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Make a Simple RC (Remote Controlled) Robot Car

Whether you are an engineering student building a multi terrain vehicle or an electronics hobbyist trying to impress people with your skills, making a RC robot car (wireless)  is much better than the wired robot which you will have to tail while driving.

This is not exactly a robotics project. By definition, a robot is something that makes a decision based on some external parameters. There is one hell lot to do before going around telling people ‘I build robots’ but hey, you got to start somewhere right?


We will discuss a basic ‘Land Rover’ with nothing. Well not exactly nothing, but nothing complex. As I mentioned earlier this is a really simple project, so simple that not even have an embedded computer (microcontroller) in it.

The emphasis is just on the mechanical design and some basic circuitry. We learn the interface of the commercially available RF transmitter and receiver module coupled with HT12E and HT12Dpair (Encoder/Decoder) to transfer data over the air to the motors in the our robot car.

Things you will need:

Most of the components that we will be using are really common and can be bought in local electronics stores. Here is an list of all the hardware items that you will need for this project.

hardware requirements


And in terms of electronics, you will need the following major components. You may also need some other basic components such as resistors and capacitors but we will discuss them as and when we get it.

electronic requirements


Other than the above components, you will need a basic supply of tools, soldering iron, and related stuffs.

So lets get started!!

Working Logic for the RC Robot Car

Here is a flowchart to help you understand the working logic of the robot car. First we will go over the basic idea of the RC car and the working logic that is involved in the car. There are two blocks, the Transmitter (remote control) and the Receiver (robot car).

RC Robot Car block diagram

On the transmitter side, you have the switches to give the digital inputs to the encoder IC. The encoder then encodes this data and sends it to the the RF Transmitter module.

On the receiver side, you will have the RF Receiver which receives the encoded data and passes it on to the decoder. The decoder decodes the data and sends it to the motor driver IC to drive the motors.

Understanding Datasheets

The next step is to learn how to access the data sheet for the components that you are using. Its actually not that big a deal, just Google the component name and you will find links to the datasheet.

The data sheet or spec sheet is a PDF document that is provided by the manufacturer to give us a better understanding of how the component actually behaves. The real tricky part is to find what you are looking for in the PDF file that you just downloaded.

Reading and understanding the data sheet is a skill that any electronics enthusiast should master. I suggest you read the article “Are you reading the datasheet? What to look for and how to find them!” to learn how to read and understand datasheets.

So the point is spend enough time with the datasheet. You can be almost be 100% sure that every minute was well spent.

Differential Drive Algorithm

There are a lot of different types of drive algorithms for driving robotic cars. One such method is the differential drive method.

I know it sound fancy but that’s no big deal. We will be using only one pair of motors to drive the car. Check out he video for seeing how the hardware is connected. We will just have one castor wheel asides from the two motors and it will be used to give mechanical stability to the robot car.

Now the obvious question is how will the car change direction if it has only two wheels. That is when the differential drive algorithm comes in the picture. The direction control is achieved by rotating one of the wheels in one direction and the other in another direction. The following table might give  you a better understanding.

Left Motor Right Motor Direction
Front Front Front
Front Back Right
Back Front Left
Back Back Back

As you should have guessed, the car will go front or back if both  the pair of motors operate in one direction and left or right if they operate in different directions.


RF Transmitter and Receiver Module

Now here is what the RF transmitter and receiver modules will look like. There are a verity of manufacturers so don’t panic if your modules are looking different. Even the frequency in which they communicate should not be a problem as long as both the receiver and the transmitter are of the same frequency. All modules are Pin and Pad compatible. But there are some modules that have inverted numbering, like first pin will be last pin and second pin will be second from last and so on.



Making the RF Transmitter (Remote Control)

Now for the transmitter circuit, you will have to bear in mind that this is your remote. So try to make it as handy as possible (in case you are making one). Trust me, the last thing you want is a remote that is too big/heavy to carry around. Make a good closure for this circuit.

The HT12E encoder are 12 bit encoders that is they have 8 address bits and 4 data bits. The address bits can left open or pulled low. In the circuit below, you will see that each of the address pins (A0 to A7) are connected to a switch. So if the switched is ON then that line is connected to GND (Vss) otherwise the pin is left floating.

The TE (transmit enable) is a active low input to the IC. This enables the transmission. So when the switch connected to pin 14 is pressed, the 8 address bits along with the 4 data bits (AD8 to AD11) are serially encoded and sent out at the DOUT pin.

For our application (RC robot car) we will connect TE directly to GND as we have to keep sending the data as and when they arrive to the rc car.

Unlike the receiver circuit, this does not need to have a beefy battery. You could power this circuit with a 9V battery.

Click on image to enlarge it!

RC car transmitter schematic

Making the RF Receiver Circuit with Motor Driver

This is the circuit diagram for the receiver. It handles the RF reception as well as the the motor drive.

The address pin in the decoder (HT12D) behaves just like that of the the encoder. The data is received at the DIN pin from the RF receiver circuit and then this data is checked 3 times (according to the datasheet the data is transmitted 3 times and received 3 times and only if all 3 times the data is same it is decoded) and then decoded and IC checks if the address pin connection of the encoder is same as that of the decoder. If the address configuration of the decoder matches that in in the received data (from encoder) the data is decoded and latched on to the data pins (D8 to D11).

This decoded data is then send as control signals to the motor driver IC. L293d a dual H-bridge motor driver to be short. It is used to drive the motor in both forward and back ward direction. Read about the basics of DC motor drive and their speed control to get a better understanding of this concept.

The VT (valid transmit) pin is used to indicate if there is a valid transmission between the encoder and decoder. This pin can be left open or like in the circuit below, an LED with series resistance can be used to give a visual indication.

Click on image to enlarge it!

RC car receiver schematic

PCB Art work

I took some time to create a small PCB layout for the above two circuits. You can download the source file for the eagle designs and printable PCB artworks from here. I’ve never done any circuit design as a profession. This is a skill that I picked up somewhere on the run and its rather primitive. So this might not be the best layout possible but it did work for me. I’m willing to accept any help in improving this design (write to me) to help the others.

Update (April 2016): I will be unable to support this design as I have lost the original source files. Please use them only as a reference to your own design. And if you do make one good enough to share, contact me to put up your work here.

Video Demonstration

This is a video that I have made documenting the entire process of making the RC car.  If you have read all the points that I have mentioned so far, nothing I talk about in this video will be new to you. I just made this video to give you a better understand the steps involved in making you on RC robot car.

And please excuse my poor video making/editing skills. I am yet to master them.

Testing your Circuit

Since this post was published, readers have have run into various kinds of problems while trying to make the remote controlled robot car. Most of the time the problem they encountered was in RF Transmission and Reception section. It also fell into specific categories when the problem was not in the RF section.

Please read the article on how to test your RF transmitter and Receiver circuit in case there is a fault.

I strongly suggest you to read the post Circuit Debugging – Tips Trick and Techniques before attempting to make your own rc robot car. If you are still having any doubts, post your comment in that article and I will try my best to help you out.

In the mean time you might want to read about some more advanced robots that we have in our Robotics Archives. For making any robot you should have a reasonably good knowledge on embedded systems and basic electronics and mechanics.

You might wanna check out these posts for your future projects!!

That’s all for a getting started to robotics (well it is not exactly robotics) There is a lot more to learn beyond this point. This should have cleared some of the basics up for beginners and a total waste of time for the advanced readers :) anyway, since its all done lets feel happy about it in either cases.

About Siddharth

Siddharth is a Firmware Engineer, techie, and a movie-buff. His interests include, Programming, Embedded Systems, Linux, Robotics, CV, Carpentry and a lot more. At times, you could see some of his sunday projects converge on release quality. You get to know him on the following social channels.

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  • Hey, I saw you used a RF receiver right ? 3 pin RF receiver and the transmitter is at your remote control. So how do you know whch herts are the remote control giving out ?

    • Hi Vincent, The RF transmitter has 4 pins and receiver has 8 pins. I think you are speaking of the TSOP1738 IR receiver. Is that what you are asking about?

      • Yes ! I thought you using that ? Or you are using the 433KHz transmitter receiver module ?

        • The post describes the use of RF module. I did not have a video of that car (I made it quiet some time back) so, I just posted the one that use a IR receiver as they physically look alike and worked exactly the same way.

      • adarsh jaiswal

        hey siddharth i have done everything right ….no mistakes have been made by me while making the circuit still my circuit is not working……even my led is not glowing …..plzzz help it is very important.

        • Hey Adarsh, Have you read my post on testing your RF circuit? Please read it and follow all the steps listed there. After that tell me where exactly the problem is arising.

        • adarsh jaiswal

          siddharth i performed the experiment and the data is encoded through the help of wires……all my leds are glowing.

        • So when you give GND to one of the encoder inputs, one of the LEDs should turn OFF. Is that the output you are getting? If so what about the other steps? please be more descriptive for your own sake.

        • adarsh jaiswal

          yes when i am grounding pin 10 1st led is switching off when im grounding pin 11 the first and last leds are glowing when i am grounding pin 12 3rd no led is switching off and when pin 13 is grounded the fourth led is switching off as shown in the video.

          we need to ground the encoder ic or the decoder ic because i think so i performed the experiment with the decoder ic by grounding the pins and when i performed the same with the encoder ic there was no change in the leds.

        • If you see the changes then the encoder and decoder IC is working fine. Now all you have to do is check the other possibilities that are listed in that post. If its still not working most probably you are making some connection mistake or the RF transmitter receiver module is not working.

          You have to give input in the encoder and see output in decoder. It will not work the other way round.

        • adarsh jaiswal

          hey siddharth you told that the motor data inputs coming from ht12d will be connected to in1,in2,in3 and in4 but what i saw in yor diagram that instead of connecting date input coming from pin 10 of ht12d to in1 you have connected it to en1….pls explain.

        • Adarsh Jaiswal, Thanks for spotting the error. I have updated the circuit diagram with the corrected version.

      • dhruv vasu

        hi, i tested this and it is nice

    • Ok, now I get you.. The TSOP receiver last two digits denote the frequency in KHz. So here, 38KHz and the first two digits are used to denote the type of the output.

      • dhruv

        Can u plz help me I cant understand tha a b c d and where u hav used 2 dpdt switches? If 1 switch is in receiver and 1is in transmmiter. Then how one switch in receiver can control the car and turn??? Please please reply fast.

      • adarsh jaiswal

        whatever you told is right but i have grounded the the pins of ht12d for changes not the ht12e and when i gave input to 10,11,12 and 13 pin of ht12e there was no change in the leds……i am getting quiet confused plzzz help.

        and my led is also not glowing ……when i had run the l293d motor driver ic test then it did not show vcc2 in multimetre rather it showed some very less output voltage.

        can you send me the pcb circuitry for the project so that i can get it made for my convienience.

        • I have no idea of such a problem. Quite frankly, I have never tried it. I will build the circuit again and see if I get the same results.

        • adarsh jaiswal

          siddharth i have made the circuit 3 times with no error still my power led is not switching on and there is no output voltage in the l293d

        • Like I said, I have never come across this kind of problem while working with the encoder and decoder. So I cannot be of any help without physically seeing the hardware. One suggestion though, please probe the DOUT pin of the encoder with a scope and see if you are catching anything.
          About the motor driver, it can be easily damaged. Please try to replace the IC with a new one and see if that works.

        • adarsh jaiswal

          do i need to ground the addressing pins of the encoder and decoder if yes then tell me which pins.

        • No you dont have to ground it. Just leave those pins open.

  • hey man it was very useful thanks….. and i have a doubt.whats that red box that u have connected to the (d8 d9 d10 d11) pins in HT12D in RF receiver schematic. Is that the receiver on/off switch. pls tell me what it is………. well thanks in advance…..

    • Hi Sisir Kumar,

      I am glad you found the article helpful. That red box is a male pin header symbol in Eagle. It is not really essential and can be omitted. But it comes in really handy when debugging in 2 ways.

      1) Instead of connecting the motors to check if there is valid transmission between the receiver and the transmitter, you could just connect those pins LEDs and see them go ON and OFF.

      2) Sometimes you could have bricked your L293d (trust me, its really easy to brick it) and the motors may not work due to this issue. You will end up debugging the FR transmission and reception for ever with no luck.

      My suggestion, adding that berg connector will take up less than 5 minutes and save a lot of trouble let it be there even if things work as such.
      Good luck.

  • prabhat

    hey,I made this project and controlled i through my laptop but my problem is motors are producing electric noise that is interfering with my receiver module,how can i stop that?also I want to increase its range like 1 km but there are no such products in 433 mhz ASK module,so how can I increase it’s range?

    • Hi Prabhat, Thanks for asking this question. I’m surprised how I missed dealing with this issue in the post. I will update it soon with more details. For time being you can do the following,

      1) Place the receiver and the electronics as far away from the motors as possible.
      2) Add a Low pass filer to the motor circuit. (the simplest way to connect a .1 uf capacitor parallel and close to the motor terminals)
      3) Provide a metallic enclosure to the motors and ground it at one spot.

  • Thank you very much………………………….

  • hey bro.. i hav another doubt in the receiver schematic… do i hav to make power supply for both tx & rx separately. And in rx schematic at the right end there are 2 red boxes, are they motors or somethin else….. pls help…….. thanks in advance…….

    • Hey, yes you have to make a separate power supply for the RX and TX. And yes, those red boxes are (as you guessed) for the motors.

  • prabhat

    Hi siddharth,as I have already stated you my problem about electric noise,Will changing frequency of module help me ,like using 2.4 GHz module instead of 433 MHz?

    • Yes, that should help you. But that is a really costly solution for a simple problem. Do you really want to invest in a new transceiver? I would suggest you to do this as the last resort, after trying all the other methods that we discussed earlier.

  • I finished the rx circuit as per your circuit diagram. but when i switch on the battery supply the 470uf capacitor got burnt. I used 12v 1.3amps lead acid battery…. is there a problem with the battery or in the circuit or any other …………………….? pls help thanks in advance

    • What is the voltage rating of the capacitor? Rule of thumb is that you should have it rated at lease twice the maximum voltage. If you fail to have this, the capacitor may be damages. Besides are all the other connections correct? Check your soldering for any crossovers.
      Good Luck!!

  • yuva

    Hi siddharath I have a feeling that is nagging my mind several times..If I use rf transmission will I not run into a problem with interference in a robotic event were every body uses a similar freqz whether it is 343 or 433mhz…and why not zigbee is it better alternative.

    • Hi Yuva,

      Yes, that is one of of the risk factors. Your HT12E and HT12D should take care of some amount of error reduction with the address bit settings. But you can always implement some software routines to be sure that it’s ‘your’ remote that is communicating with the robot.

      Remember the frequency may be the same but the robot can always expect for a specific kind of input be be recognized as a a valid transmission.

      Say, there there has to be a “1234” before every transmission. You can be sure that none of the robots there would be programmed to be send you such a signal. Ergo, your communication with the bot will never fail.

      Again this is just my way of doing it. If you can come up with something new please feel free to share it with us.


    • prabhat

      use address pins in HT12E and HT12D so that your transmission doesn’t mix up with others.just connect address pins to ground to enable them,for example connect 1,2,3 pins both in HT12E AND HT12D to ground,so that only these two are connected.

  • Abhishek

    what about -ve terminal supply in both pcb
    what is gnd
    and what is x3-1 x3-2 etc ?? in itansmtr

    • Hi, The Gnd bus should go to the negative terminal of the battery. There are 4 pins in the transmitter as you can see in the image. The pin description is given in the module itself. The x3-1 x3-2 etc are insignificant and are just naming conventions used in the Eagle schematic editor.

  • Abhishek

    can u post clear nd well explained diagram bcs i have to made this in 1 week or send me all detail

    • I’m sorry, I feel that I have given all the details in the post itself. What kind of details are you expecting?

  • Abhishek

    and how could i knw about the terminal (-ve) for connecting to 12 or 5 volt

    • Abhishek, May I know what subject you major in? If its not in electronics, I suggest you should have some exposure to reading and understand schematics before you start making anything.

      The ground line is common for both the power supply. Please read about circuits and networks and their conventions. Like I said, for a trained eye, its all there in the post.


  • Abhishek


  • prabhat

    hey siddharth,I have decided to add capacitors to leads to reduce noise,but how can we select right value capacitor for this?my motor is rated 12v and 700ma at maximum torque. Is there some kind equation for this? I can even calculate RPM if needed.

    • Hey, just use .1uF capacitors. Its standard practice to use them as decaps. l’m sure there is much more than that to it, but for all pracical purposes you should be fine.

  • Sandeep

    Hello, I am new to this. Could you please guide me as to how ho make the entire thing myself.
    Also what is the 1M connected to pin 15-16 of HT12E. Is it a Resistor of 1Mega Ohm. What is the power rating of the rsistor?

    • Yes that is a 1 Mega Ohm 1/4 watt resistor.

  • Sandeep

    what is the type of switch used with the Power Supply

    • Hi Sandeep, In the schematic I have use a normal click to ON/OFF switch. You can replace it with any switch available near your place.

  • I must have to make this, because the way l see, this is one of the simplest. Keep it up!

  • hi, please can i add a phone camera to the receiver and how can i connect it

    • Paul, I am not sure if it is even possible. What do you mean by a phone camera? how can you connect it to the robot? are you planing to detach it form the phone and then connecting it to the bot? if so I would not recommend it. But there are other ways to add camera to your robot. There are a lot of commercially available wireless cameras that can be surprisingly cheaper than what you can make.

  • gokul

    hi.. can i use IR transmitter and receiver pair instead of RF??… In that case how to connect the two pins of IR receiver and transmitter

    • Gokul, Just IR transmitter or the IR detector can almost never be able to communicate reliably even for very short distance like 50 cm. For all practical purposes you will have to control the robot from atleast 1m away.
      So for doing that you will have to send encoded IR signals and use a IR receiver like the TSOP receiver to decode the signal. This is what your commercial appliance remote is doing for the control. This way there is almost no way to mess the data being sent.
      I will soon write something on this. Subscribe to embedjournal.com and we will let you know when the post is ready.
      Hope this helped you to an extent.

  • how costly is this?????????????

    • It should cost you anywhere form 800 to 1200 INR depending on the cost at your local market and how much you want to DIY.

  • hi siddharth.
    What about the breaks to the robot car.

    • Hi Gaurav, the robot moves when there is a signal from the remote. If there is no signal then the robot does not move or it breaks.

  • actually m going to participate in a robo race in forthcoming week.
    m asking if i would need to apply brakes at any instant, or i want stop my robo car at any instant for a fluent turn. then?

    • Hey, the motors are geared motors, so they offer good holding torque. So if the motors are not supplied, they will break with a amount good force. If you could give both the wires a logic 1’then it will aid the holding torque. But then you can always add physical breaks to the motors like in automobiles.

  • where u use dpdt switch in this…….?????????????????????

    • Hi Arya, In the transmitter schematic, I have put a 6 pin header named as “To DPDT Switch” In that 2 pins are for +ve and GND supply. The remaining 4 goes to the A, B, C, and D points of the DPST switch pair shown in the image.

  • saffy

    hey sid it is very interesting but I just have 1 doubt
    should i connect all the gnd’s in one pcb to one single point please explain me its is the only thing in my way

    • Hey saffy, all the GND points have to be connected to the supply ground. It is a common practice and it is the same for all the circuits.

  • hey dude….
    please tell me how can i solder my circuits using led transmitter receiver pair.
    and will it make any difference, if i would have used RF transmitter receiver, otherwise.
    reply asap.

  • ponnaiyaa

    what is motor rating

    • Hey, It is a standard 300 RPM, 12V, Geared DC motor.

  • Hello…….I’m Ismail and I selected this project for my science fair………can you just explain it to me the procedure of how to do it and which circuit board do I need?

    • I think I have explained all the details of making the land rover in the post. Have you read through the entire post? which part of the design are you having trouble understanding?

    • actually I’m in grade 7 and the part I didn’t undestand is that is there any circuit boards? and if there is which one should I use and the another is where did you connect the power jack?

  • saffy

    ur answer to my last question helped me
    but there are 6 wire to dpdt switches
    i connected one to +5v supply
    another to -ve terminal or ground
    and how do i connect other 4
    that abcd is to be connected in what order of h12e pins
    10 11 12 13 14 or other

    • I’m glad I was able to help. 10 11 12 13 14 is the order.

  • rajesh

    and how do i supply 5v in transmitter cicuit can 3 x 1.5v aa cells work

    • No you can’t do that. 3×1.5 = 4.5 in practice the output voltage of 3 cells in series will be a little less than 4.5v You have to use a high voltage input and regulate it to 5v. For example, use 7+ volts and 7805 or use [ 5>v>7 ] volts and a 5.1v zener for regulation.

  • rajesh

    and can i use a simple 4.8v battery from my last rc car in transmitter circuit

    • I guess that will work as expected.

  • Akshay

    Hey can i use 12 volt single battery for the motor. Is there any rating for current…??? Instead of cells.

    • Yes you can. The current rating would depend on the payload of the robot. If you are not sure, a 1000 mAh battery always works.

  • Hey, I get most of the working, but I’m in grade 11 so I do not know the working of the ICs. I have two ques:
    1. What use do the capacitors serve in the power supply diagram?
    2. What do the oscillator pins do and why do we need to connect a resistance across them? Additionally, how do you know what resistance to apply?

    • Hey, those capacitors are used to smooth out the AC ripples in the DC regulated voltage they are called filter capacitors.
      About the osc pin, most digital device has to have a clock source to work. This can be achieved in many ways and one such way is the ressistor. As far as its value is concerned, you can find it in the datasheet. I am beeing really breif… You should google to find more details. Hope that helps.

  • saffy

    sid i cant find 12v battery anywhere where did u get that from the one in video

    • I got that battery in a local elctronics store. From what I’ve heard, that battery is the most common one amongst Hobbits… But that is no big deal, any 12v battery should do just fine.. try NiCd or LiPo batteries rated at 11.1 volts.

  • saffy

    where can i buy online

    • There are a lot online vendors who sell 12v batteries. You can try NexRobotics for instance. But you should be able to get this battery off any bike repair or spare store.. a similar but little larger battery is used in motor bikes.

  • Thanks for your reply. Once again:
    1. Do I need the capacitors if I use batteries as the power source?
    2. You left a pin open in the transmitter, is it an input pin you left open as it is not required, or does it have some other function?

    • 1. No you do not ‘Have’ to use a capacitor when you are using a battery to supply your circuit. I guess its a force of habit and good practice to use them. They are not just used for smoothing the DC voltage but also act as decoupling capacitors. You can certainly do without them but in the end you will realize the need for decaps.

      2. That pin is for Antennae (see the pin description) Eagle did not have a symbol for it so I just left it floating.

  • Oh thanks! So if I want some features on this car which I have to control remotely, what do you suggest I should do?

    • The Transmitter and receiver can have a 4 bit encoded simplex communication. Which, leaves you with 16 possible combinations. I have used only those that are needed to control the motors without a microcontroller. You can always plug in an MCU on both the ends utilize the remaining combinations to perform all the extra ‘features’ you like 🙂 have fun.

  • safwan

    can i control it through pc and how

  • Akash

    I cnt undrstand d schematic diagram ,d wiring n most of d things,but I m damn intrrested in ol dis stuff.Can u plz tell me from where I can learn ol these things,lyk from where to strt……givme name of sum books or webites.I M in std 12th!
    Thank You 🙂

    • Hi Akash,

      First you can start by learning how to communicate in a public forum. This is okay for a 1 to 1 conversation but not when you are speaking to a large audience and asking for help, the least you could do is spell your question out in FULL (not in bits and pieces). It took me quite some time to grasp what you are asking.

      To answer your question, Don’t worry you have a lot of time at your disposal. Read about schematic conventions and symbols. Actually it is not very difficult if you know some basic concepts. Take up a degree in Electronics you will learn a lot more there.

      All the best.

      • Akash

        Okay,sorry for my writing -_-” .I am not sure whether ill take up a degree in electronics,I want to do this just for time pass.For time being I’ll read about schematic conventions and symbols,tell me what shall I read next.
        Thank you! 🙂

  • It doesn’t work. I can’t figure out why, and I can’t find any mistakes in the circuit. The L293D works fine, I checked separately. Few stuff I wish to confirm to find the error:
    1. Can the motor run (slowly of course) when directly connected to HT12D?
    2. Can I connect DOUT and DIN directly to check if encoder-decoder is working?
    I also observed something I can’t explain – When I connect HT12D and L293D in the circuit (without Rx module), and plug say Input 3 of L293D to D8 of HT12D, connect motor to Outputs 3 and 4, it starts spinning. Can you help?

  • mukesh kumar mannu

    hey thanks for such a wonderful post, but i am bit little confused about the circuit diagram, can you please send me the more helping statements about the circuit diagram, so that i can also build this… plz… and thanks in advance…

  • Surajit das

    Hi siddharth, first of all thanks for your wonderful information. I have a question about the transmitter and the receiver. As you showed in the article that the RF transmitter-receiver is a 315 Mhz RF transmitter-receiver. My question is can I use a different frequency other than 315Mhz to build this model.

    • Thanks Surajit.
      You can use any RF module as long as the TX and the RX are of the same frequency.

  • Federico

    Siddharth, i really like your design. Do u think i can use 548 transistors to power up even bigger motors?
    I mean, if i put – terminal of a bigger motor to C, the “1” of the logic to Base and then GND to the Emitter.

    • Federico,

      When high power motors are used, normally mosfets are preferred in the design on the drive system. The the 548 transistors are general purpose and are not capable of carrying high currents and hence a poor choice.

      There is a variant of the L293d which (L298) is capable of carrying 2A on each channel if i’m not mistaken. You might wanna look at that too.

  • Afnaan

    Hello siddhart look I have a competition
    So can I use a 27 mhz radio transmitter for this instead of the bigger one

  • sangeeth

    Hie siddarth..
    The post was very helpful for the beginners like me. I just built the entire circuit.. But the led 2 on the receiver side never turns on.. While I didnot connect the motors yet.. I just was checking by connecting led’s to l293d output.. But none turn on for all the inputs from transmitter.. How to find faulty IC in the circuit..

  • Sai hari krishnan

    Hello Siddharth,Can we use a 6v motor like ”Gear Motor 120:1 Offset Shaft” so that we don’t need a 12v battery.I would like to make this for a science exhibition.When choosing a motor how will choose the motor having suitable rpm.

    • Hey, you can use 6v motors if your application demands that. When choosing a motor, we look at the speed and the torque. If you have a high payload, choose a motor with a motor with higher torque. Or if you want your robot to move fast, look for a one with good rpm. Just know that the torque and the speed are inversely proportional.

  • akash

    What is GND and +5 in the diagrams. Upload a very clear diagram from which we can understand easily because i am a begineer.

    • Akash, the diagram is very clear. The GND and the +5v are the power inputs from the power supply schematic.

  • ankush

    Can you please send me a very clear diagram to my E- mail id.

  • Subhankar De

    Hi. Instead of the 2 DPDTs can some other kind of switch be used ?
    For example, like 2 anlog sticks in gamepad….. one to control forward and reverse direction and other stick to steer(or turn), though still using differential drive….?????
    will it be very cumbersome??

    • Subhankar De, if you plan to use the analog stick, then you will have to interface the ADC to get the analog input and then use this value as a parameter to vary the duty cycle of a PWM pulse given to the enable pin of the L293d IC to vary the speed of the motor in proportion to the position of analog stick. This is a little more complex as the RF transceiver module can send only 4 bits under this configuration.

  • mayoogh

    will the one dpdt switch controls the 2 dc motors??

  • Ramesh

    Hi, friends,
    i am Ramesh from chennai,i am going to start business using remote car,but i don’t know but the remote is working so please any one tell me clearly how the remote control is working and what are all the parts need.? and how much cost take to complet one remote control..? pls mail me r.ram2012@gmail.com

  • gourishankar

    is there any need of programming to make this robot?

    • No there is no need for any programming to make this car..

  • Hii $id!! I am just a 9th grade student.. I have a very little knowledge about this project… which topics should I consider before taking the project…..

  • what is dpdt switch
    how to use it

  • mayur suryawanshi

    where is ht12 d decoder ic in develpment board

    • What do you mean by development board? The schematic clearly shows how to connect the HT12E/D pair.

  • Hey,
    here u have described the procedure for 2 motors.. but i wanted to know that what all changes will be there if want to connect 4 motors? and also if we want to run over car at two different frequency..one at a time.

    • Hi Sudhish, in the post I have paired 2 motors together and two such pairs to make the car with 4 motors. If you need 4 wheels on either sides, you can pair 4 motors in the same manner. About the dual frequency, there are a lot commercially available module which support hardware or software selectable frequency bands.

  • Praveen

    Thats really easy to understood and a cool project.

  • Abhishek

    how should i connect the motors i cant understand?

  • Dear Readers, I have updated the post with more clarity and details. I hope this post will help you make your own Remote controlled car.


  • Abrar

    I think you had the Eagle software for making the schematic…..
    Can you mail me the Eagle.scr file for the circuits( power supply,trasmitter and receiver)
    coz i am a begginer and i dont know how to use the Eagle software
    my email nyabraham@gmail.com
    plzz z,….

  • Megh

    what is “abcd” in rf receiver schematic and what does gnd means please help thanks in advance

    • Megh,

      In any schematic, the pins labelled with the same name will be treated as a connection. This is done to reduce the mess in the schematic due to wires running here and there. This is the same for multi sheet schematics. In this case, the ABCD from the DPDT switch should be connected to the ABCD from the receiver circuit.

      About the issue with the ‘gnd’ I would suggest you read some books related to basic circuity, their symbols and conventions! There are some prerequisites, before you jump start into projects. Good Luck!

  • sir,where to connect the terminals A B C D of DPDT switch in transmitter

    • Gobi, you have to connect them to the pins labelled as A B C and D in the transmitter schematic.

  • Prashant

    hey siddharth, can you recommend any specific model for geared DC motor suitable for the above mentioned project. When i searched online, i got a number of options and don’t know which one to opt for.

    • Hi Prashant, The motors I use were purchased from a local store they have plastic gears. It doesn’t really matter.. you can choose any DC motor with your required torque/speed rating.

  • Abhilash

    Hiii,first of all ty fr posting this how to make this kind rc car i found it very usefull and looking forward to make it on my own…i am gonna use this for robo soccer competition were i have to.use one more motor other then the 4 motors for flip to hit the ball so my prblm is i want to operate it wirelessly from the same remote used for controlling the car so how to do it??should i use another rf o wid the same rf is it psbl??i will b lkng forward fr ua reply

    • Abhilash,

      Using the Encoder and Decoder pair restricts out communication bandwidth to 4bits. In the post, I’m sending only 4 types of data. In reality you could send 16 types of signal (2^4). If you have enough switched and a good understanding of digital logic design, you could make use of all the 16 possible combinations.

      Good Luck.

  • sunil kashyap

    hey thanks for the great tutorial …….. but i make as per your circuit diagram ….. and my bot can’t work……. plz tell me how to check the TX, RX …….. and tips for trouble-shooting …..

    • Sunil,

      There are a lot of techniques for debugging but most of the time, you’ll have to use your instincts and hunch to do it. I suggest you to remove the RF TX and RX modules and then take a wire and short the output pin of encoder (where you connected the RF TX Module’s data pin) to the input pin of the decoder (where you connected the RF RX Module’s data pin) and check the communication.

      This will bypass the wireless part. Now see if you are able to communicate between the remote and the bot. If you are able to communicate, then you most probably have a faulty RF module. If you can’t then you made some mistake in the wiring. Look at everything from the beginning.


      • Jeff

        Suggesting to separate the RF TX and RX from the encoder to debug was the key to me finding a problem with a bad chip. After 24 hours of frustration and being stuck, the suggestion to me 10 minutes to find my problem. Thank you for all the hard work you have taken the time to think about, post and reply to, It saved the day!

        • I’m glad I could be of help Jeff. I still remember how much time it took me to figure some very simple stuffs while doing it for the first time… I guess it is the way of nature 🙂

  • Hemendra Patidar


    i have followed he instructions about the connection and verified it twice. yet i am unable to get output voltage supply for motor.
    can you please guide me how to debug rx tx ht12e/d l293d


    • Hi Hemendra, In your case, you should split up the problem by testing the L293D alone with the motors first. This is very simple, connect the motors and give both the power supplies (12v for motor and 5v for IC) and then start giving logic high to the control pins of the driver. Make sure that the enable pins for both the motors are properly energised.

      If you do not have any problem with the driver then move on the the encoder decoder debug. Another reader had the same issue please read this thread for more details and let me know if it helps.


    Is there a problem in using 6v dc motor instead of 12 v
    and is the cost of 12v dc motor

    • No problem with the 6v motor just use the right supply voltage at Vcc2. As for the cost you will have to look it up yourself.

  • abrar

    i got doubt on the power supply
    In this project we are using a +12v and regulating it into +5V
    (so only one one +12v is required ) but in photos of your rc car it consist of two battery …

    • Aabrar, One of those batteries (black colour pack) is +12v and the other is a +9v battery. I was using the 9v battery to power the electronics and a separate 12v battery pack for the motors. This set up allowed me to program the controller alone without giving power to the motor. Needless to say you should have a common ground if you plan on using this set up.

      • yash

        Hi siddharth i am totally new to this making projects so I am always relying to making something new so I am very much interested to making your project but I a see your images of your robot it seems having aurdino at bottom of upper circuit its just another car or that only please I am wishing to make this with eager please can u provide the PCB design If available from you waiting for reply thankxxxx.

        • Yash, those images are just for an inspiration for the hardware design and does not have any relation to the one described in this post. I built those cars for various events during my second year at Engineering.

        • yash

          hey siddharth so this finally working project of rc control because i want to make it this work 100% please guide me waiting i want to make it so thanks i will try my best from your given source again thanks a lot ….

  • yash

    siddharth which software did you use for generating this circuit diagram i want to make pcb for this please tell me ……

    • Hey, I use cadsoft’s Eagle for the schematic and PCB layout.

  • jass

    hello bro
    i just want to controll 10 motore for different functions so
    than what tx and Rx we need to control 10 motors but every motor have different work… pls if possible pls email the ans to my email id :-jaswindersinghjagga@gmail.com pls

    • Jaswin, Like I mentioned to an earlier comment, there are 4 bits of data that you could transfer. Which means you could transfer 16 different types of data. Now figuring out how to send the data and how to interpret it will be your task and I won’t spoil it for you 🙂

      Good Luck!!

  • Mohammed faraz

    I made it but that doesn’t work why I don’t know

  • Rishabh Kochhar

    Hi! Instead of using the battery pack(including the 12V battery with the 7805), can I simply use a standard 9V batters?

    • Rishabh Kochhar, the 9v batteries are never meant to meet such heavy loads. You will most probably deplete the entire battery in minutes if not seconds.

  • How much this project cost to your pocket

    • Shaggy, the total project should not cost you more than 1 to 1.5k INR

  • mayoogh

    Hy siddharth
    Is there a problem in using a 6v dc motor instead of 12v
    and 9v battery instead of 12v???

    • Do you really have to ask me this? If a 6v motor is good enough for you go with it. I your 9v battery can supply enough current for the motors then go ahead use that too!!

  • mayur

    suggest Programming

  • thanks a lot siddharth…….we are using your concept in making a all terrain robot that runs on a track similar to that of a military tanker .i need to know regarding
    1.can we use the same suggested motors for the to achieve high speed?
    2.can use other RPM motors instead of yours?

    • Hi Rahul,

      I’m really glad you found my article interesting. From what I can understand, your application needs high torque motors. So I wouldn’t suggest you to use these motors. Buy some high torque (since speed is not your concern) motor and use a beefier battery. And of course you can use any RPM keep in mind that the speed is inversely proportional to the torque.

      Good Luck!! 🙂

  • milan joshi

    what is a b c d you shown in receiver diagram

    • Milan, In any schematic, the pins labelled with the same name will be treated as a connection. This is done to reduce the mess in the schematic due to wires running here and there. This is the same for multi sheet schematics. In this case, the ABCD from the DPDT switch should be connected to the ABCD from the receiver circuit.


    If we are using a 12v dc motor can we power it buy using two 9v battery(9v+9v)??

    • Nope! those batteries are not made to handle heavy loads. Try rechargeable 9v NiCad battery packs.

  • mayur

    which microcontroller r used and plz give me Assembly programming

  • Rishabh

    I bought the 293d PCB(which has a 293d IC, a 7805, 3 capacitors and a resistor). Have you used the same, or do we need to but the IC separately and use that? The board is really confusing and the pins do not seem to match with your schematic.

    • Rishabh, you should be able use it. Please visit the facebook page for embedjournal and post an image of the circuit (back and front) I will see if I can help you.

  • Rohit

    can i use ONE 9v rechargbles battery for 12 v dc motor

    • If the 9v battery is capable of supplying enough current and you are ok with a little reduction is the speed then you can use it.

  • abrar

    iam going to make a quadcopter can i use this circuit for the quadcopter
    i am no using the same motor i am using bushless motor
    will the quad work with this circuit ???
    If not what should i do? any idea…..

    • Abrar, Quadcopter is a giant leap from a RC car. There are a lot of things that you should take into account before you make a quadcoptor. So I would suggest you to start with the basics and then move on. And just to be clear, it will not work with this circuit. Nor can you use the same kind of motors.

  • hi siddarth your article is very interesting …i request you to kindly explain about the battery section briefly…what type of battery you are using….kindly say the rating of your battery…how much time this battery drive your robot….if i want to use two motor of 1000n rpm of the same motor you used but with the metallic gear what battery ratting should i use…i want a less weight battery…my robo competetion is going to occur in two days kindly reply as soon as possible…thank u

    • Hi Vijay,

      If size is your major concern, then you should use a Lithium battery. They have a high charge density to size ratio. The battery I used is a 12V, 1200mAh NiCd battery pack. Battery capacity is something which you have to calculate based on the payload, and duration of activity. I think for your application also the same rating battery is enough. The time for which the battery will last for will sightly vary since you are planning to use bigger motors with metal gears.

      Good Luck!

  • shubham sharma

    Hey i was completed my sodering in my pcb but it cant working process
    1). can i use 5v instead for 12v in ic l293d pin no. 8 ?
    2). any kind of tv or set top box remote we use in this project instead of transmmiter… or ic ht12e
    3). can i get pcb with print in vegakit shop
    plz reply me back immediately

    • Hi shubham, if you are facing some problems read the circuit debugging post here http://embedjournal.com/2014/03/circuit-debugging-tips-tricks-techniques/ to find out what is wrong with your connections. Here are the answers to your questions,
      1) No, you cannot use 5v on pin 8 of L293 if you are using the same motors that I have used in this article. 5v will be too low to drive the motors.
      2) No, you cannot use TV remote for this project. You will have to interface a TSOP receiver to read data from a TV remote.
      3) I really have no idea! is there a board matching this description listed in vegakit shop? if so give me a link and I will see if you can use it.

      • shubham

        will you give me a pcb circuit diagtam to make a pcb

  • mayur

    what are the applictions of rc car and uses

  • Hey dude your blog is a real help but I have a few questions which I hope you’ll be interested in answering. Im the president of Science Club and El Camino Real High School and for our final lab I was wanting to create and test bio fuel. I see here that your robots are powered by batteries and I was curious as to if they could be powered by the bio fuel. Do you think I could do that relatively easy and safely?

    • Hi Brittany I’m glad you found my blog helpful, please give me some more details on this bio fuel of yours. For this particular car the supply must at least be able to give 800 to 1000 mA for the motors to work. If one cell is not able to supply the required current you could try to add some more cells in parallel. But then again if the weight is increased then the motors will start drawing more current.

      You could scale down the entire approach with smaller motors and chassis. This way you could find an equilibrium between the size and battery capacity.

      Good luck!

  • Hello Siddharth . I am ayudh. I enjoyed reading your article and I would like to try out building it myself . Please help me in this project if I ask for as I am just in class 8. I don’t know much about it but I have great interest towards them and I am trying to learn about it as much as i can . Thank You.

  • shubham

    will you give me a PCB trace pic is easy to me to mounting please because i try’ed at dotted PCB the led does not glow and it dose not working all the mount are proper i have see but it dosen’t work
    you can sent me on my email
    plz comment or reply fast i have to submit my project

  • othmane

    hello i searching for an rc car with rermote controle just by using arduino

    • Arduino is a microcontroller not a wireless transceiver. You need an external RF module to send and receive data.

      • othmane

        i want to do it it just like yours with an ir receiver and transmitter if it is possible
        thank you

        • You can do it but you will have to read about IR protocols such as SIRC and RC5 (depending on the IR remote used) to decode the data received. Do some reading about TSOP receivers.

      • othmane

        what about the arduino program !!?

        • The car described in this post does not require a microcontroller to control it. So you do not need any program.

  • rohit

    can i use dvd motors instead of 12v ??


    hy Siddharth
    i had finished both transmitter,receiver circuit and gave separate power supply for both
    But when i connect the power jack for the receiver circuit the LED doesn’t lit(LED connected to the IC) but i connected the power jack for transmitter circuit ,both the LEDs lit (on the receiver and transmitter)
    but the motors are not working when i on the dpdt switches just the LEDs are blinking
    plz tell a solution………..

    • Mayoogh,

      From what you has said, I understand that the LEDs are showing valid transmission when you press buttons in the transmitter. This means that your Rx and Tx is working properly. Please check the connection for your motor driver. Give +5v and Gnd to the L293d input pins and see that if the IC is working. Sometimes there may be some issue with the IC itself. Read the article on circuit troubleshooting to know more debugging techniques.

  • tirth

    can u tell me the total cost for buying all the things

    • The total cost will vary with the type of motors you are using. The bare minimum will cost you around 1200 INR.


    hy sid
    i changed my L293D IC still it is not working
    just the leds are blinking when i turn on switch

    • Did you try to give logic inputs to the input pins of the L293d? set the pins HIGH and LOW of one motor and check if your motors are moving in any particular direction. If you have confirmed that the motor driver is working, then check what signals you are receiving in the HT12D output pins.. see if you are having a valid transmission (VT pin of decoder) in it.

  • jadeja sandipsinh

    Can I make RF transmitter and receiver? Thanks frnd for help me

    • You cannot make the module itself.. it is much too complicated. Just use the RF module..

      • jadeja sandipsinh

        What should be market price of RF module…?

  • myr

    how to move left and right direction rc car is that move ?

  • Abrar

    i am also facing a same problem of L293d IC
    and you suggested a reader to
    “give logic inputs to the input pins of the L293d”
    i didn’t got it how can i give logic inputs to the input pins of the L293d ???

    • You will have to give 5v and GND to pin 2 and 7 of L293d ic. You will also need to pull up pin 1 of the IC to enable the motor. Do this and the motor should rotate in one direction.

      • Abrar

        what do you mean by pull up pin 1 of the ic
        plz tell in detail i am just a beginner 🙂

        • Abrar, you have to have some basic circuit exposure before making any projects. You could have googled for pull up resistors yet here you are asking it to me. Instead of leaving an IC’s pin open, it is either connected to Vcc (pull up) or Gnd (pull down) through a series resistance. This technique is used to give a default value to that pin.

  • mayoogh

    Tanq sid its working
    but it produced a beep sound??

  • mayur

    how to move left and right direction

    • Mayur, I hope you read and understand this this! Just for the record “NO OFFENCE MEANT”

      I have a lot of important things to do in my life which will help me grow and make more money. Yet here I am answering questions in the comment section. I do all this to help people get started, learn and achieve something with their dreams.. I saw that you posted this question already and I did not answer it. If you take time to scroll down this line of comment you will find that I have answered more than 90% of all questions asked. The reason why I don’t answer some questions are,

      a) The question is too simple and can be found with a simple google search.
      b) The reader has not read what I have written and is asking questions after looking at the images.
      c) He/she has not provided sufficient information to solve the issue.

      Now you fall into (b). I have clearly mentioned how the left right motion is achieved in the post. Yet here you are asking me this question for the second time. If you had spent that time reading the post I might not need to spend so much time writing this lecture for you.

      Answer to your question: READ THE POST BEFORE ASKING QUESTIONS (at least before asking for the second time)

  • vishal

    hi is it possible to control the bot from pc rather using remote…???

    • You may have to use the PCs COM port to send the data and then use a controller to send this data over RF to the receiver.

  • Ravish

    Hi Sid,

    I have been planning on making the above design. But recently when i checked in PCB design suite, i came to terms with the fact that it doesn’t have the HT12E, HT12D & the transceiver modules in its libraries. I use Proteus for the record. Could you tell me of a design software where i will find all the three?

    • Hello Ravish,

      I think Cadsoft Eagle will have HT12E and HT12D in its libraries. But the RF transmitter receiver pair is something that you will be hard pushed to find. You can use normal male header pin and match it for the RF transmitter receiver. What you have to do is take a those modules and insert them into a .1 inch perf board and see how many holes are needed (Transmitter:4, Receiver:4+4+ some more holes) Then choose a .1 inch male header from the eagle library and use them as the pin layout for the modules.

      The easier way would be to create a component on your own! read the datasheet for dimensions. This way you don’t have to port to a new circuit design tool just for the unavailability of the component in the library.

      Good Luck.

  • Moutushi

    it works but my left pair of motors is works slower(a lot slower) than my right pair,what can i do?

    • Please use a tachometer to check if the speed of both the motors are the same at rated voltage. Also see if both the motors are rated at the same Voltage, RPM and Torque.

  • bharat gupta

    I want to make this wireless car but I dont understood how to make the remote setup and the reciever setup

    • siddharth i want to ask you that which one will be the ground for the 12 v+ power supply in reciever.

      • In any typical electronics circuit there can be only one ground. This ground has to be common. In this case there are two -ve terminals from the +5v and +12v supplies. You will have to connect both the -ve together and use it as the GND.

  • Subham

    hello sid, Its an amazing project and just influenced me in school level now too. I am in my way making it just not getting the 7805T ic from any online or store vendors that you mentioned in the power supply circuit diagram. Is there any substitute or other name of it that i can use or any instruction for me?

    • Subham, by far 7805 is the most common component in any hobby electronics circuit. Any store selling raw electronic components will have it. Please visit your local electronics hub.

  • rohit

    hy siddharth i am trying to make a rc car with arduino uno
    can you tell me good place for buying(any good online store)
    because i heared fake board are sold in some store i have read in some review
    and i dont want to cheated
    so plz tell

    • Rohit, there are a lot of Arduino redistributors in India. Please take a look at the Arduino official page for details on redistributor. All Arduino clones are fully compatible with the original board so there should not be any problems using them interchangeably. But if you still insist on official Arduino boards, there is one website http://simplelabs.co.in/ where I have made a number of purchases in the past and they are good you could try them.

  • Rishikesh

    I found various kinds of motor driver as you specified and also many other things you tols.
    Can you tell me the normal rates at which they are available, so I can choose a better one.

    • Hi Rishi, the L293 drive will cost around 60 to 75 depending on your local market. What other component do you want the cost for?

  • akhand

    Wat is the value of rosc

    • Please see the complete circuit diagram that I have published. According to the datasheet, Rosc for transmitter is 1M ohm and that of the receiver is 50K ohm.

  • kiran

    will the robot move forward if i press only one switch??
    In the 10,11,12,13 pin of HT12E ic you connector four switch
    my Q is whether the car move forward if I switched on the switch on 13 pin only
    ,car will move left when i press switch on the pin 12 etc like that
    or shall i need press 2 switch for moving the car forward??

    • Hi Kiran, In this configuration, you have to press 2 switches together to get the car to move in any one direction. You can always add a microcontroller or some digital logic to the receiver to make it move with one switch alone.

  • Tannmay

    you’re a fu#@%$& idiot,this crap is not at all easy peasy

    • Tannmay, In my defense, I can call you the same and say you are neither intellectually, nor creatively capable of producing anything even remotely great. But for your own sake I will refrain from doing so (pun intended!).

      If you feel that this is way over your head my advice (and a very good one) this domain is not for you. And as always, I thank you for taking the time to post a comment to share your “not-very-smart” thought here.

      Good Luck!!

      • rohan

        hi siddharth ,from where should i buy rc parts

        • Rohan, You should visit your nearest electronics hub (every major city has one) and ask them for the components listed in the post. Alternatively you could order them from online store such as NSK Electronics and Vega Robo Kit.

  • Khan

    Hi actually I am a total beginner so could u give me a more simpler circuit diagram or simpler instructions to firefox05@outlook.com I totally appreciate if u help me brother.

    • Khan, think I have tried my best to make it as simple as possible. I really don’t know how to explain it further. If you have any particular idea, please let me know I will try to help you as best as I can.

      • hilal

        yes brother siddharth it is really the simplest one, but why you have used DPDT switches? Can you please suggest me some books which may clear my basic electronics?

        • Hilal, The DPDT switch is for controlling the car. Think of it as your joystick in a video game. One DPDT switch for front/back control and another for left/right control. I’m working on a post with important books that you could use for reference. Please subscribe to EmbedJournal with your email to get notified when the post is published.

  • Rishikesh

    What is the speed of DC geared motor used in this robot?
    What is the normal speed of motor to be selected??

    • Rishikesh, I have used 300 RPM motors and its up to you to choose the speed. Bear in mind that the speed and torque are inversely proportional.

  • Sourav K

    Hi Siddharth, I understood the switch connection in the pictures using DPDT switch but could you please tell me how to connect 4 switches as you have used in the video?.. i’m making this for a science project and your reply would be very useful to me.

    • Hi sourav, The schematic is very simple. You have to connect one terminal of each of the four switches to VCC and the other terminal to D0, D1, D2 and D3 of the encoder.

  • kamlesh kumar sahoo


  • pushpinder singh

    hi siddharth..i have build the rc car bt there is a problem in the operation .as if a press dpdt switch in one direction motor is operating in forward direction bt when i reverse its motion motor is rotating in reverse direction but other motor also start moving. similarly for other motor same thing happening.. ….can u tell me what is the solution????

    i have already replaced driver ,encoder,decoder with new ones and transmitter and reciever cheked by replacing it by wires…i m using 9v battery +2 (1.5v) cells for the input of reciever ckt….can u tell me what is the problem??

    i have used the same transmitter and reciever ckt as you have given on your site

    • Hi Pushpinder, You say you are able to more the motor with the press in the DPDT switch. Then you would you do the debugging for the rf transmitter and receiver?

      Anyways, what do you mean the other motor also moves? what happens when you press each of the buttons in the DPDT switch? Please be more clear in describing your issue so that I can get a picture of what you are doing.

  • pushpinder singh

    taking first dpdt switch ..if i press in forward direction first motor connected to dpdt rotating in forward direction..bt when i press in reverse direction first motor is rotating in reverse direction as well as 2nd motor which is connected to other pdt switch also rotating..similarly same thing happening with other dpdt switch..
    1 dpdt switch in-one motor out-both motors
    2 dpdt switch in -one motor out -both motors

    i have already checked tranmitter and reciever by connecting circuits directly by wires n same thing happening ..i think transmiter-reciever pair are ok as on wires same thing happening

    i have already made 2 circuits of reciever to check whether there is a connection problem or not ..i m using 9v battery +2 (1.5v) cells for the input of reciever ckt… is it the problem???

    i hope i have cleared the things from my side.waiting for your solution..thnx

    • Hi pushpinder,

      I understand your issue but I cant figure out what is causing this issue. Generally, this kind of issues occur due to a parallel connection of motors. Please tell me if you are following the same wiring diagram for the motors as displayed in this post. If not please send me a rough schematic for your wiring from the DPDT switch to the motors.

      I thought your RF part was working from your previous questions. Is your RF circuit working or not? Also please post your comment in a single section as it is difficult for me to merge them into a single stream.

      • pushpinder singh

        yes tranmitter and reciever working properly but i m using some resistance connected between data pins of encoder and gnd..

        • pushpinder singh

          can u tell me whether we need 9v dc supply or 5v reglulated dc supply for transmitter …n also tell me the suitable source for reciever

        • You can use a 9v or 5v supply for the transmitter if you are using the schematic I have provided in the post. The receiver circuit on the other hand has to operate at at 5v only.

        • pushpinder singh

          i have sort out the problem as there was a problem in the transmitter circuit..now can u tell me how to connect joystick with transmitter instead of dpdt switches ..

  • sheon

    hello i made this bot but i have one doubt
    i have brought a 6 pin 3d joystick switch like this ( http://www.dx.com/p/genuine-ps2-ps3-controller-repair-parts-3-pin-analog-stick-black-107125#.U6_AeJSSw2k )
    can you plz tell how to wire this switch to this bot’s transmitter

    • Hi Sheon, That interface requires a little more sophistication then just wiring. I will cover it some time later in a separate post. But here is a small gist of what has to be done. That joystick has two potentiometers each for one axis. You will have to give power to the terminal pins of both the pots and connect their wipers to the analog pins of a controller and use the ADC values to control the motors with PWM.

      Good Luck!

  • Abhinav

    Hey! Siddharth, I have connected everything correctly, but then also my L293D output pins do not create a potential difference. Actually, none of the output pins are giving GND.

    • Hi Abhinav, I think your L293 IC is bricked. Please try to replace it. Also read the articles that I listed as troubleshooting guides for further debugging.

  • Kassam Ashraf

    Can i use a DC Motor tha a DC Geared Motor?

  • Kassam Ashraf

    what to do with GND?

    • You have to connect it to the negative terminal of the battery/power source.

  • i am participating in a moto GP race for which the car must move with around 50-75 km/hr.please help me out with what are the changes i have to make to my bot?

  • abdo

    Hey please, iam an amateur I just ask about programming ht12d ,ht12t?
    I dabdo.ashraf683@yahoo.comon‘t know anything about programming?
    Can you help me please?

    • Abdo, HT12e and HT12d are discrete IC’s. They cannot be programmed. But you can use it with a microcontroller that requires a program to do tasks. So please be more specific while expressing your doubts.

  • Tapas

    hi sidarth can u tell me the overall cost

    • Hi Tapas, the overall cost can be anywhere from 600 to 1500 INR depending on your requirements and the local market cost.

  • What r u doing with pin 1 to 8
    How much cost of it
    Can Ht12e and ht12d need any programming fire in it?

    • Pin 1 to 8 is for address settings. You can leave it open. You do not have to do any programming in HT12E/D

      • kanwar

        can i put antenna

        • Yes you can. There is a pin labeled ANT there you will have to connect a 15 cm single strand wire. This will act as the antennae.

  • Pravadh

    Hi Siddharth,
    I haven’t had any previous experience in robotics and circuit building before. However, I am really interested in making an RC car myself. I am currently a standard 12 student interested in pursuing engineering. As you can imagine, the posts and tutorials on this page are completely greek to me. Could you please advise me on how to pursue this project? Or perhaps help me find a version where I might understand a bit more on how to build the device?

  • mandeep

    plz help me. I make a wireless remote car

  • Ritam

    Nice post. I just have one question. What is the range of the tx? I mean from what distance will i be able to control the car?

    • Hi Ritham, the manufactures promise us 100 feet at line of sight. But in reality it is much less than that and very hard to say. It will depend from place to place with the amount of radio interference present.

  • Abhay

    I made the rciever circuit and the led is glowing it means my circuit is correct na
    its my first time

    • The LED are glowing because they are all pulled up internally. You will have to give some signal from the remote and see if any of the LEDs are turning off.

  • Vidhi

    Your project is excellent… can you tell me what would be the difference if we use 4 wheels instead of 2…?

    • Hi Vidhi, you could use 4 wheels instead of 2 with out any modification. All you have to do is, treat one pair of motors as the left motor and the other pair as right motor. How to connect them is shown in the image with the motors in the article!

  • Shankar S

    first of all thanks for the great post!
    Tell me, if we can change the direction of the motor somehow without using the DPST switch..!
    like doing something in the encoder side itself!

    • Thanks Shankar. Well you the idea is that you have to give it some logic signal at the encoder. You can think of a number of ways to achieve this. For example, you could use a microcontroller to produce the logic signal for you.

  • subal saha

    Heyyyy sidharth bro; please will you explain that what is the use of this RC car. Is it useful for some important purpose. ?

    Please answer me.

    I’m waiting for ur reply…..

    • Yes subal saha, it is very important. The important purpose it solves is that it can teach you a lot of things. If you do it on your own, there are a dozen things that you can learn from it.

  • keerthana

    Hey, I just want to clarify with my point , whether can I use triple pole douple throw switch instead of dpdt switch in making rc car wirelessly with rf transceiber module

    • Hi Keerthana, you can use a triple pole double throw switch also. But you may not need all the three poles so just assume the third pole as no-connection.

  • Kisalaya Pandey

    Thanks.. It was helpful.. Good work !!

  • chandrashekhar

    where i get the driver receiver and transmitter please post the address. thank you

    • You can get it from NSK electronics. Just google for it.

  • Vibhav Aggarwal

    Hi Siddharth Bhaiya (as I m in 8th), I read your article and it’s excellent! But I have a doubt, in the diagram of RF Receiver Circuit with Motor Driver, what does that red arrow indicate that is connected to the l2938 and +12v marked on it?

    • Red arrow indicates that you have to connect it to the 12 volt input. Its nice to see youngsters interested in doing projects.. but you should really read some basics before starting anything. Like they say “Don’t try to run before you can walk”.

  • Vibhav Aggarwal

    Thanks bhaiya. I have two more doubts.
    1. You have connected different terminals to different voltages like 5v, 9v and 12v. Can we connect all the terminals only to 9v? Why so?
    2. In your circuit of decoder and encoder, you have connected pin no. 15 and 16 with a resistor “Rosc”. Is the resistor required? If yes, what should be its resistance?

    • Hi Vibhav,

      1. Yes you could. If your battery is capable of supplying enough current, you could use it. I used 9v battery for the transmitter because it is handy an weightless. For the receiver on the other hand I use 12v battery with high current capacity to drive the motors for a longer time.

      2. The resistance is a must and you should add it. See the 3 and 4 schematic images I have attached. I have mentioned the Resistance values there.

  • Vibhav Aggarwal

    Thanks bhaiya. Your blog was really very helpful for me to understand wireless remote control system. Thanks a lot 🙂

  • Imelda

    Hi, I have a question. Is it possible to program this RC?

    • You cannot program the existing car. But with some modifications to the design (adding a microcontroller) you will be able to program the device.

  • Vibhav Aggarwal

    Hi bhaiya, I have some more doubts 🙂 please clear them. I would be very thankful to you.
    1. What if we want to add more features to the rc car. For example, some LEDs on the car which would we controlled by the remote. Can you please tell me the circuit of transmitter and reciever?
    2. Do the pins in the decoder A0-A7 and D8-D11 provide same output?

    • 1) There is a 4 bit data transmission. So it is possible to transfer 16 types of messages. I am currently using only 4 of them (one for each direction). You could use the remaining 12 to all the LEDs you need. I do not have any schematics at the moment for such a design.
      2) A0 to A7 are the address lines. They just have to match the connections in the encoder. The D8 to D11 on the other hand is the actual data. That is the output with will drive the motors.

  • Maharshi kansara

    Hey, siddharth….show I buy those circuit or I should desing it myself. ?

    • Hold on to that thought for some more time. I am working on some thing that will help you. I will update this post very soon and let you know.

  • Jai

    Hi i did whatever you said above in your project, everything works fine, but I am not getting the result as you got in your video..

    when i press the forward motor, only one motor starts to rotate.. 4 pins of receiver section is connected with the l293d motor, and whenever i press a button it only makes one motor to rotate forward and backward.

    what should i do to work in pairs???

    • Hi Jai,

      What ever result you are getting is correct. You have to press two switched for the car to move forward and the other two switches to move backwards. Refer to the table in the section differential drive algorithm in the article to get a better understanding.

      I do it in the video as well. Only is not very clearly visible.

  • Sayak Bhar

    Hi, If I want to use dpdt switches then what will be the connections? And what are the values of R2 R3 R4 R5 in the transmitter circuit?

    • The data pins can either be pulled down or left open. I think you can figure out how to wire the DPST switch based on this image, http://embedjournal.com/wp-content/uploads/2013/05/DPDT-switch.jpg

      • Sayak Bhar

        The circuit is working but its taking a few secs to respond. That is the motors are spinning 3-5 secs late!

        • 3 to 5 seconds? then there is something seriously wrong. This could be due to too much radio noise in your area. The setup tries to send the data 3 times and if all 3 times the same data is received, it treats it as a valid transmission. May be due to high noise, the data is not transmitted properly. Try in a different location.

  • satish

    The motor used here is brushed dc motor or brushless dc motor?
    as if we use brushless dc motor it will increase the speed of the vehicle.
    so which motor would be best for the rc car racing.?
    reply soon it is very urgent..as i have to participate

    • Satish, The motors used here are brushed DC motors. The topic on brushed and brushless dc motors is a post by itself and is too elaborate to be discussed on the comment line. I suggest you check out the wiki page for more information. For RC cars I suggest you use brushed motors as they have higher torque.

  • Gale

    Hi Siddharth,

    I love your design and I am testing it out right now. I currently have all the parts apart from the HT12E and HT12D (those should be coming later today). I tested out the circuit and made some minor tweaks but I got the logic to work. The motors spin and my car moves. The L293D works fine and I bought an RF link @315 MHz (Similar if not the same one as on the page). Now I am building this on a breadboard (motors are glued on the side) and I am wondering if I the RF link will have any problems and if so how to overcome it?

    • Hi Gale,

      I do realize that RF circuits misbehave (frequency issues ) on the breadboard, but the module is very stable in that regard.
      But there may be some issue due to improper contact to the breadboard plates. If possible us a relatively new breadboard (that helps as the contacts would be good and corrosion free). Just make sure stick it in fully and I think you will be safe.

      • Prakash prasad

        Hey bro..I’m a student of 10 th grade & i know very little about mother boards and things like that (little means practically zero).I’m willing to make a radio controlled car for sci pro.could u tell me what and exactly how to do and what to buy in simpler words(modular and transmitter and things like that are alien to me) i also have a old such car which has all its components in good condition (i think so).plea s reply soon..the earlier the better.a big thnx in advance

        • Hi prakash,

          I do not know how to explain it in a more ‘simpler’ way. I think this is as simple as it can get. You should do some reading and catchup.

  • Mayoogh Girish

    can you plz tell me how to make make rc car using rf module interface with arduino uno
    i have google it and found many post on it but all them are using two arduino board
    since i dont have 2 boards
    Is there any way to make it out from one arduino board???

    • You could make with one arduino but that would require some tweaking into digital electronics. Basically what I mean is that you can use a combination of gates/switched to send more data to the car and then decide on what you want to do with the data on the receiver side with the arduino on board.

  • Mayoogh Girish

    1 more Q
    i am participating in a rc car race plz tell me the best bot specification
    1)motor RPM??
    2)tire? size
    3)gap between 2 tires
    40L*B*H of bot
    plz tell it urgent

    🙂 🙂

    • 1) 300RPM has worked very will for me. Any RPM above that will be a compromise on the torque significantly. But then, that would depend on the weight of the robot.
      2) Read about wheel diameter and its effects on the robot. Basically, if the dia increases, the bot speeds up and the torque comes down. You will have to choose a balance of the two.
      3) Keep it minimum if you have to travel through rough track. Otherwise it doesn’t really matter.

      40 cm3 is too big a robot. Try to come down in size unless you are participating in robo wars.

  • falguni

    what are the values of all components?

    • Hi Falguni, thanks a lot for pointing it out. I forgot to add the values while making the schematic. Now I have updated the images with the correct values. Please have a look.

  • Vincent

    I really liked this website helped me in everystep

  • ravi

    hii..siddharth this is ravi …my connection are completed and the led is glowing at Tx and Rx and data led also glowing.. but car is not moving

    • ravi

      in my L293D dc motorboard having different structure compare to your structure ….i having M1 IN,M2IN,this are lift side and M1OUT,M2OUT this are right side,,,and EN1 ,EN2 also there…….how to connent motors to dc motor board…plzz tell me

    • Check if you are powering the motors. If that is fine, check if the motor driver is working. Read the debugging techniques post that I have posted.

      • ravi

        Give +5v and Gnd to the L293d input pins and see that if the IC is working means how to give it…
        12v means we can use small cells…23AE 12V battery i am using….it can work or not
        in my l293d circuit having the M1 IN,M2 IN in left side,,and M1OUT,M2 OUT are in right side…..which one is connect to motors and which one connnect to decoder (D0,D1,D2.D3)…plz help me…..leds are on only,,,,data led also on…but not working

        • What am I supposed to understand from this? write and email with your clear problem and I will try to help you.

  • padmanaban

    hi,siddharth thank u for ur great post .i m going to try myself! 🙂
    can we use cip-8d and cip-8e ic’s?

    • Hi Padmanaban, I have not use those ICs. But the spec says they do identical tasks only with 8 bit. You should try it out.

  • Sumeet

    Earlier the images given for transmitting circuit were different than those which are now ……..
    So , which are the correct ones ?????

    • Both are correct. I have just observed some more design rules from the data sheet.

  • what tipe of meteriles want to make remote car

    • Anything that you can cut can be used.

  • Agilan

    can we use 433mhz rx and tx

  • sreekumar

    How to design a rc car

  • Abhishek Marathi

    L293D motor driver IC
    HT12E encoder IC
    HT12D decoder IC

    Can i get this item directly from stores

    • ADBUL


  • Lucas

    Hello Siddharth!
    I am a young Brazilian, and fascinated by electronics (however, beginner), and I have some questions:
    The transmitter operates so that pressing a button it turns the motor on one side, and after another push, it will rotate in the opposite direction?
    Another question, is it really need 12V at VCC2 entry L293D? Or can I just use a battery to 5V entire receiver circuit?
    The engines will only be triggered by pressing a button?

    Because I want to build an RC shopping, and found her very interesting tutorial 🙂

  • gokul

    what does the c1 and c2 indicates in the pcb drawing. does it indicates the capacitor then what type it is please reply me

    • Sorry for that. Please download the source files and figure it from there. Like I said, I am not a very good circuit designer.

  • agilan

    if we need to use a 12v dc motor what is the corrections we need to do? and what type of motor you use?

  • sudhanva

    In that video you did not show the connections of the remote?

  • Some1

    will the circuit works if i use 555 timer based receiver and transmitter?
    can i use this transmitter?

    Where to connect the ground pins? Ever mst i connect them

    I will use this to make rc controlled car for my cat 🙂 i use 4 motors in two pairs left ad right i use 5,9v motors Mabuchi and instead L293D i use L293B Will it works good if i use these parts?

    • Hi someOne?,

      You cannot use that transmitter. You will have to connect the GND lines to the negative terminal of the battery. And you will be be better off with the L293D as the L293B version does not have clamp diodes. Go read about clap diodes and their significance.

  • Newbie

    Hi siddharth! im planning to use your design for my project, can i use EGRF-433A1 for the transmitter and receiver, it is a ultra high frequency device. Thanks!

    • Hey, thanks for sharing that module with me.. it was interesting.. I had a look at its datasheet and think that it should work. After all it is also a serial wireless link. The HT12 E/D IC was made for such noisy RF links only and should work just out of the box with it. But there is no assurances that it will work.

      Good Luck!

      • Newbie


  • Sidharth

    hello sir, actually i’m new to this electronics field and want to learn more.I have only made a line follower robot ,that to in a worshop recently held in my college.Can you suggest me on how to proceed furthur in making robots.thanks!!!

    • You can read everything you need from the internet. One workshop experience is good enough to get started. Read through all the posts that I have written on the robotics section in my blog. You can also read some articles from society of robots website it is also a very good source of information.

  • rohit

    i have seen a comment in this post that the IC ht12d/e is 4bit so we can get 16 combinations from can you plz suggest how to get those 16 outputs
    is any seprate IC for it

    • You can use a controller to read the 4 data pins of the decoder and send 16 types on inputs using another microcontroller or some digital circuit on the encoder side. That way you can make use of all the 16 possible data combinations. If you still need more data to be transmitted, you can frame your own protocol to form packet based communication with the robot.

  • Vishakh

    i want to know about power rating of dc motor and further information about motor

  • shivani

    sir, i wanted to know the probable reasons as to why ht12d did not read any output even when ht12e was correctly sendind the signals.. i made my rc car exactly on the lines u gave.. thanku

    • Hi Shivani, did you read my article on debugging the RC car cir circuit. Please follow those instructions and then if the problem persists post a comment in that post and I will try to help you.

  • Mansi

    Where do you get the L293D moor driver from?

    • You can get it from your local electronics project works shop or you can buy it from online vendors.

      • Mansi

        I am unsure of the RF RX-TX Module too. Is it the 433 MHz pair that’s available on Amazon?

        • I don’t know the exact specifics, but any 433 MHz serial link is good enough. Just make sure that it is a serial link.

        • Mansi

          the L239D is a half bridge or a dual bridge. which one is better?

        • L293d is a dual H-Bridge driver. I dont get the question here. What are you asking?

  • Rida EL CHAMI

    hello, I am using RX-2B and TX-2B instead of HT12E and HT12D. I have a problem with the oscillator resistor ! I dont have a signal ! and i dont know wich resistor i will use with the receiver and transmitter Module ! Can you help me ?

  • Rida EL CHAMI

    thank you ! i found the problem

  • sunil

    sir i want to make RF Rx-Tx module myself . please tell how to do it.

    • Sunil, RF circuits design is a dark art and often a lot of experience is required. Unfortunately, I do not have that experience to help you out. You will have to fend for yourself.

  • Actually you could get away with the 7.4V battery but you will be operating your motors at a lower speed than the rated 300RPM. Also this reduction in speed does not contribute to the increase in torque, If your application can do with a speed less than 300 RPM, you can use it.

  • Both the images are removed. it returns a 404

    • mayoogh

      1)Polymer Lithium Ion Battery – 2200mAh 7.4v
      2)Polymer Lithium Ion Battery – 1500mAh 11.1v

      • I think Polymer Lithium Ion Battery – 1500mAh 11.1v will better suit your needs.

  • abrar

    i think when i visted this blog last year i saw i video of arduino based ir remote control robot using TV remote
    can you plz tell me the circuit and arduino code for that one

    • Hi Abrar,

      Thanks coming back after such a long time. A lot has changed since then. I will try to find that code and make it into a separate post. Please stay in touch.

    • Hi Abrar, I will redo that project one more time and post the code here in the near future.

  • Aditya

    hello, plz give the voltage and rpm ratting of DC motor use in this post.

    • These are 12v 300RPM motors.

    • Aditya

      Thank you so much..Sid.

  • Gaurav Rai

    Hey i have 500rpm motors soo what types of battery i must use

    • The type of battery as in cell chemistry, I think even a NiCd battery will do the task. How long you want it to do the task is what you should be asking yourself. If you are operating the car at nominal loads, then a standard 1200mAh battery would suffice.




    • Thanks for your complement harsh. You will have to have some basic level of exposure to schematics for understanding them. Please refer to wiki. The one named BAT is the battery connector. S1 to S4 are 4 switched for the car to move front back left right. The top right two are for power regulations(12v to 5v regulation).

  • Newbie

    Hi siddhart, i want to ask, how is the source of the motor? where did you connect the power of the motor? Thanks!

  • The IC pin 8 (Vcc2) is where you give the suppy for the motors. It is internally used to drive the motors in the appropriate direction.

  • Mark Cleofe

    Hello, Siddharth!

    I am an Engineering student and I am very much impressed with your work. Actually, I will be using your work for our project. However, there are some things I cannot understand. I have a couple of questions and it will be really great if you can help me with it.

    1. What is the purpose of DC Jack you have included in the PCB design?
    2. I have attached a photo with this comment. I cannot identify what are those. And are they included in your video?
    3. It’s not a question actually, if you may, I want to ask for the Eagle design of the Receiver.

    Thanks a lot! More power to you and to your endeavors! I am waiting for your response. Thank you again. 🙂

    • Hi Cleofe, sorry about that! while exporting the image, I think I forgot the silk layer. All of them are 0.1uf filtering capacitors. I spent a good hour looking though my computer for the receiver source files without much luck. I have no clue on how it got left out in the initial dropbox upload as well. I guess I just have to recreate the layout. But It should not be that difficult as I already have an idea on the layout and the library files.

      The DC jack is for powering the circuit, It takes a standard 2mm DC jack.

      • Mark Cleofe

        Thank you so much. 🙂

  • IndianNerd556

    hey siddharth,
    I was wandering what is the length and width of the chassis
    and can u tell me where to get a proper L clamp that u used in the video. Also what kind of wires did u use for the motors when u soldered them.

  • hadrian

    Hi I know it’s a good thing for a project
    But can I ask if can I have a copy of Circuit file of receiver part of PCB design?
    Hoping that you will reply

    • Sorry for the delay Hadrian, I do not have a copy of the receiver sch/brd files. I strangely have misplaced it somewhere. Read Mark Cleofe’s commens below where he asked the same question.

  • Mark Cleofe

    Hi, Siddharth! It’s me again. 🙂
    I have already started my project using your circuit design. Thanks a lot.
    But when I bought the RF Transmitter – Receiver Module, I was asked if I was looking for an ASK or an FSK. I don’t know which one you used, but I bought the ASK one.
    Is it alright if I use this one? I have attached the photo of the ASK module with my comment and I hope you can help me again with this. 🙂
    Thank you so much. More power to you! And I am waiting for your immediate response. 🙂

    • Hi Cleofe, Sorry for the delay, I was travelling. The ones that I used here are also ASK type modules and you should not have any trouble reproducing the same output with this module.

      All the best.

      • Mark Cleofe

        Thank you!
        I have one more question. How did you built the antennas?
        Thank you again. 🙂

  • Pradyum Mohta

    i would like to know that can we connect osc1 and osc 2 without a 50 k resistor in the reciever
    and is it necessary to connect osc1 and osc2

    • It is needed. Please don’t ask!! Read the datasheet for this kind of information.

  • Dariondre

    Hello i am an electrical engineering student working on a home project, i am building an rc boat from scratch and i also want to build the transmitter and receiver. Your method of transmission looks like it would work for me but i would like to know the range of transmission, if i could operate at a couple hundred feet away.

    • 200 ft at line of sight.. I think could be possible with better antennae and highers transmission powers.

  • hitesh

    I had made the circuit as shown in diagram but on reciever I am getting only signal on led but my motor is not working I tried to debugg the problem but I wouldn’t able to find it I also replaced the ic still only getting signal on ic led and motor is not yet working (motor is also in working condition) now what to do? plz help me because there is a competition of mine in short interval of time so I don’t have much time for completing it. I hope u will help me out this as early as possible.

    • Hi Hitesh, I think you problem is not very difficult to fix. Have you read my articles on debugging your circuit? There is a link in the last para of the article. Good Luck.

  • suraj

    i made the circuit but i take it from a kits shop
    they give me a two pcb’s containing transmitter and receiver along with motor driver circuit
    i solder everything right but the car is not moving also that kit does not contain any antenna and shopkeeper told me that it does not require antenna, so i am confused what to do ??? because i check every connection and that is right

  • Snehasis Panda

    Does the RF Ttransmitter reciever module contain the encoder and decoder circuit by default?
    The one mentioned in “things you need” does it have the encoder and decoder

    • Yes you need the encoder and decoder and it is mentioned in the things you will need section (HT21 E/D). The RF module comes separately and the encoder decoder ICs come separately. You have to make the connections.

  • bhupendra

    I am bhupendra and is it possible to make transmitter module at home for gaining the knowledge

    • Making rf circuits is very complex and most probably you will not succeed in your first few attempts. That will only pull down your confidence level.

  • kajal agarwal

    hi siddharth
    its really a nice work i like to try this one at home but iam busy in shooting

  • kajal agarwal

    hi siddharth
    i like your work keep it up
    still make more and more works like
    i love you soooo much

  • buddy

    hey im trying to use a L298N motor driver IC. the problem is there are two pins EN1 and EN2 on them along with pins for output from HT12D. Is it alright if I leave them as it is or do I have to connect any seperate inputs to them?i want my motors to run simultaneously.
    also there are two pairs of ports (Vcc, GND), (Vdd, GND). what is the Vdd port for? Vcc is for power right?

    • You have two jumpers on the enable pins. Chances are they are pull ups but cant be sure. I suggest you give logic levels in the motor logic pins m11, m12, m21, m22 and see if the motors are actually working. If it doesn’t then try to pull up the en pins externally and then check if they work.

      • buddy

        What about the the Vdd and Vcc pins? Which one should I use to power the board? And what about the other one?

        • Put the multimeter on connectivity mode and place one probe on pin 4 of the l298 and the other on one of the pins (Vcc and Vdd) one of them should be connected. You have to connect the motor supply on that pin. The other one is your logic supply (5v).

          I am almost sure that Vdd is the motor supply, But its better to be safe than sorry.

        • buddy

          So i had the multimeter in connectivity mode ie the meter beeps if it is shorted. The motor ic beeped under the connection between Vcc and En1 and En2. The Meter showed some difference between Vdd and En1/En2 but the control pins for showed no potential difference or any beep for both Vcc and Vdd. So this shows Vcc is motor supply right..? And why aren’t the control pins beeping they aren’t even showing potential difference. Any idea? Your inferences?

        • Hi buddy, First do what I asked you to do. PIN 4 is what you should be worried about. The En1/En2 beeps for Vcc because they are pulled up that way. This also means that Vcc is your IC supply and Vdd is your motor supply. But do pin 4 test first.

        • buddy

          I checked the pin 4 the Vcc is the logic supply. The Enable pins were shorting with Vcc. My problem is if I manually connect battery to pin 3,4 the motor runs, but with the receiver pins it isn’t, even though they are providing same potential difference,I checked with multimeter. What do you think?

        • buddy

          hey thanks for all the help.i’ve finally reached the final stage of the project, now i made a small change to you transmitter circuit. I connected the resistors to the pins i.e i connected the resistors before the switch between the pins and Vcc. so when the switch is pressed the connection is grounded like pull up configuration. the remote and receiving part are verified, but the motors aren’t running simultaneously. the connections i made to the board are just the control pins and the motor supply. should i connect anything to the E1 and E2 pins for the simultaneous running(see the pics i posted above) or should i leave it like that????

  • vedant yadav

    i want full explanation for how to make remote

  • a

    the rf transmiter is to be made own or can be purchased ready made

  • reddy krishna

    is it possible to control 4 bulbs on & off with this remote

  • anurag

    hi siddharth i am making a rc robot and i am facing problems with my circuit
    the problem is when ever i press any button on my transmitter circuit to control my motor , my motor either operates with a delay or it never stops , i am sending u a pic of my circuit. also can u tell me how to operate a DIP switch , its there in my circuit and i dont know which pin should be high or low.please help me out.

  • Some1

    can i make this circuit by using TV remote control and TV receiver from old panasonic tv

  • Harsh

    i want to make a RC plane and i want to use this 315 MHz Rx TX module because a 2.4 GHz module is very costly . I am from India . so please answer my queries
    Should I use it ?
    if not then what to use in place of it ?
    will you please upload a video of how to make a rc plane ?

  • Abdul Mutaal Syed

    Sir can we use this rf modules???????

  • Guest

    Siddharth, i’m a engineering student, and i’m impressed by all your designs, but unfortunately i’m a newbie at this, so i’ll start with a few questions: 1) Could you please tell me what are those that i circulated ? I kinda know what it is but is better to ask. Another thing, 2) The drill used to make the holes, the size please ?, 3) In the pcb, there are green circles in the connections and there are green squares, what are the differences and i realized it is a bridge between a path or another, so it means it goes on the other face of pcb or i’m assuming it wrong ? Thanks in advance.

    • Hey, Sorry for now having component designation. I am a pathetic design engineer. here are the missing components based on your color grouping.

      Red Circles: capacitors 0.1uf
      Green One is 7805L
      pink ones are screw terminals for the motors.
      the other color circle is a 10uf capacitor.

  • Carl Aridas

    Looks like a fun project. Looking forward to doing it w the kids soon. Couple of points/questions:
    1) The link to the HT12E is broken.
    2) The links to the HT12D show only the decoder w directions to the board? Do you have a link to purchase the encoder and decoder w the circuit board?
    3) The same for the motor driver. Your link, and many on E-bay, inlcude the chip but w/o the necessary circuit board. Do you have a link to that?

    • Thanks for pointing that out carl. I have removed them completely and replaced it with pictures. A simple google search would return the proper links to the all the readers. What do you think?

  • Harsh

    Hi Siddharth . In AD8 ,AD9,AD10,AD11 of RF Transmitter you have connected 4 switches , so is 315 Mhz Rf transmitter and receiver a 4 ch system and you used 2 motors so how do you use 4 switches with 4 motors .Do you use 2 switches at a time . I know my qusetions are childish but please answer them as I am intrested in this hobby . thank you .

  • Harsh

    Hello Siddharth . I have asked some questions 3 months ago and you also have answered them . But I am not able to understand DC jack circuit . In this there is a Symbol like ^ and 2 wires from GND are attached to this ^ symbol and below them is another circuit . Please tell me and where to connect it in receiver circuit and there is a box in middle of the circuit so please tell me what is it and where to connect it in receiver circuit and in transmitter circuit there is BAT so I think its battery so where there is VCC in tx module we have to connect it with VCC of Battery and where there is GND connect it to GND ib Battery . Thank you . Please answer this question and I Know that some are silly questions according to use but please aswer them . Thank you……

  • Harsh

    These are images of circuit in which i have doubt in last comment . Thank You .

  • Harsh

    Sorry I am not able upload images .

  • Harsh

    These are images .

    • André Ferrato

      Q1: This is the battery, connected with the negative on the ground and positive on the Vcc, Vcc is the basically the main path of the circuit. Like in the PCB is like that(Image with the YELLOW path). As you may see it connects into the encoder as it does in the diagram, it goes through 2 capacitors, and the RF TX Module.

      Q2: The use of these switches is to change the encoder to LOW as it is currently HIGH, when the switches are open, the only current flowing through the system is the one limited by the encoder, that you’ll find in its datasheet. So i believe is 2ua(microamp), the voltage being received by the 10k transistors(drop voltage) is defined by U = R * I, and you’ll see that is only receiving little voltage, so the encoder is receiving the most part of it, and it’s on HIGH( each pin i mean), when you close it, you make it go through the resistor so the current passing there will be very low( its limited by the resistor) and the voltage there also will be very high, so the encoder pin stop receiving so much voltage and becomes LOW. And this is read as 0 and 1 and serially encoded and transmitted by RF module.

      Q3: It’s a DC Jack connected to the +12v path to power the circuit, a 2mm one i believe.

      Q4: It’s a voltage regulator, a transistor(LM 7805) that pick’s the +12 voltage and turns into +5v, that it’s needed. (Explained in the second image)

      My advice to you is to read about pull up and pull down resistors, to do some checking on voltage regulators, what filter capacitors are used for, how to read diagrams and how to read the DATASHEET(most important thing)

      Also i uploaded to equal images and i’m dont know how to delete one ahaha’ 🙂

      • Thanks for your efforts Anre, I really appreciate this.

      • Naga nesan

        in the transmitter circuit the are no capacitors and transistor are drawn in the circuit diagram please reply me

    • aakash

      q3- the main two ponts, from where u have to connect ur dc battery, when u are all ready with ur soldering on pcb
      q4- its a circuit of regulated power supply of 5volt, to ur circuit

  • Harsh

    Please answer urgent .

  • abrar

    Can plz provide the Link for downloading the HT12DE libraries and rf module libraries for Eagle cad software .
    because i cant find those parts in my software

  • Harsh

    The PCB layout of receiver (for eagle software)is not available for download . Please upload it on site as well as on reply on this comment . Thank you.

    • I am sorry Harish, that file is missing from my computer and I do not have the time right now to recreate it. I will do it as soon as I have some time off work.

  • Gokul Saranathan

    hi… while saying “internally pulled up the enable pins to 5v” what do you mean?

  • Gokul Saranathan

    and what about the ground pins?

  • Sowmia Shekar

    hi… (i should warn you.. my doubt might sound silly) while saying
    “internally pulled up the enable pins to 5v” in the video, what do you
    mean?. Do I have to solder the Vcc1 EN1 and EN2 together and connect it
    to the receiver?.

    • hey, yes you are correct. but you will have to add a resistance (say 1k) from the vcc1 to the EN1 and EN2 pins to allow the motors to be always enabled. You do not have to connect this to the receiver.

      • Sowmia Shekar

        Hey thank you. Yes that’s exactly what I was asking. And what about the receiver and transmitter? In the (to buy) list you’ve mentioned them individually. whereas in the video you’ve used a single circuit board for encoder(with transmitter) and decoder(whit receiver) . What is it’s name.Where did you get them from?(I cant find them anywhere 🙁 not in internet actually)
        Again sorry if i’m being silly. I dint have an electronics background. i’m just an electronics enthusiast)

        • Those circuits are pre built boards based on the schematic that I have posted in the article.

        • Sowmia Shekar

          pre built boards? means you made them?

  • Sowmia Shekar

    and what about the ground pins?

  • Sowmia Shekar

    does the RF transmitter and receiver IC youve used here has encoder and decoder in them?
    where did you buy them from?


    I have a question .Please solve it .
    According to your old list I have bought 2 12V 200 rpm DC motors so can I use 8 AA cell so they together make 12V and if not so what combination of cells should I use , as a 12V battery is costly and heavy and I will not use this car regularly so I need a cheap battery in receiver and in transmitter can I use 9V battery (as I saw them in video) which is very light weight and cheap and when I watch the video I saw 6 cells in receiver so I am confused as a 12V battery requires 8 cells but I think this is becouse your motors are of less Volts but as I have 2 12 V motors so please suggest me about the matter about .

    • 8 AA batteries will do just fine. But remember, your car can operate only for some time as those batteries are not very strong. Yes the reason for me using 6 AAs is due the my motor size.

  • Harsh

    And for receiver a 9V battery (as in photo) can be used and will 12 V 200 RPM motor will give me good speed and torque as in video . What type of motors you used in video .Please tell me in detail .

  • Harsh

    Sorry this is photo of 9V Battery for receiver .

  • Sowmia Shekar

    why do we have to connect a resistor in between the oscillators(ose1 and ose2) of HT12E

    and HT12D ?

    • sowmya please read the data sheet. The resistance is for producing the clock for the IC.


    Why have you connected 2 capacitors in TX module of PCB art work but u have not specified them on schematic diagram of TX module . I have made TX module without these capacitors . Should I add them . Are the capacitors necessary .What are the specification of capacitors .

    • Those capacitors are for filtering purposes. Its good design practice to add them on PCBs but they are not essential. You can do without it.

      The schematic does not have it because it is not an essential thing and may confuse some readers. The capacitor is just a design best practice.


    Will the battery i picture work in my receiver . I used 2 12 V 200 RPM motors .I took this battery form the torch in picture . This is a 6 V sealed lead acid battery

    • This will work but your voltage is low. Your transmission range is dependent on the input voltage, So its better to go with 9v batteries. Besides, this battery to big to be on a remote control unit.

  • Sowmia Shekar

    can you explain me how the differential algorithm actually works here…. i mean we are going to press one tactile switch to operate both the motors at the same time….. how will that happen?

    • piyush mittal

      Yeah exactly it is what that draw my attention and how it can be possible ? Basically l293d is a h bridge motor driver and whenever we press tactile switch logic 0 is transmitted and one motor gets in movement but how it could be possible to other motor?

    • You have to press two buttons to drive the motors in any one direction. This means two buttons for each motors one for forward and one for backwards.

      Ps. It is possible to drive both motors with one button. Its not rocket science. You guys should be able to figure it out. Good luck.

  • Sanju Kumar

    will these work with DC
    12 volt 300rpm motors ,and can we use 2 DTDP Switches Insted of 4 tactile .

  • Padmanaban

    i have made it!thank u siddharth! =D

  • Yash

    hey..m a starter nd know very little about electronics..so just can u help me out wid list of circuit components needed..

  • Mayoogh

    i have made this rc robot and its working well (Thanks)
    but after a continous ride for 5 min my motor just burnt off
    i am using l293d motor driver IC
    i am giving external power supply for the driver IC , I have given 12V 1.2 supply to pin8 of the l293d and it burnt after sometime
    can you plz tell any solutions for it ??

    • Motor driver can power upto 1.2 A per channel. So if you try to draw more than that then it will burn. Try to measure the amount of current the motors are drawing.

  • james smith

    Hi friends…! I am new to ECE branch. And new to robotics yet my hobby is this type of work. So can u all plz… tell me in the circuit diagram there are lots of GND terminal and VCC terminal in all the component like motor driver, receiver and decoder so can u all plz…. tell me which point of VCC is connected to which point and which point of GND is connected to which point.? as there is no line drawn in the circuit diagram. Plz…. i am new to this.

  • satvi

    Dc jack means what

  • satvi

    Receiver circuit is bit complicated …. will you please simplify it for me

  • Sowmia Shekar

    hey hi…. im almost done with the project here….But im not able to get a 750k or 1M ohm resistor (for the encoder oscillator) here….. i ve got 10K and 27Kohm resistors though… would that suffice?

  • Membx

    Where did you get the remote control system.

  • honey

    nice work keep it up

  • Naman

    Pllz send the circuit for the remote plz fast I have to make it in 2days

  • Harsh

    I receiver there is a 50 k resistance between osc1 and osc2 but I am unable to get it. Can I use 47k resistor .

  • Harsh

    I also have a 56k resistance for the same .

  • Bibs

    In the demo. Video the wire you joined between the motors is which wire

  • pratyush jindal

    can you tell me simple wireless circuit for the things i have l293d motor driver ,ht12e

  • Sowmia Shekar

    done !!! works !!! yaaaay!!!

    • Sunny Singh Surdyal

      What is used to material to creat this robot please tell me

    • Contrats Sowmiya! your car looks professional. I glad you were able to get it to work.

  • Gabbar Vk

    My motor driver has different setup…it has 12v,gnd,c1a,c1b,en1,c2a,c2b…how to connect to decoder…plz help!

  • Deveratna Kisan

    How to make the remote controller out of pcb
    Suggest me the website from where u got it !
    if it is made by u then share the picture of the pcb

  • punyakr@thore

    How can I make motor drive in both directions using 4 channel RC with single battery..

  • ayush ranjan

    where should i connect power led in transmiter circuit

  • Pranav Shivashankaran

    Can you please tell me how to connect E1,E2 and Vcc please!!!!!!(I know this sounds stupid but still please)!!!

  • dhruv devang

    we are having some problem
    we did not get the rx reciever and transmitter circuits as shown in the video .
    we so we are having problems in vcc,12v,-12v and gnd power and what is 10k,50k ,r1,r2

    • Abhishekawasthi Awasthi

      10k is 10 kilo ohm resister which is r1 similarly

  • Vedant Yadav

    i don’t understand how to make remote control

  • Vedant Yadav

    how can i get motor driver board

  • A

    can you please tell me about switches? why dpdt? and how it’s wiring would be?

  • Aswin Ramadas

    i wanted to know whether the rf tx & rf rx modules r available in the proteus ,
    if so kindly inform me

  • Praveenath Sathyamoorthy

    hi guys can any one help me with the PBC art work of the receiver circuit because in the image the codes are nt thre…..

  • Jyo Das

    Can I connect 2 motors on each output port of the L239D motor driver?

  • harsh

    i have two 12v motors of 15o rpm . can i use then

  • harsh

    for using 12 v motors , what are any changes required in the circuit ?

    Please answer fast

    Thank u for posting this tutorial .
    I liked it very much.

  • Meet

    please help by sending the links of the chips sets used in the program as i want to make this project and please help me out by giving the connections chart so that it will be easy for me u can mail me at meetpatel045@gmail,com

  • abdul sk

    can you plz tell me what are R1, R2 ,R3,R4and R5 in the diagram of RF TX module ..plzz tell mee fast

  • abdul sk

    what are C1 C2 in pcb artwork in transmiter

    • C1 and C2 are standard power line decaps (0.1 uF).

  • Master Jinx

    where did you get the pre-built circuits?
    I want to build this for a project of mine
    how fast does it go?

    • Master Jinx

      can you tell me asap
      i want to make this for a project…
      and i need to know quick

      • abdul sk

        if you want i can make that

  • abdul sk

    can you please send me the geber files at shaikabdulazeezabu@gmail.com plzz fast.
    i want the to create my own pcb

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  • abdul sk

    i had a doubt, is the circled one is 5v current or 12v current ? plz answer me..

  • Devansh

    on which thing did you made your remote control

  • Ayush Mukherjee

    How can I make it faster than this? And how can i put more functions in the car?

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