH);
      delay(100);
      digitalWrite(led,LOW);
      if(pos == 1 )
      {
       tog_on();
       t = 0;
       l++;
       tym = 0;
      }
      else if(pos == 2)
      {
       lightP(); 
       tog_on();
       t = 0;
       l++;
       tym = 0;
      }
  }
}

Credits

archit borkar

2 projects • 6 followers

Mechanical Engineer Robotics enthusiast IoT and ML enthusiast Product Design and Animation

Smart Switch Controller

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

1. INTRODUCTION

2. WORKING

3. BUILDING THE PROJECT

4. CONCLUSION

Schematics

Schematic diagram

Code

Arduino code for the project

Credits

archit borkar

Comments

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Smart Switch Controller

Smart Switch Controller

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

1. INTRODUCTION

2. WORKING

3. BUILDING THE PROJECT

4. CONCLUSION

Schematics

Schematic diagram

Code

Arduino code for the project

Credits

archit borkar

Comments

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