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Surveillance Car Controlled via DTMF



hello, i'm interested in this project but can u specify me some points

what is reqired voltage and RPM of dc motors used?

is there a difference between L298D and L298n DTMF module?

i would like to use other android phone to control it can u plz assist me with this. thanq


1) I'm using DC geared motor with 100RPM at 12V DC supply.

2) L298D is a motor driver, IC that I'm using for DTMF module is MT8870

3) I'm not sure what are the differences between L298D and L298N..... :p

4) Yeah you can use any android phone as long as apps that are being used are compatible with android version, android version of the phone that is being used in this project is 2.3.6(gingerbread)

I hope this helps you :)

Well, according to my experiments, I have concluded that in L298D the std pin on the DTMF should be kept HIGH and in L298N the std pin on DTMF should be kept LOW.


have you completely done this project?

yup,circuitary is all done ..

but m having a problem with the vnc server!!!


yaa sure u can post ur mail id here ....i wl contact u..... is my email: [email protected]


bro i used L298N can u contact me i have a prob my mail is [email protected]
I need final report of this project kindly send me My email I'd is [email protected]

I dont know about your experiments but STD pin on DTMF is used to keep check, whether a new signal is coming or D1-D4 are showing previous values(they dont get flushed even after input signal has stopped).

So, it has nothing to do with L298D or L298N. According to me difference is in the breakout board and not in the IC, as datasheet of the L298 IC doesnt specify N or D. 


Hi, What all differences should make when we use 12kg/cm instead of 7kg/cm.. Please reply me soon

can i use arduino NANO 3.0 in place of arduino UNO

plz give me your number

hi i am interested in making this project can u please share a higher resolution image of ckt diagram


resolution of image is okay for a circuit diagram, but still if you are facing any problem,

refer this link: githubcom/varun13169/Engineers_Garage/tree/master/Surveillance%20Car%20Controlled%20via%20DTMF

just add a "dot" after github, I dont know why they dont allow legit links here


this is really a great project. I have one question, what is the keypad application that you used in your project?


Thanks Brusk,

keypad application that I used was "DTMF Tone Genrator". Link to the play store is given on 10th point under Requirement section.

this project is supreb can expalin the construion please


Thanks Nishar,

Everything is explained very clearly under describtion.
If you still have any doubts please be specific.

your project is very good, but there is a problem i am facing while executing this same project. i cant use DTMF keyboard pannel from my laptop. Video footage is ok.

hope to get u as soon as possible.

Thanks Aminul,
Is your phone rooted?
Rooted phone is required in order to use VNC server.

yes my phone is rooted.. can i contact you personally? here is my email id [email protected] actually there is something i have to discuss with you.

You can ask questions here also, just post them and i'll do my best to answere them.

did you use airdroid mirror to access DTMF?

no only "DTMF tone genrator" app was used, nothing else

it would be gratefull to me if you specify the root app which you have used, shall i root my 2.3.6 android. how shall i access droid vnc . even after rooting my phone its showing me no devices found. help me out need a speedy reply

Hi!!...ur project is superb!!...just one question... How did u get the 5 volts supply needed for servo and arduino and dtmf?

Thanks Akshay,

Answere to your "one question" is hidden in Pic 1 and 2, closely look at them there are three 9V batteries two in series for DC motors and one for the arduino and servo(5V from the regulator) and DTMF dont draw much currect so I gave power to it directly from the arduino.
And I've connected there grounds to provide same reference level.

I hope this answeres your one question :p
Do like and subscribe me on Youtube to show your support

hello, i'm interested in this project.. Im just a beginner and I dont have any idea yet... Can I have the codes that you used or do you have instructions steb by step on this project?. Please help me. Thankyou in advance.

Hey, everyone was a beginner once, just start doing things and your knowledge level will automatically increase.

For detailed description checkout "Describtion" tab under "Table of Content" and for the codes checkout the "Source Code" tab. While following describtion if you run into any problem just post here in the comments and I'll try my best to resolve it.

Show your support by Liking and Subscribing me on Youtube

I bought a dtmf module but i dont find any audio port there 

You won't
There isn't any 3.5mm or any other audio port

There are two pins for audio input, therefore I used a 3.5mm(2 segment) jack to connect it from my phone

my L298 module doesn't have pwm pin.

need a speedy reply

L298 module should have PWM pins

But its okay if your module doesn't have one as in this project you dont require them, just leave those pins slots empty on Arduino and connect rest of them.

Now show your support by speedly liking and subscribing my youtube channel

!! Peace !!

first of all thanks a lot for the speedy reply.

i would like to mention some of the difference in my dtmf module 

1)instead of STD i have v,what does v depict?

2)it is given as + ,gnd

better i would mention all the pins available in dtmf they are +5,gnd,v,D3,D2,D1,D0 and on the left side i have +,g.

can you please help me out.where do i connect my phone,at the back of my module i can see "I/P"i suppose this is input but it is solded to two capacitors

No problem at all
Just google MT8870DE, open its image

In it map Pin15(std), if it maps to 'v' then yes its STD pin.

+5v gnd and D3...D0 are same, no need to worry about them.

Now, for input connect one wire from the jack to GND and other to i/p pin(most probably it'll work)
If it doesn't then connect other wire to Pin2(In-).

it is quite different from the model shown in net.i don't know what does the i/p present at the back of module signify. My dtmf has an ic8870, 5capacitors , 4resistors ,led and crystal oscillator.

is my dtmf module apt for this project?are we providiing audio input to the capacitor?is that so? if yes then the i/p at the back is my i/p. 


you were right, actually we have v as STD (v is connected to the 15 th pin of ic 8870) and for audio we  have pins(+,g) instead of port . i doubt how to connect them to our phone.shall i cut and crop my headset and solder the other end.thank you so much



Yup you need bare wires to connect it to DTMF module,
Althought I didnt waste any headset of mine :p , instead I bought a 3.5mm jack it cost me around Rs 10.

this is the first time i have started working with arduino. 

even the simplest program can't be uploaded. i really don't know what's the issue?please help me out.


I want to do this project but I don't have any idea about arduino. Moreover my friend told me that I will face problem using DTMF decoder module regarding its specification like how much input should we give and all. So can you please describe your project in detail.


I've already explained everything in detail.
Be specific about what you want to ask


when i tried to download vnc app in my phone i was unsuccessful.

but did that using laptop. how shall i do it with my phone.

we are pressing the security pin using our lap, is that so?

we are connecting our phone with lap so can you mention the working range?

need a speedy reply


VNC app require a rooted phone

And range depends on the wifi AP that you are using

sir i tried but after downloading the vnc server in phone and when i opened vnc client from my laptop, it asked for vnc server, what shall i specify there.

i'm having trouble usintg vnc server.
i installed the droid vnc server on my android phone.
and i opened the vnc viewer on my computer
how do i connect the two? i cant find a Ip adress on the vnc server app. should i switch on hotspot/wifi on the phone?
im trying to make the car without internet connection

Yeah in your case you'll need to make a Hotspot, and connect your computer to it.

can u please tell how much cost it will be ?????? and can u tell app links...there are many apps naming same


sir suggest me a app to root my phone. iam unable  to root my phone