Generally, appliances used in our home are controlled with the help of switches. These days, you can see many technologies used in home automation projects. his article presents the controlling of home appliances using DTMF technology.
DTMF is acronym for Dual Tone Multi Frequency. So, just think when you make call for customer care, they will ask you to press 1, 2 or any other number. When you press a number from your mobile, one particular action is happening. All this is because of DTMF. When a button is pressed in your mobile keypad, it will generate a tone of two frequencies. These tones are called row and column frequencies.
Generally, row frequencies are low frequencies and column frequencies are high frequencies. These frequencies for DTMF are chosen in such a way that they don’t have harmonic relation with the others, so that they will not produce same tones. The column frequencies are slightly louder than the row frequencies to compensate for the high-frequency roll off of voice audio systems.
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We have learned that each button pressed in keypad will produce a tone which differs from others. Now we should use these tones for our appliances. So this DTMF encoder is present in mobile. Output from keypad can be converted into digital form using DTMF decoder IC HT9107B. Interfacing of this IC to MCU is show below.
DTMF Controlled Home Appliances Circuit Principle:
The main principle of this circuit is to control appliances like light and fan using DTMF technology. DTMF encoder is present in your mobile and decoder is HT9107B IC. Mobile jack is connected at 1nf capacitor. Mobile jack consists of two wires (Red and black). Red wire is connected to the decoder IC and Black is grounded. When a button is pressed from mobile it generates a tone which is decoded by the decoder IC and it is sent to ATMEGA8 controller. Controller then checks for input and it produces the output according to the code written to it.
DTMF Controlled Home Automation System Circuit Diagram:
This circuit mainly consists of the following components.
- ATmega8 microcontroller U1
- HT9107B IC
- Relay
- AC Load
- Resistors – R1, R2 and R3
- Capacitors – C1, C2, C3 and C4
- Crystal Oscillator X1
Circuit Design of DTMF Controlled Home Appliances:
The decoder IC consists of an inbuilt operational Amplifier. The output of op-amp is given to the pre-filters to separate low and high frequencies. Then it is passed through frequency and code detector circuits, thus 4-bit binary code is latched.
Tone from mobile is sent to op-amp through series of resistor (100 kilo-Ohm) and capacitor (1nf). Pin1 of DTMF IC i.e. non inverting pin is connected to pin4 i.e. Vref. Pin3 is the output of operational amplifier which is feedback to pin2 using 100 kilo-Ohm resistor. 7 and 8 pins are connected to crystal oscillator of frequency 3.579545 MHz. 15th pin is data valid pin it becomes high when DTMF tone is detected else remains low. The process of frequency detection to digitalization of the signal is done by steering circuit consisting of EST, RT/GT, and resistor (10k), capacitor. Pins 11 to 14 produce the decoded output.
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The output pins of DTMF IC (i.e. 11 – 14) are connected to PB0-PB3 pins of controller. Output pins of the controller i.e PD0 and PD1 are connected to relay. Relay output is connected to AC source i.e. light or fan.
Relay acts as a switch. It produces isolation from different parts of the circuit. In our project it is used to switch AC load using 5v which is maximum voltage from controller. Relay used here is magnetic relay.
How to Operate the Circuit?
When the circuit is powered, controller continuously checks the inputs. When ‘1’ is pressed from mobile keypad, decoder IC decodes the tone and produces 1(0001), it is given to microcontroller which in turn produces high output at PD0 pin. PD0 is connected to relay. Relay is used for switching the circuit and thus fan is ON. Similarly, if the received input is 2 fan is switched off. If received input is 3 light is switched on and if it is 4, light is off.
DTMF Controlled Home Automation System Project Output Video:
Download Code
Advantages of DTMF Controlled Home Automation System Circuit:
- One can control home appliances from anywhere.
- It reduces wastage of electricity when we forgot to switch off the lights & fans and gone outside.
- It is very low cost compared to other technologies like GSM.
Limitations of DTMF Controlled Home Appliances:
- No security. Anyone can control the appliances by calling the mobile connected to module.
- Number of appliances is limited as our mobile can generate only 16 tones.
Note:
If you are interested to get code, kindly take some time and answer following questions in the comment section, so that we will send you the code.
- Why you need this project code?
- Are you trying to make the same project or different one?
- Give us more details about your project.
84 Responses
can i connect gsm sim300 modem with a sensor so that it can be used for displaying a message when a person comes to home in home automation projects
yes
it’s very useful project
I am interested in making mini projects
same projecct
can we operate 16 item by using this circuit?how???
It is an interesting project.
can i see the detailed circuit?
in this project how the cal will recvive
the phone you have connected to the development board should be kept in auto answering mode
Interesting project . can I have an detailed report on how to do it
Hi, I need this project code for my college project and I also want to get improved this project.
Hi! We are trying to make a similar project for school, and it would be very useful if you could provide the code for us We will be using a MT8870D Ic instead. Thank you very much!
Hi! We are trying to make a similar project, and it would be very useful for us if you could give us your code. We will be using a different IC (MT8870) and microcontroller. Thank you!
I Just Want It .Its Emergency.Plz Send It to me
i need the project code to complete my final year academic project.
same project
i want to submitt a project in eee day of my university. so i want your code . yes ,my project is same with your project.
if iam out side ..i will cal to that connected mobile who will recive the cal r its automatically recives
in this project ..how the cal wiil b recive
in this project how the cal will recived ..if am cal to circuit connected mobile
I want 2 make this project as my 6th sem college project with a bit modification as like adding a LCD display. It will be a great help if u can send me the codes….
It’s an interesting project to be worked on. I want to make this project as my 6th sem college project with a bit modification as like adding a LCD display…It will be a great help,if u can send me the codes.
I am interesting in it.
Hi.. This project is so good. I want to implement this project as my 6th same project. By using this i have to handle my home devices. For that i want code of this. I like to implement same circuit. Plz i require the code and more details about this project. I have choosen this project from many other projects cause this is very interasting and application oriented project. Thank you. Plz send mail me code.
Good project its help me as a minor project
it was very use full project
I need the same project for more than 10 appliances, can you help me..
You can connect up to 16 appliances…It depends on coding…where are you facing problem in programming part or hardware??
Hi.. This project is so good. I want to implement this project as my 6th same project. By using this i have to handle my home devices. For that i want code of this. I like to implement same circuit. Plz i require the code and more details about this project. I have choosen this project from many other projects cause this is very interesting and application oriented project. Thank you. Plz send mail me code.
I want to prepare this project for assignment.
I am making same project
your idea of controlling home applicances with mobile phone is too good…i am verymuch interested in doing as my finalyear project but with some modification like ..why can”t we take help of instrumemtation amplifier to stop taking calls from numerous receivers…instead only one can operate it .ireally want this code badly so that my keen interest in working on this project is satisfied and can come upon this project as my final year project.please sir send me the code
Code is uploaded..please check the article
you give a good idea about this project we also want to make this project but just some different we add that how we protect it from other if some pre install no one call then it work otherwise not,this project for our final year project. please sir send me the code.
sir your idea about controlling home appliance with DTMF based is to good we make a same project but modification that only some mobile no who are in special contact list call then home appliance work other wise not,we work it for our final year project. plez sir send me the code.
Go through the article.Code is already uploaded.You can download it…
you give a good idea about this project we also want to make this project but just some different we add that how we protect it from other if some pre install no one call then it work otherwise not,this project for our final year project. please sir send me the code. Thank you :))
Can i use the atmega8l-8pu microcontroller??? If so, what changes do i need to make in the circuit??
Iam interested in doing the same project. i selected this project as part of my course work on embedded sytemss & rtos. I want to develop a low cost automation system in order to reduce electrical energy wastage. moreover iot is the future hence.. Iam interested
I’ making this project as my acedemic tasks in engineering so that i needed the code.
i’m implementing the same project as mentioned in above circuit diagram.
plzz send me code asap.
i’ll be thankful for u fo helping me.
Can i use 6v dc relay instead of rtb14024f
Yess that is a relay…
this is trending project also this is my final year project..we are trying to use ic MT8870 as decoder ,also we want to add some security feature to this project.can u please send us the codes of this project so that i could get some help.
Hi.. This project is so good. Iwant to implement this project as my 6th sam project. By using this i have to handle my home devices.For that i want code of this. I like to implement same circuit. Plz i require the code and more details about this project. I have choosen this project from many other projects cause this is very interasting and application oriented project. Thank you. Plz sendmail me code.
i need the circuit daigrams and layouts ..i m doin this project please mail me d ckt daigrams nd layouts asap
what is the frequency of atmega8
I am pursuing for the exactly same project for my college submission. I need the hex code to load it in IC.
We are pursuing for the same project in our college and have completed the circuit part but are having some problems with the coding part. We tried to convert your code version into hex file but it showed some error! Can you please share your version of hex please. Thank you
Can i get the details abouts this project?
Tq.
Im interesting in this project
I need project code for completion of my final year project
i want to know code of this project since i want to design a irrigation motor which can be controlled by dtmf decoder
you gave a idea how to control appliances by using dtmf,now i want to implement a irrigation motor controlled using DTMF.so i require a code to implement it
I have chosen this as my mini project….it would be very helpful if you provide me the code.
I have took this as my mini project.if u provide code it will be helpful
IT SEEMS SO INTERESTING AND I HAVE TO GET DEVELOPED MORE ON THIS PROJECT CAN U PLS HELP ME OUT?…..
I am trying to control home devices by a land phone .I need the circuit diagram and the code. If you can it would be a big help. Thanks in advance.
yes i am making a project similarlly this project for 7th sem minor project
Hey i found this project very interesting. I am planning to do the same project as my 7th sem project as i want to do a project based on microcontoller. So i would require the code to implement this.
It would be really helpful if u could mail me the code and the detailed circuit diagram.
Thank you
I need the project ti complete my final college project
same project
I am trying to make the same project for our mini project in our college.
I am doing the project as give : DTMF based Home Automation.
So, I request you the send the coding for the given project of mine.
your idea of controlling home applicances with mobile phone is too good…i am verymuch interested in doing as my finalyear project but with some modification like ..why can”t we take help of instrumemtation amplifier to stop taking calls from numerous receivers…instead only one can operate it .ireally want this code badly so that my keen interest in working on this project is satisfied and can come upon this project as my final year project.please sir send me the code
i am doing some research projects on DTMF. I choose your project.
I will be writing 6-7 page research paper on this project.
would be thankfull if you mail me complete schematics and the code.
And also we will try to include the feature that only specific people can call.
Thanks.
Interesting project I am also work on this project so plzzz send me the full details
I will be glad if I can be given directives on how to go about the construction and the coding as I drop my mail
I am doing this project as my mini project in 6th semester of my btech .but I don’t have the code.
Can you please send the code of the project.
A link is provided to download the code below output video.
hey can anyone plz give me a report file of that project
Hi.i want to make this project as final year project n try to implement some additional features in same project……so send me the code for this project……I will be thankful to you
Hi monika,We have provided a downloadable link below the output video.Please download the code from there.
I want to enhance my practical skills by doing such mini projects,
so I want the code for this project to implement the same.
bcz m working on this
i need tge code we are dping the same project
I like this project very much and I want to make some changes in it and make it as my mini project
I want to make It as my project with modifications such as in security
hi. may i know the function of crystal oscillator?
i wanted this kit and how much it costs
Sir,do I need to define the operating frequency of atmega8 microcontroller program as given above in Download Code folder program like “#define F_CPU 12000000” just above the #include line?????
what is the external oprating frequency of atmega8 and which crystal oscillator we need to use?
8MHz or 16MHz (with appropriate fuses).
Hi! We are trying to make a similar project, and it would be very useful for us if you could give us your code.
I am trying to make the same project for our major project in our college.
I am doing the project as give : DTMF based Home Automation.
So, I request you the send the coding for the given project of mine.
I want this code for making home appliances based project for my college project exhibition.
Will u plz send me the code ??
I wanna make a similar project to control common home appliances. Please me give me the detailed description along with the circuit
I interested with this project but i want want send more tone dtmf for one command as example : send #01 for light on the lamp and send *01 for light off, so could you send me that code. Thank you
please can i have the code for this project i need it for my college project exhibition please !!!!
I just want to make the same project