Table of Contents
Overview
The report describes a method for creating a DTMF-based home automation system. DTMF, or Dual Tone Multi Frequency, is an acronym. The system enables users to transmit commands to numerous home equipment, including fans, lights, and bulbs, through their mobile phones. Commands are transmitted using a cell phone’s dialling capacity for numeric codes. The system has a relay module and DTMF decoder for controlling any device. The microcontroller receives the programme code. The circuit’s wide operating range is its key benefit. Our home appliances may be managed and monitored from anywhere. Four lightbulbs have indeed been employed in our system to represent AC loads, and a 12 V transformer provides electricity to the circuit.
Components Required Table
| S.No | COMPONENTS | QUANTITY |  |
| 1 | Arduino | 1 | https://www.amazon.in/Scriptronics-ATmega328P |
| 2 | DTMF | 1 | https://www.amazon.in/Mt8870-Decoder-Module-Telephone |
| 3 | Relay | 4 | https://www.amazon.in/Robotbanao-Channel-Module |
| 4 | Angle Holder | 2 | https://www.amazon.in/CONA-2501-Angle-Holder |
| 5 | DC Cooling Fan | 1 | https://www.amazon.in/SunRobotics-Cooling-Cooler |
| 6 | Jumper wires | 40 | https://www.amazon.in/YUVS-Jumper-Wires-female-Pieces |
| 7 | Mobile Phone | 1 | Use your phone |
Block Diagram
Introduction
Develop a system that, with authentication, enables users to operate numerous home appliances remotely using a cell phone-based user interface. employing Dual Tone Multi-Frequency (DTMF) technology to control home appliances.
DTMF (Dual Tone Multi Frequency)
A signalling technique for identifying the keys or, better still, saying the number dialled on a push button or DTMF keypad is called DTMF (Dual Tone Multi Frequency).
Push-button keypads in phones and mobile devices employ a multi-frequency tone dialling system to indicate the number or key that the caller has selected.
DTMF has made it possible to signal phone numbers in the voice frequency band over great distances. As the name implies, DTMF uses a pair of sine waves to represent each key.
Circuit Design and Operation for DTMF-controlled Homes
We can see two groups with varying frequencies in the above figure. A tone is known as Dual Tone Multiple Frequency is produced when one upper and one lower frequency are combined. In this project, dial pad keys like 1, 2, 3, 4, and more are used to manage air conditioning units.
Here, an aux wire has been used to connect a cell phone to the DTMF decoder circuit. Before describing how the project will continue to function, it is important to understand the DTMF decoder’s output for each key that is pressed.
Source Code
#define Relay_Bulb_1 8
#define Relay_Bulb_2 9
#define DC_5V_Fan 10
#define Moble_Change_Control 11
#define D0 4 // DTMF Binary Input D0
#define D1 5 // DTMF Binary Input D1
#define D2 6 // DTMF Binary Input D0
#define D3 7 // DTMF Binary Input D0
void setup()
{
// DTMF Input Diclaration
pinMode(D0, INPUT);
pinMode(D1, INPUT);
pinMode(D2, INPUT);
pinMode(D3, INPUT);
// Output Controls
pinMode(Relay_Bulb_1, OUTPUT);
pinMode(Relay_Bulb_2, OUTPUT);
pinMode(DC_5V_Fan, OUTPUT);
pinMode(Moble_Change_Control, OUTPUT);
}
void loop()
{
// Mobile key pad Done Reading s
int Binary_Input_1=digitalRead(D0);
int Binary_Input_2=digitalRead(D1);
int Binary_Input_3=digitalRead(D2);
int Binary_Input_4=digitalRead(D3);
if(Binary_Input_1==1 && Binary_Input_2==0 && Binary_Input_3==0 && Binary_Input_4==0) // Mobile key 1
{
digitalWrite(Relay_Bulb_1, HIGH);
}
else if(Binary_Input_1==0 && Binary_Input_2==1&& Binary_Input_3==0 && Binary_Input_4==0) // Mobile key 2
{
digitalWrite(Relay_Bulb_1, LOW);
}
else if(Binary_Input_1==1 && Binary_Input_2==1 && Binary_Input_3==0 && Binary_Input_4==0) // Mobile key 3
{
digitalWrite(Relay_Bulb_2, HIGH);
}
else if(Binary_Input_1==0 && Binary_Input_2==0 && Binary_Input_3==1 && Binary_Input_4==0) // Mobile key 4
{
digitalWrite(Relay_Bulb_2, LOW);
}
else if(Binary_Input_1==1 && Binary_Input_2==0 && Binary_Input_3==1 && Binary_Input_4==0) // Mobile key 5
{
digitalWrite(DC_5V_Fan, HIGH);
}
else if(Binary_Input_1==0 && Binary_Input_2==1&& Binary_Input_3==1 && Binary_Input_4==0) // Mobile key 6
{
digitalWrite(DC_5V_Fan, LOW);
}
else if(Binary_Input_1==1 && Binary_Input_2==1&& Binary_Input_3==1 && Binary_Input_4==0) // Mobile key 7
{
digitalWrite(Moble_Change_Control, HIGH);
}
else if(Binary_Input_1==0 && Binary_Input_2==0&& Binary_Input_3==0 && Binary_Input_4==1) // Mobile key 8
{
digitalWrite(Moble_Change_Control, LOW);
}
else if(Binary_Input_1==1 && Binary_Input_2==0&& Binary_Input_3==0 && Binary_Input_4==1) // Mobile key 9
{
digitalWrite(Moble_Change_Control, HIGH);
digitalWrite(DC_5V_Fan, HIGH);
digitalWrite(Relay_Bulb_1, HIGH);
digitalWrite(Relay_Bulb_2, HIGH);
}
else if(Binary_Input_1==0&& Binary_Input_2==1&& Binary_Input_3==0 && Binary_Input_4==1) // Mobile key 0
{
digitalWrite(Moble_Change_Control, LOW);
digitalWrite(DC_5V_Fan, LOW);
digitalWrite(Relay_Bulb_1, LOW);
digitalWrite(Relay_Bulb_2, LOW);
}
}
Output Images
